DSS rejecting too many frames

[broadsword]

Hi all, I've just been stacking some frames of the Needle Galaxy in DSS but it has only accepted 32 out of 42 light frames. I've had it reject one or several before, but not that many. The frames all looked OK, and the star detection was about 60 at the start. Some of the frames had stars that were a bit eggy, so could that be the cause? I would rather have kept them in than lose them.

Is there a simple fix to make DSS accept more frames?

Thanks.

[Bizibilder]

Yes there is - when you first click on "Register frames" you get a box where there is a button you can tick to "select XXX% best pictures and stack them" (or similar wording). Change it to read 100% (if it doesn't - I think the default is 70% or 80%) and it will force DSS to stack all 100% of the pictures that you tell it to.

[broadsword]

Perfect, thanks again Roger.

[broadsword]

Well, guess what, no joy (again)for me from DSS. I was on accept 98% anyway as it turns out.

Is there any info to look out for in the table showing data for each frame below the image box in DSS? Anything to indicate the frames are duff?

Otherwise, is it the stacking mode maybe? I'm

using Kappa Sigma clipping with 5 iterations.

[Freddie]

If DSS doesn't like your stars, there is very little you can do about it as DSS will not be able to relate one set of stars in one image to the stars in the next and will therefore refuse to include that particular image in the stack. You could try adjusting the setting so that DSS detects fewer stars, that can sometimes help.

[broadsword]

Thanks Freddie. What would be the kind of thing that it doesn't like about the stars? And is it just the star detection slider that you use to reduce the number? Thanks!

[Freddie]

If the stars are a bit off round, it doesn't see them as stars. Yes, use the star detection % to reduce the number of stars that DSS detects maybe to something like 20.

[broadsword]

Hi Freddie, no dice with this, looks like the stars are too oval. Guess I'll have to get some more data!

[dph1nm]

You can try the manual star editing tool in DSS. This sometimes let you select stars that it has rejected automatically.

NigelM

[broadsword]

Thanks Nigel, is it in an obvious place in DSS? I tend to get a bit lost in it...

[dph1nm]

If you click on an individual image in the list to bring up its picture, then a menu of icons appears at the right hand side of the picture, one of which is star edit mode (you may have to however over the image with your mouse to get it to appear - I can't quite remember).

NigelM

[broadsword]

Hi Nigel,

Oh yes, I've seen that. I'll try it out!