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Vignetting on the 2485mm lense



Hi! I have noticed that there is a slight Vignetting when using the 24-85mm lense at the 85mm setting when using a Hoya filter ie:- a normal UV, or a 82b. Has anyone,any ideas of an alternative,to using these filters, in order to eliminate this problem.
Many Thanks.
> I have no experience with the use of filters on this lens, but using > the Contax flash, positive film and a film scanner, one can see > clearly a remarkable vignetting at wide angle.
The vignetting you see with the flash is likely to be light falloff from the flash which may not have sufficient coverage to cover the wide angle – not mechanical vignetting. Again, you shouldn’t see mechanical vignetting at the longer focal length (narrower field of view) if it does not occur at shorter focal lengths (wider field of view). If you examine the relative illuminance diagrams for the lens, there is a steeper drop-off at 85mm than at the shorter focal lengths. Perhaps this is what you are seeing?

I wonder which Contact flash you used. Although I mostly use studio strobes, I have used the TLA 360 flash a lot and have not experienced any vignetting at any range, sine the TLA 360 has a matching zoom range from 24-85mm. One thing about using the TLA 360 is that you have to point down the head when your subject is closer than one meter or so. It states in the user manual.

>While I cannot now recall whether the original post of this thread mentioned this issue, is it possible that the flash head of the TLA360 was not zoomed to the apprropriate focal length for the lens setting? That is, the flash was set to 85 degrees while the lens was at 50 degrees, or something

When you are using the TLA360 flash head on top the N1 (hot shoe), the zoom is automatically set when you change focal length at the lens. However, if you use the extension cord, I believe you have to set the zoom range manually since the extension cord has only 3 pin while the hot shoe has five pins. You may also have to set the ISO manually too. But everything else, including TTL, is all sync up.

Sorry Guys. My original question was regarding Vignetting when using normal HOYA filter.
Is there any other manufacturer that make a thiner filter, that could possibly elimnate this problem? Granted this situation is only applicable at the 85mm setting,as I zoom closer to the 24mm the problem clears.

B+W, Hoya and other manufacturers make thin filter for wide/super-wide angle lenses. They usually call it gslimh filter and generally there is no thread in front of the filter in order to reduce the rim size. Hoya now have a gPro 1h filter series which use thin glass and contain a front thread. The front thread allows putting a lens cap on when not shooting.

If it is the filter rim that causes vignetting, it usually happens at the wide-angle side not at the 85mm. I use Contax filters mainly but I do have a Hoya 82mm UV HMC filter for my other lens. I mounted it to the 24/85 zoom on the N1 and I just couldnft see any vignetting visually.

Did your problem goes away if you remove the filter?