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Old 21-09-2014, 02:50 PM
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PRejto (Peter)
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PRejto is offline
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 1,303
Seeing? Optics, Focus?, ???

I could use some advice. I'm kind of stumped. I never quite ran into this problem when I used my KAF8300 CCD on my TEC140. But, my Trius is giving me fits (and not such good ones at that!).

As you can see from the attached screen shot of CCDInspector, I had reasonable seeing (I presume) given all the FWHM values in the 2s. I used FocusMax and have a large sample of V curves. To my eyes blue looks shockingly poor, but, I cannot focus any better. The FWHM values make me think the images should look better. The .jpgs are in order of R G B and are at 160%. 5 min exposures with the blues showing very good aspect ratios. Aligned and stacked in CCDStack.

Is this seeing, optics, poor focus (but why if poor focus? I even ran v curves just with the blue filter (Baader) and cannot do better)?

I know Greg Bradley has complained about "bloated" stars using the Trius on his TEC180. Perhaps this is something similar. If so, it seems to be due to blue for some reason.
Attached Thumbnails
Click for full-size image (CCDINS.jpg)
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Click for full-size image (Mean Red.BBS-00000012.jpg)
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Click for full-size image (Mean green NN.00000006.jpg)
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Click for full-size image (Mean blue. BBS- 00000009.jpg)
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