Rear filter mods...

[Blighty]

Fellow Apuggers,
I recently acquired a Nikon AF 16mm fisheye. It comes with a few rear fitting filters. I was thinking of using one of these and sticking an Ilford SFX filter to it. My question: Is there an obvious reason (one that I have completely overlooked) why this would not be a good idea. Many thanks, Blights.

 

[AgX]

To my understanding supplied filters near the lens are part of the optical calculation. Exchanging them for thinner foil filters could harm the performance of the lens.

In my 500mm catadioptric lens the filter slot lies at the rear of the lens and the user is advised at least to have the supplied clear filter inserted. So check with your set of filters.

However for using filters near the focal plane in systems which are not calculated for that a foil filter should be used.

 

[Blighty]

Thanks for your reply AGX. I'm actually using one of the supplied filters (the warm up) and I've stuck an SFX filter to that. So all the optical elements are still present.

 

[Blighty]

Well, in answer to my own question, I tried my DIY SFX rear filter and it worked rather well (at least the negs look good). On the down side - and a pretty big down it is 'n all - there's an awful amount of faffing around to do before you get the shot. Firstly, you've got to compose the image, make a note of the focussed distance, meter it and apply compensation etc. Next - and this is the real ballache - you've got to remove the lens, remove the rear filter and replace it with the SFX filter, remount the lens and set the distance plus focus shift. Other than that, it's dead easy . Maybe I'll post some images when I print them.