Re: [APML] Focus Problem with Pentax 67

[Roland Roberts <roland@astrofoto.org>]

>>>>> "jw" == Jason Ware <jtw@galaxyphoto.com> writes:

    jw> If it is focused at the edges and out of focus in the middle its
    jw> humidity induced film creep. Many, including myself have solved
    jw> this problem with a steady steam of nitrogen. You can get parts
    jw> and tanks from a welding supply.

It appears to be a steady gradient across the film.  I've just scanned
the film and am looking at it now.  It doesn't really look like donuts
after all, more like little chevrons on one side and coma on the other.
For one roll, the E200, the gradient is left-to-right, but for the other
roll, PPF, it is top-to-bottom.  This change between the two is quite
curious and I'm not sure what to think at this point.

regards,

roland
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Roland B. Roberts, PhD                             RL Enterprises
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