CCDciel is free software released under the terms of the
GNU General Public License
From the menu Edit → Preferences. Set the global preferences and options for the program.
You can change the program language from the list if you prefer to use another language than the one selected automatically. The program must be restarted after changing the language.
The base capture folder should be specified. The other configured sub-folder are created under this one.
Normally you not need to change the temporary file folder. This is only required on Windows if the default path based on your user name contain accentuated non-ASCII characters. Be sure you specify a path with only ASCII characters.
File and folder name
You can specify how the image files are named and if they are stored in named folders. A typical imaging session will produce a great number of files so it is important to preserve the details for later processing.
One way of working is to make subfolders based on object name and select for file names all details; object name, the filter, a date sequence, exposure time, binning. This is all depending on personal preferences and image processing software used later.
For folder name you have the choice between two date. One to make a folder with the same UT time as for the file name, the other is based on local time and change at noon to allow to put all the files for a given night to the same folder.
For file name, if Date/Sequence is checked the UT date and time is appended. If it is not checked a sequence number is appended to make the file unique.
You can reorder the different elements with a mouse drag and drop of the sequence number column.
At the bottom you can select to save all log messages to a file for further inspection or debugging. it is recommended to always let it checked.
You can look at the log using the function in the Help menu.
If this option is checked it also save the images in the case the auto-focus fail to find stars, they can be used later to help to adjust the parameters.
The log file and failed auto-focus images are conserved for a period of 30 days, then they are automatically removed.
And you can activate a TCP/IP server to get remotely the status of CCDciel
The informations on top will be set in each FITS file for the OBSERVER, ORIGIN and TELESCOP keyword.
The latitude and longitude of the observatory is used to get the Alt/Az position of the object, or for the scope_alignment script. It is mandatory you set them before you can use the timing functions in the sequence planner.
The “Horizon profile” and “Minimum observing elevation” are used to compute the object rise and set time in the sequence planner. If this values are set the rise/set time are relative to this limits.
You can set only one value or both. In the last case the highest elevation is used.
The horizon profile file is the same as the local horizon line in Skychart.
This settings affect only the preview, the FITS files are always recorded in RAW format to allow further preprocessing.
If you use a color camera you can debayer the preview image by checking the corresponding box and selecting the color pattern for your sensor. If you don't know what to select, make a test on a colorful subject on daytime. You can also do some color balance with the cursors on the right.
The reference image help you to frame a previous image, for example to continue a sequence.
Select the threshold and color for the display of the reference image.
The image clipping indicator level. You can set the low and high threshold in ADU for this indicator.
Bad pixel map
The bad pixel map prevent the auto-focus function to lock on a hot pixel.
Select the threshold for detection of hot pixels for the bad pixel map.
Preview stacking allow you to stack the preview frames in real time. This feature is normally use for demonstration in public event.
You can select to disable this option to not risk an unwanted use during your imaging session.
Using a dark frame subtraction before the image addition improve the result quality.
This dark image must always be in 16bit format, even for a 8bit camera.
Select the preview rate for the video. Video require a suitable camera and is available only with INDI devices.
Configure how you prefer to cool down and warm up you CCD sensor.
Consult your camera documentation to know if you need to limit the temperature change.
In this case check “Limit temperature change” and indicate the maximum rate in degree (Celsius) per minute.
Check the corresponding box if you want your camera to start cooling as soon it is connect to the program and indicate the target temperature you want.
Enter the camera pixel size and maximum ADU, or if applicable for your driver, check the box to get it automatically.
The maximum ADU is used to avoid saturated stars during autofocus.
The pixel size is required to speedup the astrometry solving by estimating the image scale.
Configure the method to use to capture a flat series from a sequence.
For the twilight flat it is require to configure the automatic exposure as the sky lightness change a lot during dusk or dawn.
You can also configure this automatic exposure for a use with other light source.
At each exposure the program will adjust the exposure time between the two limits to maintain the image level.\
Set the shortest exposure time that give an uniform sensor illumination. This depend on the kind of shutter used by the camera.
Set the longest exposure time you want for a flat. You have to take the corresponding dark separately.
Then give an image mean level range that make an acceptable flat. Start with 80% of your camera full range but check there is no saturated part in the center of the flat image, specifically if the vignetting is important.
Select this method if you use dome flat or light panel.
You can also select automatic exposure, but at the difference of the twilight flat the exposure is adjusted only once for each filter, then the same exposure time is use for the series.
If you need to point the telescope at a specific position to frame the panel you can enter the required azimuth and elevation.
Select the size in unbinned pixel of the star detection area and the size of the zoomed window for the focus mode. If you use a binning different than 1×1 for the focus operation the window size is reduced accordingly.
Normally a single pixel star is rejected as a hot pixel. If your optical configuration produce undersampled image with single pixel star you can check this box. But be careful to make a bad pixel map to reject the hot pixel.
If this is not already done by your focuser driver you can activate a backlash compensation. But be sure to let it disabled if the compensation is done elsewhere.
Indicate the number of additional steps to use for the compensation, this must be greater than the actual backlash, don't hesitate to use a large value.
Indicate the direction the focuser will always finish to move, the best depend on your configuration. If you configure the auto-focus this control is disabled and will be set to the same as the focus move direction.
If it take some time for the focus position to stabilize after a move you can set a delay to wait after every focuser movement. This is more likely of use if the motor directly move the primary mirror of a SCT.
Focuser temperature compensation
If your focuser can measure the temperature you can set here the temperature coefficient (in steps per Celsius) used to adjust the focuser position between the exposures, or to shift the auto-focus V curve accordingly. The coefficient is positive if the focuser needs to move UP in position when the temperature drop. The routine will adapt the focuser if the temperature difference is larger then 0.5 degrees.
Note that for a reflector telescope you typically have to turn the focuser OUT to correct for tube shrinkage. For a refractor you typically have to turn the focuser IN since the change in refraction coefficient is dominant and much larger then the tube shrinkage.
The temperature coefficient will help to reduce the number of autofocus actions required. It will work best when the temperature drops slowly and all parts of the telescope have time to adapt to the changing ambient temperature.
The compensation factor has to be measured empirical. Start with an almost zero factor=1 and monitor the autofocus focus position in the log as function of the reported temperature. If you sufficient data points which show a repeatable temperature coefficient enter the estimated factor in this menu. Some telescopes like a SCT could have less predictable coefficient and you most likely have to disable the coefficient and rely on the autofocus routine only.
If the factor is set well, the result of each autofocus routine run should be close to the previous focus position.
For each filter you can set an offset in focuser steps that will be applied to the focuser when you change the filter.
The filter exposure factor is used for the auto-focus functions and the automatic sky flat. For example if your R filter require two time the exposure of the L filter set : L=1 R=2
This section is initially empty. It can be hard to fill with the right values for your specific equipment. It is strongly suggested you use the focuser calibration wizard to set the correct default parameters.
After the wizard is run it select one of the focus method Vcurve or Dynamic depending on your focuser capabilities. You can return at this page if you want to change the method or adjust some parameters.
Select the auto-focus method:
|Method||Target field||V- curve focusing||Dynamic focusing|
|Slew to database star||Always a bright star||+++||+++|
|Stay in place||Medium bright stars||++||+++|
|Stay in place||Faint stars||+||++|
|Stay in place||Narrow band filter + faint stars||-||-|
|Dynamic focusing can work in the bottom non-linear part of the V-curve. HFD as low as 3 (twice minimum)|
|V-curve requires HFD in 15-10 range minimum. Below HFD 10 not optimal performance.|
If the auto-focus fail to find stars and the journaling to file is active, the image is saved in the same folder as the log so you can review them later to help to adjust the parameters.
V curve parameters
The autofocus routine finds the focus in four focus movements using the slope information from the V-curve learning.
It is important the program know your telescope focal length to estimate the image scale to speedup the solving process. Enter telescope focal length, or if applicable for your driver, check the box to get it automatically.
You can also adjust the timeout (in seconds) for a solve operation.
For each software you can adjust a few option to make them work quickly and reliably with your images.
PlateSolve 2 options
You can adjust how to correct the mount position after plate solving a control picture.
If your mount allow to sync anywhere select “Mount sync”, if not select “Pointing offset” to make the correction in software.
Use “Pointing offset” if your telescope use a pointing model, this avoid any problem by using Sync with the model, but this can result in a wrong position to be reported in other softwares.
Then set the precision you want/can reach and the maximum number of pointing/correction retry before to give up.
Set the parameters (exposure time, binning and filter) for the control exposure. This must give enough stars with your telescope/camera combination for the astrometry resolver to work.
If your mount need some time to stabilize after the movement you can increase the delay to wait before to take the plate solving picture.
Configure here what you want to do when the mount reach the meridian.
Automatic flip options
For PHD2 you need to set the network name of the computer running PHD2 and the port number.
Set the options for dithering between the exposure, the number of pixel (in the guide camera) and if you want to dither only in RA (if you have a lot of DEC backlash).
The settle tolerance define how we consider the autoguiding as good after a dither operation or after it start.
It must stay within the number of pixel for Min.time. But we wait for the maximum of Timeout if this is not possible.
Set also the maximum time to wait if a new calibration is required.
Star lost action
In the case of guide star lost (passing clouds…) we can try to restart the guider after some time. This is useful if the star as moved out of the search area, but if the clouds are still there we can start guiding on a hot pixel. A value of zero disable this function.
Then we can abort the current sequence after some time, maybe the next object on the plan is in a clear area.
For Lin_Guider you can choose to communicate by a local Unix socket or by the TCP network, on Windows only the TCP option is available. The selection must correspond to the one in the Lin_Guider general setting.
Set the number of pixels for dithering between the exposure.