Bortle 8 galaxies [Deep Sky] Acquisition techniques · Tony Gondola · ... · 54 · 1854 · 15

Rajat Kumar:
Hey, 
Just an unusual target suggestion: https://www.astrobin.com/kdvhgi/B/

The galaxy in the image looks like a smudge () but it is quite faint. I'm sure with a larger aperture and longer integration, this faint dwarf can be images quite well. With my gear and pristine bortle 8 skies, I should not even have tried.

Clear skies!
Rajat
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Interesting target that easily resolved. I wish I could give that one a try but I can't get anything below +20......trees.

Tony Gondola:
I've just started experimenting with a 8" SCT and I'm amazed at how often the focus needs to be adjusted

Yes, that's right. Temperature fluctuations (usually caused as it drops during the night) will cause this - an "on axis" guiding set up can monitor this on the fly and a secondary focuser can allow you to lock the mirror and also auto focus on the fly. Of course you can manually re-focus periodically as well. The big 14 inch mirror also suffers from mirror flop unless it's locked; it wreaks havoc with flats otherwise. Not too sure how bad the flop is with the 8 inch mirror.

Tony Gondola:

Tony Gondola:
I've just started experimenting with a 8" SCT and I'm amazed at how often the focus needs to be adjusted

Yes, that's right. Temperature fluctuations (usually caused as it drops during the night) will cause this - an "on axis" guiding set up can monitor this on the fly and a secondary focuser can allow you to lock the mirror and also auto focus on the fly. Of course you can manually re-focus periodically as well. The big 14 inch mirror also suffers from mirror flop unless it's locked; it wreaks havoc with flats otherwise. Not too sure how bad the flop is with the 8 inch mirror.

I have an old Meade OTA with silver coatings. It is surprising tight in focus with no mirror shift at all. I haven't looked at the mirror flop issue yet but given how the focus performs I'm not expecting much of a problem. It must have been a Monday morning unit!

I don't know about the Meade mirror situation - but they are (we're) a big name ; now owned by Orion I think? But the older stuff should still be pretty good quality. I've been asked to take a Meade scope (a 12" on a fork mount) and make it work; problem is that the owner isn’t sure what's wrong with it! I'd love to help them out but it sounds like a box of worms! And yes, Monday (and/or Friday afternoon) manufactured products are definitely prone to be tainted !