Lens light fall-off -- test results

[Mark Sampson]

Rael, I'm sure that it's possible in theory. However, finding a filter that would do the job would be troublesome and expensive, with no certainty of success. I'll avoid thread drift; send me a PM and I'll explain how we solved an uneven enlarger light source when I worked at Kodak.

[Jac@stafford.net]

Rael, I'm sure that it's possible in theory.

No way in our wildest dreams. A center ND filter in front of an enlarger lens for making prints from negatives would only multiply the problem. What you need is an inverse center filter which still would not work without significant vignetted area detail and contrast.
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[xkaes]

If your lens needs a CND filter, any picture taken with it will show less detail on the edges. There is no way to somehow create detail that isn't there -- OK, painting it in with some graphite, etc. is an alternative. You could use other techniques to darken the corners, which might help, but they would not add detail.

[xkaes]

Kenko is Hoya

Apparently, this is another complicated company merger -- this time Japanese. Looks like Tokina and Kenko merged at some point -- or one bought the other -- perhaps they were always the same. Then Hoya was mixed into the pot, somehow.

Here's what I found:

"Kenko Tokina and HOYA are two independent companies. HOYA licenses its brand to Kenko Tokina for camera filters being distributed outside Japan. Product planning and packaging are handled by Kenko Tokina."

It reminds me of the Osawa, Bell & Howell, Tokina, Mamiya-Sekor, Soligor plate of spaghetti from the 1970's. Tokina would make lenses that would be labeled as "Osawa", "Bell & Howell", and "Soligor" depending on the country/market/distributor. The overall company was really two companies "Osawa" in Japan and "Bell & Howell-Mamiya Co. (BHMC) in the US -- both of whom were distributors, not lens manufacturers.

So who knows makes Kenko filters. It might be Kenko, Hoya, Tokina, or another, completely different company -- or a mix of some sort. It makes me think that other "Kenko" CND filters -- sizes, densities, etc. -- might be out there. So far, I've confirmed that they made 62mm and 67mm 3X CND filters in slim-mounts (AKA, no front thread). It would be nice to see the instruction sheet on these filters since it would likely show the focal lengths/lenses they are designed for. I don't see anything on the KENKO, or HOYA websites.