Re: Lens matching (was Insomnia = brilliance?)

[Bob Clark <rcc@xxxxxxxx>]

Greg Erker wrote:
> 
> >Yes, that would be great--I was thinking along the same
> >lines, but don't have any concrete ideas yet.  Maybe we
> >could build a crude, shipable optical bench set-up with
> >a projection bulb, condensor lens, slide-holder, and a
> >place to mount a camera with the back taken off?
> 
>   I'd rather not ship whole cameras due to
> the postal costs and customs issues.
> 
I agree.

>   Are you hesitant to remove the taking lens/
> shutter assembly (from all your cameras)?
> 
Not really, but if I didn't have to take much apart, I
could borrow a camera from a friend or a store and slap
it on the bench for a quick test.

>   One idea is for me to test all my four lenses
> relative to a specific one. Then send that
> lens to you with my test slide.
> 
That would work.  My vision was to ship only this little
bench projector set-up with instructions on exactly where
to place it relative to the screen.  This could very well
be too inacurate for these tests.

Maybe we could scale the system down and project onto a
reasonably-sized ground glass (4"x5"?).  Then we could
build and ship the whole contraption along with tracings
of each lens test on the ground glass.

>   One thing I'm not sure about, regarding this
> plan is whether unscrewing the lenses from
> one shutter and screwing them into another will
> physically fit, and also if it will affect the
> focal length.
> 
>   That could make it difficult or impossible
> to get matched focal lengths in my two 225
> shutters (if things get screwed up by swapping
> or if I can't us Diacord G lenses).
> 
I don't know either...
-- 
Bob