7D Sorry for asking (7d filmakers only)

[Rick Burnett]

I've shot with the 7D since it came out, and I've experienced overheating. In fact, we have two 7D's and the both performed the same with regard to heat. Inside out of direct sunlight, no matter what temperature (and we shot on 100 degree days in buildings without AC) we never had a problem in 1080P mode. However, if ANY direct sunlight was hitting the camera to the point it was heating the plastic, it would overheat after a pretty short time. Keeping the sunlight off of the 7D with a flag solved the problem.

Now with 720P mode, the camera gets WAY hotter. In these cases, having the camera on for any length of time indoors or out causes overheating. To the person who's camera shut off after 30 second of no use, this will ABSOLUTELY help. Definitely the longer the camera is on, the more of a chance for overheating.

 

[ryanhargrave]

That being said, the 7D is the most likely to overheat because it is the only DSLR from Canon that includes dual Digic 4 chips. That means you have the possibility of heating up twice as fast, or even getting twice as hot.

and to quote you again

Is this based on your own experience, or just an assumption?

The dual digic 4 chips in the 7D (it's not the only one,BTW.. the 1D also has it) have very specific uses and none of which to my knowledge have anything to do with video shooting. The dual processor function is primarily used to offload autofocus/auto-exposure calculations that are used in the AF system on the 7D And 1D (which is not found on the 5D/60D/550D/600D). And to make those calc's in a way that supports the high fps on the 7D. The processors don't work in the "sharing" method that you describe. And even if they did, they would probably make the camera twice as COOL being that the load would be shared by 2 processors instead of one.

If anything I think the case could be made that a 7D heats up faster because of it's weatherproof/rugged body.

And even then... I've only had mine show the warning twice and has never shut down as long as I've used it.

 

[Rick Burnett]

and to quote you again



The dual digic 4 chips in the 7D (it's not the only one,BTW.. the 1D also has it) have very specific uses and none of which to my knowledge have anything to do with video shooting. The dual processor function is primarily used to offload autofocus/auto-exposure calculations that are used in the AF system on the 7D And 1D (which is not found on the 5D/60D/550D/600D). And to make those calc's in a way that supports the high fps on the 7D. The processors don't work in the "sharing" method that you describe. And even if they did, they would probably make the camera twice as COOL being that the load would be shared by 2 processors instead of one.

If anything I think the case could be made that a 7D heats up faster because of it's weatherproof/rugged body.

And even then... I've only had mine show the warning twice and has never shut down as long as I've used it.

That may not be the case, because it's not like they added a second processor to split the load, they added the second processer to do more in the same system, therefore, more heat. I don't think anyone knows exactly all the details of what two processors are doing, but, if I were to guess, I'd say it has something to do with how many pictures the 7D can take on burst, which is a lot more, and, I believe it is one of the only cameras that can output an HD signal while recording, whereas the other cameras switch to an SD version while recording. Maybe there isn't enough processing to convert to an HDMI higher rez on the single processor models which might not be a problem on the 2 processor models? When I used a 1D I never tested the output video so not sure if it too does HD on out?
And yes, possibly the body could be part of the problem as you state. Or, Canon could have come up with better cooling methods as well for newer cameras.

Regardless, it is a problem with the 7D in direct sunlight on the body, or 720P mode.

 

[ryanhargrave]

they added the second processer to do more in the same system, therefore, more heat.

Not necessarily. If more work happened in the same processor that would mean more heat. But when you offload certain processes to a second processor it actually reduces the heat load/power draw.

And based on common I/O programming, canon isn't going to reprogram their entire code base for image capture off the sensor to support splitting that function for 2 camera models. They will program the added features (the new autofocus system) to be offloaded to a dedicated processor. There are a few articles out there that talk about the AF and AE system on the 1D and 7D and how calculation intensive it is. The entire metering system blows my mind in how it reads a full RGB spectrum instead of just luminosity like the other cameras. I can't find the source off-hand but I can recall an article that implied (much like I am) that the second processor was added just for this reason.

At any rate.. these functions for AF/AE aren't used (much) in video, so it stand to reason that the 2nd processor isn't used that much either in video. We have to remember that this isn't like a dual-processor for a desktop. It's almost like the old 486 era chips in the mod 90's that came with a seperate math co-processor to handle the heavy lifting.

Your thoughts on the full HD out of the HDMI is probably right too that they may use the 2nd processor for that. Anyone know what the 1D outputs?

I know all these details may not matter much, but I feel like the 7D is being painted in a pretty negative light and it's truly a workhorse camera. From a video standpoint it's not all that different from the 60D/550D/600D, but on the stills side it's a work of beauty. I just don't think that the informal polls of forums is an accurate measure of if a piece of equipment has more/less flaws than a different model. The data seems pretty erratic in all cases.

Seems to me that the OP should look at what he needs out of a camera and buy that model. Return it if it has an overheating issue.

 

[Rick Burnett]

Not necessarily. If more work happened in the same processor that would mean more heat. But when you offload certain processes to a second processor it actually reduces the heat load/power draw.

And based on common I/O programming, canon isn't going to reprogram their entire code base for image capture off the sensor to support splitting that function for 2 camera models. They will program the added features (the new autofocus system) to be offloaded to a dedicated processor. There are a few articles out there that talk about the AF and AE system on the 1D and 7D and how calculation intensive it is. The entire metering system blows my mind in how it reads a full RGB spectrum instead of just luminosity like the other cameras. I can't find the source off-hand but I can recall an article that implied (much like I am) that the second processor was added just for this reason.

At any rate.. these functions for AF/AE aren't used (much) in video, so it stand to reason that the 2nd processor isn't used that much either in video. We have to remember that this isn't like a dual-processor for a desktop. It's almost like the old 486 era chips in the mod 90's that came with a seperate math co-processor to handle the heavy lifting.

Your thoughts on the full HD out of the HDMI is probably right too that they may use the 2nd processor for that. Anyone know what the 1D outputs?

I know all these details may not matter much, but I feel like the 7D is being painted in a pretty negative light and it's truly a workhorse camera. From a video standpoint it's not all that different from the 60D/550D/600D, but on the stills side it's a work of beauty. I just don't think that the informal polls of forums is an accurate measure of if a piece of equipment has more/less flaws than a different model. The data seems pretty erratic in all cases.

Seems to me that the OP should look at what he needs out of a camera and buy that model. Return it if it has an overheating issue.

If and only if they were using the second processor for the same load, but we don't know if that is the case, ie, if the HDMI is being driven off the second processor it might in fact use up more depending on how intensive it is, or, as you stated, it could use a little less if they pulled off all the HDMI code from the first processor and placed in on the second processor. Given the surface area of processor running two would be larger, heat could be dissipated more so, dependent of course on the construction of the chips, if they employ heat sinks, and where that ultimately ends up. But, we also don't know how well the real-time coding works in these processors. Most of your power in a chip is consumed by the clock trees and IO. If both of those are fully active on both, then no matter what happens inside, it might just get hotter from being used period. (I am a chip designer, so I have insight to at least current CMOS technologies and designs).

I think you're analogy to the co processor of the 486 is wrong though. From what I see, the processors are the same. The difference is the coding that runs on each of them. Yes, they are dedicated to 'picture/video' work, however, I imagine there is a lot of user code able to be used in them just like your standard high power DSP. I've used MANY DSP based audio processing cards (like the UAD) that each model just has more processors on them. They are dedicated to audio work, so they are built to be fast in that regard, but they clearly all can do different things. I see no difference here. Given that the 7D can also take more pictures per burst than the other cameras, I believe that they could possibly parallel process the frames on each processor to get the throughput they are getting.

Given that I own and use the 7D myself, and love the body and design, for a lot of people wanting to do video, the 7D is not necessarily the best choice. I work with people who have the t2i and they don't overheat when I have. As a stills camera, without question, it's WAY better than the cheaper cameras, but for video work, I don't think the extra price buys you that much more than the 60D, t2i or t3i for video ONLY. For some people, that's what they care about. Further, if overheating is a concern, I'd probably not use the 7D as both of ours have had issues at the same time.

 

[ryanhargrave]

I knew I botched that 486 reference as soon as I wrote it Good response as to the processors actually being the same and having a baseload heat. Hadn't really thought of that.

I've always wondered if the 1D suffers this heat issue. I haven't followed it much.

And I def agree that the 7D isn't the ideal choice for a video only camera. But I still maintain that the overheating issue seems to be sporadic at best. I've had it just the opposite when borrowing a 60D.. It was giving off a temp warning when the other 3 7D's were rocking right along.

 

[Rick Burnett]

Haha, well, the biggest problem with comparing CMOS technology is that it can be really different. There are so many things you can do to alleviate heat, power, speed, noise, etc. Until someone hacks into the multi-core systems, we just won't know what it is doing. Given the 1D is SO expensive comparatively, I've only played with one of them before, and ergonomically, it was better for stills than video. Never even looked at the footage off of it, only in camera. I've heard the only advantage is a cleaner image in low-light than even the 5D. Did not test myself. That is a good question though, I wonder if it does have heat issues as well.

Never used the 60D myself. My only comparison is to the t2i on the same shoot. Keeping the sun off the body and not using 60P and I don't have issues. I bet that is true for a lot of the cameras.