Sinar P front and rear carriers not parallel

[sudeva]

My Sinar P recently took a bad spill, and after inspecting it to make sure no gears were badly stripped, no components suspiciously loose, etc, the only thing I can find that seems funny (though I don't know if I should say "out of the ordinary," as it may always have been this way) is that the front and rear carriers seem not to be vertically parallel. It is barely perceptible to the eye and may always have been this way, but I am noticing it now. Using a digital caliper, I found that if the distance between the upper parts of the carriers is, say, 67.6mm, the distance between their lower parts is about 65.6mm. (I'm being gentle so as not to push them apart toward the top when I measure.) It's about the same on the right and the left sides. Seems like this 2mm discrepancy would be enough to affect focus. Ideas?

[Alan Davenport]

Sure, it'll have an effect. If your measuring points are 175mm apart, that works out to a bit more than 1/2 degree of tilt that is now built into the system. With a wide lens that could be significant, with longer lenses it will be less so. Also, when you stop down the depth of focus may be enough to mask the error.

In the final analysis, all this affects is your zero point where you start adjustments. Regardless of any starting errors, the groundglass will not lie. Use a good loupe to check focus across the groundglass and use your camera's movements to get it right. It will be right on the film.

[Frank Petronio]

The detents are adjustable and it can realigned by a Sinar-experienced technician such as Bob Watkins at Precision Camera Works in Chicago or Sinar Bron in NJ. Some photographers who are patient can do it themselves but go slow and be careful. Perhaps a rental house (Samy's, Calumet, FotoCare) will have an experienced Sinar tech if you are near a large city?

[erie patsellis]

Sudeva,
if you are handy (and patient) I can send you the service manual for the P cameras, it's easily adjusted, but takes some trial and error. I use a method that is similar to "winding boards" used by traditional (non power tool type) woodworkers to assess co-planarity of the standards to start with, then adjust plumb, finally adjust paralellism. all the detents are adjustable, though is sounds as though a good going over would be a wise investment (by an experienced Sinar tech) I'll second Frank's reccomendation of Precision Camera Works, I haven't had any work done by him, but he was extremely helpful on the phone several times, and when I do have my P's serviced, he's the only shop I'd even consider other than Sinar Bron.