Re: [APML] Cygnus mosaic (was Fish on the Platter)

[KGKIRKLEY@aol.com]

In a message dated 9/5/01 9:38:15 PM, tan@home.com writes:

>Ray,
>
>    Well, I think Gene, Steve, and Kent answered this question. In normal
>daylight photography, there's more than enough light to go around but for
>astrophotography, you will need 3 Schmidt's to ensure that the exposures
>were
>similar. At the very least it would make one heck of an interesting looking
>setup <g>. Even if you're willing to live with 3x longer exposure times,
>I
>cannot imagine trying to get three film holders to focus perfectly
>simultaneously.
>
>Loke

Loke:
Actually it would be possible to use 3-8 inch Schmidt's for tri-color work.
They could all be mounted on the same mount, each aligned to the other.
It would be nice if they all had the same exact focal length. (mine is 299mm, 
yours?)
Three N2 or dry air purge systems.
The problem would come in the different exposure times for the filters, 
requiring staggered beginning or ending times which would be best 
accomplished with some kind of shutter system, one for each camera (as 
opposed to the "hat trick")
Kent Kirkley

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