Hello all knowledgeable souls,

I have just taken delivery of my beautiful 12x10 twin sliding box camera with an 1855 petzval 18 3/4" f4 lens. I have been told to expect a focus shift if I load panchro film into the back. How pronounced will this be, and can I just stop down (well, waterman down) to cover the shift?

Will the shift be constant for different subject distances?, and would I still have the shift if I used ortho film or paper?

Thanks for your help, as ever,
David White