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2022-01-07:  APP 1.083 has been released !!!

1.083 Windows 64bits download

1.083 MacOS 64bits download

1.083 Linux DEB-64bits download

1.083 Linux RPM 64bits download

  • new Star Reducer Tool
  • 15-30% speed increase in processing
  • introducing Comet registration
  • support for new camera models like Canon EOS R5,R6
  • Greatly improved HSL Selective Color Tool
  • New Batch Tools
  • New File Saver Module with PNG support

black screen after integration  

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(@morrienz)
Brown Dwarf Customer
Joined: 4 years ago
Posts: 8
October 5, 2021 00:35  
Posted by: @absorbingphotons

@mabula-admin Hi Mabula,

Thank you for pointing this out! I believe I know the reason this happened. I took my dark frames while my camera was still attached to my telescope with the dust cap on the front of the scope, which I usually do. But this time, it was already morning when I did that. Usually, when I do this and it worked in the past, it was still nighttime when I took the darks, so it never presented a problem. I guess there was some light leakage into the telescope this time from the pre-dawn light, otherwise my dark frames would have appeared all grey. In my FITS Viewer program, the auto-stretch appeared completely normal for my darks, but I guess it had not stretched them enough because I too see they are brighter than normal.

Long story short: may this be a word of warning to anyone taking dark frames to make sure you disconnect your camera from your telescope/imaging train and cap it so that this doesn't happen to anyone else. 😆 

Thanks for getting to the bottom of this Mabula, I appreciate it! A warning in APP would be great so others don't run into this same issue.

I have also had light leaks ruin darks that I tried to take in daylight, with the lens cap on my APM 140/970 refractor and my ZWO ASi294MC Pro camera, but I was able to immediately see the light leak in the stretched darks so it didn't go on to cause me later problems, and I just retook them later that night after dark. The light leak appeared to be coming in via the camera body somewhere, not via the OTA etc. I tested that by taking darks in daylight again with the camera removed from the OTA and the camera aperture blocked with a thick tight fitting black cap, and I still got the exact same light leaks showing on the sensor. 

Chris M


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 2893
October 7, 2021 21:25  
Posted by: @absorbingphotons

@mabula-admin Hi Mabula,

Thank you for pointing this out! I believe I know the reason this happened. I took my dark frames while my camera was still attached to my telescope with the dust cap on the front of the scope, which I usually do. But this time, it was already morning when I did that. Usually, when I do this and it worked in the past, it was still nighttime when I took the darks, so it never presented a problem. I guess there was some light leakage into the telescope this time from the pre-dawn light, otherwise my dark frames would have appeared all grey. In my FITS Viewer program, the auto-stretch appeared completely normal for my darks, but I guess it had not stretched them enough because I too see they are brighter than normal.

Long story short: may this be a word of warning to anyone taking dark frames to make sure you disconnect your camera from your telescope/imaging train and cap it so that this doesn't happen to anyone else. 😆 

Thanks for getting to the bottom of this Mabula, I appreciate it! A warning in APP would be great so others don't run into this same issue.

Hi Brian @absorbingphotons,

Glad that we have found a clear explanation for your problem 😉 and that there also is good explanation from your side that confirms that indeed a data capture problem was the source of all problems.

I am implementing a warning system for this right now and will make sure it is in the 1.083 stable release 😉


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 2893
October 7, 2021 21:30  
Posted by: @morrienz

I have also had light leaks ruin darks that I tried to take in daylight, with the lens cap on my APM 140/970 refractor and my ZWO ASi294MC Pro camera, but I was able to immediately see the light leak in the stretched darks so it didn't go on to cause me later problems, and I just retook them later that night after dark. The light leak appeared to be coming in via the camera body somewhere, not via the OTA etc. I tested that by taking darks in daylight again with the camera removed from the OTA and the camera aperture blocked with a thick tight fitting black cap, and I still got the exact same light leaks showing on the sensor. 

Chris M

Hi Chris @morrienz,

Thanks for sharing your experience in these matters 😉 Indeed, I suffered myself a lot a couple of years ago when I had light leakage in my optical train. I simply could not make good flats and darks in daylight because light was entering the system through a very expensive Takahashi adapter.... 🙄 I could only solve it by modifying my optical train with another adapter. Sometimes it can be very hard to find the cause...

Anyway, I will make a warning system that detects such a light leakage in darks and bias frames when they are subtracted from the lights. If too much pixels get clipped to zero, the system will start to warn 😉 and tell the user that he needs to check

  • sensor gain and offset levels for lights and darks/bias
  • and otherwise light leakage

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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 2893
October 7, 2021 21:42  
Posted by: @mabula-admin

Hi All, @dickvantatenhove, @jan-monsuur, @nobbybuddy, @morrienz, @vincent-mod, @tchylek, @absorbingphotons

Let's solve this issue then!

I will need to see all data sets to understand what is happening. I have so many data myself and test data of other APP users  and I have never seen this problem appear myself, so at the moment i can only assume something fishy is happening in either

  • APP or
  • in the data itself (sensor gain/offset problems)
  • or in the capture software that is being used...

Anyway, without seeing the data it will be hard to solve this and give you a good explanation.

Please upload your data if you have not done so already here:

https://upload.astropixelprocessor.com/

username and password : upload

Please let us know when uploaded and we will test a.s.a.p.

Mabula

Hi All, @dickvantatenhove, @jan-monsuur, @nobbybuddy, @morrienz, @vincent-mod, @tchylek,

Do I need to check your data as well to see if we can solve the issue completely and in all cases?

Mabula


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(@morrienz)
Brown Dwarf Customer
Joined: 4 years ago
Posts: 8
October 8, 2021 05:44  
Posted by: @mabula-admin
Posted by: @mabula-admin

Hi All, @dickvantatenhove, @jan-monsuur, @nobbybuddy, @morrienz, @vincent-mod, @tchylek, @absorbingphotons

Let's solve this issue then!

I will need to see all data sets to understand what is happening. I have so many data myself and test data of other APP users  and I have never seen this problem appear myself, so at the moment i can only assume something fishy is happening in either

  • APP or
  • in the data itself (sensor gain/offset problems)
  • or in the capture software that is being used...

Anyway, without seeing the data it will be hard to solve this and give you a good explanation.

Please upload your data if you have not done so already here:

https://upload.astropixelprocessor.com/

username and password : upload

Please let us know when uploaded and we will test a.s.a.p.

Mabula

Hi All, @dickvantatenhove, @jan-monsuur, @nobbybuddy, @morrienz, @vincent-mod, @tchylek,

Do I need to check your data as well to see if we can solve the issue completely and in all cases?

Mabula

Hi Mabula. It was quite a while ago this happened to me, twice, and I don't think I kept (or would now know which darks they were even if I did keep them) the two sets of darks that caused the problem for me, so unfortunately I'm not able to send in any useful data now. I wish I'd kept and knew which were the first ones that caused the problem as they were darks that I am fairly sure had previously been working fine in APP but then just out of the blue one day started giving that black final integration problem. At the time this discussion wasn't as well developed and didn't have as many reports of the issue and I just reported it here, took new darks, which was the advice to me then from Vincent, and those worked, so we left it at that.

The warning will be very useful.

Cheers and Thanks, Chris M


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 2893
October 10, 2021 21:01  
Posted by: @morrienz

Hi Mabula. It was quite a while ago this happened to me, twice, and I don't think I kept (or would now know which darks they were even if I did keep them) the two sets of darks that caused the problem for me, so unfortunately I'm not able to send in any useful data now. I wish I'd kept and knew which were the first ones that caused the problem as they were darks that I am fairly sure had previously been working fine in APP but then just out of the blue one day started giving that black final integration problem. At the time this discussion wasn't as well developed and didn't have as many reports of the issue and I just reported it here, took new darks, which was the advice to me then from Vincent, and those worked, so we left it at that.

The warning will be very useful.

Cheers and Thanks, Chris M

Thanks Chris @morrienz,

Probably your capture software has made an adjustment/correction for the sensor offset. So the metadata was reporting it as the same, but the data was actually shot with a different offset... this happens now and then. So my advise is always:

  • don't shoot calibration data and lights with different software packages
  • don't shoot calibration data and light with different versions of the same software package

I know many make dark libraries and that this can be usefull. But please be aware that if there is an software update of your capture software, things might be different with regard to the sensor gain and offset which can upset your routine... I have seen this problem many years with different capture packages unfortunately.

Mabula


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 2893
December 2, 2021 22:39  

Hi All, @dickvantatenhove, @jan-monsuur, @nobbybuddy, @morrienz, @vincent-mod, @tchylek, @absorbingphotons,

For APP 1.083 stable, which will soon be there, I have implemented the warning system now and I have completed eliminated the cause that was creating black integrations. This will no longer happen.

A black integration would occur if you would have

  • multi-band/color data
  • background neutralization enabled in 5)NORMALIZE
  • an adaptive pedestal was needed because of a data problem where the background values of the reference frame without the pedestal would be negative...

The warning system is implemented in both the calibration engine as well as the normalization engine...

2) Calibrate, warning system shown when too many pixels clip to zero despite using the adaptive pedestal, indicating a serious data problem:

Warning underexposure BadSensorOffset LightLeakage

5) Normalize, warning system kicks in when background values of the reference frame are negative without the needed pedestal, causing Background Neutralization to be disabled because it can not work properly with data that has negative background values corrected for the artificial pedestal.

Warning underexposure BadSensorOffset LightLeakage Turn Off Background Neutralization

So this will always warn the user when a data problem is detected and the resulting data can still be processed without getting a black integration ;-), but the user is now aware that something is not right with the data and by fixing the issue, he/she will get better results for sure!

The problems that were causing black integrations were always one of the following 3:

  1. data is underexposed
  2. bias/MasterBias/dark/MasterDark frame(s) are not compatible with lights due to having a different sensor offset/pedestal
  3. a light leakage in the optical train so the bias/dark frames are not good

Thank you all for reporting the issue.

Mabula


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(@dickvantatenhove)
Brown Dwarf Customer
Joined: 4 years ago
Posts: 8
December 4, 2021 11:27  

Thanks Mabula for solving our darkframe problems!. Looking forward to the new version! 

Dick


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(@morrienz)
Brown Dwarf Customer
Joined: 4 years ago
Posts: 8
December 4, 2021 19:24  

Thanks very much for putting this new warning in Mabula.

Chris M


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