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Posts Made By: Jeff Blazey

February 20, 2008 05:36 AM Forum: Equipment Talk

What size secondary mirror for 6" Reflector with 2" EP??

Posted By Jeff Blazey

Steve:

As diagonals and holders are relatively cheap, get two or three very high quality ones. I suggest a 1.25" or 1.33" minor axis and a 1.00" and just try them out. That's roughly 21-22% and 16% respectively central obstruction by diameter. The 1.00" diameter diagonal can give great, high contrast high power results and I've found that light drop off at the edge is gradual and the eye is not that sensitive to it. But if you truly insist on a big fully illuminated field, also try a 1.5".

"We learn by doing and learn best by screwing up in the process. Well, I've learned a lot. "

March 13, 2008 07:14 AM Forum: Refractors

overcorrection worse than undercorrection?

Posted By Jeff Blazey

My eperience is that it depends on the degree. A mild over correction (1/5th wave or better) is hard to detect but may actually be usefull for a portable instrument as the lens will typically appear undercorrected during cool down, resulting in a more useful image quicker. Also, the eyepiece used can offer a degree of over/undr correction so you need to be careful in your assesment of the lens by star test by using different eyepieces.

As usual, nothing is easy.

Why do you ask?

Jeff

March 25, 2008 04:30 AM Forum: Refractors

Vixen NA140 Neo Achromat

Posted By Jeff Blazey

Yes, if properly done:

http://alice.as.arizona.edu/%7Erogerc/chapters/Chapter%205.html

Jeff

March 26, 2008 05:57 AM Forum: Pictures of Me and My Telescope and........

Dream Setup

Posted By Jeff Blazey

Wow! Spooky real.

April 3, 2008 07:31 AM Forum: Equipment Talk

TEC 6 Vs Mewlon 180 Vs FS-102

Posted By Jeff Blazey

Benjamin:

I own a TEC 6 as one of my "travel" scopes. It's an amazing instrument weighing only 9 pounds bare naked, robust construction, has never needed collimation, has exceptional optics and cools quickly...for a Mak..in about an hour if you leave the fan running and the visual back open to promote air circulation. I highly recommend it. They run $1800-2400 used depending on condition & accessories.

The other Travel-Mak is an IM-500. It weighs even less (7 pounds)and the one I had sported excellent optics. Used is around $450-600 again depending on condition and other stuff offered with it. I consider this scope a bargin, even at list price.

Jeff

April 3, 2008 07:44 PM Forum: Equipment Talk

Would you rather have a bigger SN or a smaller MN?

Posted By Jeff Blazey

William:

How about a tough question next time?

Easy, the MN86 and if your back can't take that beast the MN76 is a particularly compelling package in my view, even at list price.

Jeff

April 3, 2008 07:47 PM Forum: Refractors

April 4, 2008 05:55 PM Forum: Refractors

william optics annouces new 150mm and 158 mm ed sc

Posted By Jeff Blazey

I repeat myself. How much?

Jeff

April 6, 2008 08:53 AM Forum: APM

Maybe a new 6" ED below $ 5,000 from APM ??

Posted By Jeff Blazey

Markus:

Thanks for the update,new products and your honesty.

So what's the possibility of 200 to 250 MM F12-15 ED doublets for us who have larger refractors in a permanent installation?

Jeff


April 15, 2008 06:11 AM Forum: Equipment Talk

Digital Setting Circles Vs GOTO, Pros-Cons?

Posted By Jeff Blazey

Thank you all so much for the advice. What I think I'll do is add DSC to the GM-8 and GOTO to the GM-11.

Thanks again.

Jeff