Camera Controls

Correctly adjusting the camera controls is essential for any type of imaging, and it is equally important to understand the function of the various controls in order to understand which adjustments are needed.

Camera controls that appear on a wide range of cameras are described below in Common Camera Controls.

Subsequent subsections describe features specific to individual camera manufacturers.  The same functionality may have different names across manufacturers.  Different models from the same manufacturer may have differing features.  The manufacturers are described in alphabetic order.

Common Camera Controls

The controls listed below are generally expected to be available across a wide range of cameras from different manufacturers, although not all cameras will have every control listed in this section.  These controls are to be found in the Camera Control Panel (which by default is shown to the right of the main camera image). 

Capture Format and Area

These controls allow you to control the resolution of images that will be captured (Capture Area) and also the type of image that will be captured (Colour Space – for example mono, RGB, etc). Additionally you can choose the type of image of video file to be created when saving images and adjust other related options.

Capture Format and Area
Colour Space	· The colour space control determines the image format each frame is captured in.  In general, there are four categories of colour spaces o Monochrome o Colour o Raw o Compressed · See Colour Spaces Explained for more detail on the colour space to choose and the implications of each choice.
Capture Area	· This controls the size (in pixels) of each frame captured. · For most cameras, the choice of a smaller capture area selects capture of a subarea of the full sensor area – this is often termed ROI (region of interest) capture. · As well as giving smaller saved files, selecting a smaller capture area often gives a higher frame rate.
ROI Position (pan/tilt)	· When a smaller capture area is selected, it is usually also possible to choose which region of the sensor is used – selecting the appropriate Region of Interest (ROI). · Only shows if the selected Capture Area is smaller than the maximum.
Binning	See Binning below further information.
Output Format	· Output format allows the choice of the format any captured files will be saved in.  The options for capture format can be found in Capture Formats Explained.  The following rules apply: · For 'Snapshot' (single frame) captures, one of the still capture formats (PNG, FITS, TIFF and JPEG) are always used, even if the selected output format is a video format (AVI or SER).  If the output format is a still file format the selected format is used. · For multi-frame captures, the selected format is always used.  If a still file format is selected each frame will be saved to a separate file. · If the camera is in Still Mode, video file formats will not be shown as options in this control. When the output format is set to ‘Auto’, a compatible video format is selected if the current exposure is less than 5 seconds and a compatible still format is selected if the current exposure is greater than 5 seconds. The preferred output formats specified in the settings dialog are used (providing the preferred format is compatible with the type of image being captured – for instance 16-bit depth images cannot be saved to AVI format). [Note: If the ‘Start Cameras with Auto Output Format’ option is checked in the General Tab of the settings then cameras will always start with this control in ‘Auto’ mode.]
Debayer Preview	· Only shows for RAW colour spaces. · Allows the user to choose to debayer (convert to colour) or not the raw image for display. · Does not affect the image data saved to file (but does affect the file metadata for SER, ADV and FITS format – setting the correct debayer preview setting should help ensure that compatible processing applications automatically debayer the saved RAW files correctly). · As well as switching the debayer function on and off it is possible to override the Bayer pattern used if, for some reason, the wrong pattern is selected automatically.

Binning

Binning is a technique used to improve the signal-to-noise ratio of an image at the expense of reducing the resolution. Binning works by taking the value of 2 or more neighbouring pixels on the sensor and either adding or averaging them to produce the value for a single output pixel.  Binning is usually 'symmetric' - meaning that the same number of pixels are averaged over in each direction. For instance, a binning value of '2x2' or just '2' means that a 2 by 2 block of sensor pixels are used to make each pixel in the final image – this will reduce the resolution of the final image by a factor of 2, but also increase the signal-to-noise ratio (S/N ratio) of the image by a factor of 2.

As an example, with a 1280x960 sensor, using 2x2 binning will give an output image of 640x480. Using 4x4 binning will give an output image of 320x240.

A binning value of '1' or '1x1' means that no binning is being applied.

It is important to note that some cameras add pixel values when binning (meaning that the image will get brighter when binning is turned on), while other cameras average the values (meaning that the image doesn't get brighter, but the noise reduces instead).  In both cases, the same increase in S/N ratio is achieved in the final image – if a brighter image is required and the camera averages then just turn up the gain – the result being the same as if the camera had added pixels.

Additive Binning

Unbinned (width 2x, height 2y)	Binned 2x2 (width x, height y)

Additive binning – no other changes were made to camera settings between the unbinned and binned images.  Applying the 2x2 binning halves the size of the captured image and brightens the image by a factor of four.  Note that a considerable level of noise is visible in the brighter right hand section of the image in both frames.

Averaging Binning

Unbinned (width 2x, height 2y)	Binned 2x2 (width x, height y)	Binned 2x2 with extra gain (width x, height y)

Averaging binning – no other changes were made to camera settings between the unbinned and binned images.  Applying the 2x2 binning halves the size of the captured image but does not brighten the image in this case.  However, looking closely at the bright area on the right-hand side of the image shows that applying the binning has significantly reduced the noise in this area (and across the rest of the frame).  Increasing the gain further does brighten the binned image producing a similar image to the additive binning result both in terms of image brightness and noise level.

Camera Controls

The camera controls are the primary controls for setting up the camera, and includes key controls such as the length of the exposure and the camera gain.

Camera Controls
Exposure	· Exposure controls the length of time that the camera collects photons for each frame.  · Longer exposures allow more photons to be collected and will therefore give brighter images.  · For most cameras, the selection of a longer exposure can limit the frame rate.  For instance, setting an exposure of 100ms (1/10s) will limit most cameras to a frame rate of 10 frames per second. · Each camera will have its own limits for the length of exposure it allows. · Some cameras (particularly webcams) may report incorrect ranges of allowable exposures to SharpCap. · The LX checkbox in the exposure control has only one effect – it changes the range of the exposure slider from minimum exposure to 5s (LX unticked) to 0.5s to maximum exposure (LX ticked).  This is necessary because for cameras with a very wide possible exposure range it becomes difficult to adjust the exposure accurately if the slider range runs all the way from 0.01ms to 1000s.
Gain (sometimes called Analogue Gain)	· The gain control acts as an amplifier for the signal received by the sensor. · Turning up the gain will increase the brightness of an image without needing to increase the exposure duration, but at the cost of the making the image noisier.
Frame Rate Limit	· Limits the rate at which frames are processed by SharpCap, even if the camera is creating frames at a higher rate. · This affects the rate at which frames are saved to any capture file and the rate at which the UI is updated. · This can be useful for configuring an all-sky camera to ensure that the frame rate during the day (when exposures are shorter) is similar to that during the night.
Flip	· Apply a horizontal or vertical (or both) flip to an image to correct its orientation. · Note that if you are using a colour camera in RAW mode, adjusting the Flip control will effectively change the bayer pattern of the camera (for example flip vertical will change RGGB to GBRG or vice-versa). · If you are using dark or flat frames they must be captured with the same flip settings as your light frames to work properly.
Temperature [Read Only]	· The current temperature of the camera sensor. Note that if the camera has more complicated thermal controls (for instance a Peltier cooler), the current temperature will appear with those controls in the Thermal Controls section.

Image Controls

The image controls shown above are a typical selection of the controls that can be found on a wide range of cameras. Some cameras will not have all of these controls available – in fact some cameras may only have the ‘Timestamp Frames’ option.

Image Controls
Gamma	· Neutral gamma is 1.  · Correctly interpreted, gamma of less than 1 will boost the shadows and mid tones, gamma greater than 1 will lower the mid tones and highlights.  · Some applications and cameras treat gamma the opposite way around –  increasing gamma boosts the shadows. · See http://www.orpalis.com/blog/color-adjustments-brightness-contrast-and-gamma/ for more details on gamma, contrast and brightness. · In most cases it is best to leave the gamma control at its default setting.
Contrast	· Increasing contrast will typically make the dark pars of the image darker and the bright parts brighter. · Sometimes this can help pull out detail in the image. · In most cases it is best to leave the contrast control at its default setting.
Brightness	· Increasing brightness will typically make the image brighter by the same amount. · Brightness may be called ‘Offset’ or ‘Black Level’ on some cameras – the controls all have the same effect regardless of name. · For deep sky imaging, the brightness/offset/black level control should be adjusted to ensure that no areas of the image are at minimum (zero) brightness. This can be checked using the histogram function. · Increasing brightness can help pull out detail in the darker regions of the image.
Timestamp Frames	· Applies a UTC timestamp in the top left corner of the frame. · As well as the visible timestamp a machine-readable timestamp is embedded into the first 8 bytes of the pixel data of the frame. The machine-readable timestamp is a 64-bit integer that is the number of 100ns intervals since midnight on 1st Jan 0001 (see https://msdn.microsoft.com/enus/library/system.datetime.ticks(v=vs.110).aspx for details)
White balance	See White Balance below.

White Balance – Images shown from colour cameras can frequently show incorrect colours.  This can be due to a range of reasons, such as:

· One colour (often green or red) being more sensitive to light than the other colours.

· The type of illumination the image is being taken under – for instance tungsten, LED or fluorescent lights for non-astro images.

Different cameras have different controls to enable colour balance to be adjusted to give images showing the correct colours.

Although these controls differ in detail they all effectively allow the brightness of the colour channels to be adjusted relative to each other to correct the colour cast in the image.

Some cameras offer an auto white balance option – these often work well for ordinary images but can sometimes be confused by astro images, so should be used with caution.

Use the histogram control while adjusting the white balance and other image controls such as gamma, contrast and brightness – if it is noticed the histogram trace for any of the colour channels has gaps (i.e. levels with zero count appear in the middle of the histogram – see graphic below), it probably means the white balance (or other) adjustment is being done in software on the PC rather than in hardware on the camera.  Histograms such as the one below indicate data is being lost.

In this case, it is best to set the white balance back to default (remove the gaps in the histogram) and to correct the colour balance after stacking. This will avoid the data loss caused by applying digital white balance correction in SharpCap.

Pre-processing

Preprocessing
Subtract Dark	· Subtracts the selected dark frame image from each frame captured by SharpCap, allowing artefacts such as amp glow and dark noise to be reduced. See Capturing and Using Dark Frames for more details. [Note: the dark frame is subtracted before any other processing of the frame (such as live stacking or any FX effects) and the subtraction of a dark frame affects the saved file.]
Apply Flat	· Corrects each frame for brightness variations caused by vignetting or dust spots. The flat frame correction code has been highly optimized so that on a fast PC it can run on every frame even when high speed imaging using a USB3 camera. See Capturing and Using Flat Frames for more details. [Note: the flat frame correction is applied after dark subtraction but before any other processing of the frame (such as live stacking or any FX effects) and the application of a flat frame affects the saved file.]
Banding Suppression and Banding Threshold	· Some cameras show varying horizontal bands in dark areas of the image (these may only be noticeable after the image levels are stretched to show faint objects). The image below shows a sample of this type of banding: · SharpCap’s banding suppression function can help remove this type of banding in each frame from the camera before it is saved or processed. · The Banding Suppression control sets the strength of the banding reduction effect. · The Banding Threshold control specifies a brightness level above which the banding suppression is not applied – ensuring the adjustments are only made to the darkest parts of the frame where the banding is most visible. · The best way to adjust these controls is as follows: o Set the camera up to take dark frames o Use the display stretch if necessary to make the banding more visible o Initially turn up the banding threshold to maximum o Turn up the Banding Suppression control gradually until you are happy with the amount that the banding has been reduced o Now turn down the banding threshold control gradually – at some point the banding will re-appear because the threshold will have been set too low. Turn the threshold back up a little to make the banding disappear again and you are done. · The Banding Threshold has no effect if Banding Suppression is set to zero. · If you use these controls then you should use the same settings for them for both dark and light frame capture.
Planet/Disk Stabilization	· Enabling this option when imaging a planet or a full solar/lunar disk will offset each frame image to place the planet/disk in the centre of the frame. · If this option is enabled when imaging other types of target, the results may be unpredictable. · Stabilizing the planet/disk to the centre of each frame affects both the image as shown on screen and the image data saved to any image or video files. · Because the image is being moved, areas that are outside the recording area of the camera may be brought into view – they will show in a dark grey colour. · This feature may be most useful for the focusing stage – by keeping the planet in a constant location, judging the point of best focus either by eye or using SharpCap’s focus tools will be easier. · Planet/Disk Stabilization is only available for cameras that are running in live view mode at a bit depth of 8 bits. If your camera is running in Still Mode or is using a high bit depth mode, this control will not be available.
Background Subtraction	· Enabling this option will remove a constant, auto-detected, background level from each frame. This will help remove the background brightness caused by light pollution (sky glow), and in particular help remove any colour cast to the background of the image due to light pollution. · This option is designed to be used where there is a significant amount of light pollution to be removed. If you have very dark skies or are using narrow band filters, you may find that this option brightens the background of your image slightly, since it tries to adjust the background level of each colour channel to the 5% point on the histogram. · This option is compatible with dark and flat frame correction, and should ideally be used with both (or at least dark frame correction). Dark frames remove the unwanted brightness caused by the camera itself, this option removes the unwanted brightness caused by light pollution. · The adjustment made to the image brightness may be different for the different colour channels in colour images (this allows correction for a coloured sky glow). The correction however does not vary with position in the image, so gradients in sky glow will not be removed. · Enabling this option will affect both the image shown on screen and the image data saved to file when capturing. · Using the ‘Simple Offset’ option will apply the same correction value to all pixels in the image – this may affect the colours of bright stars as (for example) an orange/red sky glow will lead to the largest reduction being applied to the red channel, possibly making bright stars take on a blue/green hue. · Using the ‘Blended Offset’ option will cause SharpCap to avoid making such large adjustments to the brightness of pixels that are close to full brightness – this will reduce or eliminate any shift in star colours caused by the background subtraction option. This option should be preferred in most cases over ‘Simple Offset’. · DO NOT capture calibration frames (flat, dark, bias, darkflat, etc) when this option is enabled. This option should only be used when capturing light frames.

Mini Histogram and Display Stretch

This control shows an always-on mini histogram of the current image and allows the image displayed on screen to be ‘stretched’ without affecting the data saved to file when capturing. Stretching the displayed image means that the brightness and/or contrast can be enhanced, or faint detail can be brightened easily.  The stretch function provides similar effects to the Image Boost options in the FX dropdown but with finer control.

Adjusting the Display Histogram Stretch

Basic operation of the stretch adjustments involves dragging the position of the three vertical dashed yellow lines using the mouse. These three lines represent the histogram levels that will be displayed as black, mid grey and white respectively.

It is usually most useful to adjust the black and mid-level lines. Adjusting the mid-level line so that it is no-longer half way between the black and white level lines will create a transfer curve, shown as a yellow curve on the histogram that controls how the image pixel values are converted to displayed screen brightness.

Moving the mid-level line to the left will create a curve that initially rises rapidly then flattens out. This will have the effect of boosting the brightness of the darker areas of the image, making it easier to see faint detail. Moving the mid-level line to the right will create a curve that is initially relatively flat before rising more sharply near the white level. This has the effect of darkening the brighter areas of the image, perhaps making more detail visible in those regions.

The default settings of the Display Histogram Stretch (image displayed without adjustment):

The mid-level line moved to the left, enhancing the brightness of faint detail:

The mid-level line moved to the right, enhancing contrast in bright areas of the image:

Moving the black-level line to the right will effectively darken the whole image. This can be useful to give a blacker background – making background noise and light pollution less noticeable.

Display Histogram Stretch Buttons

The top, lightning bolt, button will perform an auto-stretch designed to pull out faint detail in the current image. This will adjust the black, mid and white level lines automatically based on an analysis of the brightness levels in the image. You can adjust how strong a stretch will be applied when using this button in the General Tab of the SharpCap settings. Using the auto-stretch feature requires a SharpCap Pro license.

The middle, circular arrow, button will reset the black, mid and white level lines back to their default positions, removing any display stretch currently in effect.

The bottom, save, button will save the current image exactly as seen onscreen as a PNG file. Unlike the normal SharpCap image saving functionality, this saved file *will* include the effects of any display stretch currently in effect. Note that the saved image file will have a bit depth of 8 bits regardless of the bit depth setting of the current camera.

Any changes made in the Display Histogram Stretch section only affect how the images are displayed on screen – there will not be any changes made to the images saved to capture files (except those saved using the ‘Save Exactly as Seen’ button in the display histogram stretch control.

Camera Specific Controls

The controls listed below will appear in addition to the common controls listed above.

Altair Camera Controls

SharpCap supports all current models of camera produced by Altair Astro.  If the camera is a new model and not in the Cameras list, please check for an updated version of SharpCap which may include changes needed to support the camera.

Further information can be found at the Altair Astro website.  Drivers, software and technical notes can be found at the Altair Support website.

Camera Controls
Auto Exposure Target	Controls the how bright a frame the auto exposure will aim for (when enabled). When this is set to a low value the auto exposure will tend to give an under exposed frame with few highlights. When set to a high value the auto exposure will tend to give an over exposed frame.
USB Speed	Controls how much of the USB bus speed the camera will try to use.  Higher values will usually lead to higher frame rates, but setting this value too high may lead to very low frame rates, irregular frames or no frames at all.
Flip	Allows the orientation of the image to be flipped either in the horizontal, vertical or both.  Not available in RAW modes.
Fan	Allows the Fan to be turned on/off on cameras that have a fan.

Image Controls
White Balance Adjust	Performs a single auto adjustment of the image white balance.
Negative	Converts the image to a negative representation (black becomes white, white becomes black, colours are reversed).
Colour Tint	Adjust the green/magenta colour balance of the image – lower values give a magenta tint to the image, higher values a green tint.
Colour Temperature	Adjusts the red/blue colour balance of the image – setting this value higher will make the image appear redder, setting it lower will make it appear bluer.
Digital Processing (On/Off)	Enables/Disables the digital adjustments to the image in the Altair Driver. · When this is switched to 'On', controls like Gamma, Brightness, Colour Tint, etc. are active. · When switched off, these controls are disabled. Switching this to Off may give a small performance boost.

ASCOM Camera Controls

ASCOM cameras have relatively few controls available in SharpCap.  Drivers and further information can be found at the ASCOM Standards website.

There is no guarantee all ASCOM cameras will offer all the controls listed below.  For instance, some ASCOM cameras have no cooler at all and of those with coolers some may offer direct control of cooler power while others may not.

Camera Controls
Options	Allows the ASCOM configuration dialog for the camera to be shown.  May have additional camera options that can be configured.  The camera is temporarily closed while the dialog is displayed and will restart when it is closed.

Thermal Controls
Actual Temperature	The current temperature of the camera sensor (read only).
Heat Sink Temperature	The current temperature of the heat sink (if any) in the camera (read only).
Cooler (on/off)	Allows any cooler present on the camera to be turned on or off.  If the cooler is turned on, then the cooling level may be controllable using one of the two controls listed below.
Cooler Power	Allows the percentage power that the cooler runs at to be set.
Target Temperature	The temperature that the camera will attempt to cool to (adjusting the cooler power automatically to achieve this temperature).

AstcamPan Camera Controls

You can find driver downloads and other information about the cameras on this website : here.

Camera Controls
Offset	Allows the black level to be adjusted.  This control should be adjusted with the camera covered to ensure that both sides of the black level peak in the histogram are visible and distinct from the zero level to ensure that black level noise can be averaged out correctly in stacking.  Called offset or brightness on some other cameras.
Turbo USB	Controls how fast the camera will try to push data over the USB bus.  Setting a higher value will try to move data faster and give higher frame rates, but setting a value too high can cause: · Dropped frames. · A collapse in frame rate. · Or even no frames at all. In general, leaving this setting on Auto will work well in most circumstances, but if there are issues with no frames, stuttering frames or low frame rates then try adjusting this option.
High Speed Mode	May improve the frame rate under some circumstances.  Changes from using the 12bit ADC on the camera to using a 10bit ADC.  Enabling high speed mode may increase image noise when the gain is set to a low value.
Hardware Binning	Only applies when binning is enabled.  Calculates binning on the camera itself rather than in software in the camera driver.  Increases gain and noise and increases frame rate.

Atik Camera Controls

SharpCap supports most Atik camera models. You must install the latest Atik core software otherwise SharpCap may be unable to detect or control your camera.

Camera Controls
Preview Mode	Available on some cameras – when enabled the readout time of the camera may be decreased at the expense of reduced image quality. Enabling Preview Mode may be useful for framing and focusing, but it should be disabled for capturing images.
Capture Dark Frames	Only available on cameras with a physical shutter. When enabled the shutter will not open when taking an image, allowing dark frames to be captured without needing to cover the telescope aperture.
High Speed Mode	Available on some CMOS cameras – putting the camera into high speed mode will increase the frame rate, which may be useful for solar/lunar/planetary imaging. High Speed Mode should be disabled for deep sky imaging or live stacking.

Image Controls
Digital Gain	Available for CCD cameras that do not have an analogue gain control. Digital Gain artificially brightens the image by enhancing the brightness of each pixel by multiplying it by the digital gain factor. This can be useful to allow shorter exposures for focusing, framing, etc., but should be disabled when capturing images.

Thermal Controls
Temperature	The current temperature of the camera sensor (read only).
Cooler Power	Allows the percentage power that the cooler runs at to be set.
Target Temperature	The temperature that the camera will attempt to cool to (adjusting the cooler power automatically to achieve this temperature).

Basler Camera Controls

Drivers and further information can be found at the Basler website.

Basler Specific Controls

Capture Format and Area
Colour Space	Basler cameras use non-standard colour space names for RAW modes. · BayerBG8 – equivalent to RAW8 with BGGR Bayer pattern. · BayerRG12 – equivalent to RAW12 with RGGB Bayer pattern. · Bayer GB12Packed – equivalent to RAW12 with GBBR Bayer pattern.  In packed 12 bit modes, 2 adjacent pixels are packed into 3 bytes (1.5 bytes each) rather than requiring 2 bytes each in unpacked mode.  This may increase frame rates in some circumstances as it reduces the amount of data that needs to be transferred from the camera to the computer.
FPS	The number of frames per second that the camera will attempt to deliver to the computer.  When left on auto it will aim for the maximum possible rate.  Note that the frame rate set in manual mode may not actually be achieved due to factors such as the exposure being too long or the data rate between the camera and the computer being insufficient to cover the desired frame rate. If aiming for a limited frame rate, then setting this to a low value is better than leaving this at a high value and setting the 'Frame Rate Limit' control as it should reduce the CPU load on the capture computer.

Camera Controls
Black Level	Allows the black level to be adjusted.  This control should be adjusted with the camera covered to ensure that both sides of the black level peak in the histogram are visible and distinct from the zero level to ensure that black level noise can be averaged out correctly in stacking.  Called offset or brightness on some other cameras.
Digital Gain	An additional gain that can be applied to the image.  Each step above zero doubles the image brightness but also doubles the noise levels

Processing Controls (should be Image controls for consistency with other cameras)
Auto White Balance	Automatically adjust the white balance of the image when the 'Adjust' button is pressed.
White Bal (R) [Colour Modes only]	Controls the relative intensity of the red channel of a colour image.
White Bal (B) [Colour Modes only]	Controls the relative intensity of the blue channel of a colour image.
White Bal (G) [Colour Modes only]	Controls the relative intensity of the green channel of a colour image.

Celestron/Imaging Source Camera Controls

SharpCap should support all Celestron branded Skyris and NexImage cameras (manufactured by The Imaging Source) as well as Imaging Source branded DMK and DFK cameras.

Drivers and further information can be found at the Imaging Source website and the Celestron website.

Camera Controls
Focus	Controls the focus of the built-in camera lens (if available).
Iris	Controls the aperture of the built-in camera lens (if available).
Pan, Tilt and Roll	Physical controls to pan, tilt and roll the camera if it has motor drive to allow it to be controlled remotely.
IR Cut Filter	Turn on/off the IR cut filter on cameras equipped with a controllable filter.

Image Controls
Colour Enhancement	Enhance colours in the image.
Highlight Reduction	Reduce the relative brightness of the highlights in the image.
Denoise	Apply a noise reduction filter to each frame (will also tend to reduce detail).
Colour Enable	Switch colour cameras between colour and monochrome mode.
Sharpness	Apply a sharpening filter to each frame to enhance detail (will also tend to increase noise).

White Balance
White Bal (R)	Controls the relative intensity of the red channel of a colour image.
White Bal (B)	As for White Bal(R) above, but controls blue.
White Bal (G)	As for White Bal(R) and (B) above, but controls green channel.

iNova Camera Controls

SharpCap supports a range of iNova cameras.

Drivers and further information can be found at the iNova website.

Camera Controls
Black level	In theory, the same as the black level control documented for other makes (copy from QHY?), in practice does nothing due to a bug in the iNova SDK.
Pixel Clock	How fast the internal CPU of the camera runs.  Higher speeds can give higher frame rates but sometimes too high a speed will lead to no frames at all.
Horizontal Blank	How long a delay the camera should apply between reading one scan line of the image and the next.  Usually best left on auto, but manual tweaking can sometimes improve frame rates, with lower values giving faster frame rates.   As with many of these speed controls, going too far can cause the frame rate to collapse to zero.

Moravian Instruments Camera Controls

SharpCap supports CMOS Moravian Instruments cameras. CCD based cameras may also work.

Drivers and further information can be found at the Moravian Instruments website.

CMOS cameras may have additional choices for the colour space options – for instance

· RAW8 slow

· RAW8 fast

· RAW12 slow

· RAW12 fast

The ‘fast’ modes may give higher frame rates. Other read modes may be available depending on the model of camera.

Moravian Cameras may show the option to control the camera fan or cooling if those features are present on the camera.

Player One Camera Controls

SharpCap supports the full range of Player One cameras.

Drivers and further information can be found at the Player One website.

Player One cameras currently do not have any specialized controls.

Point Grey Camera Controls

SharpCap supports FlyCapture based Point Grey cameras. Spinnaker based cameras are not supported. USB, GigE and Firewire models are all supported.

Drivers and further information can be found at the Point Grey website.

Note that you may need to restart SharpCap to detect GigE cameras if they are connected after SharpCap has been run.

Camera Controls
Auto Exp Target	This indicates the brightness that the Auto options for Exposure and Gain will aim for when enabled. Higher values (above zero) indicate brighter exposure, negative values indicate lower exposure.
Actual Temperature	This indicates the temperature of the senor in Celsius

Depending on the colour space chosen (i.e. RAW, MONO or RGB), different Image Controls from the list below will be available.

Image Controls
Digital Processing	Turning this control on will enable the other image controls listed below but may reduce frame rate slightly. Turning this control off will disable the other image controls but ensure that image data viewed and saved will match the data read from the camera sensor without any processing in software.
Gamma	Adjusts the gamma of the image
Brightness	Adjusts the brightness of the image. Warning: This is not a simple Brightness control that merely adds a constant offset to the values of all pixels. The exact implementation of this control is unclear, but in RGB mode it appears to affect the relative strength of the colour channels.
Sharpness	Applies a simple sharpening to the image (note that this will also increase noise in a noisy image)
Hue	Adjusts the colour tint of the image
Saturation	Controls the strength of colour in an RGB image
White Bal (Red)	Controls the relative intensity of the red component of a colour image
White Bal (Blue)	Controls the relative intensity of the blue component of a colour image

QHY Camera Controls

SharpCap supports a wide range of QHY CMOS cameras, including QHY5L-II, QHY5-III, QHY174, 178, 224, 290, 163 and 183.  The cooling features of the QHY ColdMOS cameras are supported as well as the GPS features of the QHY174-GPS.

Drivers and further information can be found at the QHY website.

Camera Controls
Amp Noise Reduction	This control is available for some cameras and when activated will reduce the amount of amp glow created by the camera for long exposures. In general, it is best to leave this control on the 'Auto' setting as it will apply the amp glow reduction when appropriate.  If amp glow reduction is enabled manually, this may result in incorrect images for certain exposure and gain combinations.
Row Noise Reduction	This control is available for some cameras and can be adjusted to reduce banding effects between camera rows.
Offset	Allows the black level to be adjusted.  This control should be adjusted with the camera covered to ensure that both sides of the black level peak in the histogram are visible and distinct from the zero level.  This ensures that black level noise can be averaged out correctly in stacking.
Speed	Control the transfer speed being used by the camera.  May increase frame rate in some circumstances.
USB Traffic	This controls how fast the camera will try to push data over the USB bus. Setting a lower value will try to move data faster and give higher frame rates.  Setting a value that is too low can cause: · dropped frames · a collapse in frame rate · or even no frames at all
Use DDR Buffer	Available on some cameras.  Turns on/off the use of the internal DDR buffer on the camera.  Using the DDR buffer may improve frame rate and reduce problems with dropped frames.
Optimize Light Level	Allows the sensor on the camera to be optimized for low or bright light levels.
Filter Wheel	Allows a QHY filter wheel connected via the camera port to be controlled. Note that a connected filter wheel may not be detected if it is still initializing when the camera is opened in SharpCap.
Enable Live Broadcast	Enable live broadcast of the images being shown in SharpCap via the QHY video broadcast application.

GPS Controls
GPS	Enable or disable the built-in GPS functionality on cameras that support it. The GPS feature allows frames to be timestamped precisely to microsecond precision.  GPS may require the camera to be supplied with 12V power.  When GPS is enabled and has a satellite lock the timestamp for each frame taken from the GPS system is used for the timestamp in capture settings files and SER file frame timestamps.  Without further adjustment, frame times will be accurate to millisecond levels, but to get microsecond precision the following controls must be adjusted correctly.
GPS Calibration LED	The GPS calibration LED must be turned on to be able to correctly adjust the following two controls.  The camera must also be covered so that the light from the LED can be seen in the image. Turn up the gain so that the light can be seen easily.
Calibration Start Pos	With the GPS LED on, turn the calibration Start Pos down to zero and then turn it up until the calibration light appears as a glow at one side of the image.  Then turn the value down a small amount until the light vanishes again.  Setting this control allows the GPS frame start time to be corrected for the time difference between the camera circuitry requesting the frame starts and the actual exposure starting.
Calibration End Pos	With the GPS LED on, set this to a value just above the calibration Start Pos value and then turn up the value until the LED light vanishes again. Turn the value down a small amount until the light re-appears. This allows the end of frame time to be adjusted for the time difference between the camera circuitry requesting the frame to stop and the frame having finished. After calibrating the Start and End Pos, don't forget to turn the calibration LED off again.  Also, note that the calibration needs to be repeated after having changed the camera exposure or the camera colour space.

Image Controls
White Bal (R) [Colour Modes only]	Controls the relative intensity of the red channel of a colour image.
White Bal (B) [Colour Modes only]	As for White Bal(R) above, but controls blue.
White Bal (G) [Colour Modes only]	As for White Bal(R) and (B) above, but controls green channel.

Thermal Controls
Cooler Power	Allows the percentage power that the cooler runs at to be set.  If set to Auto, then the cooler will automatically attempt to cool the sensor to the temperature given by the Target Temperature control.
Target Temperature	Sets the sensor target temperature for use when the cooler power is set to Auto.

Starlight Xpress Camera Controls

SharpCap supports the full range of StarlightXpress CCD cameras. Drivers and further information can be found at the Starlight Xpress web site.

Capture Format and Area

Some Starlight Xpress cameras have interlaced sensors, meaning that only half of the lines on the sensor can be read at a time. When a camera with an interlaced sensor is in use, SharpCap adds an Interlace Handling control to allow various ways of dealing with the interlaced camera to be chosen.

The options for Interlace Handling are

· Capture Odd then Even Rows - this option will expose the camera twice for each frame shown in SharpCap, first capturing the odd lines of the sensor, then the even. This is the only option that gives full sensor resolution, but frame rate is halved (for instance with a 2s exposure selected, the image will only update once every 4s)

· Interpolate from Odd Rows – this option will only expose the odd rows of the sensor, but will generate a full-size image by generating data for the even rows by averaging (interpolating) the data of the odd rows on either side. Frame rate will be normal, but there will be less detail in the image

· Interpolate from Even Rows – as Interpolate from Odd Rows, but exposes only the even rows of the sensor, with the odd rows being generated by averaging

· Capture Odd Rows – exposes the odd rows of the sensor and forms an image only half the normal height (290 pixels for the camera shown above). Frame rate will be normal, but images will be distorted due to halving the height of the image

· Capture Even Rows – as Capture Odd Rows, but captures only the even rows.

· Capture All Rows (2x vertical bin) – this option exposes all pixels on the sensor, with a 2x vertical binning being applied before reading the sensor. As for Capture Odd Rows and Capture Even Rows, the image will be distorted due to being half normal height, but the sensitivity of the sensor is maximised as all pixels are exposed and measured in each frame.

Image Controls

Image Controls
Digital Gain	Starlight Xpress CCD cameras do not have an analogue gain adjustment option, but the deep well depth means that a usable image can be generated even at relatively low saturation levels. Unfortunately, such images are very dark due to the signal on each pixel being low compared to the maximum signal. The digital gain option provides a way to compensate for this problem by boosting the whole image after it is read from the sensor, by a factor of up to 100x. The use of Digital Gain is particularly helpful when focussing or using the Polar Alignment tool.
Black Level	This is a software black level adjustment. It should only be necessary to adjust this control when using the Digital Gain option (to keep the black level of the histogram down to a reasonable range).

SVBony Camera Controls

SharpCap supports the SV305 and SV305-PRO cameras directly. Older SVBony cameras (SV105, SV205) are supported via their Webcam drivers.

You can find driver downloads and other information about the cameras here.

Camera Controls
Black Level	Allows the black level to be adjusted.  This control should be adjusted with the camera covered to ensure that both sides of the black level peak in the histogram are visible and distinct from the zero level to ensure that black level noise can be averaged out correctly in stacking.  Called offset or brightness on some other cameras.
USB Speed	Controls how much of the USB bus speed the camera will try to use.  Higher values will usually lead to higher frame rates, but setting this value too high may lead to very low frame rates, irregular frames or no frames at all.

Image Controls
Sharpness	Applies a simple sharpening to the image (note that this will also increase noise in a noisy image)
Saturation	Controls the strength of colour in an RGB image

ZWO Camera Controls

SharpCap supports the full range of ZWO cameras, including support for high resolution ASI1600 cameras and cooled cameras.

Drivers and further information can be found at the ZWO website.

Camera Controls

Camera Controls
Turbo USB	Controls how fast the camera will try to push data over the USB bus.  Setting a higher value will try to move data faster and give higher frame rates, but setting a value too high can cause: · Dropped frames. · A collapse in frame rate. · Or even no frames at all. In general, leaving this setting on Auto will work well in most circumstances, but if there are issues with no frames, stuttering frames or low frame rates then try adjusting this option.
High Speed Mode	May improve the frame rate under some circumstances.  Changes from using the 12bit ADC on the camera to using a 10bit ADC.  Enabling high speed mode may increase image noise when the gain is set to a low value.
Hardware Binning	Only applies when binning is enabled.  Calculates binning on the camera itself rather than in software in the camera driver.  Increases gain and noise and increases frame rate.

Image Controls

Image Controls
White Bal (R) [Colour Modes only]	Controls the relative intensity of the red channel of a colour image.  Along with White Bal (B) this can be used to correct the white balance of an image.  Note that setting either of the two ZWO white balance controls to auto sets them both to auto.
White Bal (B) [Colour Modes only]	As for White Bal(R) above, but controls blue.  Note that there is no control for the green channel, but that isn't needed as the relative strength of the green channel can be increased or decreased by making the opposite change to both red and blue.
Mono Bin [Colour Cameras only]	Only applies when binning is selected. Creates a monochrome binned image rather than a colour binned image.

Note: ZWO cameras no longer offer a Gamma control – the ability to adjust Gamma was removed by ZWO several years ago.

Thermal Controls

Thermal Controls
Cooler On/Off	Turns the camera cooler on or off.  The camera must be connected to 12V power to allow the cooler to operate.
Target Temperature	The temperature the camera will try to achieve if the cooler is turned on.
Cooler Power [Read only]	The current power percentage that the cooler is running at.

Miscellaneous Controls

These control the auto exposure and auto gain functions of the camera.

Miscellaneous Controls
Auto Exp Max Brightness	Auto Exp Max Brightness sets the target level for the maximum brightness point in the histogram in the range 50 (targets a histogram peak at about the 20% level) to 150 (targets a histogram peak at about the 60% level).
Auto Exp Max Exp	Auto Exp Max Exp is the maximum exposure (in seconds) that can be used when auto exposure is enabled.
Auto Exp Max Gain	Sets the max allowable gain in the same way.

DirectShow Cameras

Microsoft DirectShow is an architecture for streaming media on the Microsoft Windows platform.

There are a vast number of webcams and frame grabbers on the market.  In general, SharpCap should work with any of them but some cameras/grabbers have buggy drivers which may prevent them from working correctly with SharpCap.  The controls available in SharpCap are determined by the driver – SharpCap just shows the controls the driver makes available.  Sometimes more controls are available in the Video Capture Pin and Video Capture Filter dialogs provided by the device driver. These can be accessed using the Pin Options and Filter Options controls in the Capture Format and Area and Image Controls sections respectively. To show the respective dialog, press the Show button for that control.

Examples of the Pin and Filter dialogs are shown below:

Video Capture Filter	Video Capture Pin

Note that the controls available in, and the design of, the Video Capture Filter and Video Capture Pin dialogs is determined by the camera driver for the camera being used, not by SharpCap.

Additionally, SharpCap allows the images being captured from a webcam to be processed by sophisticated features available to dedicated astro cam users – for instance Live Stacking and Polar Alignment are both usable with images coming from a webcam or frame grabber provided a long enough exposure can be set to start seeing details and/or stars. 

Webcams

Many budget webcams usually need some adaptation to be used for imaging.  This usually involves removal of lenses, auto-focusers (which includes the infra-red filter) and addition of a webcam 1.25” adapter and IR cut filter. 

Microsoft LifeCam (webcam)

The Microsoft LifeCam HD is a common web cam which can be modified for astro use – it would typically be used for lunar/planetary image capture but not deep sky objects.  Its capability can be seen in the Jupiter images at the SharpCap gallery .

These webcams can be found on eBay for around £15 and would need an IR cut filter (around £10 on eBay).  Modification details can be found at  http://dslrmodifications.com/lifecam/lifecam1.html, showing the camera being fitted into a disused or low cost telescope eyepiece.

Original Microsoft LifeCam	Modified and fitted into a 1.25” eyepiece
Showing IR cut filter	Sensor view

Frame Grabbers

A frame grabber is an electronic device able to capture frames from an analogue video signal.  The frame grabber is a USB device.  The analogue video signal is commonly supplied by a day/night CCTV style security camera.  This type of camera, generically called an astro video camera, is commonly based on the LN300 style CCTV body, usually with enhanced firmware or electronics which allow for internal stacking of video frames.  Camera output can be to a frame grabber or an analogue screen.  This arrangement is commonly used for live image display and internet video broadcasting of astronomical objects particularly in outreach type scenarios.  This arrangement has proved to give satisfactory results under heavily light-polluted skies.

A typical video capture device is the EzGrabber from http://www.ezcap.tv/.  [Note: there are lots of clone devices that look the same as the ezcap but may contain completely different hardware and have different drivers – sometimes these drivers have compatibility problems.]

Well known manufacturers of the astro video type cameras are Revolution Imager and Mallincam.

A typical setup comprising frame grabber and astro video camera is shown below.

Analogue video camera with Bluetooth adapter for accessing the camera’s internal menu.  Video/power balun (left hand side) used to connect ethernet cable.	USB2 video frame capture device.  Shows in SharpCap as a USB 2861 device.
From left to right – video frame grabber, balun, ethernet cable, balun, analogue video camera.

SharpCap will see this USB frame grabber as a USB 2861 (typically 28xx) device.  The details of the camera connected to the frame grabbing device will not be detected by SharpCap.  The camera is controlled by its own internal menu system and is usually accessed via a USB or Bluetooth connection.  This type of camera typically has a maximum resolution of 720 x 576 and will be NTSC or PAL.

SharpCap view of a frame grabber	Astro video camera internal menu

Modified Webcams

Modified webcams are those which have been electronically modified.  Typical modifications are long-exposure (LX) and amp glow removal.  SharpCap 3.1 and above no longer support LX modified webcams - you should use an earlier version of SharpCap (3.0 or earlier) to control these cameras. Details on their use can be found in an earlier version of this user manual.

DirectShow Controls

DirectShow cameras have a fixed set of available controls defined by Microsoft, however not all cameras will offer all these controls.

Format & area (Video format) · Colour space · FPS · Resolution · Frame divisor

Camera controls · Pan · Tilt · Roll · Zoom · Exposure · Iris · Focus

Image controls · Brightness · Contrast · Hue · Saturation · Sharpness · Gamma · Colour Enable · White Balance · Backlight Compensation · Gain

Virtual Cameras

SharpCap can talk to a wide range of cameras directly and even more via either an ASCOM or DirectShow driver. It also has a pair of testing (simulated) cameras that can be used to try out the features of the program on cloudy nights. The Virtual Folder Monitor Camera adds another way to get images into SharpCap – it can read existing or newly added image files from a directory opening up new ways to use SharpCap. As a couple of examples:

· You have a camera that isn’t supported by SharpCap, even using a DirectShow or ASCOM driver, but you have an application that will capture frames from that camera and save them to a folder. You can use the folder monitor virtual camera to load each new frame saved to the folder into SharpCap, allowing you to access SharpCap tools like focus measurements, live stacking, etc.

· You have a series of image frames of a target captured with either SharpCap or another capture application. You can use the folder monitor virtual camera to live stack these frames in SharpCap (or repeat the live stacking with different parameters if these were frames originally saved in SharpCap).

The virtual folder monitor camera only has a limited set of controls available – it’s obviously not possible to adjust camera controls like exposure, gain or colour balance when the images are being read from saved files! The resolution and colour space values are also determined by the contents of the image files being loaded and cannot be changed.

You do have the ability to browse for the folder that contains the files you want to work with and move through the list of files in the folder either automatically (in play mode) or stepping forward/back manually in pause mode. Additionally, dark subtraction and flat frame correction can be applied and the frame rate limit can be set.

To select the folder source, press the ‘Browse’ button and either select a folder (which will process all image files in that folder) or select a single image file (PNG, TIF, FITS and JPG supported), which will process all image files of that type in the same folder. When you select a new folder:

· If the folder contains image files then the first image file of the selected file type is loaded into the camera and displayed, then the camera is paused automatically, allowing you to make any adjustments necessary or select tools such as live stacking before pressing the ‘Play’ button to begin processing the other images in the folder

· If the folder does not contain any image files then the camera will enter play mode automatically, which means that the first image will be processed and appear on screen soon after it is saved into the selected folder.

The playback controls (Rewind, Step back, pause, play, step forward) provide a way to move through the image files present in the folder.

Image files are always processed in date order (starting with the oldest first). The resolution and colour space values are selected from the first frame processed, and files that have different resolutions or colour space settings will be skipped. If SharpCap runs out of files in the folder (or if there are no image files in the folder initially) then it will wait for new image files to be added and load them when they appear.

If multiple image files are present in a folder and the ‘Play’ function is selected then they will be rapidly displayed in turn with no pause between images unless

· The frame rate limit control is set to limit the rate at which frames are displayed or

· Live Stacking is selected, in which case a new frame will be loaded only after the previous frame has completed any live stacking calculations, ensuring that no frames will be skipped by the live stacking.

The Virtual Folder Monitor Camera is a SharpCap Pro feature.

Test Cameras

The Test Cameras are useful to experiment with and understand settings and their effect.  Much of the material in this manual has been derived from the Test Cameras.  Hence this document can be used as a learning aid without having a telescope or camera attached to the PC/laptop or when the sky is cloudy.  The use of a suitable lens (which can be purchased for a few pounds) will allow astro cameras to be tested without waiting for clear skies.

Test Camera 1 (Deep Sky)

See Common Camera Controls for a description of generic camera/image/display controls.  [Note:  some of the common controls currently have no effect, for example gain.]

· Image – click the Properties button to load a PNG file stored in the SampleFiles folder.  Other user created PNG, JPG or FITS files can be stored here for access via the test camera.

· Random Rotation – applies a random small rotation to each frame shown in the capture display area.  On/Off, default = Off.

· Random Offset – applies a random offset effect to the image shown in the capture display area.  On/Off, default = Off.

· Random Seeing – applies a random seeing effect to the image shown in the capture display area.  The seeing effect is a blurring of the image.  On/Off, default = Off.

· Random Noise(On/Off) – applies a random noise effect to the image shown in the capture display area.  Default = 10, range 0..50.

· Add Dark Noise – will, by default, apply the file SampleFiles\1280x960x32RGB_dark.png to the image shown in the capture image.  The image used for dark noise can be changed by pressing Properties – the image must be the same size as the main image.

Test Camera 2 (High Speed)

See Common Camera Controls for a description of generic camera/image/display controls.  [Note:  some of the common controls currently have no effect i.e. gain, exposure, gamma.]

· Focus Offset – simulate focuser movement and can be used in Focus Score > Graph.  Default = 0, range -10..+10. Note that this Focus Offset control is only available if the selected focuser in the Hardware Settings is set to None.

· Random Offset – applies a random offset effect to the image shown in the capture display area.  On/Off, default = Off.

· Random Seeing – applies a random seeing effect to the image shown in the capture display area.  The seeing effect is a blurring of the image.  On/Off, default = Off.

· Random Noise – applies a random noise effect to the image shown in the capture display area.  Default = 10, range 0..50.