Post by southernskies on Aug 9, 2018 5:06:44 GMT
Reading replies to my first post on the Video Astronomy Images Board, I didn't realise that the ToupSky camera control and imageacquisition software that I use is badged differently (for example as Rising Sky) for use with other cameras. So it seems that there may be many more users than I had previously supposed. Some earlier threads on this forum seem to indicate that other, probably newish, users have had some difficulty using the software. I also was bewildered by the plethora of features and options that the software offers when I first started to use it. And that was after already being quite conversant with regular cooled CCD mono still-camera imaging, calibration and post processing procedures to get LRGB results. But I have now had nearly two years experience of using the software and I thought that possibly that might justify my setting out some observations as to my work flow and a few other matters which I hope may help others to realise the full potential of the software. I do apologise if it seems presumptuous for a new member to be handing out advice in this way. I do also apologise for the length of this posting but it has proved difficult to condense it any further.
My emphasis is on DSO viewing (particularly group viewing such as at public outreach sessions) with imaging being only of secondary importance for keeping a record of objects viewed. Thus these observations may not be appropriate for all users, particularly those who specialise in planetary imaging. And, of course, experienced users may well adopt different techniques and settings to better suit their preference. In what follows I have referred to setting values that are displayed by ToupSky and it may be that other variants of the software may use different values. Also it should be noted that the behaviour of ToupSky is camera-related so that, for example, while my main camera can use the differentiated Video and Trigger exposure modes an earlier autoguiding / planetary imaging camera only has access to the Video mode albeit with extended exposure options.
Basic workflow for DSO viewing/imaging using a colour camera
Initial Setup
1. Set camera resolution as required (suggest maximum)
2. Set gain to maximum (10.0)
3. Set a fairly aggressive gamma (to about 0.40)
4. Set bit depth as required (suggest maximum available)
5. Set digital binning as required (suggest 1, i.e. no binning)
6. Set black level to 0
7. Set cooling parameter(s) to suit camera (as required)
8. If using a colour camera, do not set color mode to grey
(You will usually find that these settings will be remembered from one use of the software to the next)
Viewing/Imaging Process
1. Set exposure mode to Video
2. Set exposure length to maximum for video (5 seconds)
3. Set the display zoom to “fit to window”
4. Slew to target and frame target to suit (the 5 seconds exposure length should be sufficient for this purpose depending on your telescope's aperture but if necessary switch to Trigger Mode and increase the exposure length a bit)
5. Switch to Trigger Mode
6. Select a longer exposure length and click the Loop button
7. On completion of the exposure, examine the histogram and set the left slider bar to rest at the bottom-left of the displayed bell curves
8. On completion of the next exposure examine the displayed on-screen image and determine if the exposure length should be increased or decreased. If so, click the Stop button and repeat steps 6 and 7 using a different exposure length
9. On completion of the next exposure examine the RGB bell curves in the histogram and determine if they need to be balanced so that all three curves peak at the same place. If so, adjust the colour balance red, green and blue sliders and continue to loop through exposures until they do.
10. Import a suitable dark field correction image from your library (see below) and check the Enable check box.
11. Consider using the sharpen tool and experiment with different settings 0% - 500% (suggest that if it is used the setting is kept quite modest at, say, 25%)
12. Using the live stack feature, select the average mode and deep sky options and select the number of images to stack (suggest that 3 or 4 is sufficient). Then check the Enable checkbox.
(The green exposure progress bar will continue to the end of the current exposure at which point the live stack input will display “1”. But then the progress bar and the image display will appear to freeze and they will only unfreeze after exposure of the second image in the stack has been completed.)
13. When the required number of the stack has been completed as indicated by the input and output numbers, click the Snap button in the capture and resolution section.
14. Using menu item File|Save save the captured image to file using a suitable file name.
Dark Frame Capture and Use
It is advisable to create a library of dark frames covering a range of exposure settings that can be accessed whenever a new exposure setting is used for imaging.
1. Cover the front of the telescope
2. Click the histogram Defaults button to make sure that the left and right bars are returned to the left and right sides respectively
3. Select an exposure setting
4.In the dark field correction section, uncheck the Enable checkbox, select a number of dark frames to stack (suggest that 3 or 4 is sufficient) and click the Capture button.
(After each exposure you may see red, green and blue hot pixels displayed on screen depending on the quality of your camera and the length of the exposure.)
5. Once the total number of selected dark frame exposures has been completed, click the Export button and save the resulting dark frame to your library using a file name that describes the exposure setting used.
(You can prove that the dark frame has been captured properly by checking the Enable checkbox and waiting for another exposure to complete whereupon you should see that any previously displayed hot pixels have now been completely removed from the display.)
6. Repeat steps 3 to 5 for additional exposure settings until your library contains all of the possible darks that you are likely to need.
Flat Field Correction
This is a new feature in the latest version of the software dated 16th June 2018. Its arrival is welcome and in theory it should serve a useful purpose. But, in practise, it is difficult to use. The problem is that unlike the dark frame feature it does not include a file export and import facility meaning that one can only use a flat frame that is captured when the program is open. Creating and using a library of flat frames is not presently possible. That's fine only if one is able to set up for the night before dark or one has a translucent panel (or some such) available for use after dark. Maybe the program designers will get their act together and include a file export / import facility soon? Until then I believe that most users will not make use of this feature. (Edit : This problem has now been rectified. In version 4.7 (and possibly in earlier versions too that I did not download) the flat field correction feature does now include the same file saving and retrieval functionality as the dark field correction feature.)
Auto Capture of Images
Instead of using the live stack feature to smooth out camera noise and then using the Snap button to save the resultant stacked on-screen image, individual exposures can be saved separately by using the auto capture feature and then, if required, the images can be stacked using some other software such as RegiStax.
1. Use menu item Options|Preferences to access the Preferences dialog.
2. Select Auto Capture and then use the various entry boxes to compose the outline of the folder/file name to be used when saving images. Check the Total Images checkbox and set the required number of frames to be captured. (If [target] is to be included in the sub-folder name, use the Target option to make sure that the target name is included in the list of nominated targets.) Click Apply and close the dialog.
3. Using the targets drop-down list on the toolbar, select the target to be imaged.
4. After composing the image and setting appropriate exposure, histogram, etc., etc. values as described in the basic workflow above, use menu item Capture|Auto Capture to start the image capturing process. You can monitor progress by using the Browse menu.
Tweaking Images for Outreach Use
The software's Image and Process menus offer a wide range of post-processing features that can be employed on any imported image including one created using the Snap button. During an outreach session they can all, in theory, be used to “improve” the image captured by the camera. In practice, due to time constraints and the sometimes limited attention span of visitors, it is better to employ just one or two to demonstrate that the acquired image contains more data than was immediately apparent. Probably the most useful feature is the Curve... option that creates a histogram stretch and which can be found in the Image|Adjust sub-menu.
Regular Post-Processing
Good as the software's own post-processing features are, one may prefer to use more powerful software such as Photoshop to extract the most information from the captured images. Even 'though the emphasis is on taking images for record keeping purposes there is no reason why the images cannot be improved for display to the best advantage possible. Just do not expect the end result to be comparable with regular astrophotography images that usually result from many hours of image acquisition, calibration and post-processing.
I hope that this may help.
My emphasis is on DSO viewing (particularly group viewing such as at public outreach sessions) with imaging being only of secondary importance for keeping a record of objects viewed. Thus these observations may not be appropriate for all users, particularly those who specialise in planetary imaging. And, of course, experienced users may well adopt different techniques and settings to better suit their preference. In what follows I have referred to setting values that are displayed by ToupSky and it may be that other variants of the software may use different values. Also it should be noted that the behaviour of ToupSky is camera-related so that, for example, while my main camera can use the differentiated Video and Trigger exposure modes an earlier autoguiding / planetary imaging camera only has access to the Video mode albeit with extended exposure options.
Basic workflow for DSO viewing/imaging using a colour camera
Initial Setup
1. Set camera resolution as required (suggest maximum)
2. Set gain to maximum (10.0)
3. Set a fairly aggressive gamma (to about 0.40)
4. Set bit depth as required (suggest maximum available)
5. Set digital binning as required (suggest 1, i.e. no binning)
6. Set black level to 0
7. Set cooling parameter(s) to suit camera (as required)
8. If using a colour camera, do not set color mode to grey
(You will usually find that these settings will be remembered from one use of the software to the next)
Viewing/Imaging Process
1. Set exposure mode to Video
2. Set exposure length to maximum for video (5 seconds)
3. Set the display zoom to “fit to window”
4. Slew to target and frame target to suit (the 5 seconds exposure length should be sufficient for this purpose depending on your telescope's aperture but if necessary switch to Trigger Mode and increase the exposure length a bit)
5. Switch to Trigger Mode
6. Select a longer exposure length and click the Loop button
7. On completion of the exposure, examine the histogram and set the left slider bar to rest at the bottom-left of the displayed bell curves
8. On completion of the next exposure examine the displayed on-screen image and determine if the exposure length should be increased or decreased. If so, click the Stop button and repeat steps 6 and 7 using a different exposure length
9. On completion of the next exposure examine the RGB bell curves in the histogram and determine if they need to be balanced so that all three curves peak at the same place. If so, adjust the colour balance red, green and blue sliders and continue to loop through exposures until they do.
10. Import a suitable dark field correction image from your library (see below) and check the Enable check box.
11. Consider using the sharpen tool and experiment with different settings 0% - 500% (suggest that if it is used the setting is kept quite modest at, say, 25%)
12. Using the live stack feature, select the average mode and deep sky options and select the number of images to stack (suggest that 3 or 4 is sufficient). Then check the Enable checkbox.
(The green exposure progress bar will continue to the end of the current exposure at which point the live stack input will display “1”. But then the progress bar and the image display will appear to freeze and they will only unfreeze after exposure of the second image in the stack has been completed.)
13. When the required number of the stack has been completed as indicated by the input and output numbers, click the Snap button in the capture and resolution section.
14. Using menu item File|Save save the captured image to file using a suitable file name.
Dark Frame Capture and Use
It is advisable to create a library of dark frames covering a range of exposure settings that can be accessed whenever a new exposure setting is used for imaging.
1. Cover the front of the telescope
2. Click the histogram Defaults button to make sure that the left and right bars are returned to the left and right sides respectively
3. Select an exposure setting
4.In the dark field correction section, uncheck the Enable checkbox, select a number of dark frames to stack (suggest that 3 or 4 is sufficient) and click the Capture button.
(After each exposure you may see red, green and blue hot pixels displayed on screen depending on the quality of your camera and the length of the exposure.)
5. Once the total number of selected dark frame exposures has been completed, click the Export button and save the resulting dark frame to your library using a file name that describes the exposure setting used.
(You can prove that the dark frame has been captured properly by checking the Enable checkbox and waiting for another exposure to complete whereupon you should see that any previously displayed hot pixels have now been completely removed from the display.)
6. Repeat steps 3 to 5 for additional exposure settings until your library contains all of the possible darks that you are likely to need.
Flat Field Correction
This is a new feature in the latest version of the software dated 16th June 2018. Its arrival is welcome and in theory it should serve a useful purpose. But, in practise, it is difficult to use. The problem is that unlike the dark frame feature it does not include a file export and import facility meaning that one can only use a flat frame that is captured when the program is open. Creating and using a library of flat frames is not presently possible. That's fine only if one is able to set up for the night before dark or one has a translucent panel (or some such) available for use after dark. Maybe the program designers will get their act together and include a file export / import facility soon? Until then I believe that most users will not make use of this feature. (Edit : This problem has now been rectified. In version 4.7 (and possibly in earlier versions too that I did not download) the flat field correction feature does now include the same file saving and retrieval functionality as the dark field correction feature.)
Auto Capture of Images
Instead of using the live stack feature to smooth out camera noise and then using the Snap button to save the resultant stacked on-screen image, individual exposures can be saved separately by using the auto capture feature and then, if required, the images can be stacked using some other software such as RegiStax.
1. Use menu item Options|Preferences to access the Preferences dialog.
2. Select Auto Capture and then use the various entry boxes to compose the outline of the folder/file name to be used when saving images. Check the Total Images checkbox and set the required number of frames to be captured. (If [target] is to be included in the sub-folder name, use the Target option to make sure that the target name is included in the list of nominated targets.) Click Apply and close the dialog.
3. Using the targets drop-down list on the toolbar, select the target to be imaged.
4. After composing the image and setting appropriate exposure, histogram, etc., etc. values as described in the basic workflow above, use menu item Capture|Auto Capture to start the image capturing process. You can monitor progress by using the Browse menu.
Tweaking Images for Outreach Use
The software's Image and Process menus offer a wide range of post-processing features that can be employed on any imported image including one created using the Snap button. During an outreach session they can all, in theory, be used to “improve” the image captured by the camera. In practice, due to time constraints and the sometimes limited attention span of visitors, it is better to employ just one or two to demonstrate that the acquired image contains more data than was immediately apparent. Probably the most useful feature is the Curve... option that creates a histogram stretch and which can be found in the Image|Adjust sub-menu.
Regular Post-Processing
Good as the software's own post-processing features are, one may prefer to use more powerful software such as Photoshop to extract the most information from the captured images. Even 'though the emphasis is on taking images for record keeping purposes there is no reason why the images cannot be improved for display to the best advantage possible. Just do not expect the end result to be comparable with regular astrophotography images that usually result from many hours of image acquisition, calibration and post-processing.
I hope that this may help.