Restoring An Ansco 8x10 Commercial View Camera

[Ian Grant]

The difference, of course, is in the example you provided, the glass rests from the back on a routed lip whose T distance never changes independent of GG thickness. In my instance, the glass rests on a routed lip inside the frame and the effect T distance changes with varying glass thickness.

No, the same as yours.





Fits from the inside, so yes glass thickness is critical. It seems odd that Kodak would switch to a less accurate way of mounting

Sheet lass now is made to higher tolerances compared to 60 years ago, but even nominal 2mm can vary by +/- 0.15mm.

When film holders became International fit sizes post WW2, they were based on Kodak outside dimensions, with 5x5 the old 0.200" T registered was changed to 5.00mm / 0.197" +/- 0.178mm.

With 10x8 the T register is 6.60mm +/- 0.406mm. I'd measure that T depth register of your back. I will be improving the screen on the Specialist 3 back and will measure the glass thickness first.

Ian

 

[thronobulax]

No, the same as yours.

Sorry, I was referring to the Ansco back photo you provided.

View attachment 6639

View attachment 6640

Fits from the inside, so yes glass thickness is critical. It seems odd that Kodak would switch to a less accurate way of mounting

Sheet lass now is made to higher tolerances compared to 60 years ago, but even nominal 2mm can vary by +/- 0.15mm.

When film holders became International fit sizes post WW2, they were based on Kodak outside dimensions, with 5x5 the old 0.200" T registered was changed to 5.00mm / 0.197" +/- 0.178mm.

With 10x8 the T register is 6.60mm +/- 0.406mm. I'd measure that T depth register of your back. I will be improving the screen on the Specialist 3 back and will measure the glass thickness first.

Ian

Yeah, it's puzzling why this would be done. I now have to go look at my Graflex 2x3 GG and see how they are built/measured.

 

[thronobulax]

@Ian Grant Aha! We have an answer back from Richard Ritter.

From the Department Of Old Dogs, New Tricks:

These backs were designed for the ground surface of the glass to face the photographer, not the lens. The idea was that some photographers like to use them in studios and mark the glass with compositional information.

This means that the inner rabbit on which GG rests defines the T distance, not the inside of the glass to the back mount point. Apparently, someone (it may have been me when I cleaned the glass for all I know) installed the GG with the ground side facing inward throwing off the T distance by the thickness of the glass.

The good news is that simply reversing the glass fixes this - he said that the T distance to the rabbit looks otherwise correct.

The better news now that I know this, is that any replacement glass will work in the future, so long as the ground side is installed facing outward.

Perhaps this is all old hat to you, but I'd never run into this before...