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Captured by
RICHARD COFER

VdB 141 Ghost Nebula

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Posts Made By: Walter Hamler

November 25, 2003 01:47 PM Forum: Telescope Making

How Short Can the Upper Cage be?

Posted By Walter Hamler
Tom, here is a pic of a friends 16" that will fit in a suitcase when disassembled(the whols scope). The secondary cage is about 5" tall. As you can see he adds a shroud at the front. I can testify that it works and gives stupendous images!

Walt

November 30, 2003 04:31 PM Forum: Equipment Talk

UPGRADING

Posted By Walter Hamler
If you aren't into photography and only an occasional user then why not an 8" dob like Orion or Skywatcher (Hands on Optics).

Walt

December 4, 2003 07:29 PM Forum: Equipment Talk

Central obstruction and 100% FIF.

Posted By Walter Hamler
Chris, I have a 10" f/6.2 and use a 1.83" diag. I feel sure the 2.14 will be totally acceptable for your uses. I even doubt you will notice any falloff with a really widefield ep like the 31mm. That's not to say thay there won't be falloff, there surely will be. It's just that the eye is pretty accomodating in that arena and you likely could not see the difference from 2.14 and 2.5/2.6. It's also doubtful you could detect the difference in diffraction and CO effects between the two, so I would recommend the 2.14.

Walt

December 4, 2003 07:40 PM Forum: Equipment Talk

Powermate v. Barlow

Posted By Walter Hamler
I honestly cannot tell you firsthand but several of my friends have used my 2.5 Powermate and compared with Daiken and Meade barlows and they all said the Powermate always gave superior views. Most recent was at Chiefland on Saturn using a TEC 140 and a Meade 12" SCT. The seeing was excellent several nights in a row and some rather stupid magnifications were being touted. I saw it a about 350x in the 12" and the images were VERY nice.

Walt

December 9, 2003 12:03 PM Forum: Telescope Making

14 inch 1 inch thick plate mirror

Posted By Walter Hamler
Phil, I have worked three plate glass mirrors, an 8, a 10, and a 16. I would say from my limited experience that the plate is actually somewhat easier to grind and faster to polish. However, you will discover that you need to wait at least a half hour to an hour to make final focault readings because it takes a little longer than pyrex to stabilize after polishing sessions.
Many years ago our club built a 14" plate glass dob that was an f/5. It was a great scope and gave very nice views in the summer months, but in the winter it took several hours to equalize to the point reasonable images were seen. That was in a climate that would get down to below zero C often and the mirror would be transported from a warm environment. We learned to set up several hours before dark!
I say go for it and enjoy the experience and the views!

Walt

December 10, 2003 03:23 PM Forum: CCD Imaging and Processing/Solar System

King Rama IX's Birthday - Saturn & Jupiter

Posted By Walter Hamler
In 1969 my wife and I were visiting friends in Chachoengsao and my wife commented on how wonderful it was for the local village to decorate the area so nicely in honor of our wedding anniversary (Dec 5th)! We were quickly told that it was for the King's birthday, which was a big celebration and honor for the people every year. We have never forgotten our anniversary, and your King's birthday!
Happy Birthday, and great pictures also.

Walt

December 18, 2003 01:51 AM Forum: CCD Imaging and Processing/Solar System

M42 with Canon 10D

Posted By Walter Hamler
Rick, except for the intense colors this is how M42 looked to me through a friends 16 under very dark skies recently.
I took the liberty to adjust the colors to show what we saw.
Absolutely stunning photo btw!

Walt

January 1, 2004 09:57 PM Forum: Equipment Talk

Can old focusers be upgraded?

Posted By Walter Hamler
Here is an example of my mods to a 4" refractor that had a 1.25" focuser. I adapted a 2" JMI Reverse Crayford to it very easily and it works great. JMI, Moonlight, and Feathertouch make higher end flat base Crayford focusers that should be readily adapted to your use. Some will say that a Crayford that is designed for a newt application will not provide enough focuser travel. I can only make the observation that every eyepiece I have ever attached to my 4" in the JMI focuser with the 2" diagonal has reached focus with no problems. Feathertouch makes refractor focusers now I believe, but I am sure they are very pricy. It just depends on how bad you want a "better" focuser.

Walt

January 1, 2004 10:42 PM Forum: CCD Imaging and Processing/Solar System

Northwoods Orion

Posted By Walter Hamler
Very nice shot, Jeff! Is that pretty much "straight" from the camera or did you have to tweak in Photoshop?

Walt

January 4, 2004 04:37 PM Forum: Telescope Making

Getting Started In My First Project

Posted By Walter Hamler
In the appendix of the Kreige book is an excellent design for and 8" f/6 dob, exactly what you have. A truss is great if you really need a compact design for storage/transport considerations, but they are somewhat more difficult to execute. I have made two using the Kreige design in the appendix. The total weight was about 18 lbs for the ota and about 30 lbs for the rocker box and groundboard combined, maybe a little less. The nice thing about using a tube is that it is very easy to make it to rotate, keeping the eyepiece always at a perfect position. I was able to do all my observing with thr 8" f/6 while seated in a regular chair while the scope was on an equatorial platform.

Walt

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