I need help.
Can those of you who own a 645n (or 645), remove the film magazine, set the camera at
"B" and see if the cog wheel on the left side of the film chamber (the one that
transport the film) moves slightly clock-wise when the shutter opens and the mirror
goes up (when the the shutter closes the wheel turn counter clock-wise and transport
the film). Note that this is when the shutter opens. I need to know if this behavious
is normal or if it stays perfectly still when the shutter opens.
The reason is that I still have sharpness problems due to film flatness issues. Pentax
have checked the camera but everything is within factory specifications. My latest
films included bracketed shots where one had the lower third of the image out of focus
while the rest was sharp. This was at F:11 with the 120mm at infinity.
Most of my time exposed aurora shots at F.4 was unsharp to a variable degree. The most
extreme (45mm at F:4) had the star trails convex upwards(!), something that can only
be due to a curved film.
Pentax will hopefully send me a new film magazine soon but I'm not convinced that this
is where the problem lies. This slight clock-wise movement, wich might be normal for
all I know, slackens the film somewhat.
Pål
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