8x10 150mm = 120mm by cropped how much?

[Richard Fenner]

Thanks people. Yes Leonard, this is what I meant but seemed unable to properly describe.

I was curious about the need to provide lens data - it seemed to me as long as it covered (and I knew they did), it was irrelevant. Still, in the past what people think to be irrelevant is sometimes relevant. I realise at f22 the 120mm only has an image circle of 312mm, but that should mean at f32 it covers, and this scenario requires no movement. Previous threads on this lens indicate no problems covering 8x10 with only a whisker of movement.

Glenn, I'm often puzzled when people complain about clip marks in the image area. There is a solution - change labs!

[Ernest Purdum]

Regarding the focusing problem, I suppose you don't have a means of measuring the ceiling height. If you did, you could place the camera at that distance from a wall, focus, lock the focus and set the camera on the floor lens up.



With an unknown ceiling height, a somewhat more elaborate procedure should work. With the camera on the tripod pointed up, focus on the ceiling and lock the focus. Measure the distance from the camera back to the floor. Now point the camera at a wall and move the camera until the wall is in focus (a dolly or cart of some sort would be very helpful). Now move the camera backward by the distnce of the back to floor measurement taken earlier. Refocus and lock.