X, Y PIXSZ mssing from fits header when binned


I normally do image sequences binned 1x1 and the fits header includes both binning and x, y pixsz keywords.

I just did a sequence binned and although the header has the binning keywords: scale, focallen, and pixscale - it does not have xpixsz or ypixsz in it. I’m not sure if it was caused by having bin set to be x2 but those keywords are missing. I believe they should be included - and represent the pixel size in microns, including binning.

On a related note - when I just save an image that I have grabbed, I would like it to be populated with all the basic fits info that should be available at the time. I’m not sure why the fits header info needs to be in a sequence to be stored with the image.



You’ll need to be more specific here. Here is a 2x2 image from a sequence:

This should already be happening. You’ll need to be far more specific with regard to type of image missing data or at least more specific with the info you feel should be there. Information that “should be available at the time” does not help me understand your complaint. Here is a frame and focus frame, saved to disk:

You can see it contains tons of header data…


Woops - sorry - I got things mixed up. Let me rephrase what I see. The problem didn’t happen during a sequence - it happened when I manually saved files. So here is the issue:

When I save an image manually, the fits header has a lot of info but it is missing the XPIXSIZE and YPIXSIZE values.

This was with 2.5.10

So this is a minor problem but I think it is missing that info.

My example also says the FILTER is None. It may be that I did not have the filter wheel connected at the time but I probably did - so that is something else to check. I notice your example that you manually saved also says None there. Is it missing X, Y PIXSIZE?

I can send the example fits file if need be, but would prefer to send it privately.

Thanks - and sorry for confusion.



Can you clarify what this means? Saving what type of frame manually? FF? Plate Solve? Auto Focus? Sequence frame etc?


Take a picture with frame and focus - then right click on it to save as mono fits.

If I just want to take a picture with a given filter, binning, and exposure and have it saved to a file in the most direct way - this seems to be the way to do it. Use frame and focus, Take One, then right click on it and do save as mono fits.

If there is another way just to take and save a fits image without a sequence I’m happy to go that way. But this way appeared to drop the XPIXSIZE and I think the Filter name.



OK thx. This has been addressed for FF frames.


Great - thanks.



Downloaded and tested and confirm all the items are in the FITS. Thanks. Frank