Ed Richards
29-Feb-2012, 13:39
Been doing some tests on vignetting with filters on my 47mm XL (FOV 120 degrees) and 80mm SS (FOV 105 degrees). This should also apply to my 110mm XL, but on 4x5 it is pretty unusual to get to the edge of its image circle.)
I use the center filter and the Lee adapter for this on the 47. This works fine, but it is a bit of a pain. I tried using an 86mm filter on the center filter, and had significant vignetting. Back to the Lee. Since polarizers are not a good idea on ultra wides, I only need to use one contrast filter on the 47.
I had been using a 67-72 step up ring on the 80, but noticed vignetting in several pictures with significant rise. (You should not put filters directly on the XL lenses, there is no enough clearance with the front class.) I put the lens on the Sinar so I could get more rise than the Ebony, and did some testing. First, I think this lens has a larger image circle at F16 than the manufacturer lists. I raised it to where I was sure I was out of image circle, but found I was still not vignetting without a filter. Using the 72, I got significant vignetting. Less with a 77mm filter, and none with the recommended 67mm Extra Wide, which has a filter diameter of 82mm. (Bought one of these to try, took 6 weeks to get, and when I ordered a second one, I found they are discontinued except in MRC coating, and not yet available in that.) The 67mm EW should be the same as using a Heliopan 67-82 step up ring (they make the only brass rings and the others tend to bind) and a B+W or Heliopan filter.
I then tried the Lee adapter ring for wide lenses, and it alone added a very little vignetting. This might have been due to the Lee polarizer ring I have on the holder. No additional with a filter. Adding the polarizer lead to very significant vignetting.
I do not have a square polarizer to try to with the Lee holder, but it should be less of a problem than the round one. There should also be less problem with light getting in between the polarizer and the filter. But I do not use a polarizer much, so I may just decide to stick with one I have to save money. The square would be a problem with grad filters, but I never seem to use those either.
I then tried a 67-86 step up ring and B+W filter on the 80. Got some vignetting. The only adapter ring in that size I could find was a crappy Century ring, which was thick and so badly made that it would not screw all the way into the lens and the filter would not screw all the way into it. In 86mm, the B+W filter is also very thick, so between the two problems I can see how would be worse than the 82. Adding an 86-105 ring and the Lee polarizer only made things worse.
Bottom line - You need extra wide filters to get the least vignetting with the 80 and similiar lenses. The Lee system is close enough to be acceptable. You have to use a Lee type system to use filters on the 47 if you use the center filter.
I use the center filter and the Lee adapter for this on the 47. This works fine, but it is a bit of a pain. I tried using an 86mm filter on the center filter, and had significant vignetting. Back to the Lee. Since polarizers are not a good idea on ultra wides, I only need to use one contrast filter on the 47.
I had been using a 67-72 step up ring on the 80, but noticed vignetting in several pictures with significant rise. (You should not put filters directly on the XL lenses, there is no enough clearance with the front class.) I put the lens on the Sinar so I could get more rise than the Ebony, and did some testing. First, I think this lens has a larger image circle at F16 than the manufacturer lists. I raised it to where I was sure I was out of image circle, but found I was still not vignetting without a filter. Using the 72, I got significant vignetting. Less with a 77mm filter, and none with the recommended 67mm Extra Wide, which has a filter diameter of 82mm. (Bought one of these to try, took 6 weeks to get, and when I ordered a second one, I found they are discontinued except in MRC coating, and not yet available in that.) The 67mm EW should be the same as using a Heliopan 67-82 step up ring (they make the only brass rings and the others tend to bind) and a B+W or Heliopan filter.
I then tried the Lee adapter ring for wide lenses, and it alone added a very little vignetting. This might have been due to the Lee polarizer ring I have on the holder. No additional with a filter. Adding the polarizer lead to very significant vignetting.
I do not have a square polarizer to try to with the Lee holder, but it should be less of a problem than the round one. There should also be less problem with light getting in between the polarizer and the filter. But I do not use a polarizer much, so I may just decide to stick with one I have to save money. The square would be a problem with grad filters, but I never seem to use those either.
I then tried a 67-86 step up ring and B+W filter on the 80. Got some vignetting. The only adapter ring in that size I could find was a crappy Century ring, which was thick and so badly made that it would not screw all the way into the lens and the filter would not screw all the way into it. In 86mm, the B+W filter is also very thick, so between the two problems I can see how would be worse than the 82. Adding an 86-105 ring and the Lee polarizer only made things worse.
Bottom line - You need extra wide filters to get the least vignetting with the 80 and similiar lenses. The Lee system is close enough to be acceptable. You have to use a Lee type system to use filters on the 47 if you use the center filter.