Posts Made By: Doug Scobel

How about charts and a Telrad? GOTO by Armstrong. You did say cheap after all!

Doug

Congratulations, Marcin! You have every right to be proud of your accomplishment. You've joined something of an exclusive club, there aren't that many people that make their own optics any more. Every time you look through your scope you'll get that same warm, fuzzy feeling. Way to go!

Be sure to post pictures when you get it all finished, not that any home made telescope is ever truly finished - there's always something to change!

Doug

Mitch, as you can see there is a lot of support for either orientation. It's easy enough to flip the fan around, so I plan to try both ways in my next scope (6" f/4.5 RFT Newt) to see what works best. I'll probably mount it using Velcro to make flipping it easy.

I'll post pics and results when I get it done.

Doug

This is just a follow-up. I tried some, and yuk! Doesn't wet, and it's even messier than red rouge. It's awful stuff to work with - I threw it out.

ZiO is much better, slower than CeO and works very nicely, doesn't stain, etc.

Doug

I'm 51. You can read all about me in my profile (I think that's why it's there )

Doug

After scrounging around the house to see what I had on hand, I decided to do a side-by-side test. The four samples, running top to bottom, are:

- Testor's (for plastic models)
- Rust-Oleum
- Krylon Short-Cuts
- Krylon Ultra Flat black (sprayed into a small container and brushed on)

The bottom sample is black flocking (from McMaster-Carr) for a really black reference.

To the right of the vertical bar at the left side of the photo is a shot taken more or less straight-on, which indicates the overall darkness of the paint. This indicates how black it is.

To the left of the vertical bar at the left side of the photo is a shot (rotated and mirrored to line up with the first image) taken at a grazing angle, with the light source beyond it. This indicates how flat (non-reflective) it is, particularly at grazing angles.

The results? Krylon Ultra Flat Black, with the Testor's a surprising close second. The Rust-Oleum and Krylon Short-Cuts don't come close. Of course the black flocking is way better than paint, but for touch-up work either the Testor's or Krylon Ultra-Flat should work well.

Best,
Doug

Well, yesterday I sent an email to where I purchased it to tell them my experience with it and to ask if any bad ones had gotten out. They didn't say one way or the other but they voluntarily decided to send me a new one no questions asked. It's on its way as I type. Which tells me the answer was yes. Hopefully I just got a bad one - sounds like everyone else's experience with them is quite good.

I'll keep y'all posted.

Doug

Well, my replacement 3.2mm BO/TMB eyepiece arrived yesterday, and a miracle occurred - it was clear last night! I set up my 13.1" and 6" Newts (both f/4.5) on my driveway to do some serious testing.

I first spent a lot of time on both scopes getting the collimation as good as I could get it. Which was good because it gave both of them ample time to cool down. Steadiness was pretty good - I would say about 7/10.

Essentially, I got the same results with the replacement as I did with the first one. Very noticeable coma (I mis-classified it as astigmatism in my first post) in the outer half of the field. Saturn showed an annoying flare away from the center of the field when the planet was positioned from about halfway from the center and getting worse to the edge. Detail in the planet and rings suffered too. Stars exhibited coma, again first becoming objectionable about halfway to the edge. No amount of refocusing would help.

I compared it against a 5mm Radian by itself, the 5mm with a 2x TeleVue Barlow (effectively 2.5mm), and an 8mm Radian w/Barlow (4mm). In all cases everything was extremely sharp across the entire field (except for maybe the most extreme edge). Saturn's appearance was virtually unchanged as it swept across the field, even at 596x. Same thing with stars.

Apparently this eyepiece cannot handle the fast f/4.5 light cone. I do have a ParaCorr on its way so I'll report what difference that will make. My third scope is an 8-inch f/8, but I did not make the effort to set it up also. Others have said good things about this eyepiece at slow focal ratios plus over 500x in an eight inch I'm not sure would have been valid, so I didn't bother.

Thanks for all your replies and comments.

Doug

I made this accessory box that hangs on the front of my Dob's rocker box. Gel cell battery for powering fans and dew control rides in the lower compartment, eyepieces in the upper. I keep the cover closed because when observing here in Michigan dew (and even frost!) is ever-present. Any time I want to switch eyepieces they're right there where I can reach them.

Doug

Can't wait to take a gander at it/through it, Jim!

I couldn't tell - are you excited about it?

Doug