Hello Richard, Long time no see. Just examined your 150mm f10 design. Short Flint is a very interestring glass. I've got one design which is modification of...
What's the widest Field Of View possible for a Cassegrain system? I would like +/- 5degrees, but I have only seen like +/- 1 degree in the literature. Thanks !...
This strange idea came to my mind when I was meeting. Seems I didn't pay attention to my manager.(^^) Is a *plastic flattener* possible? Can amateurs make this...
With the given constraints, this one, coming up in a discussion on another group, didn't appear to be all that bad: 140 mm f/12 doublet VS: 0.7870 to 0.3896 at...
Two flattener examples were demonstrated in "Practical Computer-Aided Lens Design". One for Cassegrain and the other one for R-C system. I followed the...
Hello everybody, Glad to be back! 8-D A flat field design. 120mm f/8, C-F color correction, visual use. Glad to be back! 8-D A flat field design. 120mm f/8,...
This was a new term to me. I finally figured out that it is: ( X - Y )/X, where X and Y are the separations of the plus and minus chief rays out of the paper...
Is anyone aware of vendors of lens elements or completed lens stacks (such as C mount etc) that supply Zemax models of the lenses online? I have Zemax and...
It can actually get down to about f/10 without too much more complication in the design (200 mm f/10): http://users.rcn.com/rflrs/schiefspf10-14x.atm ATMOS...
What is the best f-number for a telescope? I see that many telescope have high numbers like f/22. But then I am thinking that the scope angular resolution is...
These are results of my new toy, OSLO. OSLO is too diffuclt for the beginners. I can't figure out how to setup optimized operands. However I invented a strange...
However, if we slow it down to about f/8.5 and lose the crown isoconvexity constraint in the secondary: http://users.rcn.com/rflrs/Ptz10-37x.atm ATMOS input...
I reported this find elsewhere, but thought I could also report it here. Design dbl03-12x (directory rflrs) shows a 100 mm f/13.5 doublet. While the two...
In directory rflrs, file Ptz09-72x.atm gives a 48 mm 300 mm f.l. design. For imaging, however, file Ptz09-72g.atm shows the ghost reflection off the sensor to...
Here is my attempt at simulating an Orion/Skywatcher 80mm f/7.5 doublet. Is this anywhere close to actual performance? SURF 1 RADI 330.0291 DISZ 5 GLAS ZKN7 ...
Do the Chinese glass manufacturers sell small slabs or molded piece like Jagaer used to do? Would be fun to try out, maybe use as telephoto lens. Don...
I was wondering if anyone has had any kind of experience with Stabilite Mirrors, and/or their scopes. I was looking for a large mirror and found their web site...
Hello everybody, This is my achromat design. An 100mm F12 air-spaced refractive system. It took me years to figure out how to work it out. 8-( References...
I played with this some, electing to do it in the visual C-e-F wavelength. I adjusted R4 so that blue and red have a common focus at about the 70 percent zone....
I've been trying to do a design using CaF2 and BSM14, trying to get something that looks similar to the chromatic focal shift Takahashi publised for the 128mm...
In a message dated 6/11/2007 3:06:30 PM Central Daylight Time, ... You have to understand the logic of these telescope companies. They will NEVER pick a mating...
Just some quick questions about the Optimization Tools.... What is a good way to weight the wavelengths for visual use? I've been using 10 for green, 3 for...
Hopefully, I have apples and apples, now: dbl02-21.atm and dbl02-23.atm in directory rflrs. Are the differences worth saying one is significantly better than...
