Canon 5D Digital SLR Signals A New Era

bgerber

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Feb 10, 2006
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Canon's prosumer EOS 5D 12.8 MP full frame digital camera boldly expresses Canon's view that full frame digital sensors should and will be available in lower priced cameras.
 

enewmen

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Simple question.
The camera looks great. Good samples to download.
Does the 5D camera really use a Digic II chip like all the other Canon cameras? How is the CMOS sensor any different than the 6.2 MP sensors already used?
Just thinking if this is a glimpse of things to come in compact cameras (except the the heavyweight optics).

Thanks !
 

dorkus

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Jun 22, 2006
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hello,

Does the 5D camera really use a Digic II chip like all the other Canon cameras?

i highly doubt it's the exact same silicon, but it's the same basic processor, yes. developing ASIC chips like DIGIC is very expensive, so companies will tend to design it for the widest possible range of applications. in this case, Canon is using the same processor design in everything from the $150 PowerShot A series to the $8000 EOS 1Ds. i would guess the D-SLR cameras have higher clock speeds, more on-chip memory and registers, wider busses etc. to deal with the increased throughput though... similar to how nVidia will make low-end and high-end versions of the same basic GPU core.

How is the CMOS sensor any different than the 6.2 MP sensors already used?

if you're referring to 6MP sensors in compact cameras, then it is a fundamental device difference. the compact digicams use CCD (charge coupled device) technology, while CMOS (complementary metal oxide semiconductor) is a newer technology. in current implementations, CMOS has superior noise and dynamic performance, but are more difficult to implement for moving video. they are also more expensive to produce.

also, the sensor is physically much, much larger in the D-SLR cameras - in the case of the 5D, it is the full 36mm x 24mm size of a 35mm film frame. non-full frame D-SLRs are usually APS-C size, which is about 23mm x 15mm. the 1/1.8" sensors in most small digicams are a paltry 7.2mm x 5.3mm. smaller sensors for a given resolution translate to smaller pixel sites, which means less light and less sensor area per pixel, which means higher gain and lower dynamic range. this in turn means more noise and lower overall image fidelity with a smaller sensor, and is the primary reason why the image quality of a digicam will never be as good as a D-SLR. and of course it's a question of optics, though i think the lenses in many of the compact Canons are actually pretty good, all things considered. fixed lenses can be optimized for a given sensor and retrofocus geometry, something that cannot be done as easily with an SLR setup.

Just thinking if this is a glimpse of things to come in compact cameras (except the the heavyweight optics).

in terms of sensor size, no. in terms of sensor technology (CMOS), maybe. in terms of overall image quality... the current compact digicams are fairly comparable to the DSLRs from a few years ago, but i think they are starting to hit a point of diminishing returns, at least with the current sensor technology. but obviously technology will continue to improve across the board.

dorkus
 

dorkus

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Thanks for all the info.
I appreciate it :)

'welcome. :)

not to be snarky, but i'd like to point out that the 5D is capable of much, much better image quality than what is demonstrated in the two samples in the review. to be frank, those pictures could have been taken with a point-and-shoot digicam and come out about the same in photographic quality, if not absolute pixel count.

the article also makes no mention about selecting the proper lens for the camera. the extremely high resolution and full frame sensor will reveal every deficiency in anything but the highest-quality lenses, such as the best Canon primes or their "L" professional lenses. a suitable lens such as the Canon 24-70L will run $1200+; if you are not willing to invest in such glass, you will be better served by a much less expensive APS-C camera like the EOS 30D or Rebel XT which can use the lower-cost EF-S lenses. in fact i would argue that the image quality from the 30D is every bit as good as the 5D's, pixel count not withstanding.
 

dorkus

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Jun 22, 2006
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yeah, dunno... the article was posted only recently. canon D-SLR product cycles are usually about 18 months, so we should see a replacement next spring.
 

mkafilm

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Hello

I was wondering where I could get a information on the on-board image sensor control registers for the 5D? Looking for a sensor data sheet ideally.


Thanks
Jon
mkafilm@ aol.com