Planetary vs DSO - What scope?

Kirkus (Kirk) · #1 15-10-2011, 06:33 AM

Hi everyone. I've been away for a while. We had some health problems in the family which not only took me away from my hobby, but also created the necessity to sell a bunch of stuff, including all of my equipment. After several years I'm happy to say the health problems have been healed (knock on wood), the finances also, and I'm planning on replacing my equipment.

I've pretty much decided on an Atlas EQ-G (EQ6) mount. My question has to do with what type of scope to purchase.

Before everything went south on us, I'd just bought a SC8. I only used it several times, mainly for planetary photography, before it had to go. So I'm considering another one, or possibly a SC9.25. Would a different type of scope be better for DSO photography? Probably something with a faster F-ratio? Would a SC with a focul reducer work well for DSOs?

Any suggestions are very much appreciated.

It's nice to be back!!

Poita (Peter) · #2 15-10-2011, 08:00 AM

The pervading wisdom seems to be that for dso that a fast refractor is the way to go. A triplet Apochromat or similar, 4 or 5".
If imaging, you could consider something like a C11 SCT with hyperstar, that turns your C11 into a short focal length f2 scope! You can then shoot some DSOs without guiding. That way you get a great planetary scope that can also do DSO without having to get long exposures. You could add an inexpensive ED80 refractor for other DSO work and visual and guiding. I'd go a C11 Edge over a 9.25 due to the hyper star capability and the coma reduction, and it is still easy to manage.

http://starizona.com/acb/hyperstar/images.aspx

Then on a budget you could add something like an ED127 refractor would be a good start, or a TSA120 takahashi if you are cashed up.

Glad to hear you are well, I went through a similar situation with NHL, I hope your health stays good and you get to enjoy plenty of clear night skies!
If you added

Gem (Grant) · #3 15-10-2011, 08:03 AM

I have enjoyed both DSO and planetary through my C9.25. It is a fine OTA.

The_bluester (Paul) · #4 15-10-2011, 07:20 PM

Seems that Hyperstar and Fastar are much the same creature. My 9.25 has the "Triffid" secondary mirror to use them.

Poita (Peter) · #5 16-10-2011, 12:43 AM

I stand corrected, there is indeed a Hyperstar for the 9.25

http://starizona.com/acb/hyperstar/ordering.aspx

Kirkus (Kirk) · #6 16-10-2011, 02:27 AM

Quote:

Originally Posted by The_bluester

Seems that Hyperstar and Fastar are much the same creature. My 9.25 has the "Triffid" secondary mirror to use them.

Quote:

Originally Posted by Poita

I stand corrected, there is indeed a Hyperstar for the 9.25

http://starizona.com/acb/hyperstar/ordering.aspx

That's just crazy! I had no idea. I only have several years experience with an entry level setup (my old one) but I thought I knew more than I do. That's actually very cool. Thanks!

::

Because I do have a budget of around $2,500(US) I've decided to put the biggest chunk of it into a mount and not the scope itself. I fought with an entry level mount before and would like to not have to do that again.

I think I've decided on a Celestron CGEM. The mount itself goes for $1,500 before tax but I can get it bundled with a Celestron 8" SCT for right around $1900. The mount bundled with a 9.25 is another $500 and that wouldn't allow me to purchase all the other stuff that's needed.

Thanks for the feedback!

Poita (Peter) · #7 22-10-2011, 02:45 PM

You may want to read some reviews of the CGEM first, but I agree, spend the bulk of your budget on a good mount.

Kirkus (Kirk) · #8 23-10-2011, 05:34 AM

Quote:

Originally Posted by Poita

You may want to read some reviews of the CGEM first, but I agree, spend the bulk of your budget on a good mount.

Thank you, Peter. Actually, over the past week, and some more research, I've settled on a CGEM rather than an Atlas EQ-G. I can get one with either an 8" or 9.25" for a much better price than buying the mount and OTA separate. The budget is going to determine which one I purchase.

Poita (Peter) · #9 23-10-2011, 10:33 AM

That pricing you are getting is pretty sweet, I'd probably save a few more dollars and get the 9.25, apart from the better aperture, their resale value is way better than the C8 and will work better with Hyperstar if you go that route in the future.

Kirkus (Kirk) · #10 03-11-2011, 07:36 AM

I really appreciate the advice and comments.

It looks like the CGEM is going to be my mount. As far as the OTA goes, it looks like the budget is going to be a little larger than I originally thought

. So I'm looking at either a regular Celestron 9.25" SCT or an 8" SCT Celestron HD Astropgraph.

Does anyone have an opinion on the trade off between the regular 9.25" SCT and the 8" Astrograph?

Is the difference in photography between the two worth the smaller size. I don't know very much about "astrographs".

Poita (Peter) · #11 03-11-2011, 08:39 AM

The 8" will have a flatter field, you get pinpoint stars that are effectively coma free right out to the edge.

I'd go either the 8" EdgeHD or the standard C11.
The 9.25 has a good reputation, but in reality is just a little flatter than the standard C8 or C11, it isn't anywhere near as good as the EdgeHD series in this regard.

Depending on your seeing, the C8HD will be great for planetary, though with hyper star you would need a slim barrel camera like the QHY8Pro or your obstruction size starts to get too large.

I'd personally save the extra money and get the EdgeHD9.25 or EdgeHD 11" scope, but the 8" can do wonderful photography, like this:
http://www.flickr.com/photos/jasmel9...in/photostream

Kirkus (Kirk) · #12 03-11-2011, 11:44 AM

Thank you, Peter.

That photo really surprised me... coming from an 8.

These kinds of decisions are really difficult to make. I have a few months to think about it, read about the different choices, pick the brains of you guys here, etc. I just hope I make the right decision. Thanks again for the help.

Poita (Peter) · #13 03-11-2011, 11:55 AM

There is no wrong decision in this case, they will all do what you want, BTW, what is the price difference between the C8 HD, the standard 9.25 and the 9.25 EDGE HD?

Kirkus (Kirk) · #14 03-11-2011, 01:05 PM

These are all US dollars and are on the CGEM.

C8 = $2200
C8HD = $2500
C925 = $2800
C925HD = $3500

This is from OptCorp here in the states. If their prices aren't beat a lot by another store, I'll buy from them because they're real close to where I live and I can get 2-day shipping for next to nothing.

Poita (Peter) · #15 03-11-2011, 02:04 PM

I'd get the C11 edgehd for $3999 if the budget stretches that far, but have a look 2nd hand

http://www.astromart.com/classifieds...fied_id=752835

http://www.astromart.com/classifieds...fied_id=752771

http://www.astromart.com/classifieds...fied_id=752651

http://www.astromart.com/classifieds...fied_id=752646

Kirkus (Kirk) · #16 04-11-2011, 03:23 AM

I always forget about used. Probably to my detriment. Thanks, Peter!

Poita (Peter) · #17 04-11-2011, 03:54 AM

You could probably get a used C11 or C9.25 Edge HD for the same price as the new C8 EdgeHD.

Kirkus (Kirk) · #18 04-11-2011, 04:10 AM

I know I'm full of questions. I hope it doesn't get to be too much.

I'm curious about Hyperstar. I'm wondering if a DSLR camera attached to the front of an 8" or 9.25" SCT would block that end of the telescope too much? If I use Hyperstar am I looking at buying a smaller CCD camera also?

I've seen DSLRs attached using Hyperstar, but the scopes look more like 14" or 16".

Poita (Peter) · #19 04-11-2011, 04:49 AM

Your best bet would be something like the QHYPro or any other barrel shaped CCD. You can hook up SLRs, not sure if that begins with the C11 though - but email the guys at starizona and they will give you your options, they are extremely helpful.