Diffusion Filtration

mattharding · September 11, 2004

I have a shoot coming up (super 16) where I am shooting a man in his late 40's who the director is trying to make appear a little younger. He has a very youthful appearance, but in close-ups I've noticed on previous projects, some subtle wrinkles under his eyes and forehead really kill the youthful image.

I have always stayed away from much filtration on 16mm (this is finishing on video only), but what I'd like to consider for this project is some light diffusion for the close up work and not for the wide shots. I'd want it to be subtle enough so that the use of the filter is not even identified as such, yet it would just slightly take the edge off the wrinkles on the close ups.

So my question is, due to the fact that I have to time or money for test shots, what might be a safe filter when shooting close-ups in the 80 to 120mm range? I would rather have no perceptible diffusion at all then to have too much. I was thinking a 1/4 black pro mist? Even if there are some spicy highlights in the frame...will I still be okay without obvious cheesy halos? Or any other thoughts? I want to be able to intercut the close-ups with wider shots that would have no diffusion.

David Mullen ASC · September 11, 2004

Diffusion filters vary in the amount of halation they cause, which in turn lowers contrast more and more as the grade gets higher. White ProMists halate a lot by design, Black ProMists a little less, and Soft-FX and Classic Softs even less than the Black ProMists. Finally there's the Tiffen Diffision-FX filters, which don't halate at all, just soften detail.

Which you prefer is a matter of taste, but I'd say that the most "invisible" type of diffusion would be the Diffusion-FX. But I have no idea which grade to use because I don't have much experience with them -- I like a little telltale artifacts like halation. In-between, there are the Tiffen Soft-FX and the Schneider Classic Softs -- you might try a Soft-FX 1/2, the lightest grade. You'd never "see" the diffusion and it would cut fine with wider shots that were unfiltered. To my eyes, Black ProMist diffusion definitely has a "look".

Avoid shooting too stopped down with diffusion filters lest you see the pattern in the glass.

mattharding · September 12, 2004

Thank you, David. That's very helpful....I hope I am able to find that exact level of diffusion that will take care of the facial inperfections yet not appear obviously fake. I wish I could test!

Greg Gross · September 12, 2004

Just a suggestion I had not sure if practical. Can you use Kino-flo ring

light (soft light to front of camera) to soften look(no filter). Then control

with angle,height of camera?

mattharding · September 12, 2004

That is a good idea....but for the close-ups I plan on keying with something like a 5K, pre-diffused then through a 6x6 bleached muslin and 1/4 cto to warm up the skin tone slightly. Probably does not get any softer than that and I will have control over the modeling. I think the face is going to need just a bit of help in front of the lens to take the unattractive edges off. Thoughts?

Michael Nash · September 12, 2004

I'd also recommend the Classic Softs or Soft-FX. Similar to those are Mitchell diffusion filters in grades A, B, and C.

Talk to the makeup artist and tell him/her your concerns, especially about the wrinkles near the eyes which will be seen in closeup. Lastly, there is some possibility of touching up the image in post or telecine, although that could be tough with moving shots.

Greg Gross · September 13, 2004

Gentlemen,

Thank you very much for your posts! I have learned a lot by reading your

technical descriptions,type of materials,filters.

Keith Mottram · September 13, 2004

I've had good results shooting clean and then diffusing in post with Genarts and/or Tinderbox plugins. This gives you increased flexability if you do not have the ability for tests. The plugins work in Shake/ Discreet and even After Effects, so if your doing a DI this could be an option.

Keith

Alvin Pingol · September 14, 2004

I'm sort of with Keith's decision on this one, seeing as how you can't do any tests.

Of course, using optical diffusion will give you results that are not reproducible in any post production suite, but just the fact that you cannot test is a bit frightening. Remember, you cannot remove diffusion!

You may end up with something that is way too powerful. Then what?

Or perhaps, you get a filter that is too weak for your tastes. This could be fixed somewhere during post, but take note that it would probably be a lot easier to digitally enhance a weak filter than it would be to lessen the effects of a strong one.

Seeing that you'll be finishing on video, you may even end up choosing a slightly stronger-than-usual filter to compensate for the smaller viewing screen. However, it still may end up being too much.

Is digital diffusion an option you are considering?

mattharding · September 14, 2004

Thanks first of all for all the interest.

I am open to any option but I must say I have never really been completely happy with digital diffusion but am open to higher-end options that I've never tried before. The other problem, as many DPs have, is that once I drive away from the set I may not have any control or say on what is done to the image. I may not even be invited to the telecine much less the edit session. So that 's why I would love to get at least some diffusion on the negative. It sounds like from what David said that if I go with the lightest diffusion, there is just about no way I can have too much. Sound right? At least there will be some softening.

The other option that I've been somewhat happy with in the past is finding a transfer suite that is open to putting and optical filter into the transfer machine. Maybe another option.

David Mullen ASC · September 14, 2004

I think if you use the lightest diffusion grade, you probably will be fine if combined with careful lighting. I've shot close-ups before in 16mm with a 1/2 Soft-FX without it looking too diffused.

You might shoot some tests with a few different grades during the actual shoot as a test for a FUTURE project...

F Bulgarelli · September 15, 2004

I understand your concern since diffusion, specially on men, could be very touchy. I would definetely go with no haloing effects like you mentioned. I'm with Mr Mullen, I think SFX is probably one of the most versatile and subtle diffusions out there.

good luck

mattharding · September 15, 2004

I think if you use the lightest diffusion grade, you probably will be fine if combined with careful lighting. I've shot close-ups before in 16mm with a 1/2 Soft-FX without it looking too diffused.

David....do you think I would still be okay shooting CU's at around 80mm? or tighter?

Also, did you have something specific in mind when you said "careful lighting"? Looking out for too hot a highlight? Proper exposure?

I really appreciate all the feedback.