Configuring SharpCap

SharpCap configuration is carried out in the Settings dialog, which can be accessed from the File menu.

General Tab

The General tab contains a variety of settings that are divided into four groups – Startup, Display, Saving and Misc.


Startup Settings

Show tips when SharpCap starts

This option is checked by default.  The Tip of the Day appears when SharpCap is started but can be disabled for future start-ups here or when SharpCap starts.



Automatically connect to camera when SharpCap starts

When set, SharpCap will automatically reconnect to the last used camera at start-up.  If set, this setting can be overridden by holding down the Control key when starting SharpCap, which will skip opening a camera at start-up.  This setting is enabled by default.

Automatically restore camera settings

When set, SharpCap will save the current settings of each camera when you close the camera (or close SharpCap) and restore those settings the next time the camera is opened. The saved settings are stored in a hidden capture profile called ‘_autosave’ (this profile may be visible in older versions of SharpCap used on the same PC). If you do not wish to reload the previous settings then hold down the <CONTROL> key while the camera is opening. This setting is checked by default.

Display Settings

Display in night vision colours

Selecting this option causes SharpCap to display in a dark colour scheme which is better for night-time use. You can also switch between the two colour-schemes by pressing the <F12> key. This option is unchecked by default.



Normal vision (day) colours

Night vision colours


Use night vision to preserve dark adaptation of the eyes during a capture session if intending to observe visually.

Auto Stretch Intensity

This setting controls how aggressive the Auto Stretch functionality in the Mini Histogram and Live Stackingis. Setting this option to a larger value with result in the Auto Stretch buttons brightening the darker regions of the image more strongly. You can adjust this option until the Auto Stretch buttons give results that suit your tastes.

Saving Options

Save capture settings file alongside each capture

When this option is checked, SharpCap will save a text file containing all the camera settings alongside the capture file each time a new capture is started. This file is useful to check the settings used for particular images at a later date. This option is enabled by default.

Start cameras with ‘Auto’ output format

This option is checked by default.  This option will set the Output Format control into Auto mode when a camera is opened. When the Output Format is in Auto mode a compatible video format will be chosen automatically for exposure times of less than 5s and a compatible still file format for exposure times of more than 5s. If possible, the preferred formats will be used (providing they are compatible with the camera settings in use).

Save 10/12/14 bit images in FITS files without stretching to 16 bit

This option is off by default and should only be enabled for special use cases where post-processing software has issues with pre-stretched images. If in doubt, do not turn this option on.

By default, SharpCap will stretch 10,12 and 14-bit images up to use the full 16-bit range (0 to 65535) when saving those images to file (FITS, TIFF, PNG or SER formats). This is desirable because without applying this stretch the saved images would appear very dark and would all require brightening before the image could be seen properly. However, some image processing software (particularly photometry software) cannot process such pre-stretched images correctly. If you encounter this situation then you can turn this option on to make SharpCap save unstretched FITS files.

Preferred Video Format

AVI is the default video format. This determines the auto selected format in the camera section of the Camera Control Panel.




Preferred Still Format

PNG is the default still format.  This determines the auto selected format in the camera section of the Camera Control Panel.

Saved target names

This option is a pre-configured list of object names.  Objects can be added to the list or removed from the list and the list re-ordered.


To add a new object, for example M42 or Whirlpool Galaxy, type the name anywhere into the Saved target names list.  Click Apply to save the amended list.  The amended list will be available the next time SharpCap is started.


The list also appears in the Tool Bar near the top of the screen under Object Name.  Objects added in Saved target names will also appear in the Tool Bar dropdown list.



·         Object Name undefined (the default), captures saved in folder:  YYYY-MM-DD\Capture

·         Object Name defined, captures saved in folder:  YYYY-MM-DD\Object

·         Moon selected as Object Name, captures saved in folder:  YYYY-MM-DD\Moon

Misc Settings

Record extra information in the log for troubleshooting

This option is off by default. When turned on, SharpCap will write significantly more information to its log – in some cases this extra information may help track down issues. Turning this option on may result in SharpCap running more slowly or becoming less responsive due to the extra information being logged, so it is not recommended that you turn this option on unless asked to by SharpCap support.

Log all QHY GPS data to file

SharpCap supports QHY cameras with built in GPS. When the GPS is activated on such cameras, the default behaviour is to store the GPS data (time, date, location) in FITS headers or in the capture settings file. However sometimes it is desirable to keep a more detailed record of the GPS information – enabling this option will create such a log file in CSV format in the root capture directory each time a GPS enabled camera is used.

This option is disabled by default and you should restart SharpCap after changing this option to be sure that it takes effect.

The format of each line of the log file is

<PC Clock Time>, <GPS Status>, <Frame Number>, <Frame Start Time from GPS>, <Frame End Time from GPS>, <Latitude>, <Longitude>, <RawLatitude>, <RawLongitude>

The RawLatitude and RawLongitude are the un-decoded values received from the camera. Contact QHY for the steps necessary to decode these values if you wish to decode them separately.


Hardware Tab

This is the hardware screen for a default SharpCap installation.  The fields Focuser, Filter Wheel and Mounts all show as None.


This is the hardware screen when various ASCOM compliant hardware has been configured. 

·         This section will only need to be configured if a computer-controlled focuser, mount or filter wheel is to be used from within SharpCap.

·         The ASCOM platform must be installed to be able to select any hardware in this section.

·         Ensure ASCOM drivers for the hardware are installed and configured. 

·         The ASCOM platform comes with a range of simulated hardware drivers that can be used for testing and experimentation.

Note that there is an option to choose whether SharpCap automatically connects to the selected ASCOM hardware each time a camera is opened or not. If this option is checked then SharpCap will attempt to connect to all selected hardware automatically when a camera is opened. While convenient, if the hardware does not respond (perhaps it has not been switched on) then you may see an error. If you prefer you can uncheck this option and then manually connect each item of hardware when needed. This option is checked by default.

Filenames Tab

This tab allows fine control over how captured images and videos are named and organised.


Save captured files to

This allows the top-level capture folder to be selected.  All captured files will be saved into this folder or subfolders created within this folder. 

The capture folder in a default installation will be on the logged-in user’s desktop and is called SharpCap Captures. Note that SharpCap will check that the top-level capture folder exists and that it is not full each time SharpCap starts. If the top-level capture folder is found to be missing, full or read-only then the folder will be reset to the default of Desktop\SharpCap Captures.

The browse button allows other capture folders to be selected or created.

Speed Test

This button will carry out a hardware performance test of disk write speed.  Running this test will discover if the camera’s capture rates are being degraded by disk write speeds.

Organise captured files into subfolders

If this is unchecked, all captures will be saved in the top-level capture folder.  When checked, captured files will be saved into subfolders according to the rules selected below.

Options and combinations for folder and file names are available.  Sensible defaults are offered in the initial, default installation.  Examples of using the options are given below.

Date and then Target Name

Below is an example of a saved file organised by date then target name.  File names are derived from the creation time of the capture and are in the format HH_MM_SS.  Note the higher-level directory is named after the date and the inner directory named after the target.


Target Name and then Date

Below is an example of a saved file organised by target name then date as seen in the Notification Bar (green = success).  Note the higher-level directory is named after the target and the inner directory named after the date.image

Create WinJUPOS Compatible File Names

Below is an example of a saved file using a WinJUPOS compatible name – a combination of date and time.  This uses mid-point time in the capture for the WinJUPOS name.  Using this option will make loading video files into WinJUPOS for de-rotation easier.


Use UTC times in files and folder names

When this option is checked, all dates and times used for filename generation will be UTC times. When it is unchecked, local times will be used.

Below is an example of a saved file using the UTC time format.


The letter designates time zone, Z = United Kingdom.

Use sortable date format (YYYY-MM-DD)

When checked, the date format YYYY-MM-DD will be used for all dates, making it easy to sort file and folder names in Windows Explorer.  When unchecked, the date formatting rules appropriate to the PC’s regional settings will be used.  This option is checked by default.

Save capture settings file alongside each capture

When checked, each capture file will, have an associated settings file saved with it.


22_06_22.avi & 22_06_22.CameraSettings.txt


The text file to the right contains capture settings from the Camera Control Panel – useful for reference in future observing sessions or analysis during a post-processing session. 


The name of the text file reflects the time of creation. 


The captured data (video or still) and the CameraSettings.txt file will have the same timestamp in their filenames.





This section provides extra options for filenames generated as part of a sequence of files (for instance when capturing frames to PNG or FITS format a file will be created for each captured frame).

Include time in filenames will put the current time (the time at which the frame was captured) in the filename for each captured frame.

Create subfolder for each sequence is enabled by default. When enabled, each new sequence of files will be stored in a separate subfolder. When disabled, many sequences may be saved in the same folder, depending on higher level folder naming choices.


Append Filter Name will add the name of the current filter to the file name. For this option to be effective, you must have selected a filter wheel in the Hardware Tab and ensured that it is connected correctly.

Sample Filenames

This section shows sample filenames that would be generated based on your choices for file and folder naming above. The first sample shows how a filename will be generated for a single file capture (where multiple frames are saved into a single video file in AVI or SER format). The second sample shows how filenames will be generated for a sequence of files capture (where each saved frame is stored in a separate image file in a format such as PNG, FITS or TIFF).

If Filename Templates are in use then these samples show the filenames that would be generated by the Single File and Sequence templates.

Filename Templates

All capture file names in SharpCap are generated through a system of filename templates. When you adjust the various check boxes and options for file naming, SharpCap automatically generates filename templates that represent your choices. These templates are then used later to generate the actual file names. In fact, as you change the various options in for file and folder naming you can see the Filename Templates shown in the lower portion of the tab updating to represent your choices.

Sometimes you may find that you cannot obtain the file naming that you wish to achieve using the various file and folder naming options available. In this case you can choose to Edit Filename Templates Manually rather than have the templates created automatically based on your file/folder naming selections.


Editing the filename templates manually requires some care, but provides ultimate control over how your saved files are named. Each filename template consists of text containing one or more tags. A tag consists of a tag name surrounded by curly braces ( ‘{‘ and ‘}’ ). Tags are replaced by values when a filename is needed, so the tag ‘{Date}’ is replaced by the current date and ‘{Time}’ is replaced by the current time. The available tags are:



The date and time that the capture was started


The date that the capture was started


The time that the capture was started


The name of the target object entered (or ‘Capture’ if no name entered)


The name of the camera being used


The name of the currently selected filter


The extension of the file (ie AVI or PNG). There is no need to put ‘.{Extension}’ at the end of a template.


Sequence captures only. The index of the current frame in the sequence.


Sequence captures only. The date on which the current frame was captured


Sequence captures only. The time at which the current frame was captured




Live Stacking only. The total number of stacked frames so far


Live Stacking only. The total exposure of stacked frames so far


Live Stacking only. Is the current save an autosave?


Sequence captures only. The exposure of the current frame.


Sequence captures only. The gain of the current frame.


Sequence captures only. The black level (offset/brightness) of the current frame.


The type of frame (ie light/dark/flat) as selected from the toolbar dropdown.


Some Tags can have an optional format string to change the way they are used in the filename:


Applies To




Date, DateTime, FrameDate

Use a sortable format for dates



Any time or date tag

Use UTC times and dates



DateTime, FrameTime

Use WinJupos compatible format



When you make changes to the filename templates you will see typical filenames updated in the Sample Filenames area described above, helping you understand how your filename templates would work.

It is important to take care when customizing filename templates as you may accidentally set up templates that have undesirable results (for instance writing over previous capture files). You should always test manual changes to filename templates before embarking on an observing session.

[Note: The toolbar dropdown for Frame Type is only visible if the Edit Filename Templates Manually option is selected]

Memory Tab

On 64-bit versions of Microsoft Windows, SharpCap can access additional memory to improve performance and help handle the large amounts of memory needed to perform certain functions like running Live Stacking on very high resolution cameras.

If you have only have 4Gb or less of memory, or you are using a 32-bit version of Windows then your only option here is to remain on the Classic option for memory management.

If you have more than 4Gb of memory and are using a 64-bit version of Windows then Paged will be the default option for memory management (although you can switch back to Classic if you prefer).


Choosing Paged memory allows SharpCap to access more memory in total. Paged memory is divided into two categories:

·         High Speed Frame Cache – this memory is used to store frames captured from the camera before they are written to disk. If you are using a high speed USB3 camera and have a trouble with dropped frames when capturing because your disk drive or SSD cannot keep up then a large high speed frame cache will help.

·         Live Stacking and Display – this memory is used to support live stacking operations and also to support the transformation and processing of images prior to display on screen. If you are Live Stacking with a high resolution camera then having a large amount of memory allocated to this category will help avoid out-of-memory errors.

By default, 1Gb of paged memory is allocated to each category, for a total of 2Gb. If you have a SharpCap Pro license then you can increase the amount of memory allocated to each category, up to a total of 50% of your physical memory.

If you change the settings on the Memory tab then you should restart SharpCap to ensure that they take effect correctly.

Plate Solving Tab

Plate Solving is a technique to work out the location in the sky of a particular image by recognizing the pattern of stars it contains against an index of known stars. If this technique is applied to an image just captured from your telescope then the calculated location will be the point in the sky that your telescope is pointing at.

SharpCap can integrate with a number of plate solving tools based on the plate solving engine. This engine is found inside plate solving tools such as AstroTortilla, Ansvr and All Sky Plate Solver.  In order to plate solve images you must first install and configure one of these tools. Remember that you must also install plate solving index files – please see documentation for the plate solving tool which will guide you on how to install index files and which index files to install.

SharpCap will automatically detect the installation of the three plate solving tools mentioned above if they have been installed into their default locations. However, if you have installed to a custom location or installed a different based tool, you will need to configure the location of the ‘solve-field’ command which performs the actual plate solving process.


Further options to configure and fine tune the plate solving process are available as follows:

The Star Noise Detection Threshold can be configured by adjusting the numeric value of the ‘—sigma’ parameter. Higher values will tend to detect fewer stars, lower values will mean that more stars are detected. If too few stars are detected (less than 20-3) then plate solving is more likely to fail. If too many stars are detected (more than 200) then plate solving may take a very long time to complete. You may need to adjust this parameter depending on the camera/telescope combination in use.

When Automatically downsample large images when solving is enabled, images that are wider than 2000 pixels will automatically be downsampled (binned) to make them smaller before attempting to plate solve them. This option tends to dramatically improve the speed and reliability of plate solving large images with large numbers of stars visible in them.

Finally, it is possible to choose the action taken when plate solving is launched from the ASCOM mount controls. The default action is to sync the mount to the solved position and then re-centre on the target. You can change this to performing the sync only if you want.

Polar Alignment Tab

SharpCap’s Polar Alignment routine can become more accurate and easier to use if SharpCap knows your latitude and longitude. By default, SharpCap estimates your longitude from your computer’s time zone settings and estimates your latitude to be 45 degrees North or South. This is sufficient for Polar Alignment to work, but setting your correct latitude will allow SharpCap to correct for atmospheric refraction giving a more accurate result. Setting your correct longitude will ensure that up/down/left/right movement instructions are accurate.


You can choose to leave the observing location as the default setting (Estimate automatically from time zone) or choose either of the two accurate location options – using the location from your ASCOM mount or specifying a location manually. If you choose an accurate location option then you can enable the option to correct for atmospheric refraction.

The location provided does not need to be perfectly accurate – latitude and longitude correct to the nearest degree are accurate enough.

Finally, you can use the ‘Geolocate’ button to find your current location automatically if you are connected to the internet. This will send your IP address to an internet server which will respond with your approximate location. This approach may not work for all internet providers and will probably not work well if you are connected to the internet via a mobile device.


Start-up Scripts Tab

This tab allows a list of Python scripts, to be run at SharpCap start-up, to be configured.  Such scripts can be used to add additional features or customizations to SharpCap every time it is started.  Use the Add, Remove, Move Up and Move Down buttons to manage the list of start-up scripts.

For example, the following Script will create a button on the toolbar that selects the first camera when pressed.  The code can be created and saved by following the information in Scripting.

def selectFirstCamera():
SharpCap.AddCustomButton("Test", None, "Select the first camera", selectFirstCamera)


Save the script somewhere (call it for example), say on the desktop and configure File > SharpCap Settings > Startup Scripts accordingly.




Deselect the camera, restart SharpCap and the button Test should be added to the right-hand end of the Tool Bar, together with the camera having been selected.




This technique is good to use for the start-up script as it allows creation of custom toolbar buttons and have them load every time SharpCap is started.

The Test button can be removed via File > SharpCap Settings > Startup Scripts, highlighting the script, selecting Remove and restarting SharpCap.