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Image Circle for Mamiya RB67 Lenses?

Neil Poulsen

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May 28, 2005
Messages
528
Format
4x5 Format
Does anyone have an idea of the actual image circle of Mamiya RB67 lenses? Probably, it varies a little, with longer focal length lenses having larger image circles.

The actual "6x7" Mamiya format is 5.6x6.84. From a Pythagorean calculation, this implies that the image circles at a minimum is 8.84cm. If all RB lenses cover Mamiya's "6x8" format, which is actually 5.6x7.5cm, then we can expect an image circle of 9.36cm at a minimum. But of course, it could be larger . . .

. . . which is the reason for this question.
 
They won't cover a 4x5, it that's what you're asking for. Even my 250mm, when in focus at infinity, I can't even see any of the aperture from the corner.
 
I've tried my Mamiya RB67 lenses on 4x5 and this is what I get:
37mm Fisheye hits all edges but obviously misses the corners.
50mm just misses the corners.
127mm covers 4x5 easily.
360mm just misses the corners
 
The 75mm shift lens has 40mm additional side-to-side coverage per specs. So, 75mm + 40mm = 115mm side-to-side coverage.
 
Thanks for the responses.

Actually, I'm interested in what kind of movements can be achieved using these lenses with the 645 format. The responses are pretty encouraging. Of course, one can get a certain amount of movement, because 645 is a smaller format than 6x7. But, I was wondering about what kind of movements might be possible beyond that point.

I've tried my Mamiya RB67 lenses on 4x5 and this is what I get:
37mm Fisheye hits all edges but obviously misses the corners.
50mm just misses the corners.
127mm covers 4x5 easily.
360mm just misses the corners

Did you notice how much of the 4x5 negative was sharp?

The 75mm shift lens has 40mm additional side-to-side coverage per specs. So, 75mm + 40mm = 115mm side-to-side coverage.

I hadn't thought of using the shift lens. May not be needed though, given the possible coverage.


Oh, how neat. Gives the area covered. I didn't expect this. Funny it doesn't give the diameter of the actual image circle. But, that's easily calculable from the information provided.
 
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