Shorter focal length refractor recommendations?

[astolpho]

Hey guys!

So I'm sort of new to the astrophotography field even though I've been around astronomy for over a decade.

I didn't know it had so much to go into it and I've learned an immense amount of things these past few months I've been reading about it.

So here's my question for you guys:

I currently own a Celestron EdgeHD 8" with the Advanced VX Mount. I also have an Orion ShortTube 80 along with the Orion SSAG. My imaging camera is a unmodified Canon T5i /700D.

I've been so busy lately that I have only been able to take the scope out twice the past 3 months and haven't had a chance to do some imaging.

While laying in bed to go to sleep I keep on reading about how the scope is tough to image at 2032 at f/10, but I also have the .7x focal reducer to help me a bit going to 1432mm.

From what I've read and seen around, these focal lengths are more for smaller objects but not so much larger nebulas.

I'm thinking of getting another scope, a refractor at a shorter focal length to sort of cover most objects in the sky and I'm looking for suggestions.

I'm not looking for something too pricey since I've spent so much on the Edge setup already but something that will give me some decent pictures.

I looked at a few Orion and Astro-Tech scopes at lower than US$500.00 and they looked pretty good. The Orion ED80 for that price is probably the most I want to spend but I also want to be able to use my same advanced VX mount of course.

Also, what other equipment would I need to ensure I get good shots? I know on the Edge once properly polar aligned and after setting up guiding with either my 9x50 scope or ST80 I can guide fairly well but how does guiding work on these smaller scopes? Is it even needed? And what kind of adapters would I need to attach it to the VX mount? Dovetail, rings..? Since I have the ST80, could I use the same dovetail and rings that I use to piggyback on the EdgeHD standalone on the mount?

And last, how would I connect my Canon T5i/700 to it for prime focus photography?

Sorry for so many questions! But thank you in advance!!

[nicoscy]

You set the budget at $500, but for $3.99 more you can get the Explore Scientific 80mm F6 Essential Series Triplet. 

You will have a lower focal ratio (f6 Vs f7.5 for the Orion ED) and better color correction.

However your budget should also include a field flattener, mounting rings, a solid dovetail and a second dovetail on top with a clamp.

This will allow for a flat field in your photos, rigidity when mounting your scope and a mounting platform for your guidescope which yes, you will need for good guiding.

To connect your Canon I suggest this thingie.  You could also get a basic T-Ring adapter from Amazon.

[astolpho]

Nicosy,

Thanks for the answer!

I was also looking at Orion's ED80T which seems to be similar to the Explore Scientific but I'll take your word on it!

I believe I can use my Celestron T-Adapter (it splits in 2 pieces, one for when using the .7x focal reducer on the Edge) and it looks very similar to that one you pointed out.

Is back focus an issue on these refractors? I guess close to about 1000 is what I'll have to spend, so if I do get the Explore Scientific, a field flattener I see it goes for a bit over 100, and the rings plus the dovetail on top..

Is it smart to guide with the ST80 on these 80 refractors? Being they're the same size and all, for weight purposes.. Or is there a guiding scope recommended for them? Maybe I could use the Celestron 9x50 findescope that I have added a t-thread adapter so I could use the SSAG on the Edge with the focal reducer but I wonder how would I mount it top the top of the refractor..

Thanks again!!

[astolpho]

Nicoscy,

The link you posted for the Explorer Scientific is leading me to the Orion but I believe this is the one you are talking about:

http://www.highpointscientific.com/explore-scientific-80-mm-essential-ed-triplet-refractor-ota-with-accessories-es-ed0806-01

Seems like a very solid choice and it is faster at f/6.

I see it comes with a Vixen style dovetail but a small one that while it should go just fine in my VX Mount I won't have be able to attach any rings so I'm assuming I'd replace that with a longer dovetail with rings that have mounting on top of them for the guide scope. Any recommendations on that?

I also found explorer scientific field flattener here which should be the one to use:

http://www.highpointscientific.com/explore-scientific-field-flattener-lens-ed-apos-ffedapo-00

The focused size is also set at 2", and I have quite a few 1.25" eyepieces for my EdgeHD; is there an adapter or diagonal to convert it? I won't be doing much visual work, mostly AP but just in case I want to view for a night..

Thanks again!!

[astolpho]

So after chatting with Jonathan from Explore Scientific for a good 2 hours I got some info and I wanted to share with you guys if you think it's good enough.

So instead of rings around the scope, it already comes with a vixen style dovetail. It also has a Synta/Orion shoe on top from what I see and I found this page:

http://scopestuff.com/ss_fring.htm

With the FROR or FRS8 brackets I could use my Celestron 9x50 findescope that I can attach my orion SSAG to with the adapter I bought and I should be home free?

Adding the field flattener for about 160, I'd just need to get that bracket and I don't need to get anything from what I can see since I already have the T adapter for my Canon.

Any input is appreciated! Thank you!!

[astolpho]

So adding to this predicament I'm in.. Since I already have the edge OTA, instead of getting a separate refractor, wouldn't I benefit from investing in a HyperStar setup?

It does bring me down to f/2 at mid 400's, fairly wide and at f/2.. What do you guys think?