Posts Made By: Jeff Blazey

Another view

Floyd:

It's a beaut! You'll really like the G-11.

Jeff

Roland:

If you see this and can pry yourself away from the raging 4" ED debate can you elaborate a bit on the design & performance aspects of these scopes? They seem to occupy a rather unique place in your product history.

I had one of them at a public star outing outside of Cincinnati last weekend. There were a couple of dozen scopes out and the APO went un-noticed for a while. I had the Denk II's (with power switch) in with my trusty 25-year-old 26 MM Celestron "silver-top" Plossls. Seeing was actually quite steady. First up Jupiter. Very nice at mid-power with belts & festoons easily visible. About a half dozen people stopped by and their reactions were all one of two types: First a looong pause at the eyepieces followed by a closer inspection of the instrument which was followed by a direct comment to me like "That's an exceptional view! What scope is it?" Or an immediate exclamation of "Wow", or something like that, followed by basically the same questions. The same was true for M-13, the double-double (in particular!), the double cluster, M15, M27 or whatever, I had the scope pointed to. I also noticed that a hand full of people kept returning for a look. One guy named Scott in particular seemed to be really enjoying the scope. He had a 12", F6 I believe, Dob there with an exceptional optical train made by a local optician that was giving up a very nice star test. We both remarked on how little difference there appeared on M15 at the same power per inch of aperture. The bigger Dob did indeed resolve more stars but the overall visual impacts were very similar. My own comparisons with other scopes showed the 152 F9 to be very high on the visual "punch" meter....but I am just a bit biased.

I thought you might appreciate a bit of feedback on a 15 year old product of yours that's still in very active use.

Jeff

If you choose a standard 7" O.D. aluminum tube Barry at D&G has both tubes and endcaps that will take your AP focuser assuming it's an early 90's vintage or younger. Then you just need to have the inner cell made.

With regards to baffling, well take you pick. Some people let the focuser tube openning set the stop, others control it with the baffleing. If you control it with the baffling then only one stop is necessary to set the fully illuminated field at the focal plane. Whichever way you go, the primary duties of baffling is to first allow the full apeture of the objective to be used, second : eliminate stray light and third control the size of the fully illuminate field at the focal plane.

Personnally I use extensive baffling. It's not hard to make and you can even use good poster board if you want to.

I also find that heavily baffling the first few inches of the tube is very important for effective control of stray light. I've built several OTAs around the 6" F10 Jaegers lens using 7" O.D. tubing. I use 7 Baffles with the first 5 baffles spaced 3/4" apart. These 5 are all the same size, being 6" I.D. with an O.D slightly smaller then the I.D. of the tube. The seventh is approximately 2/3'ds down the tube and is sized to give me ~1-1.5" of fully illuminated field at the focal plane, depending on what the focuser of choice will pass and what size hole mandrels I have. The sixth one is located between the 5th & 7th and sized the same as the 7th one. All of the baffles are spaced and glued on to 3-4 stringers. I then paint them flat black AND wrap the whole assembly with black flocking paper. Finally I slide the whole thing into the tube so that the first 6" I.D baffle rest up againt the back face of the lens cell. I get jet black interiors with NO stray light, even from strong of axis sources like street lights or the moon. It really makes a difference for daylight viewing.

If you use binoviewers, you also have the advantage of designing the tube assembly with enough in-focus ability so that you don't need an OCS type of system.

Hope this helps.

Jeff

Let's get down to basics.

How much do you want to spend? 8)

What's the max length you're willing to lug around? 8O

Jeff

Simple: Mak-Newt. Specifically an MN55 or MN66.

Compact, small central obstruction (20-24%), large & highly corrected field, 30-40mm eyepiece friendly, barlows well for high power use and best for last...affordable. 8)

Next question?

Jeff

Yeah! Nice chair you got there Markus!!

Jeff

This is a good thread, very useful.

I HATE giving anything less than a 5 star rating. I just don't like to be negative but I can see that there needs to be honest feedback to help police the classifieds and set standards.

I'm also hesitant to give less than a 5 star rating because, being fairly new to the community, there appears to be a lack of "standards" and I don't want to be unfair. For example, I've had a few transactions where payment had been sent (usually via Paypal), no word had been received that it arrived, and I had to prod the seller after a week or so about shipping. After the prod shipping was usually quick. Is that a 4 star transaction?

Another reason I'm hesitant to give less than a 5 star rating is that I'm very protective of my rating and I fear retaliation via a bad rating for me. I've seen this many times here. Is there a procedure here where a rating like this can be removed?

Jeff

Bill:

I'm a refractoraholic myself and I really don't want to be cured. However, sometimes I do drink from a top shelf Mak-Newt or Mak-Cass. Specifically, I can recommend the TEC & Intes labels. I've had lovely drams from the TEC8 (F15.5) and Intes M715 single malt Mak-Cas's. But I also regularly partake in shots from my MN86 as well. Both vintages are highly recommended. Just remember though, it's ok to drink to excess with these critters as you'll never had a headache afterwards.

Jeff

Why Hillary of course!