Canon 5D mark 2 - Video Noise test
Sorry to bring up a topic that gets discussed so much throughout this forum and the internet in-general.
I've owned my Canon 5D mark 2 for a few years now and have used it in several projects. Despite claims that the camera is capable of low-noise up to 1250, I find it hard to have no noise in my image, even at very low ISO's. Perhaps I'm naive, but I was under the impression that, for example, if I shoot a subject which is well exposed (1-2 stops down), that has some dark areas in the frame, those dark areas would not produce noise, due to the low ISO. If I decide to increase the ISO then my noise levels will increase marginally until 1250, where you can see that horrible noise and artifact lines etc.
However, I'm not finding this to be correct. I'm not sure what I'm doing wrong or if my camera is faulty and producing a lower-than-normal quality with it's images. As an example, here are some test shots. They were all recorded using the most recent Magic Lantern firmware, with Marvel Cine picture type, shot 2 stops down, with a ScanDisk Extreme 60MB/s Compact Flash, lit only with day light.
I used 2 different lenses to get the required exposure: A Canon 24mm-105mm prime lens, all shot at aperture 4 and a standard Canon 50mm lens, all shot at aperture 1.8
Click on the picture to see them larger.
1. Canon 24mm-105mm, aperture 4, ISO 1250 - I expected this shot to be noisy as it has a high ISO and perture 4... However pictures do not do justice to how un-useable this shot would be!
2. Canon 50mm, aperture 1.8, ISO 200 - I expected the blacks and shadows to have little-to-no-noise in this shot. I'm using a very low ISO and aperture 1.8, letting in lots of light. There is, however, lots of noise in the shadows on the left hand pillow as well as a lot of noise on the pillows themselves. Again pictures do not serve to show the real extent of the noise as, when played back, the noise in the image moves and fuzzes, becoming very distracting.
3. Canon 24mm-105mm, aperture 4, ISO 320 - Again, I expected low noise levels in this picture - I considered 320 to be a low ISO but there is LOTS of noise in the shadows at the left of the frame and the upper right frame.
4. Canon 50mm, aperture 1.8, ISO 100 - getting a good exposure on the subject (central frame) and using the lowest ISO on the camera, I expected no noise what so ever... NONE. I thought any shadows or dark areas would have nice blacks, with no grain... I was wrong. like the last picture, there is noise in the left frame shadows and the top right frame.
Basically, it seems as though it's not impossible to have no noise in your dark/shadowy areas on a Canon 5D mark 2. However, I know this is not true because I have seen LOTS of beautiful images shot on the 5D mark 2. So there's either something wrong with my camera or perhaps I've never seen 5D footage with shadows in the shot.
I have neat video and magic bullet etc, so can tidy up an image but, frankly, I shouldn't have to. I also know that the H.264 codec is pretty crappy but that shouldn't make a difference. Having good exposure, with an aperture below 2 and low ISO, using a decent Compact Flash, should produce a quality image straight from the camera, with no messing around.
Could somebody help me out and show me where I'm going wrong?
Just as a test I would transcode these videos to ProRes or a PC equavalent to see if it makes any difference...wondering if what you are seeing are compression artifacts vs true noise.
Quote - if I shoot a subject which is well exposed (1-2 stops down)
How do you decide that it is 1-2 stops down and not 2-3 or 3-4 stops down?
The images have a wrong white balance, which affects the way the noise looks. When shooting, it’s better to use as a simple tone curve in the camera as possible. The look of the image is established in post-processing, not during the shot. ISO 100 for Canon 5D2 is not the lowest noise setting, due to the design of the camera. Try ISO 200.
You can check your exposure by shooting the setup in RAW and looking at it in FastRawViewer. Incidentally, this will also let you make sure that your white balance is also correct.
When you say “good exposure on the subject”, what the numbers tell me when I use an eyedropper in Photoshop is 2 stops underexposure. Technically, we mean different things when we talk about the quality image straight out of the camera, and the quality final image. A quality image straight from the camera only ensures that you can edit it to produce a quality final image. You need to determine what a quality image is for the final look. If you are shooting film, can the resulting negative be considered a good quality image? Yes, of course you can consider it a good quality image if you can print a good positive from it, but by the sheer look of the image on the negative film, you would say that the look of it is good, if your criteria is to be close to the final image as possible.
The closer the camera is to high-end, the greater the difference between the camera output and the final look of the video.