RE: [APML] Focusing an ST-4

[Emmanuele Sordini <vega@bloomingstars.com>]

Hi Gene,
thanks for your response.

At 12.14 23/05/2003 -0500, you wrote:
>1) Focusing onto an artificial bright object (such as a street lamp or an
>artificial star) lying far enough away (HOW far away is another matter). No
>more ages spent aligning, putting together and taking apart the whole
>equipment.
>
>---------------
>
>What you can do with this idea is use it to get an EP parfocal.  There are
>rings you can buy that go around the barrel of the EP so that you can set
>the distance.

Yes, that's a good idea: either a ring or also a mark scratched of some 
kind could make do.
I was wondering, however, if using a distant, still man-made object could 
be a viable replacement for an ever-moving star... that way, I could do my 
tests with a much simpler and lighter setup and just by looking somewhere 
out of my room's window :-))


>---------------
>
>2) Focusing with a PC. Trouble is, the ST-4 is not a webcam so one can't
>have a continuous, real-time flow of frames. Perhaps, a hartmann mask could
>be of some help here, and the software used could make a big difference as
>well.
>
>----------------
>
>IIRC this works quite well.  Download time for each frame is minimal.

Yes, but what program is best suitable for that? I'm wavering between the 
old-style MS-DOS program from SBIG (for which I don't have an old-styled 
MS-DOS system ready) and the newer ImCap, which, however, has a somewhat 
cumbersome user interface.

Emmanuele

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