Rookie Error?

[Grifflin]

Hello Everyone

Took the rig out into the back garden the other weekend just to spend some more time going through the set-up process and getting used to the software etc.  Once set up, chose M27 as a target, again more to get some time using the image capture software (NINA).  At the end of the evening took my Flat Frames and packed up the rig.  All good.

When I came to processing (PixInsight) I discovered that I couldn't calibrate my Flats with my Darks.  Some error talking about incompatible geometry.  Did some investigation and realised that all my lights (and other calibration frames) had all ben taken Binned 2x2 but I had failed to set my Flat Frames to match and they had been taken Binned 1x1. 

To my mind that is a busted night of imaging as I had already dismantled the rig completely so would not be able to reproduce the Flat Frames.  Fortunately for me I'm still experimenting so no great loss.  However, is there anyway of recovering from this other than just processing without Flats...or is this just a good learning experience?  🙂

Any thoughts?

Neil

[Clarkey]

I don't use PI, but could you not re-size your flats to match the others?

[Grifflin]

Really good point...didn't even think of that!  Something to investigate over the weekend.  Thank you

[vlaiv]

PI has integer resample which is software binning - simply bin your flats x2 in software and you should be fine.

[Grifflin]

Wow...ok...software binning!  Everyday is a school day!  Thanks Vlaiv, going to give that a go.  I'll let you know how it goes  😃

[Grifflin]

23 hours ago, vlaiv said:

PI has integer resample which is software binning - simply bin your flats x2 in software and you should be fine.

Worked a treat....almost.  Original size of Flat (in pixels) was w=4144  h=2822.  After using IntegerResample they came down to w=2072 h=1411.  However, it appears that the Lights and other calibration frames (all originally Binned 2x2) are 1 pixel out (w=2072 h=1410) and PI doesn't want to calibrate.

One pixel out 😔

[vlaiv]

5 hours ago, Grifflin said:

Worked a treat....almost.  Original size of Flat (in pixels) was w=4144  h=2822.  After using IntegerResample they came down to w=2072 h=1411.  However, it appears that the Lights and other calibration frames (all originally Binned 2x2) are 1 pixel out (w=2072 h=1410) and PI doesn't want to calibrate.

One pixel out 😔

You should probably crop original flats to twice required resolution - 4144 x 2820 and then bin it x2 (or simply crop binned version to exact size).

"Firmware" binning (CMOS don't really bin data in hardware due to sensor electronics) - should really be the same as software binning - but that depends on how it is implemented in camera software. Maybe ASI decided to discard one row for some reason when binning in firmware - so try to replicate that.

[Grifflin]

Thanks Vlaiv....yep, all good and calibrated.  Used the Crop tool to shave off 1 pixel of the resized flats and PI was happy.  A useful learning in changing the geometry of images in PI.  I think the lesson for me here is to double check settings before taking the images....all round easier that way!  😃