Chromatic Abberation Askar 140APO · C.Sand · ... · 8 · 453 · 3

C.Sand 3.31
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Just a word of warning. Got sent two copies by Agena (who is accepting my return thank Agena), both had CA. The first was only blue star bloat, though rather severe. FWHM values of ~1.7 for red and green and 2.2 for blue. The second copy you can see below (if anyone really wants I'll dig up images for the first copy as well). Both were with the same 0.8x reducer/corrector, so yes it may be the correctors fault but doubtful. Ignoring the glaring issue, the scope is fairly sharp and would work well as a solar scope with a quark (though those have their own set of issues).

Equipment used:
Askar 140 w/ .8x
ASI2600MM
Antlia LRGB
AP Mach1
OAG w/ asi220mm
ZWO eaf (yes the focus curves were good)
Dew heaters on, balanced well, shooting near zenith, etc. Believe me the scope got the best chance it could.

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andreatax 8.66
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I knew the 140 wasn't terribly well corrected and no suprise there given the price.
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C.Sand 3.31
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andrea tasselli:
I knew the 140 wasn't terribly well corrected and no suprise there given the price.

You knew?! Why didn't you tell me, gosh that could have saved soooo much time...

Seriously though, so initial tests look good, so I think the first two batches or so were done well (or actually had qc) and the rest have just been as they come.
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kevinkiller 1.81
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YIKES!!

I’ve been wanting one of these scopes for a while but Agena has them “back ordered “ until the end of May (originally end of April last month)

what do you think the best approach would be to get one that’s within spec?

is it possible?
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C.Sand 3.31
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John Stone:
YIKES!!

I’ve been wanting one of these scopes for a while but Agena has them “back ordered “ until the end of May (originally end of April last month)

what do you think the best approach would be to get one that’s within spec?

is it possible?

I don't think you should try for one to be entirely honest. Getting a good copy might be possible, but to me it looks like Askar was careful with the first few batches and are now just mass producing. I know someone with a good copy, they have slight errors but of course for a $2000 140mm scope nothing to worry about. If I remeber correctly they ordered very early and got the second or third batch. 

Agena told me in our emails that other 140's didn't have issues/weren't showing as severe issues. It's possible I got unlucky, but seeing some results of other people (though with the 103) I think it's very unlikely to get a good one. If you were able to order a number of them and test them all ASAP, I think that's your best bet to get a passable copy. Of course then this involves shipping and everything, so I really don't think this is viable unless you live within driving distance of Agena.
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kevinkiller 1.81
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I'm so sad!  :-(

What else if not the Askar that's good and round at the edge of a FF sensor?

Is there anything comparable?

Why can't I get a copy that takes images like this on FF camera ... so nice!
https://www.astrobin.com/full/e9san7/0/
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C.Sand 3.31
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John Stone:
I'm so sad!  :-(

What else if not the Askar that's good and round at the edge of a FF sensor?

Is there anything comparable?

Why can't I get a copy that takes images like this on FF camera ... so nice!
https://www.astrobin.com/full/e9san7/0/

Yep, that would have been nice. Only a tiny bit of CA in that one, the ones I had we noticibly worse. Anything comparable is looking to be $$$ more. I think I'm settling on an Esprit 120, though that's ~1k more.
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triplej3 0.00
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Send akar an email and let them no about your problems. I have a sharpstar 61 edph and they sent me a new objective lens free of charge that performs much better than the old one with purple stars
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C.Sand 3.31
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Jordan Morley:
Send akar an email and let them no about your problems. I have a sharpstar 61 edph and they sent me a new objective lens free of charge that performs much better than the old one with purple stars

I'm not looking for a replacement. I don't have much faith in the series, I was just hoping that it'd work out well enough that I could justify using it for a while.
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