doug wrote:Thanks... Frank ! And my apologies too. I will look around for a Schneider. Though I think the focal length for my U16 setup needs to be about 80mm. I hadn't considered reversing the lens but maybe as you say this helps. Also closing down a stop or two ? Or more ?
I'm actually using an APO-Componon HM 2.8/40 which I picked up for around £100 - quite a bargain as this is a cracking lens. I was still able to get in close on the Eumig Mk 8 with a 2/3" camera sensor. Reversal is optional for S8 to 2/3" as this is about 1:1. Slight benefit with R8, with 16mm I mount it the normal way around.
Here are some measurements for R8/S8/S16 for full frame (opened out gate) capture to 2/3" sensor:
R8: Reverse mount with about 67mm of extension (including adaptors). Distance form the film plane to the lens about 53mm
S8: Reverse mount with about 59mm of extension (including adaptors). Distance form the film plane to the lens about 55mm
S16mm: Normal mount with 54mm of extension, 62 mm to the film plane.
The main body length of the lens is 30mm, but when reversed mounted there is an extra 11mm protruding but only 24mm dia., the main body being about 46mm dia.
Going with a 50mm lens will give you a bit more space from the film plane to the front of the lens, an 80mm lens will give you a lot of space! I would recommend the shortest focal length you can fit to minimise the effects of relative vibration between the projector and the camera.
Usually f5.6 is the sweet spot, f4 is quite useable with this lens.
Frank
Off all the things I've lost, I miss my mind the most.