The SharpCap Sequence Editor

The SharpCap Sequence Editor provides a much more flexible way of configuring SharpCap’s sequencing engine than the Deep Sky Sequence Planner discussed above. Many automated imaging tasks that cannot be set up using the Deep Sky Sequence Planner can be configured using the Sequence Editor. For example:

·         Automating lunar, solar or planetary imaging.

·         Automating Live Stacking sessions.

·         Automating imaging of multiple targets in succession.

·         Automating capture of a mosaic of images.

These tasks are achieved by constructing an imaging sequence that consists of running a number of individually relatively simple steps in order. These steps can be thought of as building blocks from which the sequence as a whole is constructed. A full list of the available building block steps can be found below, but to give an idea of what is available, steps allow you to do things such as:

·         Select a camera

·         Change camera settings

·         Capture frames as still images or a video

·         Send commands to hardware – GOTO mounts, and electronic focusers and filter wheels

·         Perform plate solving and autofocusing operations

·         Wait for a fixed interval or until a time of day or an event (for example sunset)

·         Repeat groups of other steps

·         And many more – see Available Steps.

If you are familiar with computer programming, you may have spotted by now that the SharpCap Sequencer is essentially a very simple programming language. Some things that you might expect to find in programming languages (variables and conditional statements) have been deliberately left out of the SharpCap sequencer to prevent it from becoming too complicated.

It’s important to be aware that the additional power and flexibility that is available through the Sequence Editor means that it’s possible to design sequences that are essentially nonsense. For example consider the following sequence :


This sequence can never complete successfully – the first step closes any camera that is currently open and the second step tries to capture 10 frames. Attempting to capture the frames will always give an error because there will be no camera open when the capture frames step starts.

When designing your own sequences, think about the order that you would do things if you are using SharpCap manually and place the steps in the same order.

The Sequence Editor user interface

The Sequence Editor shows in a separate window to the main SharpCap window. You can display the Sequence Editor window at any time and it will automatically show the most recent sequence that you have worked on. You can keep the Sequence Editor window open and switch back to the main SharpCap window to perform non-sequence related tasks without needing to close down the editor window.

The initial view you will have of the Sequence Editor window (with no sequence loaded) will look like this:


The Sequence Editor Window is divided into nine major areas as highlighted below:


1.       The Menu – this provides access to loading and saving sequences, standard editing operations such as cut/copy/paste and sequence run/stop/test commands.

2.       The Available Steps area - this area shows the list of sequencer steps that can be used to build up your own sequences. You can use the mouse to drag steps that you wish to use from this area into the main sequence list.

3.       The Sequence list – this area shows the list of steps in your sequence. Each step shown here will be executed in order (from top to bottom) when you run the sequence.

4.       The Action Buttons – these buttons provide quick access to common actions – Undo, Redo, Test, Run, Stop, etc

5.       Selected Step Properties – when you click on a step in the Sequence List, any adjustable properties of the step will be shown and can be adjusted here.

6.       Trash Can – drag steps here from the Sequence List to delete them.

7.       Progress – the progress and ETA of a sequence are shown here when running a sequence from within the editor

8.       Sequence Listing – this area shows the current state of the sequence in code form. Note that you cannot edit the sequence by making changes in this area, this is for information only

9.       Sequence Log – sequence related log information is shown here when running a sequence from within the editor


The Menus

File Menu

The file menu allows actions relating to saving and loading sequence files. The choices available are:

·         New - remove all steps from the current sequence so that you can begin designing a new sequence. Note that if you accidentally activate File->New without having saved your previous sequence, you can use the Undo button to go back to your previous sequence.

·         Open – load a previously saved sequence from a *.scs file. The current sequence will be discarded.

·         Save - save the current sequence back to file. This option is only available if the current sequence has already been saved or was loaded from file. Saving will overwrite the previous saved version of the sequence.

·         Save As… - save the current sequence to a new *.scs file. You will be prompted to enter the file name for the new *.scs file.

Edit Menu

The edit menu provides operations to assist with editing sequences. Note that many of these operations have a keyboard shortcut which can also be used – the keyboard shortcuts are shown alongside each menu item and there is no need to open the menu to use the keyboard shortcut.


·         Undo – undo the most recent change made to the sequence being edited. The addition, removal and reordering of steps as well as the changing of step properties can all be undone using the undo button.

·         Redo - redo the most recent change that has been undone. Note that if you make other changes to the sequence after using the undo button then redo is no longer available.

·         Cut/Copy/Paste - these are standard clipboard operations that allow you to remove, duplicate or rearrange steps in a sequence. These options are available providing that it least one step is selected within the sequence list.

·         Delete – delete the currently selected steps from the sequence being edited.

Sequence Menu

The Sequence menu provides action related to running, stopping and testing sequences and their steps.

·         Run - start running the current sequence from the beginning.

·         Stop - stop any sequence that is currently running. Note that the sequence may not be able to stop immediately.

·         Test Single Step - test the execution of a single step of the sequence. Using this option runs the currently selected step within the sequence being edited, allowing you to check that it works properly.

The Available Steps Area

This area displays the steps that are available to build up the sequence. Since there are a large number of available steps, they are grouped into categories such as Camera, Guiding, Focuser, etc.


You can add steps from this area to your sequence in two ways:

1)      Drag the step from the Available Steps area to the required position in your sequence.

2)      Double click on the required step in the Available Steps area. This will insert it in the sequence just after the currently selected step.

Note that you can search the available steps by typing part of the name of a step that you wish to find into the Search Available Steps box. When you have entered text in the search box, any steps that do not contain your search text will be hidden, as will any step categories that no longer have any steps to show.

You can clear the search text in order to show all steps again – do this using the ‘X’ button to the right of the search text box or by deleting the text you have entered.

The Sequence List

The sequence list shows the steps that are currently a part of your sequence. When you run the sequence, these steps will be executed in order (top to bottom). Each step will begin after the step above has completed.

Some steps (for instance the Repeat 2 times step shown below) can have other steps placed inside them. The Repeat 2 times step is a parent step in this context and the steps it contains are sub-steps. In this particular case, the result will be that the sub-steps will be run twice during the execution of the sequence.


You can move steps around in the sequence list to re-order them by dragging them with the mouse. You can also drag steps into or out of parent steps, or between different parent steps.

If you click on a single step in the sequence list, any adjustable properties of that step will be shown in the Selected Step Properties Area. You can make adjustments to the values of the properties of the step – for instance changing how many frames will be captured, what the exposure should be set to or how many times to repeat a particular set of sub-steps.

You can delete steps that are no longer required by dragging them to the Trash Can or by selecting them and then choosing Delete from the Edit menu or by pressing the <Delete> key on your keyboard.

You can also use standard Cut/Copy/Paste functionality to work with the steps in the Sequence List. Once you have selected one or more steps, you can Cut or Copy them using the appropriate menu items or keyboard shortcuts. Choosing to Paste after steps have been Cut or Copied will add the steps after the currently selected step in the Sequence List.

The Action Buttons

The action buttons provide shortcuts to some of the items available in the File, Edit and Sequencemenus.


Additionally the Pause button which can be used to pause (and then resume) a running sequence.

The Emergency Stop button can be used if there is the risk of damage to equipment due to the commands being carried out by a running sequence. Pressing this button will not only stop the sequence as if the Stop button had been pressed, but will also send stop movement commands to any connected Ascom mount or focuser.

Selected Step Properties Area

Many steps have adjustable properties that configure exactly what the step does – for example the image below shows the properties of the Warm up Camera step – you choose the values for properties such as the Warming Rate and the Time Limit for this step.


When editing a sequence, it is best practice to have the camera that you intend to use to run the sequence open and to have any ASCOM hardware that you intend to use connected. This allows SharpCap to customize the ranges and options available in the various step properties for your configuration – for instance when configuring steps to set the exposure or gain of a camera, the correct minimum and maximum values will be enforced if the camera is connected.

Changes made to step properties can be undone using the Undo button or the Undo entry in the Edit menu.

Note that care should be taken when setting step properties, particularly if you adjust them when SharpCap is not connected to the device or camera that they will apply to. Incorrectly setting properties may cause the sequence to terminate with an error when run – for instance if you mis-spell the name of a filter, SharpCap will attempt to move the filter wheel to a filter that does not exist (perhaps ‘Grene’), leading to an error.

Trash Can

You can delete steps that are no longer required in the sequence by dragging them from the Sequence List to the Trash Can.


The Progress Area

The Progress area shows the current progress state of any running sequence.


·         The ETA - shows how long before the sequence is expected to complete and also the time at which completion is expected to occur. Note that this is just an estimate as some steps (for instance the measurement of sky brightness) may take a variable amount of time to complete. For some advanced sequences it may not be possible for SharpCap to calculate how long the sequence will take to run.

·         Progress Bar - this is just a visible representation of how far much of the sequence has already been executed and how much is still to complete it.

Sequence Listing

The Sequence Listing area shows the current state of the sequence in code form – in fact the text shown is the text saved to the .SCS file when the sequence is saved. Some people who are familiar with computer programming may find this view of the sequence helpful.


Note that it is not possible to modify the sequence by editing the text shown in this listing area.

While it is technically possible to edit a sequence by saving it to .SCS file, editing the SCS file in a text editor and then re-loading it, this is not recommended. If any mistakes are made in editing the sequence file, SharpCap may give an error when attempting to re-load it.

Sequence Log

The Sequence Log shows information about what the sequencer is currently doing and what steps it has already completed when a sequence is running.

The start and completion of every step will be shown in the log, along with extra information for some steps (for instance a count of the number of still frames captured so far).


If an error occurs when running a sequence, there will be an ‘Error’ entry in the log which will explain the reason for the error – for instance :

21:07:02 Error     : 'No camera selected.' while running step Capture 10 live view frames


Always check the Sequence Log for useful information if you have a problem when running a sequence. It may also be worthwhile checking the main SharpCap Log for additional information.

Working with the Sequence Editor

Following the guidelines laid out in the rest of this section will help ensure that you can design your imaging sequences quickly and accurately with as few problems as possible.

·         Don’t try to use the sequence editor until you have become familiar with using SharpCap manually. Many of the steps available in the sequence a mirror manual actions that you can take in the SharpCap UI and being familiar with how they work and what order they should be used in will help when it comes to designing a sequence.

·         Design your sequence with the camera that you intend to image with open in SharpCap. Also have any Ascom hardware connected to SharpCap. SharpCap can use information from the connected camera and ASCOM hardware to help ensure that step properties have the right minimum and maximum values and options available.

·         Think about what you would do before you start running your sequence. You could design a sequence that you only run when the camera is already set up and the telescope is pointing at the target – that sequence might be fairly simple and start off by capturing frames. You could design and alternative version that will include all the setup steps – opening the camera, setting the camera settings, slewing the mount to point at the target, etc. it may be a good idea to start with the simpler version first and move on to the more complicated version later.

·         Use the Test button frequently when you are designing your sequence to test individual steps and make sure that they do what you expect want to do and work correctly. If you want to test multiple steps then you can place them within a containing parent step temporarily – the Save the camera settings and restore them when this block finishes step can be useful for this purpose.

·         Test all the different steps in your sequence individually before running the sequence as a whole, especially if you intend to run the sequence unattended.

·         Don’t try to design a very complicated sequence straightaway – start with simple ones, make sure that they work as you expect and reliably before adding more complicated steps to your sequence gradually.

·         Remember when designing a sequence that SharpCap will simply try to carry out the steps that you have selected even if they make no sense. If you are using SharpCap manually then you can’t try to capture images when there is no camera open because the capture buttons are all disabled. There is no such protection when you are designing an imaging sequence using the Sequence Editor – if you had a step that will try to start capturing when the camera is closed, SharpCap will attempt to carry out that step and then your sequence will end with an error.

Running your Sequence

You can run your sequence by using the Run button in the Action Buttons area or the Run menu item in the Sequence menu. Progress will be shown in the Progress Area and the Sequence Log.

If you close the Sequence Editor window while a sequence is running then the Sequencer Progress Window will be shown automatically to ensure that you still have the ability to see the progress of the sequence and to control its execution.

Note that the SharpCap menus and camera controls are disabled while a sequence is running – this is to prevent inadvertent actions or changes to the controls from interfering with the proper operation of the sequence. This also prevents you from closing SharpCap while a sequence is running. To close SharpCap  or access the menus/toolbar, you must stop any running sequence.

The Show a prompt… step does allow you to optionally re-enable the adjustment of the camera controls while the prompt is waiting for the user to click OK. This is designed to allow manual adjustment of controls at appropriate points in the sequence (perhaps to set up the correct exposure for flat frame capture).

Available Steps

This section lists and describes all the available sequencer steps that can be used to build a sequence.


Step Name


Open Camera '<Camera Name>'

Open the named camera, closing any other camera that was already open.

Close Camera

Close any open camera.

Put Camera in Live Mode

Place the currently open camera into live mode (for video capture)

Put Camera in Still Mode

Place the currently open camera into still model (for deep sky imaging, for instance). Note that not all cameras support still mode.

Start capturing frames

Start capturing frames using the current camera settings. Note that frames will continue to be captured indefinitely (or until a Stop Capturing Frames) step is executed.

Stop capturing frames

Stop capturing on the selected camera.

Start capturing now and then stop when <Astronomical Event> occurs

Starts capturing immediately and then stops when the specified astronomical time of day occurs.

The specified time of day can be any one of : Astronomical Midnight, Astronomical Dawn, Nautical Dawn, Civil Dawn, Sunrise, Solar Noon, Sunset, Civil Dusk, Nautical Dusk, Astronomical Darkness. Note that depending on your latitude and the time of year, some events may not occur. An error will occur if the selected event does not occur in the next 24 hours.

Capture <Frame Count> live view frames

Capture the specified number of frames in live view mode. The camera will be placed in live view mode if it is currently in still mode.

Capture <Frame Count> still frames (guiding required : <Require guiding active while capturing>)

Capture the specified number of frames in still mode. The camera will be placed in still mode if it is currently in live view mode.

If the Require guiding active option is set then SharpCap will take the following additional steps:

·         An error will occur if a guiding application is not being monitored (see the Monitor Guiding Application step)

·         Capture will be paused if guiding is not active

·         SharpCap will attempt to restart guiding and will resume capturing if guiding resumes

·         SharpCap will discard any frame that is less than 95% complete when guiding is lost (an extra frame will be captured to compensate)

Load Camera Profile '<Profile Name>'

Load all of the capture settings stored in the named capture profile.

Set Output Format to <File Save Format>

Set the output format for saved images/videos to the specified format.

Set Resolution to <Value>

Set the camera resolution to the specified value

Set Colour Space to <Value>

Set the camera colour space to the specified value

Set Binning to <Binning Value>

Set the binning of the camera to the specified value

Set Exposure to <Exposure Length>s

Set the camera exposure to the specified length. Note that exposures of less than 1s can be set – for instance 0.030s for 30ms.

Set Gain to <Gain Value>

Set the camera gain to the specified value.

Set offset to <Offset/Brightness Value>

Set the offset/black level/brightness of the camera to the specified value

Set <Control Name> to <Control Value>

Set another camera control to the specified value. Use this step to set controls that do not have a more specific step (such as gamma, white balance controls, etc).



Cool the camera down to <Target Temperature>°C at up to <Cooling Rate>°C/minute

Cool the camera down to the specified target temperature. The rate of cooling can be limited, as can the tolerance (how close to the target temperature the camera must get for the step to be considered finished).

The camera will have its cooler turned on (if necessary) and the cooler will also be put into automatic (temperature controlled mode) if necessary. If the camera does not have a cooler, or the cooler is not temperature controlled then an error will occur.

If the target temperature set is warmer than ambient temperature, or if it is colder than the coldest temperature that the camera cooler can achieve then this step may never finish as the camera temperature will never reach the target.

Set the target temperature to <Target Temperature>°C

Change the target temperature for the camera cooler to the specified temperature.

Turn the camera cooler off

Turns off the camera cooler by one of the following three means:

·         If the camera has a cooler on/off control, set it to off.

·         If the camera has a manual cooler power control, set the cooler power to 0%

·         If the camera has a temperature controlled cooler, set the target temperature to the maximum value.

Note that using this step on a cooled camera may cause the sensor temperature to rise rapidly.

Warm the camera up to <Target Temperature>°C at up to <Warming Rate> °C/minute

Warm the camera up to the specified target temperature.  This mirrors the cool down step in that warming rate and completion tolerance can be specified.

Additionally, a time limit can be set for this step – the step will complete when the time limit expires even if the warming procedure is not complete.



Select Mount '<Mount Name>'

Make the named mount the selected mount – this is equivalent to changing the mount that SharpCap uses in the Hardware Settings.

Connect the currently selected mount

Attempt to connect to the currently selected mount if it is not already connected. This could cause an error if the mount is not connected to the computer or not configured correctly.

Disconnect the currently selected mount

Disconnect from the currently selected mount. Other mount related operations will not be possible after this point until a mount is connected again.

Unpark the mount

Unpark the mount if it is parked

Park the mount

Park the mount to the default park position

Move the mount to (RA, Dec) <RA/Dec co-ordinates>

Slew the mount to the specified co-ordinates. See co-ordinates in the sequencer for details on the formats that are accepted for RA/Dec co-ordinates.

Move the mount to Alt=<Altitude>, Az=<Azimuth>

Slew to the mount to the specified altitude/azimuth co-ordinates. Note that not all mounts support AltAz co-ordinates.

Offset the mount position by RA=<Right Ascension Offset>, Dec=<Declination Offset>

Offset the current mount position by the specified offsets in RA and Declination. This may be useful for moving a target slightly off centre in the field of view.

Plate solve a single frame, sync the mount and re-GOTO the target co-ordinates

Re-centre the target using plate solving. This is equivalent to using the Plate Solve and Resync tool and follows the same configuration options as that tool.

Set mount tracking rate to <Tracking Rate Name>

Set the mount tracking rate. The available options are None (tracking stopped), Sidereal, Lunar, Solar, King.



Select Focuser '<Focuser Name>'

Make the named focuser the selected focuser – this is equivalent to changing the focuser that SharpCap uses in the Hardware Settings.

Connect the currently selected focuser

Attempt to connect to the currently selected focuser if it is not already connected. This could cause an error if the focuser is not connected to the computer or not configured correctly.

Disconnect the currently selected focuser

Disconnect from the currently selected focuser. Other focuser related operations will not be possible after this point until a focuser is connected again.

Move focuser to position <Focuser Position>

Move the focuser directly to the position specified. For example move the focuser to position 11950.

Move the focuser by <Focuser Offset>

Move the focuser by an offset from its current position – a negative offset will move the focuser to smaller position values, a positive offset to larger position values.

Autofocus between <Start Focuser Position> and <End Focuser Position> with <Scan Step Count> steps allowing for backlash up to <Backlash Allowance>

Perform a multi-star FWHM based autofocus between the two focuser positions specified.


See the documentation on focusing in the sequence planner for more details.

Autofocus from offset <Start Focuser Position (Offset)> to <End Focuser Position (Offset)> with <Scan Step Count> steps allowing for backlash up to <Backlash Allowance>

Identical to the above autofocus step except that the start and end points are defined relative to the current focuser position rather than with absolute focuser position values.



Select Filter Wheel '<Filter Wheel Name>'

Make the named wheel the selected filter wheel – this is equivalent to changing the filter wheel that SharpCap uses in the Hardware Settings.

Connect the currently selected filter wheel

Attempt to connect to the currently selected filter wheel if it is not already connected. This could cause an error if the filter wheel is not connected to the computer or not configured correctly.

Disconnect the currently selected filter wheel

Disconnect from the currently selected filter wheel. Other filter wheel related operations will not be possible after this point until a filter wheel is connected again.

Move filter wheel to position <Filter Name>

Move the filter wheel to a new position (specifying the name of the filter to move to).

Move filter wheel to position <Filter Wheel Position>

Move the filter wheel to a new position (specifying the filter position number to move to – these numbers count upwards from 1 to the number of filters on the wheel).



Each repeat type step can have one or many other steps placed within it as sub- steps. These sub- steps will be run one or more times depending on the type of repeat specified by the repeat step.

Repeat <Repeat Count> times

Repeat the sub- steps a fixed number of times.

Repeat until <Astronomical Event> occurs

Continue repeating the sub steps until the time of day specified by <Astronomical Event> occurs.

The specified time of day can be any one of : Astronomical Midnight, Astronomical Dawn, Nautical Dawn, Civil Dawn, Sunrise, Solar Noon, Sunset, Civil Dusk, Nautical Dusk, Astronomical Darkness. Note that depending on your latitude and the time of year, some events may not occur. An error will occur if the selected event does not occur in the next 24 hours.

Note that no new runs through the sub steps will begin after the specified time, but any sub- steps in progress at the specified time will continue running until the end of the list of sub- steps is reached.

Repeat for each filter in <Filter List>

Repeat the sub-steps once for each of the filters specified in the filter list.

Repeat for each Alt/Az co-ordinate in <Co-ordinate list file>

Repeat the sub steps once for each set of altitude/azimuth coordinates listed in a text file. The text file should contain one coordinate pair per line.

Repeat for each RA/Dec co-ordinate in <Co-ordinate list file>

Repeat the sub steps once for each set of RA/declination coordinates listed in a text file. The text file should contain one coordinate pair per line.

See coordinates in the sequencer for more details on the format required for these coordinate values.

Note that it is also acceptable to place a target name at the start of each line – SharpCap will then use this name as the observing target for or file naming as well as using the coordinates values from that line. The target name should be separated from coordinates by a comma. For example:

M42, 05 35 17.3 -05 23 28



Connect the all currently selected hardware

Connect all the hardware that is currently selected – this is a shortcut for connecting the focuser, mount and filter wheel individually. Note that there won’t be an error if there are hardware categories that do not have a selected device.

Disconnect all currently selected hardware

Disconnect all currently selected hardware. Again a shortcut for individually disconnecting the mount, focuser and filter wheel.

Play the <Sound to Play> sound.

Play a Windows sound on the standard sound device of the computer. You have the choice between two different sounds – alert and error. The sounds that play for these two options can be configured in the ‘Change System Sounds’ section of the Windows Control Panel.

Run '<Program to run>' with parameters '<Arguments>' and <Wait for command to exit?>

Run another Windows or Command Line application, optionally waiting for the other program to finish before continuing.

It is best to specify the program to run by its full path (or to select it using the Browse button).

You can also specify command line parameters to be passed to the program being run.

It is possible to run batch files or PowerShell scripts using this step to perform more complicated actions.

Save the camera settings and restore them when this block finishes

This step can have multiple sub steps added to it. The camera settings in effect at the beginning of the step are stored and then reapplied to the camera after the sub steps have completed.

Using this step can be useful to allow alternative camera settings used for a particular task (for instance focusing) before returning the camera to the original settings.

Show a countdown for <Delay> seconds with message <Message Text>.

This step will show a message on screen for a fixed number of seconds (showing the number of seconds remaining as a countdown).

Show a notification in <Notification Colour>: '<Notification Message>'

This step will show a notification in the SharpCap notification bar, allowing you to choose the text to be shown and the colour of the notification bar.

Show a prompt '<Message Text>' and wait for OK to be pressed. Camera controls enabled : <Enable Camera Controls>

Show a prompt window containing a message and wait for the user to press the OK button before continuing.

Optionally, you can allow the camera controls to be re-enabled during the period that the prompt is shown – this allows adjustments to be made, perhaps to get correct flat frame exposure levels.

Wait for <Delay> seconds

Pause the sequence for the number of seconds specified before continuing.

Wait until <Time of Day>

Wait until the specified time of day before continuing. Note that the time specified is a local time.

Wait until <Astronomical Event> occurs

Wait until the time of day specified by <Astronomical Event> occurs before continuing the sequence

The specified time of day can be any one of : Astronomical Midnight, Astronomical Dawn, Nautical Dawn, Civil Dawn, Sunrise, Solar Noon, Sunset, Civil Dusk, Nautical Dusk, Astronomical Darkness. Note that depending on your latitude and the time of year, some events may not occur. An error will occur if the selected event does not occur in the next 24 hours.


Write '<Log Text>' to the SharpCap Log

Add the specified text to the main SharpCap log – this can be useful to help track the progress of your sequence.



Use <File Path> as a dark frame

Load the specified image file and use it as a dark frame. The file must be in a still image format that SharpCap can read and also be valid (in terms of size, bit depth, etc) as a dark frame for the current camera settings. See capturing and using dark frames for more information.

Use <File Path> as a flat frame

Load the specified image file and use it as a flat frame. The file must be in a still image format that SharpCap can read and also be valid (in terms of size, bit depth, etc) as a flat frame for the current camera settings. See capturing and using flat frames for more information.

Start Live Stacking

Start live stacking (no action is taken if live stacking is already active). Note that it is an error to use live stacking from the sequencer while periodic dithering is enabled.

Stop Live Stacking

Stop live stacking. This will disable live stacking and hide the stacking UI. No images will be saved – use the Save Current Live Stack step to save before stopping.

Pause Live Stacking

Pause live stacking if it is currently active.

Resume Live Stacking

Resume live stacking if it is currently active and paused.

Reset Live Stacking

Reset live stacking (clear the current stack and start a new one). The current stack will be saved if the option to Auto Save on Reset has been enabled, otherwise use the Save Current Live Stack set before resetting.

Live Stacking Apply Auto Stretch

Apply an auto-stretch to the live stack histogram.

Live Stacking Auto White Balance

Apply an auto-white balance to the current live stack.

Live Stacking Auto White Balance from star colours

Apply an auto-white balance to the current live stack, basing the balance on star colours.

Live Stacking Reset Stretch

Reset the stretch on the live stack histogram to default.

Live Stacking Reset White Balance

Reset the colour balance of live stacking to default.

Save current live stack (<Save Type>)

Save the current live stack in one of the following ways:

·         FITSRawStack16Bit – equivalent to Save as 16 bit Stack

·         FITSRawStack32Bit – equivalent to Save as RAW (32 bit) Stack

·         PNGWithStretch – equivalent to Save with Adjustments

·         PNGAsShownOnScreen – equivalent to Save exactly as seen

·         AllFormats – save in all of the above formats

Live Stack for <Frame Count> frames then save as <Save Type>

A shortcut step that will activate live stacking (or reset it if it is already active), then stack for the specified number of frames, then save.


File Naming

Arrange file and folder names to keep sequence captures together.

Placing this step in a sequence before any capturing happens will change the file naming patterns to group all captures from the sequence together. Each separate capture initiated by the sequence will be given its own subfolder – for instance


#1 – 25 light frames of M42

Set imaging target name to '<Target Object Name>'

Set the target name (which affects the naming of saved image and video files).

Prompt to enter the target name

Prompt the user for the target name – the sequence will not proceed until the target name is entered.

Set frame type to '<Type>'

Sets the frame type to be captured to one of Light, Dark, Flat, DarkFlat, Bias or Other. Note that the frame type specified here only affects file naming.



Monitor Guiding Application

Attempt to connect to the guiding application/device as configured in the Guiding Settings. An error will occur if a connection cannot be made to the selected guiding application/device.

This step must be executed before any other guiding/dithering related steps.

Disconnect from Guiding Application

Disconnect from the currently connected guiding application/device. No other guiding/dithering steps should be performed after this step has executed.

Start guiding if necessary

Request that the connected guiding application start guiding. This process may involve automatically connecting guiding hardware, starting exposure looping, selecting a star, calibrating and finally guiding.

If guiding is already active then no action is taken.

An error will occur if guiding cannot be started.

Wait until guiding is active

This step will not allow the sequence to proceed until the connected guiding application/device reports a ‘Guiding’ status. Manual intervention may be required to start guiding at this point.

Stop guiding

Send a request to the guiding device/application to stop guiding.

Pause guiding if active and restart when this block finishes

Temporarily stops guiding while the sub-steps of this step are run. This can be useful for moving the mount or performing plate solving without guiding interfering.

Request a single dither from Guiding Application

Requests a single dither operation from the connected guiding application. The settings specified in the Guiding Settings will determine the details of the dither operation.

Dither every <Dithering Interval> seconds

From this point onwards in the sequence (until a Stop Periodic Dithering step is executed), SharpCap will execute a dither operation periodically. The dither operation can only occur at certain points in the sequence – between steps or between frames of a Capture Still Frame step. Because of this, the interval specified is the minimum possible interval between two dither operations – the interval will usually be longer as SharpCap waits for the next suitable dither point after the interval has expired.

Stop periodic dithering

Cancel periodic dithering – it can be restarted by running another Dither every <dithering interval> seconds step.



Run the sequence of steps in <Sequence to run>

This step allows you to specify another sequence file. All of the steps in the other sequence file will be run when this step is executed.

Define a subroutine called '<Subroutine Name>'

Defines a subroutine with the given name. The subroutine consists of a series of steps placed within the define subroutine step. The subroutine can then be used repeatedly throughout the sequence by calling it multiple times without needing to duplicate the contained steps many times.

Call a previously defined subroutine called '<Subroutine Name>'

Call a previously defined subroutine to run the steps within it at this point in the sequence.

Using subroutines can help make designing and maintaining complex sequences easier.

Import subroutines in <Sequence file to import>

This step will read the specified sequence file and load all of the subroutine definitions found within that file. Those subroutine definitions can then be used in the current sequence.

Note that steps in the loaded sequence file that are not subroutine definitions or part of subroutine definitions will be ignored.

Measure the sky background to set optimum deep sky settings between <Minimum Exposure (s)>s and <Maximum Exposure (s)>s

Perform a Smart Histogram Brain measurement to set the optimum exposure/gain/black level settings for the camera. Once the measurement is complete, the recommended camera parameters will be applied before the sequence continues to the next step.

Note that this measurement should be performed with any filters that you intend to use in place.

The following parameters can be adjusted:

Channel to Measure – which colour channel to measure the brightness on – set to luminosity for mono cameras.

Avoid frame corners/edges – check this option if you suffer from vignetting (darkening) of the image near the corners/edges. This will stop SharpCap from considering those areas, which would otherwise lead to a much longer exposure recommendation.

Minimum Exposure & Maximum Exposure – the maximum exposure will be determined by the limits of your tracking/guiding setup – for instance if you can get good images up to a 2 minute exposure but suffer from trailing stars beyond that point, set a maximum of 120s. Set the minimum exposure based on other considerations, such as the number of image files that might be produced or the need for sufficient bright stars for alignment.

Aim for Unity Gain – if checked, SharpCap will try to pick a gain value close to unity gain. If unchecked, SharpCap will try to find the maximum dynamic range possible in the resulting stacked image. Note that because of the amount of noise that is inevitably present in deep sky images, we do not believe that unity gain offers any real advantage over other gain values.

% Noise increase allowed – set this to the amount of additional noise (above the theoretical minimum) that you are prepared to accept in your final stacked image. Accepting a small amount of additional noise allows reduction in the sub-exposure duration and hence less problems with tracking/guiding. Exceptionally long exposures may be recommended if this is set to very low values (<5%), particularly if you have dark skies or are using narrowband filters.

Run the python script in <Python script file>

Run the SharpCap Python scripting code found in the specified Python file. This may allow you to achieve results that are not available via other sequencer steps.

The sequence will not continue until the python script finishes running.

Run a periodic task called '<Task Name>' every <Interval> seconds

The steps placed within this step form a periodic task and will be run periodically during the running of the following parts of the sequence.

The task will be run only between other sequencer steps in the main part of the sequence or between exposures in a Capture Still Frames step.

The task will be run at the next suitable time after the interval has been completed – that means that the time between successive runs of the task will almost always be longer than the defined interval and will never be shorter than that interval.

Periodic dithering is implemented using this approach.

Stop running a periodic task called '<Task Name>'

Cancel a periodic task that was previously started. After cancellation, the task will not be run again.



Auto stretch the display.

Adjust the display stretch parameters to automatically stretch the image for best visibility of faint detail.

Reset the display stretch.

Reset the display stretch parameters to their default (unstretched) settings.

Set the display Zoom level

Change the zoom level of SharpCap’s image display. Note that if you have two-monitor view enabled, this will affect the zoom level on the primary monitor (the one with SharpCap’s menus/controls) only.

Co-ordinates in the Sequencer

The coordinates should be in RA/Dec notation and a wide variety of forms are accepted, for instance any of the following forms will be accepted as the co-ordinates of the Orion Nebula

05 35 17.3 -05 23 28

05 32 49.8 -05 25 21

RA 5h 35m 17s | Dec -5° 23′ 28″

5h 35m 17s   -5° 23′ 28″


RA= 5h 35.4m, Dec= -05° 27´

RA: 05h 35m 24.0s Dec: -05°27'00"

5h RA, -5° DEC

RA 05h 35.4m |Dec. -05° 27″

RA 05h 35.4m, dec. –05º 27’


5.58805 -5.391

(05:35:20.556, -05:18:32.593)

(83.84, -5.309)

In all cases, RA co-ordinates are assumed to be in hours (not degrees) if the value is less than 24.