View Full Version : Ebony Fresnel and graduated neutral density filter

Edwin B.
10-Feb-2005, 13:00
I've been using an Ebony 45SU for several months with the standard GG setup. It has a Fresnel sandwiched between the GG and a protective glass. I've noticed that it is difficult to position NDG filters accurately based on visual inspection of the GG. I am wondering if part of the problem is the Fresnel. It seems that as the dense portion of the filter enters the frame that the reduction in illumination is partially spread across the entire frame making it difficult to discern where the transition is. Right now my work arounds involve positioning with a 0.9 NDG filter with the lens stopped way down and then swithching it out for whatever strength NDG I really want to use. Positioning the filter while viewing through a loupe also helps a great deal. Does anyone know if fresnel screens encumber NDG usage? If not any advice on technique would be appreciated.


Steve Hamley
10-Feb-2005, 13:01

I think what you're seeing is a natural part of grad usage. Here's a suggestion.

a) Put a Post-It note on the filter with the edge at the transition point. Much easier to position.

b) Cut a step in the post it with one edge corrsponding to the beginning of the transition and one corresponding to the end (full density).

Of course, stop down as much as you can.


Dan Baumbach
10-Feb-2005, 13:02
I can't answer your question about fresnel screens encumbering NDG usage but I can tell you what I do for ND Grads. I put a post it note where the graduation starts. The black square is easily seen and position. The post-it leaves no marks or residue on the filter.

- Dan.

Edwin B.
10-Feb-2005, 13:03
Dan and Steve,

Thanks for the suggestion. I will certainly give it a try. It sounds sensible enough and I don't think I would have even considered placing adhesive on my filter myself. The major benefit of your approach is that it should be as easy to place a 0.3 as a 0.9. Also, to Steve, I know what I wrote must sound like "a natural part of grad usage" and it may well be. The reason I ask is that it just seems so much more difficult with a view camera than the 35mm and MF cameras I've used, none of which to my knowledge had Fresnels and I'm trying to figure out why.

Steve Hamley
10-Feb-2005, 13:04

The reason why is that with lenses longer than about 120mm, all grads eseentially become "soft step". That's one reason why a lot of LF photographers like the "harder" Singh Ray filters.

Also, if you have lenses with small front elements, the transition is a larger fraction of the lens area.