Posts Made By: Larry Janowicz

Absolutely TAL
Larry

Nathan,
Unless your scope is an exception it should perform very well. I am assuming that your optical train has no weak links ( decent diagonal and eyepieces). Don't get frustrated over the inability to use higher magnification all the time. Seeing is really important. I have been observing Mars with a 5" SCT and a 90mm achromat over the past several weeks from my home. There were only three nights in this period where I was able to see the detail that I knew both scopes could reveal.
I have used 76 mm and 80mm achros on Mars in the past and, when the atmosphere permitted, the views were great and higher magnification ( about 180x) was used to used to full effect.
I've viewed through a few Meade achros and have no reason to expect you will not get the same results
Larry

Check:
http://home.europa.com/~telscope/hensoldt.txt

Larry

I can get 624x out of my 60mm refractor. Says so on right on the box...
On good steady nights I would use 300x on a 6" dob I made. The motions were very smooth and the balance was perfect. I suspect I could have gone higher but tracking by hand became more of a challenge after that point.
Larry

Can the magic word "Questar" extend this thread?
Larry

It seems you stumbled on a rarer item.
Although 3" and 4" were sold it seems that Brandon had also made at least one 6":

http://bellsouthpwp.net/g/m/gmb1329/USS.html

"(Chester Brandon's one-of-a-kind telescope has earned a reputation as being both a semi-apochromat and a flat-field refractor. The Brandon refractor, with its inherent advantage in imagery, contrast and definition, is one of the most remarkable instruments, of its size and kind, currently in operation.)

With achromats, the characteristic color shift, makes the interpretation of color less accurate, but it may also have a desirable affect on contrast. Whatever the exact reason, the attributes of an f/15 achromat can be starkly beneficial on some objects, especially on Jupiter, and the Brandon refractor seems remarkable in this regard. It may be that the "master lens maker" designed his refractor with Jupiter in mind: The Great Red Spot appears almost ruby red at its core, and is engulfed by luminous aquamarine gas clouds. The surrounding multicolored bands of hydrogen, ammonia and methane stand out in almost three-dimensional relief."

Why not check out this site and send an e-mail. Brandon was linked to this group and I'll bet someone there could answer a few questions.
BTW-D&G did the restoration work on the Brandon 6". It's a decent bet that someinformation might be available from Barry Greiner.

Larry

The white 90mm maksutov was the 97E model. It was on the market for several years.
Larry

David,
Can you be more specific?
Are you tightening one and loosening the others?

I'm old enough to need bifocals and also have some astigmatism in one eye. Is it a problem? Yes, a little. But not one that has bothered me enough to attempt specific solutions. The only thing I have ever done about the issue is to refuse to wear plastic lenses. They scratch.Period. Amen.

At lower powers I use longer eye relief oculars and at higher magnifications with smaller exit pupils I simply take the glasses off. It is nice to have a loop holder to let them dangle around the neck.
Larry

Good Luck!
After you get the main mirror settled comfortably in the cell start your collimation process by getting the secondary in place. Google search on collimation and you'll get tons of decent hits.
As for the focuser you are stuck. The focal length of the main mirror is the focal length of the main mirror is the focal length.... blah blah. It ain't gonna change. Unfortunately that barlow is necessary if the focuser is going to stay where it is or the main mirror is going to stay where it is.
Post back so we can all see what new words you might have learned after you roll up your sleeves and get to work. I think you'll wish more people would ask for advice or assistance before the purchase.
OH.... before you start anything make sure that the scope actually needs a total collimation effort. If it's just a main mirror adjustment there is no need to bite off more than needs to be chewed.
Larry