So I took a picture of a mountain scene at f 32 and there is a lot of light fall off, question is if I would of taken it at a lower f stop would there have been less fall off? and at what f stop would there have been none? If I were to purchase a center filter what density would be the best on average?

Thanks a million for answering to this beginner. Claude

-- Claude Benoit (cbenoit@home.com), July 17, 2001

Answers

I have a 90mm 6.8 Grandagon-N and use it almost exclusively for landscapes. Although I am not a large format veteran I have never really found any fall-off with this lens at least to the point that it causes a detrimental effect on the image, although I admit my eye might not be as experienced as others.

By using a 'lower' f number you would be actually using a wider aperture which would increase fall-off. I usually use it at f22 or f32 though occasionally have shoot at f16. I assume you mean to 'stop down' the aperture when you say to use a 'lower' f number?

It would be helpful for all to provide more information, such as; did you use any filters (polarizer?), or rise/fall on the lensboard? I shoot about 80% chromes and 20% negs with the Rodenstock and have never felt a need to buy a center filter for it. It does really well for me.

-- Andy (akkup@ibm.net), July 18, 2001.

I also use a 90mm Grandagon-N, and I agree with Andy, that fall-off is seldom a problem with this lens. By f/11 the illumination is as even as it gets, and stopping down further won't make much difference.
Using a polarizer can make some areas of the sky look a lot darker than others, and if those areas happen to be in the corners of the frame... well. Slight underexposure will exaggerate the vignetting effect of a wide-angle as well.

-- Pete Andrews (p.l.andrews@bham.ac.uk), July 18, 2001.

I use the o.45ND center weighted filter from Heliopan on my 90mm f/4.5 Rodenstock Grandagon

-- Ellis Vener Photography (evphoto@heartstone.com), July 18, 2001.

Ellis....

I see you have a center weighted ND filter. I am using a Schneider Angulon 90mm on 6 x 17 and am noticing (as one would expect) light fall off at f32. A SA90 XL 5.6 would be great, but ive gotta find that second job yet. Where did you get yours from? I live in Australia and i havent found one yet...! I have had a look on at the heliopan site but no no avail....

-- Phil Brammer (filsta@goconnect.net), July 22, 2001.