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Any experience with the Astro-Tech AT65EDQ

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#1 jmasin

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Posted 11 August 2011 - 03:19 PM

This little scope (FL 420mm) is pretty inexpensive. Looks like a potentially good wide-field scope. No corrector/flattener required...

Anyone use/experience this guy? I'm finding it tempting.

Jon

#2 zerro1

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Posted 11 August 2011 - 03:50 PM

I've been using one for the last year, and I LOVE it! Picked mine off someone who bought it at NEAF 2010 as a guide scope...He said it was too heavy for his needs... :grin:

#3 Erskin71

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Posted 11 August 2011 - 05:03 PM

Just got mine this week. With the moon up I've mostly just been messing around. I like the back is marked with numbers (not sure what this area is called) so I know exactly where I come to focus. Makes it easy to set up every night and start shooting. Seems to be well built. So far so good.

Too heavy? It weighs 4.75 pounds. His loss you gain I guess :)

#4 Adam E

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Posted 11 August 2011 - 09:02 PM

I have an AT-65EDQ, and I like the scope. There are a few old threads in the refractors forum that discuss different viewpoints on some of the scope's highs and lows from a variety of owners.

I have found the integral flattener to be particularly nice in terms of reflections. When using an ATFF on other scopes in conjunction with LRGB filters, and / or an LPS filter, I have had some nasty reflection problems at times on bright stars. I have yet to see a reflection in an image when using the little AT-65EDQ. It seems that the flattener is spaced far enough up in the tube as to not induce reflection problems with your imaging filters.

The scope also produces a very flat field as far field curvature. I see no elongation of stars across the FOV of an ST8300M.

The one let-down with the scope, in my opinion, is the focuser. While the rack and pinion focuser is heafty enough to support my ST8300M and Filter Wheel without drawtube sag, it does not have the ability to function properly with the weight of my camera and wheel with the scope pointed above like 60 degrees. Basically, the drawtube will slip with the weight of the camera. The only way to eliminate this is to tighten the tension adjustment of the focuser to the point where it is impossible to adjust focus. During the two imaging runs that I've had with the scope, I adjust focus with one hand beneath the camera pushing up towards the scope while adjusting the focus knob with the other hand. Reaching focus is a time consuming and clumsy affair as you can imagine. To me, along with the base cost scope, you have to figure in the expense of replacing the focuser with something like a MoonLite or Feathertouch unit, as that's the true amount of money you'll spend to get the scope fully functional with a heavy CCD camera.

If the stock focuser were better, I would say that the scope, and its $549 price tag, represent a tremendous bang for the buck. Given that an approximate $400 focuser upgrade (MoonLite 2" CF / AT65 Flange / 2.5" Drawtube Length / Dual Rate Tri-Knob with Shaft Lock) is really needed to make the scope liveable, I'm not sure that almost $1000 total cost is such great bang for the buck.

My completed images from last Fall...

Posted Image

Posted Image

Baggghhh, now you've got me thining about the MoonLite again. I never went through with upgrading the focuser, but with Fall coming, maybe I should suck it up and shell out the cash.

#5 sullij1

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Posted 11 August 2011 - 09:23 PM

Have one, Great Scope!

Posted Image
PLEIADES M45 by Sullij1, on Flickr

Highly recommended.

#6 buckeyestargazer

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Posted 11 August 2011 - 09:33 PM

Jon,
I would echo most of AdamE's comments. This is a great little scope for the money. The original reason I bought it was because with my OAG, filter wheel, and camera the back focus requirement threw off the effectiveness of the flatteners/reducers I had, so I wanted to try this scope because of the flat field. And it does have a flat field. However, the integral flattening lens does limit the scope in terms of reducers or other flatteners. At f/6.5 it's not super fast, and any attempts I've made at reducing have been met with disaster (weird shaped stars).

AdamE mentioned that he thought the focuser was not up to the task. I have found the focuser to be pretty rock solid, and can handle my imaging train just fine. However, I have one of the original 4 units in the USA, and I know that after those first 4 they changed the focuser. So I may have a different focuser than what they come with now.

Here's my latest (and only) attempt so far with this scope:
NGC7000

#7 jmasin

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Posted 11 August 2011 - 10:12 PM

All, thanks.

I'm disappointed to hear the above experience with the focuser - looks like the optics are clearly capable. As I'll be imaging with an 8300 and FW, I'll definitely have some weight on it.

I'm looking for a way to image more... something that I can grab, put up on the mount and click "go". I just have such limited time to manage the reflectors and bigger scopes I have now... trying to fit some imaging in between when I actually have time...

Thanks for the reviews, think I'll keep thinking :)

#8 Adam E

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Posted 11 August 2011 - 10:38 PM

@Joel...

Wow, I never new the first of the AT-65s had a different focuser. Not sure how much different my focuser is, but my scope's vintage is definitely well into the production run.

I'm also really glad you threw in a comment about reducers. I have always wondered what would happen if you put a non-flattening reducer on the scope, but from your experiences, I think I can stop wondering.

@Jon...

I don't mean to be completely discouraging, because there's a lot of good to be said about the scope, especially considering that its only competition comes from Takahashi and is significantly pricier.

I just really, really don't like the stock focuser.

As an aside, there is a second-hand AT-65EDQ up for sale at the infamous "other site." The owner has a poor price, IMO, and is listing the scope with, IMO, accesories that are really not needed. Maybe a better price could be worked out. Shave a buck or two off the scope and that focuser upgrade gets essentially cheaper.

#9 jmasin

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Posted 11 August 2011 - 10:43 PM

I wonder if I could get a reasonably priced adapter to put my 3" FT (might be 3.5 i forget) on it?

It might look odd, but I wouldn't care, and I KNOW that holds the load!!

#10 buckeyestargazer

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Posted 11 August 2011 - 11:03 PM

@Joel...

Wow, I never new the first of the AT-65s had a different focuser. Not sure how much different my focuser is, but my scope's vintage is definitely well into the production run.

I'm also really glad you threw in a comment about reducers. I have always wondered what would happen if you put a non-flattening reducer on the scope, but from your experiences, I think I can stop wondering.


I bought mine used and the original owner bought his at NEAF(?) when they had the first 4 there. He wasn't aware of this focuser thing either. Don't ask me why, but at one point I had two 65EDQ's in my possession, and I noticed right away that the focusers were slightly different, so I contacted Astronomics and Michael Bieler mentioned this to me. In my opinion both focusers felt "solid" but I never actually tried the other focuser under the stars.

I'm still hopeful of finding a reducer/flattener that works with this scope. Thinking that the field was flat and I didn't need a flattener, I've tried an AP CCDT67 (just a reducer), but it's apparent that reducing this scope still means needing a flattener too. I don't know if there's anything out there right now that can do the job with this scope. But it's a pretty wide field without reduction.

Jon, I really would not hesitate to buy this scope if I were you. It's a good performer and I think you might be OK with the stock focuser, but as you say if you can put your feathertouch on it you are good to go.

#11 roryt

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Posted 12 August 2011 - 03:06 AM

I have not used it, but some friends on my local forum do, with great results. A very good example is Aggelos Kechagias (a CN member also), check his latest at http://astrocorinth.webs.com/

#12 jacquesdeacon

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Posted 12 August 2011 - 03:41 AM

@Adam,

I see you also have the Astro-Tech AT106, whats your thoughts on the refractor for imaging with the SBIG ST8300?

#13 jmasin

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Posted 12 August 2011 - 09:28 AM

@Joel,

Thanks!

Any idea what the threading is on the stock focuser? i.e. to the tube? I think putting my FT on there would be the way to go. I think I'll get some comic relief seeing the AT65 with a 3.5" focuser mounted on the AP900 :lol: Overmounted and overfocused :lol:

Like I said, I'm really looking for a solution to add a few more weekends of imaging to the year. Some widefield, especially going into the winter/large object time, would be ideal.



#14 jgw12936

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Posted 12 August 2011 - 10:00 AM

I have one and wanted to use my 2 inch FT focuser on it. I sent the original focuser to Wayne at Starlight Instruments and he is making me an adapter. Since he has the information now he may be able to make you an adapter as well.

Jim

#15 buckeyestargazer

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Posted 12 August 2011 - 10:03 AM

Sorry Jon, I have no idea what the tube threading is that mounts the focuser. I actually have a moonlite focuser on my AT8RC that I could put on the EDQ; all I would need is the correct flange from Moonlite. But I haven't found it to be necessary. I'm shooting 30min subs now with no problem, not noticing any focuser sag. I haven't checked to see if there is any tilt in the focuser yet.

Good luck! :grin:

#16 jmasin

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Posted 12 August 2011 - 10:11 AM

Thanks Jim and Joel, that helps!






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