Erica's World

Canon 20D

http://www.virtualtraveller.org/5dv20d/5dv20d.htm

“20D tends to overexpose quite badly in contrasty light”
“The 5D viewfinder is similar to that on film cameras such as the EOS 100. By comparison the 20D viewfinder is like looking down a tunnel.”
“One of the advantages of the EOS 20D over the 5D is that it can shoot 5 frames per second. The disadvantage, which I imagine may be linked to this, is that the shutter is loud. The EOS 5D only does 3 frames per second, (but) it is much quieter than the 20D.”
“One of the annoying things about the 20D is that once it goes to sleep (power saving mode), you need to half-press the shutter button to wake it up again. The 5D wakes up on pressing any of a number of buttons, such as the menu button or the button to illuminate the top LCD.”
“The 5D will shoot at 50ASA (when enabled through a custom function). The 20D's slowest film speed is 100ASA.” -useful for shots showing mov't. Can be got around w/ neutral density filter.
“with its 1.6x crop-factor and 5 frames per second the 20D (is) ideal for telephoto.”

“As an example a 24mm lens on a 1.6 crop factor camera will produce the same field of view as a 38mm lens on a full frame 24X36mm camera. The math is simple, just multiply the crop factor by the existing lens focal length (1.6 X 24 = 38).” (My telephoto lens is 75-300, 300×1.6=480!!!) “It is important to note that this is not an increase in the lens's actual focal length or magnification power but just a smaller field of view due to the 20D's smaller sensor.”
“It looks like the proponents of the 20D for telephoto nature photography are onto something here. We have the bear filling the frame at this focused distance. The higher pixel density of the 20D's sensor provides for the most detail in this same focal length and same focused distance series even though the 20D has the same output resolution as the 1D Mark II and less output resolution than the 1Ds Mark II. As you can see with the full resolution crops of the bear's nose the 20D has more pixels to draw out detail in the image.”

—-

Canon 5D

http://www.virtualtraveller.org/5dv20d/5dv20d.htm

Significantly more vignetting
“The samples above are 100% crops. The 5D crop has more pixels, but doesn't appear to show any more detail. Perhaps the 17-85 lens is sharper at 68mm (not its maximum zoom) than the 24-105L is at 105 (maximum)?”
“The 20D has a built in flash but the 5D doesn't. This is not a huge loss as the 20D built in flash is pretty pathetic, but sometimes a pathetic flash is better than nothing at all.”
“The screen on the 5D is about twice the size of that on the 20D”
“Shooting in Raw+large JPEG mode (which I would recommend for a number of reasons), the 5D will take approximately 45 shots on a 1Gb compactflash card, compared with 77 on the 20D.”
“The ability to show RGB histograms on the “info” screen on the 5D is useful, as it gives a more accurate representation of the exposure and enables you to re-take the shot if one of the channels has “clipped” (ie over-exposed).”
“One bizarre change is that the remote release socket on the 5D is the opposite way around to that on the 20D, meaning that on my cheap “compatible” cable release, the cable points forward towards the lens rather than backwards towards the photographer.”
“With full frame and 12.8 megapixels the 5D would make the perfect wideangle body”

“Depth of field is related to lens focal length, focused distance and aperture and has nothing to do with film format size or sensor size. If we must move closer to the subject with our larger sensor equipped cameras and same focal length lens to obtain the same FOV as the 20D, we should expect to see less depth of field for any given aperture used with the larger sensor equipped cameras. If you like an out of focus background, for any given lens focal length, aperture and FOV it will be easier to achieve with the larger sensor equipped cameras. Conversely the 20D with any given FOV, lens focal length and aperture will always have more depth of field.”

Effects of larger sensor size

http://www.virtualtraveller.org/5dv20d/5dv20d.htm

24mm on the EOS 5D is slightly wider than 17mm on the 20D.
” The shots above show the whole frame captured with the 20D and the 5D with the 200mm f2.8L lens, from the same vantage point. This clearly show the effect of the 20D's “crop factor”. On the 20D, this lens has an equivalent focal length of 320mm.”
The three samples above speak for themselves. The first is an “actual pixels” crop from the 20D. The second is a crop from the 5D frame to the same pixel width and height. The third is the crop from the 5D “upsampled” so it matches the field of view of the 20D crop. The 20D has very clearly captured more detail. This is not surprising as it has a “higher resolution” sensor, in the sense that its pixel density is higher than that of the 5D.

“To some extent these optical design issues can be overcome. However, Canon just hasn't found it necessary from a marketing standpoint to make lenses wider than 35mm that have great resolution center to edge. This situation puts the 1.6 and 1.3 crop size cameras at some disadvantage when it comes to using wide angle lenses to achieve a 50mm equivalent normal FOV or super wide angles to achieve a wide angle FOV. However, this problem is mitigated to some degree by the fact that the cropped sensors use the most central part of the lens's coverage area where it is optically at its best.”