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Canon XL H Series HDV Camcorders
Canon XL H1S (with SDI), Canon XL H1A (without SDI). Also XL H1.


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Old September 28th, 2006, 04:05 PM   #1
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Some pointers on adjusting the exposure??

I am a pretty experienced XL series shooter. I know all of the ins and outs of the auto exposure and zebra patterns and all that gobbly gook. Lately I am experiencing severely underexposed images. You know....they look kind of flat and washed out.

I am looking for pointers and workarounds for limitations of the camera. I usually rely on the zebras to judge exposure but with the H1 you need that damn peaking on most of the time to focus. At first I did okay but lately I am not happy with the footage as it looks too dark. I did adjust my EVF to try to calibrate it so I don't think that is the issue.

So how do you set your zebras and what do you use as a cuttoff visually? What about auto iris for those times where you need it? Any tips would be great. As I stated....I am underexposing too much.

Thanks!
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Old September 28th, 2006, 04:44 PM   #2
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I had pretty much the same experience based on the CVF being much too bright so the first step was to crank that down some. Second, there is one simple truth: if the zebra stripes are set to 100 and you increase exposure to the point where they are visible and then back off until they just disappear or set exposure so that they only appear in places where blow-out is acceptable you will have acheived the maximum exposure possible. This does not mean that the video may not appear too dark in some circumstances. In those circumstances you must increase the gamma in parts of the tonal range that you find too dark. This can either be done in post where you have relatively large freedom or by tweaking the gamma (knee, shoulder) in the camera where you are more limited and where what is appropriate for one set of circumstances may not be for another. For this reason I prefer to do it in post. In addition there are precious few images I have captured in still or video that have not benefitted from gamma tweaking and/or color correction in post. The catch is that this takes time and there are those that don't like my method (zebra stripes + post) based on that and for other reasons (which I don't recall but perhaps others will comment).

I learned to do things this way from the first digital SLR I owned. The gamma was just too shallow at the shadow end and you had to get the maximum possible exposure (using the histogram) and then raise shadow gamma in Photoshop on every single shot. The manufacturer got wise and rebalanced his curve in a later model (and let you download a curve to the camera as well - wouldn't that be nice for the XL-H1!).
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Old September 28th, 2006, 07:29 PM   #3
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I have had exposure issues too, and I've been shooting film for over 40 years and video for nearly 30... Yes, the viewfinder is too bright.. but, unfortunately, I find I need to keep it bright to focus accurately... I leave peaking on all the time too, so I don't have the benifit of zebra stripes... (make documentaries, tend to work fast and handheld)

I took an entire day and shot footage similar to what I normally shoot, and tried different exposure settings to get used to the image in the finder... Large white buildings, for instance, look completely blown out in the finder and still look a little dark on the monitor..hmmm

I've ended several previous posts this way...

New finder, please...
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Old October 1st, 2006, 03:44 AM   #4
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I find the exposure quite hard to manage. At first I put the Zebra @ 70 IRE, everything went completely dark. Then I turned the Zebra @ 90 IRE, and I got good exposure at mid but really blown out highlights. I had quite even light (fluorescents). Maybe I should put the knee point adjustment (KNE) to low.

So I think the answer is, if you can, go for even, dull and booring light - tweak in custom settings or in post. Chase higlights and shadows, with a lightmeter. Does anyone use lightmeters? Does the camera have any white clip in the menus?
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Old October 1st, 2006, 10:42 AM   #5
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Light it well! Also, I regularly put the nd filter on (even indoors) and open up the iris more. Seems to really help get more color and detail with a more open setting.
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Old October 19th, 2006, 12:58 PM   #6
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Under exposure

This is a classic example that illustrates the need to ALWAYS shoot with a good (professional) CRT monitor.

You are all correct - you cannot rely on the viewfinder for accurate exposure. However, having said that, by shooting a load of trial footage you should be able to learn to assess how the camera performs.

Pro shooters never rely solely on the viewfinder for exposure, they will always reference to a monitor. If you cannot afford to buy a good monitor, hire one. If you cannot afford to hire one... perhaps you could get yourself a second hand light meter and learn to read exposures (you would need to find out the asa/iso rating of the HI - the XL1s was rated at 3500 asa/iso, I believe - perhaps Chris H or someone would know this.

One final point - at least you are underexposing - you can actually do something about that in post - you can easily lift the exposure level by a good few stops (overexposing is the biggest crime, because once you lose detail in the burned out highlights, you lose it for good!).

Good luck.

Alistair
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Old October 19th, 2006, 02:39 PM   #7
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I think that's supposed to be 350asa not 3500 but I don't know film so I could be wrong. Does no one use the little light meter in the top left corner. I usually pick the most critical object (lighting wise) zoom in until that fills the frame expose for that by having it a notch below middle. then fill up the rest of the frame. Then I compensate my picture for that exposure. But that's just me.
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Old October 19th, 2006, 05:06 PM   #8
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Quote:
Originally Posted by Alistair Briggs
One final point - at least you are underexposing - you can actually do something about that in post - you can easily lift the exposure level by a good few stops (overexposing is the biggest crime, because once you lose detail in the burned out highlights, you lose it for good!).
While this is more or less true one doesn't want to overdo it with these cameras that only use 8 bits. Have a look at the histogram when boosting exposure in post. You will see the "pickets" start to separate as gain is boosted. If they get too far apart one sees "posterization" in the resulting image (interestingly enough the place I see most poserization is in broadcast HDTV). This is why I advocate using the zebra stripes to get the maximum possible exposure without "blowing" highlights. You may still have to/want to raise shadow gamma but you are less likely to get to the point where posterization appears.
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Old October 19th, 2006, 06:39 PM   #9
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Use TV Mode for Auto/Manual Exposure

A tip which Chris Hurd pointed me towards is shooting in TV Mode and using the Exp Lock button to switch between Manual and Auto exposure. As far as always using a CRT well many times it is not possible in documentary handheld situations. I do use the exposure meter in the viewfinder but whites are still hard to judge. Also remember settings in the camera can make your exposures more difficult in some situations.
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Old October 19th, 2006, 07:26 PM   #10
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The problem that I have isn't necessarily exposure per se.. it's getting the "look" I want.. I like to intentionally underexpose, overexpose, blow out windows - all the bad stuff - just as I would if I was shooting a feature.

I can zoom in and set my exposure, then frame my shot and dial the exposure up or down - but the viewfinder won't allow me to accurately estimate the image I want.. again, I shoot documentaries, mostly hand-held, with just a sound-person, so a monitor is not an option.. I have occasionally mounted a 7" Marshal monitor on my left handgrip, just above the follow-focus knob (I use the knob to manually focus the 20x, much better) - it's better, but it makes the camera pretty cumbersome going through doors and getting in cars..

I repeat - and I said this again to a Canon rep last week - new finder please..
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Old October 20th, 2006, 08:07 AM   #11
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Well guys when I originally posted this I had just finished a 2 month ordeal moving out of my old house, moving to a temp location, and then moving again to my new house once the current owners were gone. During this time I was not able to use the camera much and may have forgotten many of these little tricks. Either way, I recently setup the zebras to be 100 and I would gauge my exposure by not letting zebras in except when I am exposing a subject and the background could be overexposed.

Well.....guess what? I went too far the other way! I have too much blown out crap in the footage. Not all of it....but I guessed a little to high on a few shots. You know.....you think "last time I underexposed when I thought I was dead on....so this time....when I think I'm dead on....I'll open up a little and I should be right...."

Wrong.

Oh well. I think I have it figured out again and fortunately what I shot wasn't critical. When I do studio work I use an external monitor but when out in the field I have to really on the EVF.

Thanks all. Let's keep up the intelligent dialogue....it is really helpful.

Marty
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Old October 20th, 2006, 12:04 PM   #12
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Quote:
Originally Posted by Nick Hiltgen
I think that's supposed to be 350asa not 3500 but I don't know film so I could be wrong. Does no one use the little light meter in the top left corner. I usually pick the most critical object (lighting wise) zoom in until that fills the frame expose for that by having it a notch below middle. then fill up the rest of the frame. Then I compensate my picture for that exposure. But that's just me.
Sorry, it is indeed nearer 350asa/iso - a slippery extra ‘0’ got in there!

With something so critical as exposure and so fickle as mini DV and HDV, its no wonder so many people get it wrong. When setting exposure, you have two or three choices to make: Expose for highlights; Expose for your subject (like Nick is doing above); Or let the camera choose the exposure, which will essentially be an average of what is in the field of view.

The first option means you have no danger of overexposing - this may make your subject appear dull (underexposed), but not necessarily. The second option is generally what you aim for - but watch out for the highlights! (round and round we go!). The third option is only rarely an option - setting the camera to auto exposure may sometimes seem the only way to control changing light, but this is where you will always get inconsistent results. Choose the aperture yourself - don't let the camera do it for you!

I guess the problem is, if you are shooting doco or verity style, without lights or reflectors, then you will always be at the mercy of whatever the big light in the sky throws at you. You can do things to make sure you have some control. Get a friend to hold reflector for you. Don't shoot out in the midday sun – mini DV/HDV can't cope with too much contrast. Find nice diffused areas of light. If you do shoot in the sunshine (early morning or late afternoon is always best), use the sun as a backlight, not into the subject's face, and use a reflector to 'kick' some light onto the subject.
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Old October 21st, 2006, 06:22 AM   #13
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I will say this, either I'm getting to be a better shooter (unlikely) or HDV and the xl-h1 seems to have a little better lattitude then my previous cameras(more likely). Of course it's possible neither are true and I've just been extremely lucky on my past few shoots. (most likely)
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Old October 21st, 2006, 09:02 AM   #14
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Quote:
Originally Posted by Nick Hiltgen
I will say this, either I'm getting to be a better shooter (unlikely) or HDV and the xl-h1 seems to have a little better lattitude then my previous cameras(more likely). Of course it's possible neither are true and I've just been extremely lucky on my past few shoots. (most likely)
I don't doubt that you are a more skilled shooter Nick. After reading Alistairs post I have to add that I was in one of those situations where I was at the mercy of the sun and it was a bright day.....a lot of hard shadows and hot spots in the same scenes. I have to say in the few shots where it got cloudy the camera looks great. But you have to be careful of the harsh contrast of mid-day sun.

I'd like to ask another question I just thought off. On a few occasions I had to switch off one of the neutral density filters to accomodate the shade. Then, I apparently forgot to turn it back on and I was shooting for 3-4 minutes with just the one ND when the sun came back out. I used the auto iris to get a basic level and locked it in. Upon reviewing this section the video has an odd color cast.....very magenta and un-natural looking. The footage looks weird. At the point where I realized I was at a very high f-stop value I switched the 2nd ND filter back on, the iris opened back to 2.2-5.6 range again and the colors seems to go back to normal.

Has anyone noticed a color shift when shooting with one of the ND filters on and the iris stopped way down? I am not sure exactly where it was at but when I turned the iris wheel it completely closed very quickly...so at least f8.0 I'd say. I know these HD lenses have diffration issues that cause a softness if stopped down to far.....but does that affect color too? I had an issue like this with my Xl2 a long time ago.....a more bluish tint but same situation.

Thanks.
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Old October 22nd, 2006, 04:37 AM   #15
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Quote:
Originally Posted by Marty Hudzik
Has anyone noticed a color shift when shooting with one of the ND filters on and the iris stopped way down?
Yes Sir! Soft focus and shift in WB. We where shooting a scene on a road in the countryside, nice weather for shooting, partly cloudy and quite much lite. Couldn't believe my eyes when I came home; Some of the footage in really strange color and how on earth could I pull focus that bad...! (infinty @ f8 / ND6 or something). Strange, very strange. Fortunately I tried some different settings.
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