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#16 |
Inner Circle
Join Date: Dec 2005
Location: Bracknell, Berkshire, UK
Posts: 4,957
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Re: ex1r lcd brightness out of the box
Come on Doug get off your high horse for a moment please. I agreed that your method is completely valid, I don't have to resort to questioning your knowledge or practices to justify my own approach and there are plenty of examples of my work on the web for anyone to take a look at. What is so "ironic" about my willingness to continue to learn about new methods and techniques while at the same time sharing the way I work with others?
I very, very often shoot for direct to air, I don't always grade in post. Besides with the EX cameras unless you've modified your knee or are strictly sticking to CG2/4 then your going to be producing illegal levels which will need some work in post for broadcast work anyway. Look at any of the airshow or storm chasing programmes that I shoot and you will see that I can nail exposure with just the LCD in some extremely difficult and varied lighting conditions. Yes, I do expose a tiny bit conservatively, because over exposure cannot be fixed in post. I am not guessing at my exposure, nor am I lugging around a WFM, I am using the LCD to accurately judge exposure and if you'd read my post using the histogram and spot meter if I need to. I am not asking for advice on S-Log shooting in the other thread. I asked for a discussion on the subject and laid down my cards with the method that I use as I believe that there are multiple approaches (including zebras) that can be used and I'm curious and wish to explore alternatives. Would have been nice if you could have contributed, perhaps you could have let us know what zebra level you use for S-Log where mid grey is often set at 38IRE but white only exposed at 68IRE to allow for whiter than white highlights, or are you afraid that someone might not agree with your approach? Yes race cars do have rev counters but many drivers will shift based on the noise, a sound recordist will often hear a high level in his headphones that he will know is too high without looking at a meter. The counter/meter etc are indeed invaluable guides, but guides is all they are. A colourist using a monitor is an entirely appropriate example as isn't a camera operator trying to achieve exactly the same thing as a colourist? I.E. a good like image? What is more important, whether the overall picture is pleasing to view or whether faces are at 70 IRE, or whatever you set your zebras too? The EX1/F3 LCD can be easily shaded with the simplest of hoods wrapped around it, even a piece of cardboard can be used. The OP is using a loupe so shading/viewing angle isn't going to be an issue for him anyway. Yes it's small but size does not change the relative brightness levels and it can be sufficiently accurately calibrated using the pluge bars along with the brightness and contrast controls. I do prefer an external VF, but that's not what's being discussed here. Also how do you use Zebras when perhaps one shot might be nothing but sky then the next might be something very dark. Do you change zebra levels or just normalise everything to 70IRE, perhaps heaven forbid, you might even have to look at the picture on the LCD and make a judgement call? Cinematographers use light meters because they don't have nice colour monitors outputting the actual output of the sensor or film stock. In fact in the early days of film exposure was judged by eye, light meters were a relatively late invention in the 20's and 30's. It is my opinion that if film had never been invented and we had gone straight to electronic capture, then light meters would never have become the exposure tool of choice for movie producers. So come on Doug, I thought you were a big enough boy to not have to resort to completely unhelpful comments such as to whether I've posted examples of my work online or why have I asked to discuss exposure on anther thread to justify your own ego and methodology. You don't have to criticise the fact that I am still willing to learn just because I choose to use a method that works very well for me that is different to yours. I did not, do not, criticise you for choosing to use zebras, that's your choice, but IT IS NOT THE ONLY WAY TO EXPOSE, there are a multitude of other perfectly valid methods, each with it's own pro's and con's, possibly even a light meter! THE most important thing is for people to have a range of valid and acceptable alternatives so that they can choose the one that works for them. You chose Zebras, I choose not, but at some point in your career you have to make that choice, the best choices are made when you are given alternatives, not - this is the only way that works because I said so and anyone that disagrees with me doesn't know what they are doing.
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Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com Last edited by Alister Chapman; November 9th, 2011 at 03:06 AM. |
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#17 |
Trustee
Join Date: Sep 2004
Location: Chislehurst, London
Posts: 1,724
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Re: ex1r lcd brightness out of the box
Doug in the red corner v Alister in the blue corner,
is anyone keeping the score? Keep at it lads, ps. I used zebras for my exposure
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#18 |
Inner Circle
Join Date: Dec 2005
Location: Bracknell, Berkshire, UK
Posts: 4,957
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Re: ex1r lcd brightness out of the box
Jim. I do sometimes use Zebras at 100% (as I stated in my first post), or at least Zebra 2 which is fixed to 100IRE. The reason for using 100% zebras is as an indication of areas in the image that are at or near to being overexposed or being compressed by the default manual knee or Auto Knee. The zebras normal have a 10% window, so when set to 100% when a video level reaches 95% you will see the zebra pattern, indicating that that area is close to over exposing or in the knee compression zone and will therefore be being compressed. One very important issue with this that you need to be aware of is that as the EX records up to 108IRE it is possible to have highly over exposed areas that do not exhibit any zebra pattern with zebra 1 as the entire over exposed area may be above the 95-105 IRE window of the 100%, so, no visible zebra is not a guarantee that you don't have clipped highlights with zebra 1. Zebra 2 on the other hand which is fixed at 100IRE has no upper limit so will still appear on the image with levels higher than 105, but if you use a manual knee lower than 95 having the Zebra at 100 is less useful.
60-70IRE knee is used to set exposure on skin tones and similar brightness values such as typical foliage, grass and many natural objects. Again remember you have a 10% window so if the knee is at 70 then onset is at 65 and it goes away again at 75. For many faces and skin tones the zebra set at 65 should give nominally accurate exposure of faces when you are starting to see zebras on the face. Watch out however for highlights on cheeks and foreheads which will be at a higher level than 60IRE (or possibly the upper end of the window at 70IRE) if exposing the rest of the face correctly. Of course actual desirable exposure level will depend on the mood of the scene, lighting effects, contrast ratio's etc. You also have to consider how your shadows and highlights are behaving once you nailed your faces etc so often then need to come up or down in exposure to suit.
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Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com |
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#19 |
Inner Circle
Join Date: Dec 2005
Location: Bracknell, Berkshire, UK
Posts: 4,957
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Re: ex1r lcd brightness out of the box
Vincent: Which menu setting do I use to get 4 Zebras on the screen at once like that?
Funny.
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Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com |
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#20 |
Trustee
Join Date: Sep 2004
Location: Chislehurst, London
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Re: ex1r lcd brightness out of the box
Just follow your animal instinct :-)
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#21 |
Inner Circle
Join Date: Aug 2006
Location: Poland
Posts: 4,086
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Re: ex1r lcd brightness out of the box
Don't know the exact menu setting Vincent used, but it must have been saved into PP4 for sure :)
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#22 |
Vortex Media
Join Date: Jan 2009
Location: Florida
Posts: 3,438
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Re: ex1r lcd brightness out of the box
Hey Alister, relax. I disagreed with your first post so strongly that I just couldn't sit on the side and let it go by without saying something. You do the exact same thing all the time whenever you strongly disagree with someone -- so don't call the kettle black.
Your second post fills in a lot of missing information and I'm glad you took the time to elaborate on your methods. If my post that offended you so much had anything to do with spurring you to take the time to provide further explanation, then I'm glad it worked. Hopefully your methods will now make more sense to the people reading about them. This thread isn't about how you and I set exposure (with decades of experience under our belt) . This thread was started by someone (and is being read by others) who is having trouble learning to set the exposure and is asking for our advice. Please go back and read your first post again. Is that REALLY what you would tell a novice or someone in one of your classes? With no further explanation? I hope not. In my opinion, it starts a novice down the wrong path and will lead to nothing but trouble for the rest of his career. The #1 issue I run into in my workshops and classes is exposure. 50% of the questions people have, are directly related to not understanding how to set exposure. And for you, a respected DP, to tell them to just calibrate the tiny LCD on their camera and then expose so the picture looks pretty -- is not the right way to go. Maybe YOU can do that and get good results, but I feel strongly that is terrible advice to be giving to a beginner. I agree that experienced professionals in all occupations may not rely on scopes, meters, and other tools after a certain point in their career -- but you don't tell a beginner that he can ignore them. That's just bad advice. As I said before, setting exposure is not hard. It does not require any extra equipment. It does not take any extra time to get it right. You don't need to expose conservatively. And there is no excuse for not nailing the exposure on ALMOST every shot. Nobody's perfect, but with the proper use of zebras, you can come very close. BTW, I'll meet you behind the south hall on Monday morning at NAB, just behind the packing crates. Bring your gloves. I'll be the one wearing stripes and riding a high horse.
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#23 |
Inner Circle
Join Date: Dec 2005
Location: Bracknell, Berkshire, UK
Posts: 4,957
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Re: ex1r lcd brightness out of the box
Again I can't agree with you Doug. Being a true blood Brit, I'd prefer pistols at dawn, but hey, different methods of resolving an issue.
I do defend my corner very often, I'm not disputing that. But I don't feel I need to take it to a personal, prove this, show me that level and as I said I don't disagree with your methodology, just that it is not the only way. I do spend time teaching how to calibrate a VF or monitor in my workshops and I do teach how to expose without aids such as zebra, metering or WFM's. I think being able to judge exposure by eye is a critical part of the video production craft and the sooner it is mastered the better, in my opinion. I believe there is too much reliance on aids, setting this brightness to that level etc. It cramps the artistry that's supposed to exist in imagery. If working by setting "x" brightness at "y" level really is the best way to work, then why not use one push auto iris for every shot as this will expose very consistently. But as you and I both know, that is far from ideal, we as human beings are able to much better judge an entire image and make a sensible choice than a dumb camera (or at least I like to think so). So, yes certainly using zebras is a very valid approach to exposure, but it still doesn't replace a correctly calibrated viewfinder in my opinion or the ability to interpret what that viewfinder is telling you about the image you are creating. Your milage probably differs from mine, but there wouldn't be a lot of point in these forums if it was all black and white. You'd just read the manual and follow the instructions.
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Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com |
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#24 |
Trustee
Join Date: Nov 2006
Location: Honolulu, HI
Posts: 1,435
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Re: ex1r lcd brightness out of the box
Very intriguing! From what I've read so far, if a director says to shoot a scene and make it look dark, Alister can shoot a scene that looks dark, and Doug will be able to tell everyone exactly how dark it is.
Just out of curiosity, Alister, how do you calibrate an EX1 viewfinder lcd? What are the exact steps? Are you using charts and/or color checkers? I've always relied on histograms and zebras, but your method is also valid as long as the lcd is properly calibrated, which I don't think I've done properly. I know how to set pluge bars, but my lcd can't do blue guns only for color calibration. |
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#25 |
Trustee
Join Date: Sep 2004
Location: Chislehurst, London
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Re: ex1r lcd brightness out of the box
As the self appointed referee in this debate. I actually use both methods, Zebra and LCD screen. I set my LCD screen up about once every two weeks or just before any job. I shoot a short clip and put this on a time line. I look at it on-screen and also compare the LCD screen to the display on my monitor and make any adjustments if needed. I also use the SMPTE bars to fine tune the LCD screen.
When on location I will also use the zebras to ensure that highlights are not totally blown. However, I do find the lines a distraction in most shooting situations, so I turn them off once the exposure has been set. I think a properly calibrated LCD screen is vital, having a poorly set up screen doesn't inspire confidence when shooting. LCD screen have come a long way over the past few years and can provide up to 90% accuracy for determining exposure. Doug likes to achieve the colour and perfect exposure in camera, which is a good way to work. However, colour and exposure can be fine tuned in grading, which doesn't take that much time with most or today;s fast computers. Alister is an experienced DP and knows how to achieve a look, using whatever tools are at hand. This reminds me of my stills photography days. Pointing a exposure meter at a scene will produce an average reading, which will work in most situations containing multiple tones. However, when photographing a "Black Cat in a Coal Cellar" then the exposure is going to be wrong, the subject will be rendered as a mid tone grey. An experienced photographer will know where to place the exposure in order to interpret the black cat, or white dove on snow, correctly. Just my thoughts
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#26 |
Major Player
Join Date: May 2002
Location: West Central Florida
Posts: 762
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Re: ex1r lcd brightness out of the box
I'm also coming from a still photo background and I always wondered about setting proper exposure either by using my handheld meters OR by using the EX1's internal exposure reflectance readout. For example, if I take one of my Kodak 18% grey cards and point the camera at it and dial in an exposure that reads "50" in the viewfinder, can I assume that I'm getting the proper exposure for mid-tone values?
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#27 |
Inner Circle
Join Date: Dec 2005
Location: Bracknell, Berkshire, UK
Posts: 4,957
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Re: ex1r lcd brightness out of the box
That's pretty much correct Dave. An 18% Mid Grey card should equate to around 50% on the EX spot meter. However exposure is more subjective than that. With film where you couldn't see the actual recorded image while shooting you had to make a judgement based on using a meter to measure the light falling on or reflected from the scene. Typically with film you would expose mid grey at the video equivalent of 38-40% to allow for over exposure headroom. With a video camera things are different. We can see on a monitor or measure with a WFM the actual recorded image, so we are in a much better position to accurately expose based on the entire recorded image. So while setting mid grey for 50% is a starting point, you don't have to religiously always expose mid grey at 50%, instead you should be exposing appropriately for the mood and overall contrast range of your scene.
To calibrate the EX LCD, select SMPTE Multi Bars. Then looking at the LCD, tilt it until you see the greatest contrast between the thin black bars at the bottom right of the screen and the black around them. If you can't see the 5 bars increase the brightness control in the menu. Now adjust the contrast until the until the white blocks no longer appear to be getting any brighter. On most EX's this will be the default zero setting. Now go back to the 5 black bars at the bottom right. The first left hand black bar is just below black the next is black, then just a little above black, then black again, then a little more above black. You should adjust the brightness control until you can just, no longer see the blacker than black bar, you should still be able to see the two above black bars against the black of the background bar. Most EX's end up with brightness between +20 and +24.
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Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com |
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#28 |
Trustee
Join Date: Nov 2006
Location: Honolulu, HI
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Re: ex1r lcd brightness out of the box
Thanks for your explanation, Alister! Upon reading your last post, I just realized I was making a big mistake without even realizing it. When I first set up my pluge bars 2 years ago, I used the "lcd backlight" controls under the handle to adjust the image brightness instead of the lcd menu brightness! Duh.... Now that I messed up the lcd backlight setting, what was the default? Was the bar graph in the middle? Or full right??
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