Battle of the Big Stoppers - LEE vs. Hi-Tech

[Bart_van_der_Wolf]

Would a IR-cut filter "fix" that...such as a http://www.bhphotovideo.com/c/product/718009-REG/B_W_66_098703_66098703_77mm_UV_IR_Cut.html

Hi John,

Not necessarily, since the camera already has an IR filter. Perhaps the B+W filter cuts of a little closer to the visual spectrum, in that case it could make a difference.

However, in my experience with these filters (their effect is based on multiple interference coatings), the effect is not uniform across the Field of View. The more oblique rays at the edges and corners, have a longer traveling distance through the coatings and they will therefore attenuate different wavelengths than the chief rays. This results is a significant color cast from the center towards the corners. For Raw converters that allow to correct for such a color cast (e.g. Capture One, RawTherapee), that is less of a problem.

Cheers,
Bart

[rgs]

After a good deal of thought about IQ, adaptability, cost, availability and other things, I have just received a Formatt 77mm round glass 8 stop filter. I also intend to get a 3 stop one to use alone or stack with the 8 stop. One of my big concerns was the possibility of light leaks with squares. Also I could not see any reason I need a square for this type of filter (as opposed to grads). 77mm is the largest lens I ever expect to use and step down rings are cheap.   

My initial, very subjective test of the filter revealed no immediately noticeable color cast but some loss of contrast. I also found that my 50D will not meter accurately through it. Overall, I am eager to give it a more through shake down soon.