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Posts Made By: Larry Stange

May 16, 2003 06:27 AM Forum: Telescope Making

Ronchi screen with diffraction lines between?.

Posted By Larry Stange
Are thin diffraction lines that are nearly straight except for slight wobble due to heat waves BETWEEN the heavy dark Ronchi lines an indicator of a better objective? These thin lines appear on BOTH sides of focus.

re: Celestron CR150-HD.
Thanks for any analysis..... -Larry

May 16, 2003 04:15 PM Forum: Off Topic Discussions

Herb.....Wonder if a new topic

Posted By Larry Stange
There does not seem to be any slot that can be used for strickly optics theory questions and such.

If a question on optics properties, transmission properties, etc., and NOT questions on specific equipment owned were asked, it is likely to be overlooked by Physics/Optics majors because there is no TECHNICAL catagory in the forums for such.

e.g., My posting of question on telescope making. -Larry

May 17, 2003 10:47 PM Forum: Film Astrophotography - Imaging and Processing

Military Aerial Camera lens.

Posted By Larry Stange
Can anyone guess the value of a 5 inch (CLEAR APERATURE) lens in a cell that is marked Pacific Optical 3.8 F/2.0 PAXAR. The s/n is 107. The lens is in supurb condition minus wipeable smudges. It is coated. When held up looking through it and a dirty window at far off trees, the image is in extremely sharp contrast though slightly smaller to the naked eye and has a sharp 3D appearance.

I do not know if it can be used for deep space photography but it sure looks like it. -Larry

May 19, 2003 05:55 AM Forum: Off Topic Discussions

Do we have substance yet?.

Posted By Larry Stange
Not sure if I should post this on a worthless forum but here goes......

Andrew et.al., -Using the engraved screen from a scale lupe of the type we used in seismic film reading(very accurate), the lines are 1mm apart.

Taking this glass scale instead of the normal 150 LPI Ronchi screen, and resolving it down to 3 viewable lines showed a overcorrection(apprx. 1/8 wave if at 150 LPI) beginning to appear.

Because my 1mm scaling is 170% greater(more dense) than the 150 LPI, I am assuming my objective is overcorrected in the neighborhood of 1/16 or less.

Do you have any idea exactly what the overcorrection might be if you ASSUME what I saw looks a little better than the 1/8th wave error of our bookmark reference?.


May 19, 2003 07:32 AM Forum: Off Topic Discussions

Herb -can you authenticate a users ID?.

Posted By Larry Stange
Just found a person using the name Larry Stang from Florida selling on Astromart. One of his listings is on 5/17/03 in the Misc column.

I have never seen this coincidence before in any phone book. My last name ends in an e.

There is no evidence I could find on his signing a message in any forum archives, and his selling listings began 30 days ago.

Attempted an e-mail to him. The e-mail address name appears to be encrypted. (Mine is a joke.)

COULD all be just a coincidence.... but there are other similarities that hit pretty close to home here....

May 21, 2003 10:02 PM Forum: Off Topic Discussions

Herb...question

Posted By Larry Stange
Were you instrumental in any way in the disappearance of all traces of L. Stang?.

November 7, 2002 10:41 PM Forum: Telescope Making

Old Meade Fork Electronics question

Posted By Larry Stange
A nice microswitch will work from radio shack. Their ratings are usually 1 amp 110VAC. The 110VAC rating insures no arc-over up to that voltage. They can be used for small DC motors also. The larger "brush type motors" have much heavier currents and the amperage is usually on the motor. Your worse case situation would be the contacts eventually pit if the switch is under rated for the application.

November 7, 2002 10:52 PM Forum: Equipment Talk

Perfect scope battery ??

Posted By Larry Stange
A 12 volt Gel-Cell apprx. 8 ampere/hours with a constant voltage charger of 12.85 V. apprx. You can use a voltage regulator from radio shack to adjust the 12 volts down to 9 or 6 VDC too. Gel-Cells frequently show up at swap meets and are always found at radio amateur swaps in your area. Hope this helps. -Larry

November 13, 2002 05:02 AM Forum: Film Astrophotography - Imaging and Processing

Planet imaging of my problems (picture)

Posted By Larry Stange
You are right Gary about the heat dancing the images radically!. Since I am building a digital camera mount INSIDE where it is warm I tried to take low angle*
(*bad for spherical AND chromatic abberation)shots thru an OPEN window East...Too cold & dark to go outside and try to make the time consuming collimating adjustments to camera AND telescope. We both will be plagued in Calif from coast weather & desert/mtn weather causing diffraction where they converge I think. I really should cut a hole in the roof. :-) Your area SHOULD be better than mine overall. Thanks for the comments Gary. -Larry

November 14, 2002 07:19 PM Forum: Film Astrophotography - Imaging and Processing

First Moon Shot

Posted By Larry Stange
That D60 does a nice piece of work at 1/250th. Makes you want to push the retro rocket button looking at it.

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