Image circles and filters

[Ed Richards]

I am curious about whether image circle measurements are done with or without filters. I have been mapping the image circle on some new lenses - 80 and 110 xl - and I find that filters do cut into the image circle, even taking account that these lenses illuminate more than the rated image circle.

[Bob Salomon]

without

[Daniel_Buck]

Although with how conservative some of the measurements are, you might think they were using a filter, haha!

[Steve M Hostetter]

I know the center filters glass extends past the barrel and a 4" polarizer will work depending on the filter..

[Ed Richards]

Thanks Bob. I suppose that makes sense. I do not use filters indoors, and color photographers do not use the much at all. But outdoors, shooting black and white, I almost always use a filter and it cuts a chuck out of a very expensive image circle on SS XL lenses.

Maybe the real problem is that I can never see the corners well enough with shifted, wide lenses to see if am out of IC.:-)

[Henry Ambrose]

You can fix this by going to a larger diameter filter on a step ring.
The downsides are the added expense and bother of the extra gear. But not that much to have a set of 95mm filters and step rings for each lens size.

You could replace the 80 with a 72XL and get some coverage gain.
For the 110 I find it hard to imagine that missing a few mm of coverage would ever hurt you on 4x5.

I've always found that the more "normal" a focal length I could use, the more natural looking the picture. As long as I can exclude from the frame what I want, I shoot a longer lens. I used wides a lot but for reasons other than my preference -- i.e. a 47 or 58 to cover a bathroom shot.

On fortuitous occasions I've walked up to a subject building and everything was right there waiting for me. Perfect setting, perfect place to stand, perfect light, little camera movement - a relaxed and fully pleasant view. Mostly that's not there waiting for you. You find something that's not ideal. You can overcome this by technique and skill. Sometimes it appears that forcing the picture into your wide lens is the solution, but the more you force it the more forced the result can become.

[Ed Richards]

Hi Henry,

This is for my walk around kit. For big pack kit, I use the Lee system, and that is where my 72mm XL sits, as well as the 90mm 4.5 Nikon and the 47mm XL. I was looking for a light kit with max movements. As for perspective, I know what you are saying, but since I am not shooting for a client, I do not have to make things look normal. I have always shot really wide - part of the walk around kit is to get me back to carrying long lenses and trying to learn to use them well.

Any tips for figuring out when I have exceeded the allowable movements for a given lens? I am thinking about a max elevation mark on the lens board for each lens. It would line up with the top of the Ebony side rail.

[Bob Salomon]

Thanks Bob. I suppose that makes sense. I do not use filters indoors, and color photographers do not use the much at all. But outdoors, shooting black and white, I almost always use a filter and it cuts a chuck out of a very expensive image circle on SS XL lenses.

Maybe the real problem is that I can never see the corners well enough with shifted, wide lenses to see if am out of IC.:-)

Using a Fresnel screen on your camera? Keeping your eye in the optical axis when doing movements? Do you have cut corners on your GG?

[Bob Salomon]

"even taking account that these lenses illuminate more than the rated image circle."

Not at the designed specifications for the lens. Yes you can go beyond the design specs but not at the quality level the lens was designed to provide.

[Brian Ellis]

My understanding (please feel free to correct if wrong) is that there isn't necessarily a clearly defined usable "image circle" with most lenses, especially not older lenses. There's the circle of good definition, which to some extent is based on what the manufacturer thinks is good definition, and there's the rest of the "image circle." Your filter may be cutting into the image circle but not the circle of good definition.

[Ed Richards]

Hi Bob,

I have an Ebony, with the Ebony Fresnel. It does not have cut corners on the GG that you can sit through - they are cut, but blocked by the frame of the GG holder. I have a tilting loupe to stay on axis, but I just do not see enough to tell what is happening with large amounts of rise and fall.

[Neal Chaves]

I recently bought a 150mm f8 SW Nikkor from KEH and at the same time ordered 95mm Nikon filters, a L1A and a polar from them. Before mounting the filters, I checked to see that would clear the front element (the old lens tissue test) and found they both would have contacted the lens front element well before being tightened down. The result could have been a broken filter and a damaged lens. I sent back the Nikon filters and exchanged for B&W and both cleared with room to spare. Yesterday I photographed with the lens for the first time and was able to raise the front quite a bit with both filters in place before I started cutting off the the corners at the top of the image. With only one filter in place, I can use all the rise I want, but this is a field camera, Toyo 810M and rise is limited compared to a monorail.

[Henry Ambrose]

Hi Henry,

snipped.......

Any tips for figuring out when I have exceeded the allowable movements for a given lens? I am thinking about a max elevation mark on the lens board for each lens. It would line up with the top of the Ebony side rail.

Ed,

That sounds like a fine idea to me.

Henry