Any Canon DSLRs as good as the GH3?

H

harmonica44

I keep hearing about the GH3, about how it's really good on noise under low light, and I rented one and tested it for a day. It's pretty good.

However, I am going to the U.S. to shoot a documentary, along with a group and wanted me to be the DP. There will be some low light shots, since it's a documentary and we are shooting crowds outdoors, possible into the late evening. No artificial lighting for those exterior shots unfortunately.

I might need to get a camera that is better on noise. Currently I have the Canon T2i, which is horrible for it. However, I would like to get a camera but still be able to keep my Canon lenses, and not have to get an adapter or anything. Is there a Canon camera that can match the GH3's performance, especially when it comes to noise?

Thanks.
 
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A whip pan causes the image to skew with a rolling shutter sensor. On the A7s the skew will be much more noticeable in full frame mode than in the APS-C crop mode, so if you're planning to do whip pans (or fast handheld movement, or any other fast camera movement) you would definitely want to use the crop mode.
 
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Okay thanks, that's good to know. I have done fast movements on my Canon T2i, but I have asked other's and they say they cannot see a rolling shutter effect, unless I point it out to them. Why is full frame so popular, if rolling shutter is such an issue? Wouldn't a lot of videographers be against full frame, if that was the case?
 
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In my experience rolling shutter is far less of an issue in practical use than people make it out to be when they're testing cameras. It's very easy to make it show up badly in tests, those tests just don't necessarily represent situations you'll encounter frequently in the real world. For instance, whip pans can show it off dramatically; but they're not that common in most films, and even when they are used they often happen so quickly that the audience isn't likely to notice or care about the skew.

Personally the biggest practical issue I find with rolling shutter is the 'wobble' it imparts to handheld footage due to small shakes. Image stabilized lenses help to eliminate those small shakes, as do things like shoulder mounts, monopods, etc. You just have to learn how it affects your footage, and plan accordingly.

If you don't want to deal with it at all you can use one of the very few cameras like the blackmagic 4k which has a global shutter, or wait a few more years until camera processing tech reaches a point where it's not longer a concern.
 
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ItDonnedOnMe said:
.....................

Personally the biggest practical issue I find with rolling shutter is the 'wobble' it imparts to handheld footage due to small shakes.............
Click to expand...

This!

Like filming through a fishbowl with moving water.
Maybe it's because the first 10 years of my filmmaking life I used CCD camera, but heavy rolling shutter in handheld footage 'hurts my brain'. It's the reason I don't like to shoot with DSLRs.

IDOM, you are right: a few years from now and it's all global shutter again :)
 
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Okay thanks. I don't really notice rolling shutter that much, unless you shake the camera heavily, like going handheld while running. Whip pans are fast, so the viewer does not notice it seems. I asked others and they said the same thing, when I showed them tests way back. But even in running they can't tell cause the shake is so bad in handheld that you don't even see the rolling shutter, unless you show them a direct comparison between two. I have a 50mm prime but unfortunately it did come with stabilization, so I may sell it in the future for a stabilized prime. Cause it is much more noticeable on that lens, compared to the kit lens I have, which comes with stabilization.

As far as global shutter goes, does the black magic eat a lot more battery power, since the global shutter might require more electricity to make it move, as oppose to rolling? DSLR battery power drains fast while shooting on location, and I constantly have to switch and recharge batteries, so a global shutter camera, might make the issue worse, no? Wouldn't the global shutter also make more noise, compared to rolling, which makes none, so would you have to cover up the noise, so it doesn't reach the microphone?
 
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A global shutter isn't mechanical; it doesn't move. It's just a different way of reading the data from a sensor. Cameras with global shutters, like the BM 4k and Digital Bolex, use a CCD sensor instead of a CMOS sensor (which is used in most other large sensor cameras these days).

In a CCD the sensor gathers light across all of the photosites for a period of time, then stops - the camera's processor then reads out the stored values from the sensor before resetting it for the next exposure. This means all of the stored values represent the exact same period of time.

With a CMOS the sensor doesn't gather and store light values - it's just continuously gathering light and converting it to an output signal. So the camera processor starts at the top line and reads out the signal, then proceeds to the next line, and so on down the entire sensor. Because this process takes time there is a slight delay between when the top line is read out and when the bottom one is. If the camera moves at all during that delay it results in all the lines representing slightly different periods in time; this can result in a slight skew of the image (if the camera is moving laterally) or a stretch/compression of the image if it is moving vertically.

CCDs are much more complex electronically than CMOS, so they cost more to produce - especially as the area of the sensor increases. The simpler design of a CMOS also leaves more room on the surface of the sensor for the photosites, which generally allows them to perform better in low light. The lack of a read/reset cycle in a CMOS also allows for higher potential frame rates. For these reasons CMOS has become the standard tech behind most large sensor cameras despite the problems with rolling shutter.

It's possible to achieve a global shutter with a CMOS, it's just not currently practical. It essentially requires a faster processor, or more processors working in parallel, to reduce or eliminate the delay between reading the lines of the sensor. Faster processors are more expensive, draw more power, and generate more heat - all of which are problems when it comes to designing cameras that are small enough, cheap enough and quiet enough to be practical.

Technology marches on though. Processors are steadily becoming more powerful and more efficient, driven by much larger markets than cameras alone - phones, tablets, laptops, etc. It's likely that in a few years we'll see rolling shutter issues gradually fade away as the necessary processing power becomes practical to use in cameras. In the meantime you either have to learn to work around it, or live with the tradeoffs that come with selecting a CCD-based camera.
 
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Okay thanks, I understand it a lot more now. I watched Act Of Valor, shot with the Canon 5D, I read. It's an action movie with a lot of handheld movement, but I did not notice any rolling shutter, so did they do something to get away with it, or did I just not notice? Plus if you read what people think of the movie, no one brings up that they noticed it, or it was an issue.

With that in mind, is it worth getting a CCD camera in the future, for bigger projects? Will people who view my work, who are actually looking for issues, be more impressed with footage shot on CCD camera, rather than CMOS?
 
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