Posts Made By: Doug Scobel

I'm a software engineer, what they used to call a computer programmer in the olden days.

Kinda weird, I get my biggest kicks building things with my hands, like telescope mirrors and scopes to put them into, but professionally all I do is set and reset bits in a computer. And yes I've been known to go out in sub-zero (Fahrenheit) temperatures to observe, so I must have a little bit of insanity going on. :S

Doug

Hi, Steve. I can recommend use of Radians. Here's what I've been able to do afocally with a 14mm with my homemade 8-inch f/8 Newt:

http://www.umich.edu/~lowbrows/astrophotos/moon/moon9.html

Doug

And here's a shot through my homemade 6-inch f/4.5 with an 8mm Radian. I think the softness around the edges is due to the paraboloid's coma.

Doug

Wow, Jim, don't that look purdy!!! Can't wait to see it "in person"!

Doug

Dan, that story would be much funnier if it weren't true. Even at that I had to laugh. Ouch!

Doug

Hi, Jim, to compensate for the weight of the battery box/battery/eyepieces on the front I offset the center of the altitude cutouts (where the altitude bearings ride) slightly towards the rear of the rocker box. I didn't do anything with the size of the Teflon pads. I'm using a set I got in an Astro-Systems kit years ago. I think the pads are about 1.5" x 2" or so.

I'm only using a 7 amp-hour battery, which doesn't weigh that much compared to the rest of the scope, so what I did may be over-kill.

Doug

Thanks for the kind words, everyone. I like her a lot, too. With my Pentax XW30 with ParaCorr I get over two and a half degrees.

Tom, for the laps I use a soldering iron with a sheet metal attachment to melt the channels into the pitch. It's by far the best way I know of to channel a lap. The method was described in a "Gleanings for ATMs" article in the March 1970 (yes that's 1970 ) issue of Sky and Telescope.

Doug

That's why I built my 6-inch f/4.5 RFT. I get over two degrees true FOV with 30mm Pentax XW/ParaCorr combo. Pop in an OIII and you can see the entire North America nebula. It does a great job on planets and doubles too. It's my grab-n-go scope. In my not-so-humble opinion RFT Newts rock!

My situation was similar, my main scope is a 13-inch f/4.5 Dob. The RFT complements it perfectly.

Sorry, don't know about any manufacturers besides those already mentioned.

If you're curious you can check out how I built it here:
http://www.astromart.com/forums/viewpost.asp?forum_post_id=532739&poll_id=&news_id=&page=

Good luck,
Doug

Sorry about the lateness of my post, but I just noticed your little contest. Here's an image I took On July 30, and an excerpt from the text of the email I sent to my fellow club (see my profile) members:

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Here's an image I took of a thin, crescent Venus tonight from my front yard, just as the sun was setting. If you haven't seen Venus this large and thin then you'd better hurry as it's quickly heading west towards the sun. Once it reappears in the morning sky it will still show a thin crescent, but it will quickly become smaller in diameter and more fully illuminated.

I took the shot through my 6-inch f/4.5 Newtonian RFT
"Smurfette", using my Nikon Coolpix 800 digital camera mated to an 8mm Tele Vue Radian eyepiece. Due to Venus's low altitude the atmospheric seeing was not very good; this was the best of many attempts. Once Venus moves into the morning sky I hope to get some better shots as the ecliptic ought to be at a much more favorable angle, plus I should be able to track it well past sunrise.

Here's some additional info on the image:

Time image taken: 8:56 EDT
Altitude: 7.4 degrees
Magnitude: -4.4
Diameter: 48.9"
Illumination: 10.1%

Very nicely done, Gert.

Doug