Posts Made By: Judson Mitchell

I am trying to wade through Suiter's book on Star Testing and was wondering if someone would be willing to condense it to a point where a few of the features of mirrors are clarified through star tests. Most interest would be turned edges, over correction, undercorrection, collimation issues, and surface roughness. My reading will ultimately reveal these images, but others as well may benefit, plus it would be beneficial to have that information in a single location. Virtually none of the people I observe with use star tests to any extent if at all.

The followup could be how these features affect EP performance. Anyone care to take a stab at this.

My Telrad base has detached from the adhesive strips and will not stay put. Does anyone have advice to resecure the base. Seems the base has a very small surface area to contact the adhesive. Right now I am considering duct tape .

A friend recently purchased Oberwerk's 15X70 binoculars and is quite pleased with them. The are at the ragged edge for me as hand held binos. I feel that they are adequate for my use since they would be mostly for scanning and as a finder alternative. Since there is little opportunity for me to test other binos, can anyone recommend other 15X70 options that are comparably priced that are reasonably equal to Oberwerks?

I noticed that secondaries seem to come in restricted sizes and the cost jumps considerably. One in particular is from 2.1" to 2.6". What is the disadvantage in trying to use a 2.1" secondary in a 12" f/5 dob? It looks like the light cone would probably be about 1.8" as it hits the secondary. Has anyone tried this (successfully or unsuccessfully)?

I am interested in upgrading my finder scope (currently 50mm) and would like to keep the cost under $200. Are there any good options out there that can be recommended. My skies are typically less than Mag 5 and commonly more like Mag 4, so a little more aperture is welcome. Plus, I do not subscribe to the concept that crosshairs are not necessary. It is tough enough sometimes to center an object even with crosshairs. Also, want it to fit on the standard dovetail mount. Would appreciate any advice you can give.

Have you ever wondered why there are so many different “Religions” in the world?
Have you ever wondered how they came about?
Which do you believe?
Which don’t you believe?
Ever noticed any conflict of interest?
What about Greek “Mythology”?
Why is it referred to “Mythology”?
Is this the signal of another religion to debunk what was once considered legitimate?
Why are you right and others wrong?
How do you recognize the word of “God”?
How come some evangelists seem to live rather high on the hog?
What about evolution?
Are you willing to believe everything that was written down in the last 6000 years?
How do you pick and choose; or do others do it for you?
Why is there so much violence in the name of religion?
Have you ever considered that humans are really animals and have animalistic behavior?
Are you aware that as society becomes more complex more people cannot cope with it?
How do you reconcile taking some things on faith and others on scientific proof?
Do you accept scientific proof?
Have you evaluated your personal filter that controls what you choose to believe?
Have you considered the source of that filter?
Are your beliefs based on Fear? Why, or why not?
In some societies girls are in disfavor and are systematically killed in favor of boys.
What innate characteristic causes some men to embrace their children and others shun them?
What are your feelings towards non-Christians?
How do we reconcile our innate tendencies with those taught?
Ever notice how some societies are extraordinarily close?
Do you really know your neighbors?

Well, I could just go on adnasium, but the process is theraputic.

Try this with yourself, it really starts you to thinking about who you are!

My 12" mirror (GSO F/4.92) was tested and shown to be slightly undercorrected. This is confirmed by star tests. However, during mirror cooldown star tests suggest that the mirror is over corrected. Is there enough difference in thermal expansion and mirror distortion to cause this change? How much change is possible during cool down?

Recently I have turned more of my observing attention to the moon. Being a geologist, the morphology of the moon has stirred my imagination. Currently I am trying to accumulate information on Lacus Mortus at 45.0 N and 27.2 E. My quest is for any detailed study available and high quality pictures. Any such relevenat knowledge would be greatly appreciated.

Well, I will retire in a couple of weeks and was wondering if there is a support group for Retired Astronomers? So, I will be a beginner in the retirement category. Any advice?

I was doing some FOV testing on my EPs when I noticed that something was loose in my 5mm TMB Planetary. To make a long story short the lense assembly in the EP housing is loose. It will tumble the entire distance that the eyecup is raised. The problem went unnoticed since I do not use the raised eyecups and seldom have used the 5mm due to seeing conditions. Before trying to fix the problem it seemed prudent to ask advice prior to proceeding, or should it go back to Burgess for fixing?