Using a regular filter on a Nikon 90mm f8 lens

[Robert Ruderman]

Hi,

For those who use a Nikon 90mm f8 lens with their 4x5 camera -

Have you tried to use a regular (non-slim) filter with this lens? If so, do you get any vignetting from the filter ring? I am trying to figure out if what a salesman told me is true -- that you do not need to use a slim filter with this lens.

Can anyone say if this is really true?

Thanks,
Robert

[jarrod connerty]

Well sure it vignettes, but it does so upon the edge of an image circle that's likely excessive enough for 4x5 to not usually show the effect.

[Brad Rippe]

Robert,

I have that lens and I believe the image circle is approx 235mm, which is generous for 4 by 5. I use B+W filters (67mm) and have never had a vignette problem. I don't think you'll have a problem unless you are interested in very extreme movements. If that's the case, you might borrow the filter in question and set it up and check the corners.

-Brad

[Michael Hewson]

I use a Lee wideangle adaptor ring - works a treat - no vignetting.

[Steve Hamley]

Just a slightly OT comment here, it always amazes me that everyone understands and acknowledges that filters and hoods can vignette under the right conditions, yet sellers with lenses showing separation around the glass edges always claim "no effect on the image" - which of course there would be at the outer edges of the image circle, just like a vignetting filter.

Steve

[clay harmon]

Steve, if you picked up the edge separation and moved it to about an inch in front of the lens, yeah, it would have an effect. But edge separation on an element itself would not make the lens vignette, but would produce some scattered flare-inducing non-image light.

[Steve Hamley]

Clay,

Agreed, unlikely to actually vignette (I didn't mean to imply it would). But as you suggest, probably some degradation of some sort depending on the extent of the separation and the kind of degradation of the cement.

I think there would be some degradation of the image forming light near the outer edge of the image circle from edge separation. To believe there wouldn't be any degradation of image forming light would be to believe that lens designers are putting glass into lenses that isn't used (and they might for mounting the glass in the barrel but it wouldn't be much). Take a look at the Apo Sironar-S and Apo Sironar-N of the same focal length. The glass of the Apo Sironar-S is bigger as is its coverage (3 degrees more). They didn't put that extra glass in there for nothing.

Steve

[clay harmon]

Steve:

We are in violent agreement.

:^)

Clay