Posts Made By: David Hakenewerth

Because the expansion is either slower or faster it can't be both so it is an error of 4.8% We just don't know in which direction.

Dave H.

Nice photos Ron. Last year I had three fledge out from a box in the garage. For about a week I would hear the babies chirp and thought I had crickets in the garage. The nest was well hidden and the adult pair had it timed well to wait till I left for work to start feeding.

Nice Work
Dave H.

I love the use of the 55 gallon priniting ink drums on Chief. Pretty good recycling use.

Dave H.

Could one of the mirror clips be to tight?

FYI Dave H.

Hi Greg, I also think you will be highly please with Ed's mirror. I used to frequent the Zambuto Yahoo group when Ed was still working there and if I remember correctly an RTA of 1.0 means that the abberition in that dimension is all within the airy disk and an RTA of .14 means that all the photons are focused in a circle .14 the radius of the airy disk. Here is a link that kindof describes it.

http://www.telescope-optics.net/aberrations.htm

They say the claims are unrealistic because the focault test only gives you the data at maybe 4 or 5 radius's on the mirror and the rest are extrapolated and that is true. However Ed also use a Ronchi test which is sensative to the change in slope of a mirror and with it you can visually see all the data points between the 4 or 5 zones measured and tell very accurately if the transition is truely smooth. The machining method that Carl and Ed use has been taught on the Zambuto group and it truely works but still takes a skilled craftsman to master. When you read Texereau or Sam Brown and look at the focault examples that they give they don't have a lot of definition and contrast because they look like an amateurs focault test but Carls and Eds are picture perfect.

Congrats on the acquistion.

Dave H.

I'm much beter with Winter and Spring than Summer and Fall and I must admit it takes me longer when I get in dark skies because of all the extra stars but I'm guessing that most of us that still remember how to count change out by hand instead of handing a lump of bills and change at one time can identify the night sky. You bring up a good point. In another 20 years this skill may be gone.

Send me clear skies and warmer temps please
Dave H.