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Astrotech 65quadruplet or 72ED with field flattner

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#1 supercoolone

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Posted 24 April 2010 - 12:19 PM

HELP!

My wife has ok'd a $500 budget! Should I go with the astrotech 65mm quadruplet or 72mm ed with field flattner?

I've got a canon 10d and sony 350a for astrophotography so i'm pretty much limited to APC type sensors! (and a small DSI guide camera).

HELP!

#2 Cyclop_si

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Posted 24 April 2010 - 01:29 PM

For AP, 65Q, no brainer...

#3 jason_milani

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Posted 24 April 2010 - 01:46 PM

I have the 72 Megrez (same as the AT) and just sold the flattener because i purchased the 65Q. even though it's a little slower i'm sure it's a better all around imager. No vignetting, CA, spacing, etc. to worry about. I'll use the 72 as a spotting scope.

#4 jog

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Posted 24 April 2010 - 02:32 PM

I'll use the 72 as a spotting scope.


Hey jason are you saying that the AT 72 ed is no good for imaging? cause I bought one at NEAF and I love it, I want to try my hand at imaging using this scope.

#5 jason_milani

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Posted 24 April 2010 - 03:15 PM

jog, not saying that at all, here's a pic i took with the M72. Very nice scope indeed. I'm just "tweaking" things. I guess some of us get a little anal when dealing with this type of equipment. ;)

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#6 jason_milani

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Posted 24 April 2010 - 03:18 PM

.....and there IS some chromatic aberration when imaging with it as you can see in the pic.

#7 Doug76

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Posted 24 April 2010 - 06:40 PM

Tough choice, but the 65Q is designed from the get-go as an imager, so there is your answer.

#8 supercoolone

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Posted 24 April 2010 - 07:18 PM

ACK!!! I can spend another $200 and get the ES 80mm triplet!

Would that be even better?

[if my tone sounds panicky - I am - don't often get permission to spend lots of dough] :shocked:

#9 jrcrilly

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Posted 24 April 2010 - 07:48 PM

ACK!!! I can spend another $200 and get the ES 80mm triplet!

Would that be even better?


If you don't mind fiddling with flatteners (gotta experiment with spacing) and won't ever be using a larger imaging chip it might be. I'm a big believer in avoiding outboard optics myself.

#10 Stilletto

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Posted 24 April 2010 - 10:11 PM

I am honestly considering selling my 72ED and picking up the 65EDQ myself before the sale is over...

#11 Newfie Ninja

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Posted 24 April 2010 - 10:20 PM

I was leaning the other way, I am on the preorder list for the 65 but after seeing pics of the 72 in another post and how nice it looks, I was debating buying the 72 instead but I think I will hold off and go with my original thought and get the 65.
Cheers

#12 Doug76

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Posted 24 April 2010 - 10:58 PM

Whomever it may be that is thinking of primarily AP with a small scope, then my firm opinion is you are best off with the scope designed for AP as it's primary purpose. The 65Q is clearly that scope. A triplet FPL-53, almost unheard of in this aperture, coupled with an ED field flattener built in at the optimum distance from the focal plane.
No dual purpose scope (visual and AP), even with a great outboard field flattener, can be as precise.
And although the AT72ED is undoubtedly a fine scope, you will get some CA in images made with it due to it's doublet FPL-51 equivalent optics. This is a given.
There is a reason the 65Q costs more. It's the integrated and finer optics used in it's construction.

Now, after saying all that, I want one! :foreheadslap: :tonofbricks: :lol:

#13 Doug76

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Posted 24 April 2010 - 11:05 PM

And let me add, this coming from a guy that owns a 90mm FPL-53 triplet, with an outboard field flattener!

I think this site is killing me, and I may have to resign my commission!
I blame all of you! Geez! :4 :lol:

#14 pollux

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Posted 24 April 2010 - 11:15 PM

I hope the EDQ arrives soon as I am building up my mini AP set up

#15 Doug76

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Posted 24 April 2010 - 11:24 PM

Love the comics, Sir Pollux. Know the refractor guy, think I may know the CAT guy, no clue on the reflector guy.
And the reputation of the fine looking lady in the glasses has been seriously distorted by those who have no wish to know the truth.

#16 supercoolone

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Posted 25 April 2010 - 11:29 AM

Ok, to add to my confusion, I already have a canon 70-200mm f/2.8 L lens, an its got pretty flat fields...that's why i'm thinking that a 65mm quad is somewhat redundant...is it?

Questions, does the 80mm ES triplet not properly illuminate an APS sensor (field flattner or not?)

Thanks!

#17 Doug76

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Posted 25 April 2010 - 11:37 AM

The zoom lens can't match the 65Q. Always there is compromise in zoom lenses.

#18 jtaylor996

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Posted 25 April 2010 - 12:06 PM

Then you don't know that Canon lens. The transmission is awesome, and so are the MTF charts. I can't speak about the 65Q though. I'd wait for a comparison to be sure, but I wouldn't be too surprised if the Canon won.

#19 nemo129

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Posted 25 April 2010 - 12:28 PM

The 65 quad gets my vote. It sounds like it was made for what you are looking to do!

#20 Doug76

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Posted 25 April 2010 - 05:14 PM

Then you don't know that Canon lens.


Actually, I do. I stand by what I said.

#21 Stilletto

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Posted 25 April 2010 - 06:56 PM

Then you don't know that Canon lens.


Actually, I do. I stand by what I said.


Agreed. I think that even the finest of the best zooms are designed exclusively for, shall we say, NOT pinpoints of light. Every lens I have owned suffered from at least a hint of CA.

#22 wb9sat

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Posted 25 April 2010 - 07:00 PM

Let me just say something on this thread. I have found through experience, that a zoom lens is a very poor astro-imaging optical device. They have very poor color aberration and for the money, one is much better buying an inexpensive 66mm ED APO and a camera T-ring adapter.
Bill

#23 aragorn

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Posted 28 April 2010 - 10:50 AM

Hmmm. I think it's fair to say that even the finest zoom lens (and that Canon certainly belongs to the very finest available) is not optimized for the kinds of tasks that the 65Q has been specifically designed to handle. In fact, I'm certain that Canon would agree.

It's apples and oranges. Both are superb instruments, but have been intended by their designers for very different purposes.

Buy the Astotech. Keep the Canon. Count yourself lucky to have such awesome goodies at your disposal.

:)

Personally, I'd go with the 65Q if I had the budget for it. Instead, I'm looking at the AT field flattener for our C80ED.

-brian






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