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#1 Rollcrusher

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Posted 23 November 2012 - 07:24 PM

Having never owned a refractor and making a new scope purchase soon, I have to ask about this scope.

I realize I can get a whole lot more aperture with a cass or dob at this price point but I am curious as to what this scopes main purpose is for. AP or visual? Also, what would this scopes limit be for DSO viewing. I assume it would be good on moon and planets. I question the viewing because a diagonal is not included. Is a diagonal necessary to use this scope? I am using binocs on a camera tripod so a diagonal is not necessary for me.

How would this scope perform as a grab and go setup?

#2 dlapoint

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Posted 23 November 2012 - 11:23 PM

As I understand it this scope is the same as the eon I used to own. They are very good all around scopes. I found this scope really showed it;s stuff when it came to low power dso viewing.

#3 Binojunky

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Posted 24 November 2012 - 11:37 AM

A fine scope, a jack of all trades, master of non,smallish aperture limits its deep sky uses on a visual level however it will give pleasing views of a lot of things, very grab and go and you will need a diagonal, get a dielectric version , DA.

#4 Ed D

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Posted 24 November 2012 - 09:19 PM

It's a great little scope whose strength is wide field and low power viewing, although it's a decent performer for mid power lunar and planetary. With a 72mm aperture the scope is no light bucket, but the views are surprisingly bright for the size. Open clusters, bright nebulae and double stars are gorgeous through this little gem. Although I have observed faint fuzzies in dark skies with it, such as M33 and globs, it's lack-luster compared to my Dob, which is understandable. A dielectric diagonal does show more, very subtle but noticeable.

It's a very robust scope that is built like a tank. It's also not exactly light weight for a 72mm f/6. However, it is very grab-and-go. I usually put mine on my mount and tripod inside the house, select a couple of eyepieces and take the whole thing out in one trip, plus another trip for my observing chair.

As much as I love my little scope I would not recommend it as a first scope, nor would I recommend it as the sole scope to own unless one has plenty of experience with scopes and realizes what this scope can and cannot do. It is more of a specialized scope that makes a great compliment to my bigger Dob.

BTW, I'm not into AP so I can't comment on that part. I have read positive posts about using the AT72ED for AP.

Ed D

#5 Rollcrusher

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Posted 25 November 2012 - 01:15 AM

Thanks guys.

I have a thread in the cass section on a C6. Been considering another dob in this price range as well. Really just trying to consider all options before I purchase.

I do have to say though, since using the binoc setup I really have been looking at a refractor.

Seems like the Orion short tube 80mm package is the best bang for the buck but there is just something about these AT72 scopes.

#6 aezoss

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Posted 25 November 2012 - 02:38 AM

Under dark skies the AT72ED is a lot of fun and presents amazing wide field views with Hyperion 31, 24 & 13mm EPs. M81/82, M31/32/101 and the Double Cluster were particularly memorable this summer. Cruising Sgr up to Sge and Oph was a blast. I'm sure it would do even better with higher end EPs.

We usually leave it set up on an AT Voyager in a living room corner for grab and go. I can throw it outside on the deck for the kids in 5 min.

The moon is incredibly sharp with only a bit of easily ignored CA at higher powers. Gorgeous view.

Planets are sharp but obviously small at 107x (8mm+2x barlow), the highest mag I've tried. Good for checking out Jupiter's moon configuration & easily discerned features but you're probably better off with a larger scope for serious planetary work.

In my experience the AT72ED doesn't fare too well in badly light polluted areas (I say this about every scope though so YMMV). If you're in the city the small aperture just doesn't pull in enough light. Although it could just be my lousy eyes, M36/37/38, when Aur is E/SE, suck looking across the city light dome. Hopefully the 72 will do better when Aur is W come March (9x63 binocular does well, the AT should too). M45, the Hyades, M42 and Orion in general are awesome no matter where you observe them.

I do find that the field curvature is noticeable with longer focal length Hyperion EPs. I also suspect the large exit pupil might be exposing defects in my eyes that go unnoticed with my Mak. Neither of these may apply to you but it may be something to check if you're sensitive to them.

A 2" diagonal is required. A 1.25" diagnonal doesn't provide a long enough light path for some EPs to come into focus (partially inserting the EP works around this). The CNC-machined aluminum red dot finder is an excellent accessory. The RDF is well constructed and stays aligned with the OTA. Makes picking out visible targets a breeze.

The AT72ED is a good second/third scope and a great first refractor if you're into low power wide field viewing. It's rugged and reasonably priced. Coupled with a good camera tripod or AZ mount this scope can be taken anywhere without taking up too much space.

Oh, and it comes in pink, what more could you ask for?

Lee

#7 Mr Onions

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Posted 25 November 2012 - 04:40 AM

I have the WOZS66 which is obviously smaller at 66mm than the AT72,I imagine optics are very similiar,the WO is a f/5.9 doublet.
I love using mine,it's a great little Lunar scope and can take 130x on moon no trouble.
I think it's best on Jupiter at about 80x.
It's a great little low power sweeper but I use Televue eyepieces and they are tested at F/4 so you might want to check how other low power eyepieces perform in a fast scope.
If you decide to buy the AT72 you will have the perfect "Astronomy outreach" scope, for letting the public look through.
As a first refractor this would be a great choice.

#8 Binojunky

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Posted 25 November 2012 - 07:58 AM

Its also a great scope for daytime use as well, though not an ideal birding scope, if like me you tend to be a nosey person with great views from your windows, local parks etc its a nice performer, regarding night time use I,ve had mine up in the x170 range with still an exceptable image.
Optics and mechanics wise its streets ahead of the Orion ST80 however at a greater cost,DA.

#9 Rollcrusher

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Posted 28 November 2012 - 09:38 PM

Really considering this scope now (not the pink one though). Maybe get this first and piggyback it to the C6 if and when the time comes.

Any particular brand over the other as far as 2" dielectric diagonals go?

Will be buying one eyepiece at a time, so which focal length first for this scope? I do wear glasses and have astigmatism.

#10 GOLGO13

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Posted 28 November 2012 - 10:02 PM

With glasses for astigmatism (make sure you wear them). You want to get eyepieces with 20mmish of eye relief.

If you ask in the eyepiece forum and give your budget you'll get a whole bunch of options.

A few standouts from what I see are:

High end: Televue Delos, Pentax XW (10mm 7mm, 5mm)
Mid range: Baader Planetarium Hyperions
Low end: Edmunds RKE 28mm (love it so far)...not sure of others with really good eye relief.

#11 Rollcrusher

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Posted 28 November 2012 - 10:11 PM

Thanks. Do like the looks of the Edmunds.

#12 pambas

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Posted 29 November 2012 - 02:09 PM

As much as I love my little scope I would not recommend it as a first scope, nor would I recommend it as the sole scope to own unless one has plenty of experience with scopes and realizes what this scope can and cannot do. It is more of a specialized scope that makes a great compliment to my bigger Dob.


As I had just ordered this as my first scope, this is quite disappointing to read :(

Hope I made the right decision

#13 Chuckles34

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Posted 29 November 2012 - 03:04 PM

Don't worry, the AT72ED is a great little scope!!

I own one and a SkyWatcher 100ED. I've compared the two on a couple occasions from my backyard orange zone, and I was surprised how well the AT72 preformed. Yeah, the SW100 allows for a little more magnification before the image begins to dim and I could pick out a little more detail on Jupiter, but the AT72 wasn't that far behind.

The AT72 is a nice compact scope with minimum mount requirements, quick cooldown and often beats the average seeing conditions at my house. It works nicely for lunar, double stars, open star clusters, light planetary and some of the brighter DSOs.

My favorite eyepieces to use with it are 5mm, 8mm and 12mm AstroTech Paradigms and a Televue 2x barlow for (35x, 54x, 72x, 86x and 107x). I've tried a 3mm Zhummel Planetary for 143x, but the image starts to dim considerably on everything except the moon. I use ES24mm 68 degree for widefield views with nice results.

-Chuck

#14 galexand

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Posted 29 November 2012 - 08:07 PM

Oh that's a good point, Chuck. I am vaguely considering something in the 3" range, and was considering 72mm vs. waiting for at AT80ED to show up used. It's rare my skies really support magnifications over 75x (the airey disc dances!) so probably I wouldn't be missing too much if I "settled" for the 72mm. I always have the 6in dob for those really still nights.

[edited for typo]

#15 pambas

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Posted 29 November 2012 - 08:19 PM

Thanks for the eyepiece suggestions Chuck! I'll keep that in mind next time I go shopping

#16 galexand

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Posted 29 November 2012 - 10:18 PM

A follow-up to my own post...I got to thinking that maybe ability to handle magnification wasn't really the operative effect here, and that limiting magnitude at lower magnifications might be severely affected by aperture.

So I played with the limiting magnitude calculator over at http://www.cruxis.co...ngmagnitude.htm

When I played with its settings for my 150mm reflector, it pretty well matched my expectations. Notably, naked eye limiting mag (roughly transparency), and magnification power are the dominant effect. So I think it's roughly right.

It says that a 72mm reflector, for example gets 10.5 magnitude at 30x, compared to 10.9 for my newt. Which just doesn't seem like a big deal to me when the difference between the pristine drought of summer and the fog of late autumn is at least 2 magnitudes.

Assuming it's correct, I think I'm sold on the 72mm. :) On most nights (with poor transparency, poor seeing, light pollution, sometimes just sucker holes in the clouds), its convenient setup and cool-down should beat my newt handily. It'll be a great complement.

#17 Rollcrusher

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Posted 29 November 2012 - 11:57 PM

Thanks for the suggestions.

Tomorrow is the day. Unfortunately I will not be able to order everything at once.

Looks like the scope first then the diagonal and eyepiece next week.

Will see how this works out - hopefully a big improvement over the binoculars.

Thanks again.

Almost forgot, do I need to be looking for 2" eyepieces or the 1.25"? 2" diagonal or 1.25"?

#18 Chuckles34

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Posted 30 November 2012 - 06:52 AM

Give yourself flexibility and get a 2" diagonal. AstroTech 2" 99% reflectivity dielectric diagonal got good reviews and runs about $120. They were out of stock when I bought my scope, so I got a GSO model with same specs for $99 from Agena Astro. It works great!

I'm happy using 1.25" eyepieces. They typically weigh less which helps with balancing and a 24mm 68 degree eyepiece is as wide as I like to go with the AT72 or field curvature starts to bother me.

Some folks just use a wide field eyepiece as their finder scope, others a red dot finder, but I find a small right angle upright image finder scope to be the most usable. Orion sells a 6x30 for $59 that I use on both of my refractors. YMMV.

-Chuck

#19 GooglyEyes

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Posted 30 November 2012 - 01:56 PM

It also makes a great white-light solar scope with the addition of a Herschel wedge. I've been using mine, with a Lunt Solar Wedge.

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