Are (diffusion) filters becoming obsolete?

Stephen Alexander Griebel · February 22, 2006

OK, I'm organizing gear for my 1st 35mm shoot on 5222 Double-X film. I'm trying to get the scenes lit and shot as quickly as possible and spend as little on filters as I can. My question is, if editing on the computer, are diffusion filters (e.g.) and other aesthetic filters even necessary? Far more control can be gotten with computers than even the greatest of cinematographers can with all the tools in the world.

Now, I'm not talking gels or anything to do with lights (which can't be helped later) and I'm certainly not saying filters in general are gonners and just to work on the look in post (this certainly wouldn't be the place to do so!), I'm still an advocate of having a clear mood/look in mind beforehand... but other than 85, 80A filters, NDs and others to get the light balanced and control DOF, which filters are really going to make an imporovement? Everyone keeps saying to use orange filters to make clouds pop, but couldn't you just use editing tools to do the same with greater control (as long as the shot isn't blown out)?

When editing digital, you want the most basic and perfectly exposed footage possible so that you can really go for the look preconceived, or maybe you find a new one you hadn't thought about with all the options before you. David Lynch is finding this out. He was film's last big advocate and he said he's never going back after shooting miniDV because of all the options you have.

I'm also pushing the film two stops and will be underexposing from one to two stops as I see fit. I know this increases contrast which I could control much better in post, BUT, it gives you a "look" you can't get with any kind of computer touch-ups.

What I'm really asking, is what other filters/gauzes are there that do something that you can't get later?

Edited February 22, 2006 by stephen griebel

David Mullen ASC · February 22, 2006

Well, digital diffusion can look a little different; some techniques have the unfortunate effect of blurring grain, which will make it hard to intercut with the non-diffused shot.

The reasons why camera filters for diffusing aren't obsolete is that: (1) adding digital diffusion requires render time for each diffused shot, which can be time-consuming on a home system; (2) many of us cinematographers aren't also the editors, so might not be involved in post processing; (3) higher-end post routes may require equipment not budgeted for (for example, most DaVinci color-correction software cannot do digital diffusion, only digital defocusing, which is not the same thing. Only the places that spent the money on the Color ToolBox for the DaVinci have access to digital diffusion) -- in other words, diffused shots may require booking time in a Flame or Inferno suite after the DaVinci color-correction session.

Glass diffusion is very organic and interactive with the light values in the scene. And if you know you want to diffuse a shot, then why not do it in camera? Just to save on the money for a glass filter?

I am reluctant to subscribe too heartily to the concept of creating the look in post just "to be safe". We grow as artists by being bold and brave, taking risks, not by being cautious and avoiding mistakes.

Even though a lot of the diffusion in "Lord of the Rings" and "King Kong" was added digitally, Andrew Lesnie still shot some scenes with camera diffusion because he knew what he wanted, and there was no technical reason (like a bluescreen shot) not to use diffusion.

Michael Collier · February 22, 2006

Digital effects add digital noise. This is true of any edit system running any program with any combination off settings. Its a fact of life, you are boosting a level mathematically, without adding any information to fill the steps in between.

I am a fan of certain digital effects for ultra-fine tweeking, but when shooting even video I get the look in camera. (If you cant get it in camera, what makes you think you can get it in post? whats the difference between artistic inent and luck coincidence at that point?) The only effects I like in terms of DI (other than correcting mistakes) are related to contrast and saturation. Even with those my intent is only to draw the blacks where they need to be, bring the colors down (I always like to shoot more saturated than the final product will be) and make other broad value changes. However if you look at my computer you wont find any setting off more than 5%. If you cant get within 5% of your perfect image then you need more experience.

as far as diffusion goes, Mr. Mullen has it right. $200K DI, $200 glass filter.

Stephen Alexander Griebel · February 22, 2006

Deep down I was hoping that's the response I would get. I do like the organic-- analog, I guess-- look as opposed to the digital one...which is why I'm in this forum I suppose.

I did mean to primarily fine-tune in post with contrast and saturation anyway, but was just curious about the differences in in-camera vs. post diffusion....

Well, I guess I'm off to find a Virginia rental house or DP, maybe even a nice bank to rob.

By God, I'll get those filters.

Much obliged, guys.

Edited February 22, 2006 by stephen griebel

Max Jacoby · February 22, 2006

Everyone keeps saying to use orange filters to make clouds pop, but couldn't you just use editing tools to do the same with greater control (as long as the shot isn't blown out)?

No you couldn't. Color-correction tools use colors to seperate different elements, once you are in black & white that is hardly possible anymore.

Phil Rhodes · February 22, 2006

Hi,

Well actually you could, because you can do colour operations on a colour image then average it out to monochrome. I've done it. The technique is unfriendly towards subsampled video storage because it tends to highlight failings in the various colours; this can be particularly obvious if the blue channel gets noisy.

Phil

David Mullen ASC · February 22, 2006

Hi,

Well actually you could, because you can do colour operations on a colour image then average it out to monochrome. I've done it. The technique is unfriendly towards subsampled video storage because it tends to highlight failings in the various colours; this can be particularly obvious if the blue channel gets noisy.

Phil

Yes, but I think he's shooting in b&w so if he wants to change the color contrast (darken blue skies with red filters for example) he has to use camera filters.