Re: RE: [APML] Epsilon 160 and 210 informations.

["Teïva Leroi" <leroiteiva@minitel.net>]

Thank you Gen for your informations.
teiva
http://www;astrosurf.com/leroi


>> -----Original Message-----
>> From: astro-photo-bounces@seds.org
>> [mailto:astro-photo-bounces@seds.org]On Behalf Of Teïva Leroi
>> Sent: Saturday, March 15, 2003 8:22 AM
>> To: astro-photo@seds.org
>
>> Are focus and collimation easy to make?
>
>For the 210 focus is very easy after the first time.  The focuser
>is calibrated and you use a roll of film taking a series of test
>shots bracketing each exposure point.  Or you can use a knife edge
>or focusing microscope, but these can be a pain due to the camera
>rotating while you focus.
>
>With medium format, though, unless you have a vacuum back any film
>curl will move the film out of focus.
>
>Collimation if you are only adjusting the primary is easy.  The
>OTA maintains collimation very well with adjustments only needed
>every few years if at all.  If the secondary was removed getting
>the correct offset can be a large problem.  So avoid if possible.
>
>Gene Horr
>genehorr@houston.rr.com
>
>
>
>
>

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