View Full Version : Can glass filters be screwed onto the rear element?

William Marderness
2-Apr-2000, 18:17
With lenses that take a large filter, can a glass filter be screwed on the rear element? I am interested particularly in the Sironar S 240mm, which takes an 86m m filter. If not, is there a convenient way to mount filters, including gel, on the rear. I have tried a rear gel mount from Calumet, but it needs to be permane ntly attached to the lensboard, and each lens would need one, which gets expensi ve.

james mickelson
2-Apr-2000, 19:12
Do your lenses have rear element threads for mounting a filter? If not, the answer is no. If they do, the answer is yes. I had threads put on a the rear element of a lens that has a 95mm front element and a 67mm rear. It takes a short sleeve attachment to clear the curve of the rear element. It works great because most of my other large and medium format lenses take 67mm filters. It optically makes no difference whether the filter goes on the front or rear as long as filter clears the curve on the rear element. James

Bob Salomon
2-Apr-2000, 20:09
yes you can mount filters an the rear but any filter mounted behind the lens will create a focus shift = to 1/3rd the thickness of the filter so all focusing must be done with the filter in place. In addition any dust, dirt, defects, smudges, fingerprint, etc, will have more of a detrimental effect on the quality of the image as the light passing through the imperfections has already passed through the lens. These effects on a front mounted filter while possibly effecting the image will have less of an effect then a rear mounted filter.

Lastly a front mounted filter adds protection for the front of the lens. A rear mounted filter does not.

Of course you must have a quality filter but for a rear mounted filter this is even more important.

Robert A. Zeichner
3-Apr-2000, 07:57
I had a similar situation with a 210mm Super Symmar. I found a slip on series 8 filter adapter at a used camera show and removed the retaining ring. The exposed threads seem to be 67mm, just the size of filter I use on other lenses. Measure the O.D. of the rear lens cell and try to find an adapter of that size. I think Harrison and Harrison still make these types of adapters. Good luck.

Emerald Estock
6-Apr-2000, 18:56
just an idea for the filter holder for behind the lense.I bought one holder and i have velcro on all my lense boards and can use the same holder for all lenses.This works for me

Dean Lastoria
14-Apr-2000, 21:50
I use a series adapter on my rear element, and it works fine, but since this discussion is open, I was wondering about a polarizing filter. Can that work on the back? Or does that one have to be on the front?