80 Series filters still needed?

[Medavoym]

Hello!

On the RED ONE - the old M sensor - I often find myself using Tiffen 80 Series filters (80A, 80B, 80C - the last being the most frequently used) when I shoot under tungsten lighting. I find the results much better.

What is the general consensus regarding 80 Series filters with the new MX sensor? Do people still need them under tungsten lighting? I heard the MX sensor is much better in those condition, but it is so much better that it negates the use of blue filters completely?

As we make the transition from RED ONEs to EPICs, I wonder what filter items we still need to keep or lose in the transition.

Thanks!
Mike Medavoy

P.S. Another issue is Hot Mirrors, but I think I will keep those as the IR problem - although much improved - still creeps up apparently at high ND densities. But I do really wonder about the blue filters!

 

[Dan Hudgins]

Optical filters

Optical filters

It all depends on how much noise is too much as far as the 80 series, and is your source 3200K or 2600K or 1900K, the lower the K the less blue signal you have and then you open up and you may clip the red signal. So its not just noise, you can also clip with unbalanced light, and it depends on your exposure and subject matter.

As far as the de-Bayer goes, its better I think to have the red/blue balance close, the more unbalanced the more issues you get. In general the green clips about a stop or so before the red/blue when they are in balance for most sensors, you can look at your histograms for the RAW data to see what you have.

Any IR filter only blocks part of the IR, so if you need a second filter depends on how much IR you have on the subject vs. how much ND or other optical filters block visable light and pass IR through, to counterbalance the IR cut ratio.

I would use optical filters to balance the light as needed to keep blue/red signal on the sensor within +/- 1/2 stop when there is enough light to get best results, that will always be true both for film and digital cameras.

There is no way to say that "so and so much degradation" of the image is OK, for all uses. It depends on the end use and how large the screen is and how close you are to the screen and the resolution of the projector and so on.

 

[David Battistella]

I did a tungsten shoot last week and used a eighth blue on everything. Even on MX it just offsets things and I find it also makes the images slightly sharper.

The sensor is still about 5000K native so pushing the spectrum toward that, i find, helps the image.

David

 

[David Mullen ASC]

I'm not sure it's necessary anymore with the lower-noise of the M-X sensor, except maybe at really high ASA ratings (in which case, you are likely to be in very low light levels and not want to lose exposure with the blue filter) or when doing chromakey work.

I mean, if you are doing some sort of commercial shoot with a ton of lighting and don't mind opening up the iris further to accommodate the blue filter, then go ahead, but for your run-of-the-mill dramatic night interior scene with small tungsten practicals and whatnot, I'd rather have the extra stop on the lens rather than give my blue channel more signal strength relative to the other two, if it's a choice between shooting the scene at f/2 versus f/2.8.

 

[Tim Sutherland]

On the MX show I'm working on now, we shoot everything at 800 ISO, and we're just changing the white balance to 3200 instead of using blue filters. On the last show we shot all interiors at 1000 ISO 3200K for the last two episodes, and noise was not a problem.

If you're really concerned about it, I'd say use 500T or 640T settings inside. The Social Network was shot at 500T for interiors and on the Digital Projection I saw, there wasn't any noise whatsoever. And from what I've seen, I doubt they had to do any noise reduction to make it look that way. That's my reaction after shooting nearly 200 straight days with the MX.

Of course, there's no technical reason why you couldn't use the 80 series, but David makes some valid points about the actual gains from it. If you're going to give up that much stop, it's probably easier to just lower the ISO of the camera slightly, then you don't have any filters at all.

YMMV.
Tim

 

[Harry Clark]

I generally only use an 80C or 80D now with green- or bluescreen. It's my opinion that this is still one circumstance where it's best to get all three channels as much in the same ballpark as possible.
Otherwise, I have pretty much given up on the 80-series with my MX's...
Cheers,
Harry

 

[David Battistella]

I'm not sure it's necessary anymore with the lower-noise of the M-X sensor, except maybe at really high ASA ratings (in which case, you are likely to be in very low light levels and not want to lose exposure with the blue filter) or when doing chromakey work.

I mean, if you are doing some sort of commercial shoot with a ton of lighting and don't mind opening up the iris further to accommodate the blue filter, then go ahead, but for your run-of-the-mill dramatic night interior scene with small tungsten practicals and whatnot, I'd rather have the extra stop on the lens rather than give my blue channel more signal strength relative to the other two, if it's a choice between shooting the scene at f/2 versus f/2.8.

Yes.

Very good point. I see totally see that.

David