Canon 30D VS XTi - CMOS sensor size etc.

[quixoticsage]

Here is a familiar question you have probably come across already, in part. Canon 30D VS Canon XTi.

Realizing that there are alot of factors that make quality pictures, like glass, operation and what not, really, what about the CMOS size diference between these two cameras? I was almost had with the 10.1MP in the XTi... but knowing that there can be image degredation due to craming in a bunch o pixels and the likely varience between models in Canon's line up.

Sure the XTi has a higher pixel count, but it is very slightly smaller than the 30D's sensor. The XTi has more pixels, the 30D has less.

My question is really, how different are the sensors between these two cameras? Same materials used? I realize the functions of the 30D make it a better camera, but what about the picture quality? Is there a site that shows the exact difference of the sensors in these two cameras? Of course... avoiding the trade secrets and what not.

Aw heck, I should just get the 30D... and maybe by the time I can get it they will have a "40D with Full Frame Sesnor". How sweet would that be! Er... maybe not if they sacrifice something to keep it in the same price range.

 

[DSLR noob]

same size sensor. X1.6 crop.

 

[DSLR noob]

40D wouldn't be full frame. It'd be a 30D replacement, not a 5D replacement. Pixals are irrelevent. Get the 30D hands down.

 

[quixoticsage]

same size sensor. X1.6 crop.

Nope.
Canon XTi
• 22.2 x 14.8 mm CMOS sensor


Canon 30D
• 22.5 x 15.0 mm CMOS sensor

I realize this is very miniscule... but it all has to mean SOMETHING.

 

[quixoticsage]

40D wouldn't be full frame. It'd be a 30D replacement, not a 5D replacement. Pixals are irrelevent. Get the 30D hands down.

Pixels are not irrelevent. Pixel count, however can be in certain aspects. I just wonder... how the 30D gets better images? Is it really that .2mm extra and perhaps, I specualte - larger pixels in the 30D? Different algorythms? Maybe I should just stop before I go any further. It just upsets me that there is not a standard like ANSI for dslr sensors making it difficult to find a camera true to its specs.

 

[Alex_B]

image quality depends not only on pixel size and pixel count and algorithms, but also alot on the design, the materials used. So you won't get far by just using numbers, ... only the final images can tell in the end.

 

[DSLR noob]

Pixels are not irrelevent. Pixel count, however can be in certain aspects. I just wonder... how the 30D gets better images? Is it really that .2mm extra and perhaps, I specualte - larger pixels in the 30D? Different algorythms? Maybe I should just stop before I go any further. It just upsets me that there is not a standard like ANSI for dslr sensors making it difficult to find a camera true to its specs.

How? First, it doesn't take better quality photos, the photographer does, both cameras can achieve the same quality. How can the 30D compare? Because pixel count IS irrelevant, at least in terms of picture quality. the average computer screen displays 72 DPi resolution. An 8 mega pixel image is around 3,500 by 2,400 pixels on a screen. A 10 megapixel camera is about 3,600 by 2550 pixels on screen. The 8 megapixel camera takes pictures that are roughyl 2 times larger than my 21 inch moniter on its highest resolution (1,600 by 1,200). When you are viewing an image that takes up a full screen (in this case for me, 1,600 by 1,200) the pixel density is exaclty the same at the moniter's limit of 72 DPI (dots per inch, pixels per inch). Only if you are printing photos that are larger than the screen will you start to have differences. Only untill you start to print HUGE pictures will you be able to tell with the naked eye.

 

[Alex_B]

not sure, but isn't there also a difference in sport metering between the two cameras?

 

[DSLR noob]

well he is just asking about the sensor. the metering and sutofocus on the 30D are way better.

EDIT: forgot, XTi recieved the 30D autofocus system.

 

[quixoticsage]

image quality depends not only on pixel size and pixel count and algorithms, but also alot on the design, the materials used. So you won't get far by just using numbers, ... only the final images can tell in the end.

Exactly. I agree. Thats what I am wondering about between these two cameras... but then again, I pontificate and try to dig too deep. I guess to me... cramming 10.1 MP into the XTi sensor which is .2mm smaller than the 30D leaves me questioning what materials they are using in the 30D sensor and are they different quality wise.

 

[quixoticsage]

Originally Posted by DSLR noob
40D wouldn't be full frame. It'd be a 30D replacement, not a 5D replacement. Pixals are irrelevent. Get the 30D hands down.


Im sorry. You just said that pixels where irrelevant. I was just picking up literally what you said before. Yes, I agree, pixel count can be irrelevant in regards to picture quality in most cases. However, there are physics that we must not iognore. Cant have too many pixels on one sensor other wise you will end up getting more noise, especially in long exposure shots (which I do alot of with film). http://www.thephotoforum.com/forum/showthread.php?t=82208&highlight=review+Sensor

I already know about 72dpi monitor res.

The 30D, from what I am finding, DOES in fact record better quality images - depending on the photographer and other factors like lenses of course. Knowing that manufacturers such as Canon vary the build quality from one camera to the next, we can assume that perhaps the CMOS sensor between the XTi and the 30D are in fact different. Thats my question.

And by the way, you cannot predict exactly what Canon is going to do with the "40D" if there even will be one. And oh my, MAYBE some day soon a FULL FRAME SENSOR will be standard in pro/pro-sumer DLSR's.

 

[Iron Flatline]

Here's a review of the two side-by-side.

They seem to have slightly different sensors, not identical (which I assumed)

Sensors matter, pixel-count doesn't really nowadays (unless there's too many!) and firmware matters.

And of course lenses, and the photographer

 

[quixoticsage]

Iron,

You rock! I totaly agree.

Thanks for the info!

Cheers

Dan

 

[NJMAN]

Get the 30D. There is a reason why its higher priced than the Rebel XTi, mainly for the reasons explained here by other posters. I was going to get an XTi, but decided on the 30D instead. Im glad I did. I dont plan on printing huge photos, like say 16x20 or what not. But if I do, Im not worried. I have sees some crystal clear 16x20 sample prints made from an 8.2 mp 30D. They look fantastic.

 

[quixoticsage]

Get the 30D. There is a reason why its higher priced than the Rebel XTi, mainly for the reasons explained here by other posters. I was going to get an XTi, but decided on the 30D instead. Im glad I did. I dont plan on printing huge photos, like say 16x20 or what not. But if I do, Im not worried. I have sees some crystal clear 16x20 sample prints made from an 8.2 mp 30D. They look fantastic.

Yes yes. I agree. I know of the 30D's benefits for sure. I think, there is something more to the quality of pictures that you can achieve with this camera. Just because it is 8.2 Mp does not mean it is inferior to the XTi becuase it has 10.1 Mp... but because of multiple functionality features beyond that of the XTi... however... I think the pixels may be larger on the 30D sensor and therefore better pictures can be achieved even in long exposures. This is a theory of mine.. and just thought I would bounce some ideas off of others in regards to the actual physical size of the CMOS sensor and the build quality compared to the XTi sensor. More pixels... not necessarily good unless its the 5D full frame or the Hasselblad HD2 (is it HD3 now?). SOOOO... im long winded in regards to this, but I think ultimately the 30D is superior in image qaulity and functionality. Phew... Sorry for so many words. Im needing an electronic engineer type junkie to satisfy my somewhat abstract question me thinks! You response is appreciated!