Which Astrograph?

I have been looking at two scopes for imaging as a longer f/l to compliment my NP101.
The NP101 works great for wide field images, but I would like to have something that imaged at a higher res, image scale, and larger aperture to make that work better.
Looking at two alternatives;

1) 7.1" Mak/Cass f/6 which has high quality optics and designed as an Astrograph. This would give a flat, well corrected field, with a 1.4" image scale and 1080mm f/l. Well built unit with a fine ring set that would accept a guide scope and dove tail plate and a good finder scope. Cost $3250

2) 8" RC f/8 with optics that are Guan Sheng and certainly not as good as the Mak/Cass from what can be seen in optical tests done by Wolfgang.
Flat well corrected field with .95" image scale and 1600mm f/l. Comes with a Dovetail Plate but no rings for the guide scope or any method for attachment of one. But could probably come up with a solution. Has no finder, but a finder shoe is included. Two speed focuser, Crayford style, typical Chinese type. Cost $1400

Each of these scopes has its pluses and minuses and of course a huge cost difference. But, the real questions I have are,
1) Which would be the better Astrograph and produce the better images?
2) Would the larger aperture make up for the slower focal ratio and lessor optics?
3) Or would the smaller aperture with faster focal ratio and better optics prevail?

I would like your opinions on these and any other information you would like to add would also be appreciated.

Floyd,

Do you mean Mak-Newt? If not, then why not get a longer Cass for a larger image scale. By the way, neither of these scopes has a flat field, but they likely have enough depth of focus to be considered flat for a small chip size.

I've not used either model, but I would give much
weight to your mention of "Well built unit...."
You want something that is solid and will hold
focus and collimation well. That one also appears
to accept "T2" plumbing on the back end, which
will eliminate some focal plane tilt / shift
headaches sometimes associated with standard 2"
plumbing.

Hi Thomas,
Good information, thanks!

Indeed, lots of choices and each with its own pluses and minuses.

The LS200R, I just don't know, cool down is a big issue with these scopes. I have had some experience with them too. This is true with any enclosed scope I guess, but friends with 10-12" Meade scopes seem to have a big cool down issue.

I did think about the mirror shift, which is not suppose to be a problem. Also about the corrector plate dew, I certainly have experience with that with SCTs.

The big Newts are very large, heavy and long and would make things a bit complex. I prefer a shorter more compact scope.

I will look into the other recommendations, never know if you don't look!

Floyd,

Why not just buy a cheap Meade SN-8 OTA for now and be done with it? You can always start taking photos and get experience that leads you toward your dream scope....without bankrupting yourself. Yes, the focuser is crap and so is the finder scope, but those are fixed rather cheaply. The JMI NGF55 Crayford focuser is made just for that scope, and it works very well. Mine handles lots of weight with no problem. The scope rings are ready to mount a guide scope.

The SN-8 is no deadbeat when it comes to deep sky viewing, either. On a warm midsummer night when the seeing was exceptional, I saw the central star in the Ring Nebula. That was before I even knew there was a central star in the Ring Nebula, as I was a newbie to astronomy.

The collimation is pretty lousy from the factory, and you are going to have to properly align it and buy a heater strap and a dew shield and replace some crappy weak bolts. My brother said that the brightness of my SN-8 was as good as his Orion 10" Newtonian.

The f/4 speed of the SN-8 will do you a lot better than the f/6 and f/8 speeds of the scopes you are considering. f/4 gives you an exposure time less than 1/2 what an f/6 scope does, and f/4 is 4 times faster than f/8.

The Baader MPCC is very economical and will get rid of any residual coma of the f/4 mirror in the SN-8. There are online users of the SN-8 + Baader MPCC with photos posted to prove the point. Good is good, even if it doesn't cost much. Weasner has a good tutorial on his website for collimating the SN-8. I did mine a bit differently, but his way is certainly very good. The SN-8 (and also the SN-6 and SN-10) is very popular and there will be lots of information and accessories in the future to wring every lasy bit of performance out of it. The OTA is cheap enough that you can afford to tweak it without risking serious financial loss if you screw up now and then.

It's about as compact a Newtonian as you will ever see as well. JMI also makes a special case for the SN-8 and SN-10 OTA's. I have one and it makes transport very easy. Also buy the JMI NGF55 or FeatherTouch focuser and you are in business. Cost will be somewhere in the $1000 range, + or - depending if you buy new or used.

Phil