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Canon EOS Crop Sensor for HD
APS-C sensor cameras including the 80D, 70D, 7D Mk. II, 7D, EOS M and Rebel models for HD video recording.


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Old January 15th, 2010, 11:15 PM   #1
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I have some embarrassingly dumb questions

and they are mostly about exposure. (Sorry, my first DSLR camera!)

With the Canon 7d and oh, say a 15-85 EFS Canon lens (3.5f pulled out), I am having a bit of trouble gauging exposure. Simply put, I don't really know how to gauge it all.

I have been using the LCD and guessing my way in M but how do you know when you are exposing correctly (without a light meter)?

With the Sony FX1 I used to set it to automatic when I was on the go, just to get a reading, then adjust my settings manually so I at least had some sort of reference point. Is there anyway of doing this with the 7d?

I did my first test with it today at a skateboard park (indoor, pretty dark place but I'd filmed it with the FX! before with no problems)

I found myself feeling limited (largely by my lack of knowledge) about how to get brighter shots. At 3.5, I felt the only thing I could to was open the shutter and up the ISO
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Old January 16th, 2010, 02:02 AM   #2
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Hi Chris,

Welcome to the challenging world of shooting video on a DSLR!

You know that in live view video mode you can toggle the display by pressing the 'Info' button on the back of the 7D and one of the views shows you a scale at the bottom of the screen? Then, when you set up the shot, partly press the shutter button and a marker arrow will show you where the exposure is in relation to where it needs to be (left of the middle of the scale is too low, right of centre is too high - sorry if this is obvious!).

Then knowing that info, you have choices on what to do to correct the exposure (F stop, and/or ISO and shutter speed, but for shutter speed in video it's best to stay in a certain area as I'm sure you know).

Hope this helps a bit!
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Old January 16th, 2010, 04:07 AM   #3
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A separate light meter or Tram's magic lantern (when it comes out) are the two best options I think.
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Old January 16th, 2010, 06:24 AM   #4
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+1 to what Andy said. Also, you can take a still image and check the histogram - takes about two seconds. If you use a light meter, make sure you calibrate it properly with the camera.
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Old January 16th, 2010, 07:48 AM   #5
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Hey Liam,
I have found that stills expose a little differently than video so I do the same thing with the histogram, but I roll a couple of seconds of video for it instead. (this could just be in my head though on the difference)
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Old January 16th, 2010, 10:20 AM   #6
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Yes, that's a better way to do it as stills are a different color space.
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Old January 16th, 2010, 10:47 AM   #7
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Chris, as noted above the camera has a light meter, you just have to turn it on. Make sure you're in manual mode and auto things are all off. However, it is a center-weighted reflective meter, so it's going to lie to you sometimes, as any reflective meter will do. For instance, a wide shot against a dark background may overexpose and a shot like a person in front of a bright window will underexpose. So you use it carefully as a guide, just like any meter.

When shooting video you do not want to change the shutter speed or you will get funky effects. Shoot at 1/50 if you're doing 24fps, 1/60 for 30 fps. If you're in a low light condition, you can raise the ISO. It's qute a bit different from increasing gain on a traditional video camera. You can't go beyond about a +6 with most video cameras before significant deterioration, but with the 7D you can probably go up to 400 ISO or even 640 with only a little bit of deterioration. A lens that opens up to only f3.5 is not very good for shooting under the conditions you described. You're always going to have to use a higher ISO. You might want to spend a hundred bucks and get the el cheapo Canon f1.8 50mm. It feels like a toy but is a nice, sharp lens and pretty fast.
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Old January 16th, 2010, 12:58 PM   #8
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Chris, shooting indoors with an f/3.5 lens means you will need to bring up your ISO, and thereby add noise to the image. You really need a faster lens for indoors shooting. That lens closes down to f/5.6 when you zoom in, so indoors the image will go almost black I'd think. The Canon 15 or 20mm 2.8 primes would probably be ideal for shooting skateboard action.

Also, this may be obvious, but when gauging exposure, you should base it on getting proper skin tones. There should be slight white highlights on, say peoples noses, foreheads etc. If there are no areas that bright, or if there are swaths of skin that are blown out, you need to adjust.
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Old January 16th, 2010, 01:11 PM   #9
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First problem with using the LCD, is that a lot of people leave the LCD brightness in auto mode. Because of that, the level being shown on the LDC output is not locked, and you will have a difficult time judging from the LCD. Lock that to a non auto output.

Second, to get your shot close to where it should be, shoot in manual mode, locking shutter speed and f stop where you want it. Then select the ISO selection menu, and put it Auto. Turn off the ISO menu. Adjust your framing where you want it, then depress the shutter release button half way down...and check the reading the camera has selected. Then select the ISO selection menu again, and lock the ISO in that general area. You can do fine adjustments from there with the fstop selection on your lens.

In addition, and remember this is from perspective of a 5D shooter, remember to have the movie mode turned on in the first place, or no matter what you set the camera at, it will default to auto exposure when invoking video.
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Old January 16th, 2010, 05:51 PM   #10
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Shoot full manual and then use your built in meter as a guide, but rely on a Fader ND filter to fine tune your exposure. The meter will get you close most of the time, but trust your eye. The point about not having the LCD not set on auto is a good one as well. Try to calibrate your LCD as much as possible. This should help.

Spend a lot of time shooting with the camera and it's controls until you know them like the back of your hand.

It is also better and easier to control your exposure with fixed aperture lenses and not variable ones like the one that you have. One less thing to keep in mind when shoot. If find that I lock in a shutter/f-stop combo that I want to use and then use the Fader ND to control exposure.

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Old January 17th, 2010, 05:02 AM   #11
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the original post mentioned problems with not enough exposure so any kind of ND like the fader should be left in the camera case i'd say..
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Old January 17th, 2010, 09:02 AM   #12
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thanks everyone for the answers! Each one was extremely helpful!

Sorry for my noob questions but I sort of pounced on the camera before realizing what I got myself into, I am glad for it and have no regrets, I feel like I am on a new learning curve and it's fun!


Anyways, I promise to get better and then I'll take the time to answer all the noob questions for you guys hehe.

Last question, when it comes to lenses, does the video mode size format affect lens choice? In other words, I know taking stills in raw is a considerably larger pixel size, but in film mode, will i get vignetting in the corners in HD mode with wide lenses on a 1.6 sensor?

Thanks again
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