Getting Correct Exposure - Need Advice
I'm using an EX3 with a Letus Ultimate adaptor. I've got the zebra set to 95% and I'm shooting with CINE4 and HIGH SAT and some reduction to the black levels (setting that Doug recommends in the Vortex Media training DVD's).
Matrix>Setting: On Matrix>Select: High SAT White>Preset: 5600k (as done in item 12) Gamma>Select: CINE4 (identical as the F300 cameras) Black: -3 Black Gamma: -2 Anyway, I seem to be under exposing much of the footage I'm shooting. A friend of mine was with me on my first shoot with the camera and he pointed out that colors look better if the footage is a bit under exposed. So I've been trying to shoot with just a touch of zebra. This becomes a problem when I have a bright light in the distant background. The light may only consist of 3% of the entire frame, but it can show strong zebra. In this case I usually forget about it, and expose on the rest of the frame. I find myself using the Levels control in AfterEffects quite a bit to correct under exposed footage, so I've gotten used to using a Histogram. So on my last shoot, I tried turning on the histogram and I liked it. Does anyone else shoot with the Histogram turn on? Any other advice? Maybe it's because this is the first time I've used a camera with CINE GAMMA and I'm not used to the "look" of it. Dunno.... Could also be my viewfinder settings. I set them up to color bars, but maybe the knobs have gotten bumped? (thinking about putting gaffers tape over them) |
Why do you set your zebra so high? The secondary zebra is preset at 100. Most are setting there primary at 70 or 80. I'd start with that.
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Thanks Brian. Could it really be that simple? I'll try it.
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If you do have a lot of white in your picture, you have to accept zebra's. I have my zebra set to 95 and I have learned too work with that. I do knot know the cine settings - but you have to mess with the knee and slope settings. If you dont, the camere will not compress the white and white will blow out. It's been discussed in other threads and that helped me with my problems of exposure.
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btw, tried auto exposure in what would not be considered severe conditions and it clipped. Auto bad. Manual good. |
Thanks everyone. I'm going to try setting my zebra's back to 70 (factory default I think). I never shoot with auto exposure or auto focus.
Nobody ever uses the Histogram? |
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I use Zebras at 70 or 75 to see "correct iluminated caucasic faces" Then Zebras at 100 to know where are my Whites And marker (don't remember the exact name), wich is this tiny square with a changing percent value in the midle of the Lcd screen, to read exposure in any part of my frame. I find really usefull this last feature. Is like have my Spot meter inside the camera. If you understand Zone sistem (ala Ansel Adams) this will help a lot more than the histogram, couse you know exactly how bright is that spot of your scene, and that lampshape, and the dark side of that face, and that shadow down there etc. etc Trying to read all this with the histogram, is guessing, becouse that spike in the medium exposure values could be the face of your talent or the abstract art picture behind him. If Sony change the histogram for a Waveform in the next firmware update I will make a conmemorative monument here in Tegucigalpa, with old "bronce VHS tapes" LOL Any way, at the end, it does not matter wich tools you use for exposuring your image only how it looks at the end of all the process. Andres |
Well put Andres. I'm going to try some of your suggestions on my next shoot. The "shot box" is especially intriguing.
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For HD most people are putting faces around 60 - 65 instead 70 these days.
Probably on the low end for a cine gamma but I don't use it so that's just a guess. |
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Thanks again everyone. I'm anxious to try this for my next shoot, but I have nothing scheduled until next week.
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I tried using histogram as a quick way to get good exposure, shoving everything to the right and then backing off, as you would do with a still camera with RAW footage, but results were uneven depending on lighting situation. A better approach is to spend a lot of time testing and getting your viewfinder calibrated to your monitor, so that if it looks overexposed in the viewfinder, it really is overexposed. With the exception of hot spots, which zebra picks up, this works for me. And I get very different results than if I use Auto.
But I do find auto helpful on a complicated exterior shot, such as long zoom in or out with focus change and big exposure change from cu to wide or vice versa, where change is slow enuf not to notice and auto helps you bridge that big exposure divide. |
Thanks Mike, I'll keep that in mind. Good point about setting up the monitor. With our old Canon XL-1S I got pretty good about just "seeing" a good exposure in the viewfinder. Not using zebra's, histogram, etc... Maybe I just need to get used to this new viewfinder.
I watched the Vortex Media Training DVD again and Doug (the trainer) made an interesting comment. He said "personally I think it's better to err in the direction of overexposure rather than underexposure". On my first day of using our new EX3, my buddy was hanging out with me and he told me that I was overexposing the test shots we were shooting. He said that especially with HD cameras it's better to err toward an underexposure because it really brings out the colors in the image. This is something I've been trying to achieve on all my shoots since I got the camera. But now I'm starting to question this logic. Maybe it's because I'm using CINE 4 Gamma and he's has no experience with CINE Gamma. I dunno.... What gamma setting do you shoot with and do you err toward overexposure or underexposure? (Yeah, I know, perfect exposure is what we're really shooting for) Also, I've been shooting with the Doug's (Vortex Media) Picture Profile. He recommends Black and Black Gamma to be set to -2. Maybe that's another reason my stuff looks a little muddy. Dunno... |
Hi Mitchell:
It is better to err towards underexposure, because once that highlight is gone, it's gone. It's not like shooting digital SLR RAW, where you want it to be as high as you can go. Although this probably belongs in a different thread, here are my PP settings. When I used this setting, the picture through my eyes was identical to the picture on the monitor. Anything else I felt was best left to post. Matrix On Standard Level 0 Phase -5 RG +75 RB 0 GR -18 GB -18 BR 0 BG 0 Color Correct Off White Off Detail On Skin Tone Detail Off Knee Setting On Auto Knee On Point 90 Slope ) Knee Sat 50 Gamma Level 0 STD4 Black - Black Gamma 0 Low Key Sat 0 |
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In general, if you have most of the shot looking good but you still have a part of the picture that is overexposed it is going to be a bright cloud, a background window, reflections on water or chrome, etc. It is better to let those things blow out than to bring the entire exposure down and get muddy blacks all around. Muddy shadows is what ruins the picture more than some extreme blown out hightlights. Even in high-end feature films you often see blown-out hightlights. It is not the end of the world and is better than underexposing the rest of the scene. Obvioulsy, the ideal thing is to get your exposure dead-on in the first place. Why err either direction? Getting the right exposure within 1/2 to 1 stop isn't so hard if you use the zebras properly (not at 70) and have a little experience with the camera. Doug |
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Like you say. it "Depends." |
Thanks for all the great replies guys! (Doug Jensen....WOW!)
I think I've come to a couple of realizations. One that is kind of stupid and the other is helpful. 1) Expose your subject. In other words, if you're shooting an interview and the talent looks perfectly exposed, but you have some 95% zebras on a lamp (or what ever) in the background, don't worry about the zebras. On the other hand, if you have 95% zebras all over the talents face, then you're obviously over exposed. Duh! :) 2) Setting the zebra level to 100%. I played with this a bit last night. If I'm having trouble with underexposed footage then I want to turn my zebra's up (100%), not down (70%). Maybe it's because I've been a videographer so long, I'm used to 100% zebras. Because when I switched to 70% EVERYTHING had zebras. (that would take some time to get used to) The only other thing I'm concerned about it Doug's settings of: Matrix>Setting: On Matrix>Select: High SAT Gamma>Select: CINE4 Black: -3 (this is the one I'm concerned about) Black Gamma: -2 (and this one also) I turned Black from -3 to -2 for my upcoming shoot on Thursday. We'll see if that makes an difference. Maybe I should have turned them both up to -1 or something. I wish I wasn't so busy, I would like to take some time to do some test shooting and dial the camera in to my taste. |
I use Doug's settings and I'm getting beautiful results. Ouch! Now I have to get a cast for my arm...
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Good to know. Thanks Jay!
The weather's been really bad here. All of the shoots I have done with our new camera rig have been indoors with tungsten lighting. I wonder if that makes a difference? I'm guessing that Doug's settings will look fantastic outdoors with plenty of light. |
I've used the same settings indoors and out--no problems whatsoever. And from the looks of Doug's videos, the same is true for him (he states he uses the same settings).
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Have you used them with a 35mm adaptor? (that could make a difference....no?)
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No, that wouldn't work for the kind of videos we do.
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Also, are Doug's setting suitable for the EX3 or EX1? Which camera did he use? |
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If you're not used to it, it can sound confusing, but the patterns are very different (move different ways) and it shouldn't take too long to get used to it. My personal preference is for zebra 1 to be 100% (so you know what's peak white), and zebra 2 to show levels between 85%-90%. With a face, that normally means a little bit of zebra 2 on the brighter parts of the face, which tends to be easier to work with than zebraing covering the entire face. |
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I would be very careful with applying black/black gamma. Negative values will, of course, drop the shadows to black until shadows get crushed. So much of the use of this(or any) setting is a function of the overall lighting in the scene. Negative values increase the dynamic range at the expense of loss of footroom. It becomes very easy to crush the shadows, not necessarily a desireable thing if your shooting, for example, a stage production.
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Thanks Bill,
So in your opinion, when using CINE4 and HighSAT, there's no reason to reduce the gamma levels? I shoot what you could describe as "stage" shooting (lots of tungsten lighting with a dark background). My video looks like the blacks are slightly crushed, but I thought it was just because I was slightly underexposing. I'm guessing you can get away with crushing the blacks a bit of you're shooting outdoors with lots of light. But when shooting indoors wide open, especially with an adaptor, the blacks can look crushed? Dunno.... Other people are having good luck with Doug's settings, but I think the difference is I'm using an adaptor and they are not. I need to do some shooting without the adaptor but with Doug's settings. :) |
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Just for grins, if you have access to an HD monitor, even if you have to rent one for a day, take it to your venue and watch the image while you adjust the black gamma and black level. You'll surprise yourself. Image capture is not perfect. Most people think that "crushed shadow" look looks better than an exposure with proper shadows. A properly exposed image, with detail in the shadows, looks less contrasty, which is what is deceiving. |
I do have a brand new JVC L3 24-inch HD pro monitor. We're planning to do some testing with it today.
Thanks! :) |
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