Does the Auto Focus "Crop" function work?


#1

I typically use the Auto Focus Crop feature set to 15% but I noticed in these recent beta releases with the new focus/star detection updates it appears the crop feature has been disabled? I thought there was a red square box indicating the active focus area. I was just curious, maybe with the new focus/star detection this feature is not needed?

Thanks,
mahaffm


#2

Cropping is currently disabled (or rather… not implemented) in the beta. I would argue that it is probably “less” needed, but we probably won’t get away with “not needed” for all cases.


#3

Thanks Ken,
By the way the clouds are rolling in and out so I thought I would play for a while tonight with the new focus in 2.5.1.5. I must say it is working very well. I’m currently using a Celestron 8" SCT with the 80mm center obstruction. I found I needed to set the min star size to 3. both 2 & 3 seems to work best. 4 and higher doesn’t seem to detect any stars. I’m not sure what the number really mean.

Hope this helps. If you want I can post a few of the AF packs.

Regards,
mahaffm


#4

It’s essentially the smallest real star your rig can produce at 1x1 (in pixels). That said, you want this value as high as possible without affecting solid detection (sample size) at focus. The actual release will include docs to help with this…

If your AF is working as you expect it to, then we don’t really need them. Appreciate the offer though.


#5

Thanks Ken for the help. I do have another question when it comes to binning. Since I auto focus using 3x3 binning and I have the star size set to 3 pixels would that be the same as saying if I would do the auto focus with binning set to 1x1 I should be able to set the star size value up to a higher number, say maybe 9? I guess what I’m asking is the binning value and the star pix number are related? If so that might be why for my 3x3 binning auto focus if I try t use a star size greater then 4 I don’t get any star detection? I hope I explained my question well enough

Thanks
mahaffm


#6

Yes, the minimum star size is applicable to 1x1 images. When you change the binning of your AF frames, the minimum star size should scale linearly (inversely) with binning without you having to adjust the min star size param. There is a bug in 2.5.1.5 that prevents this from working properly… but that is the intent.


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