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terryw
18th October 2008, 02:00 PM
I have read yet another article deducing that due to its sensor size 4/3 will never match the performance of larger sensors used by Canikon.

This set me thinking about how a direct comparison might be made between cameras using different size sensors. The one thing that never gets mentioned is pixel density, i.e the number of pixels/sq.mm., so I've done a few calculations that might be of interest, and hopefully up for discussion.

Sensor areas are as follows:-

Full frame = 864 sq.mm
C-size = 332 sq.mm
DX = 375 sq.mm
4/3 = 225 sq.mm

and just out of interest a 1/2.5" compact sensor = 24.7 sq.mm.

The results are as follows when applied to recent models:-

New EOS 5 D (full frame) = 24,884 pixels/sq.mm
Sony 900 (full frame) = 28,472 pixels/sq.mm
EOS 50D (C-size) = 45.897 pixels/sq.mm
D90 (DX size) = 32,976 pixels/sq.mm
E-3 (4/3 size) = 44,889 pixels/sq.mm

and for E-1 users like me the density is 22,222 pixels/sq.mm.

And the compact?
IXUS 800 IS (1/2.5" size) = a staggering 323,756 pixels/sq.mm

It's interesting that an article in one of the photography magazines a while back compared Sony Alpha 200, 350 and 700 models to reach the conclusion that the 6 MP Alpha 200 performed as well, if not better in some instances, than the other two models.

Isn't it about time we stopped going pixel mad and looked for optimal performance rather than size?

Terry

Wreckdiver
18th October 2008, 02:13 PM
Here is an interesting article: http://db.tidbits.com/article/7860

It's a bit of a read, but the following sub headings relevant to this discussion:

How many pixels do you need?

Megapixels, Meganonsense

Steve

terryw
18th October 2008, 03:08 PM
Steve

Many thanks for that link. It now poses the question of how come Sigma is the only DSLR manufacturer to run with Foveon if its performance characteristics are that good, and if it's that good why don't Sigma DSLR cameras sell as well as others?

Terry

Xpres
18th October 2008, 03:41 PM
Steve

Many thanks for that link. It now poses the question of how come Sigma is the only DSLR manufacturer to run with Foveon if its performance characteristics are that good, and if it's that good why don't Sigma DSLR cameras sell as well as others?

Terry

Lenses...

I use their SD14, which is great for portraits and black and white conversions. But it's hard work getting the info out of the image and you can only do it with their terrible software. People like to have a good system around their choice of body and hate dead ends.
It's a bit of a niche camera I think.

Makonde
18th October 2008, 10:55 PM
http://gizmodo.com/5062412/black-silicon-discovery-could-change-digital-photography-night-vision-forever