Theoretical question

[EOBeav]

My apologies if this has been asked before. 

The 600D and 7D share the same sensor.  If I put the same lens (say, my 17-40 f/4 L) in front of both cameras, and snap the same shot at the same time, I should get the same image, right? 

Granted, the 7D has more niceties (sealed body, microfocusing, probably more shutter life, etc...), but I'm talking strictly the quality and characteristics of a single image. Am I thinking about this correctly, or am I missing something?

[NormanBates]

if you manage to get focus exactly the same, then yes, they'll be very, very close

but that will probably require you to focus manually, because no current canon DSLR below the 7D has AF microadjustment (edit: and if you're going to use AF then that's a very, very, very, very important feature; without it, you're just relying on luck)

and I say "very, very close" and not "exactly the same" because I've seen these results:
http://www.dxomark.com/index.php/Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/%28appareil1%29/692|0/%28brand%29/Canon/%28appareil2%29/619|0/%28brand2%29/Canon
and, while they're not exactly the same, they're very, very close, and there's no clear pattern as to which camera processes the data in the best possible way
maybe it's just sample error

[neuroanatomist]

The 600D and 7D share the same sensor.  If I put the same lens (say, my 17-40 f/4 L) in front of both cameras, and snap the same shot at the same time, I should get the same image, right? 

Granted, the 7D has more niceties (sealed body, microfocusing, probably more shutter life, etc...), but I'm talking strictly the quality and characteristics of a single image. Am I thinking about this correctly, or am I missing something?

Close, but possibly not exactly the same.  Yes, they have 'the same sensor' but they have different firmware, and they may also have slight differences in the anti-aliasing filter, etc.  FWIW, the 7D RAW files are consistently somewhat smaller than the RAW files from the T2i and T3i (although the two Rebels are identical in RAW file size).  So, something is different about the data recorded by the 7D. 

[aldvan]

And I don't know if that applies in this case, but, in mass production, the same product can be subjected to a different process of selection and quality control...

[Dave]

To buy a camera just because of the sensor is like buying a car just because of the engine.

Nobody would do that.

[photophreek]

I've seen this comparison many times on many different forums.  While both cameras have the same sensors, they are very different in many ways and not just "nice to have" feathures.  The OP should look at the specs for both cameras side by side on DP Review and you will see the differences that will certainly affect IQ.

I agree with Dave, the Chrysler HEMI is a V8 and Chev has a V8, then why would I buy the HEMI, they are basically the same engine.

One of the most glaring difference between the two cameras is the focusing system.  The 60D is the old trusted 9pt system,  Whereas, the 7d's focusing system is far superior and is the basis for capturing the image.  In addition, from my perspective, the focusing system, MA, customization of everything along with the ergonomics of the camera is more than just "nice to have". I think the OP should just spend the money and get the 7d, you will not regret it.

[iris chrome]

Just as neuroanatomist said, the quality performances of the 7D and the 60D will be very close to each other but they won't be the same. The fact that they both use the same sensor is not the only deciding factor. While 60D uses digic 4, 7D uses dual digic 4. There are probably other factors too but if you look at the big picture, the differences will probably be so minimal as to be imperceivable. Here is a link to a DxO comparison between the 7D and the 60D:

http://www.dxomark.com/index.php/Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/(appareil1)/663%7C0/(brand)/Canon/(appareil2)/619%7C0/(brand2)/Canon

Click on Measurements to see a more detailed comparison in regards to specific properties.

[EOBeav]

Thanks for the replies, everybody. I would obviously get a 7D if I had the funds for it right now. I'm just trying to look ahead when it's time for a new body. It doesn't make much sense to get the 60D over the 600D (no microfocusing, etc...), so if I'm hard up for a camera body with a good sensor, I gotta go with the 600D.

For most of my work (landscape especially), microfocusing  doesn't make much sense.  There's not going to be much need for it with an aperture of f/16 and focusing at 50 yards or so.  When I'm doing portraits with my 50mm f/1.4, though, that's probably a different story. Comparing this situation to buying a car just for it's engine is also a little flawed. There is a lot that goes into the decision of buying a camera body. The sensor is one factor, and an important one at that.

Thanks again everybody.

[Harley]

Have you considered a Canon refurbished 7D?  It's currently in stock. 
http://shop.usa.canon.com/webapp/wcs/stores/servlet/product_10051_10051_260463_-1

Cost is $1359 and they have an excellent reputation for their refurbished products.

[Dave]

f I'm hard up for a camera body with a good sensor, I gotta go with the 600D.

The 600D is a very good camera. Especially if you are going for video. Imho the 600D even is the best video SLR in the canon lineup at the moment (it's the only body with the crop zoom).

So just go right a head: If it is your first SLR you won't regret it.

[nikkito]

To buy a camera just because of the sensor is like buying a car just because of the engine.

Nobody would do that.

wait a minute, i bought a 5d mk II because of the sensor. why? because it's full frame, because of it high Iso quality and because of the 21 mpx.

are u really saying the sensor is not important to make you buy a camera or not? 

[Eagle Eye]

To buy a camera just because of the sensor is like buying a car just because of the engine.

Nobody would do that.

I'm guessing professional car drivers choose a car based on the engine.  I would find it a little shocking if a photographer DIDN'T think image quality rendered by the sensor was the most important thing in a body...  I certainly bought my cameras based on their sensors...

[EOBeav]

So just go right a head: If it is your first SLR you won't regret it.

Actually, I'm a Rebel owner right now, an XSi (450D).  Even going to a 600D will be a big improvement, but of course I could really use the features of a 7D. 

[Dave]

I would find it a little shocking if a photographer DIDN'T think image quality rendered by the sensor was the most important thing in a body

Noboidy said that image quality doesn't matter... But in MY opinion the image quality at ALL cameras is currently at such a high level, that other features are simply more important. Otherwise nobody would buy a 7D instead of a 600D.
And - back to cars - if every car has the same engine, the engine becomes quite(!!) unimportant for the choice of the right car. I'm not firm with american cars but in I guess everyone knows BMW... The BMW 5 (http://www.bmw.de/de/de/newvehicles/5series/touring/2010/showroom/index.html) had in one variation the same engine as an Opel Omega (that costs a third of the BMW). And yes, the engine is one of the most important parts of the car, but nobody would buy a car just because of a cool 500PS engine.

I certainly bought my cameras based on their sensors..

I won't. I craving for new cam and new features for new 5D but I really don't care about the sensor. Yeah, would be nice to have a little bit more ISO but, there are other things that are more important to me. And if you have to decide between 7D/60D/600D the sensor makes no difference.

Even going to a 600D will be a big improvement, but of course I could really use the features of a 7D.

The question is, what you want and if you can wait. I also have a rebel. I need more photo and more video. At the current time I would buy a 7D. But since the lack of a flip screen I won't buy.  I can wait a couple of months. There definitley WILL be a new 5D in the next months and probably a new 7D next year.
So either one of them is so cool that I will buy them or - if not - the price for the 7D will at least go down a lot.

So if I were you: I would wait. The alternative: If you need video now: Buy a 600D (or 550D) and sell it if a new cam comes out.
As I said: I think the 600D is really a great cam.

[aldvan]

As I said many times, sensor is the equivalent of film in a film camera. Can anybody say that shooting with Kodachrome 25 is the same compared to an Ektachrome 100? Sensors remain the core of IQ. You can always manually focus, play with speed, aperture and ISO, etc, but, at the end, the sensor will be the one registering your effort with its pixels, filter, etc your effort. Magnify a FF and a APS-C image and you will see the big difference.
But, I insist, manufacturing is just a part of the process. Quality control and tuning up can make to apparently identical product quite different. To be honest,  I don't know if the sensors of 7D and 600D would receive different selection...