Dear Sirs/Mdms,

Sorry if my previous questions are confusing.

I would like to know what is the distance from the tip of the Rodenstock Apo Sironar-N 210 f5.6 len's furthest rear surface (without the rear element) to the film plane of large format camera if i will installed the lens on the large format camera.

The reason i need to know the above requested information is because i want to capture a 80mm (W) x 60mm (H) rectangular flat surface object onto a 15.15mm x 15.15mm cooled CCD camera sensor such that 15.15mm width of the CCD sensor completely matches the 80mm width of the object. Hence i need to demagnify by 80mm/15mm = 5.33

I can almost achieve this 5.33 demagnification by attached the 35mm f2.8 lens onto the CCD camera and then reverse mounted the 210mm large format lens (without the rear element) on the 35mm lens. The ratio between the focal length of the large format lens and 35mm lens will provide this demagnification (i.e. 210mm / 35mm = 6, which is the closest i can get based on my existing lens).

To prevent the captured image to have ' curvature' effects at the edges, i need to position the 210mm large format lens (without rear element) exactly as it would on a conventional large format camera (the rectangular flat surface object being in exactly the same place as the film plane would be on a large format camera).

So i deeply appreciate if you can advise me:

1) What is the distance from the tip of the Rodenstock Apo Sironar-N 210 f5.6 len's furthest rear surface (without rear element) to the film plane of large format camera if i will installed the lens on a conventional large format camera?

Does this distance change accordingly to the Large format lens focal distance?

Looking forward to your replies. Thank you very much.

Sincerely,
Ho Pei Jiun