different resolution

Why arent 20D images in the resolution format im most used to?

for example

1600x1200
1280x1024
1024x768


But its not the same on the 20D as other cameras such as my older PnS.

Is it because of the cropped sensor?

Those are 4:3 ratio, the 20D is 3:2, the same ratio as 35mm film. Someone decided years ago it was a good idea, we're stuck with it.

then how come my older sony pns ccameras were normal. I mean easily resized to 1600x1200 or 1024x768.

coz my monitor is @ 1600*1200 and with my old Sony Pns ( I had a nice one f-717), I could wonderfully resize to 1600x1200 to fit my screen fully.

The Sony P&S was not 3:2 but 4:3 , that's why it scaled so "nicely"! 2560 / 1920 = 1.3333

Point and shoot cameras tend to be 4:3, professional cameras 3:2. Why? Who knows. Personally i'd like them to be square, but there's not much I can do about it.

And just to make things even more confusing... The Panasonic LX1, with a 16:9 ratio!

http://www.luminous-landscape.com/reviews/​cameras/lx1.shtml

So what are the strengths of each ratio type?

also where does the ratio come from ?

As mentioned earlier, the 3:2 ratio (used in DSLRs) comes from the 35mm film days (film frames are 36mm x 24mm, a 3:2 ratio). P/S cameras were probably developed originally to provide the same 4:3 aspect ratio that computer monitors utilize. This probably just continued to carry on through the years.

Couple of notable exceptions are that Olympus DSLRs use a 4:3 sensor and some P/S cameras offer the option to shoot in a 3:2 format. I think my A510 Powershot offers that option, but I can't remember.

Worst part is that most enlargements are not in either aspect ratio. They're either in a 7:5 ratio ( 5" x 7" prints ) or a 5:4 ratio (8x10's and 4x5's).

With the EOS 3:2 ratio, you can make 6x4 prints without having to crop.. You can't do this with a 1600x1200 (4:3) image...

4:3 images fit most montior resolutions perfectly..

That's about it

I have heard/seen several discussions about using ratios other than 1:1 related to our eyes/brain being adapted to seeing more and quicker along the horizontal than vertical directions. This is because general detail at a distance is nearly always along the horizontal and our eyes/brain can quickly take in a landscape format, whereas closer up, portrait formats help us to concentrate more and this is useful to help us pick out detail in images and text (eg why are books not printed in a square, or newspaper text printed in columns?)

This may be entirely coincidental but fine art papers typically range from 1.24 to 1.55 (4:3 = 1.33 and 3:2 = 1.5) with an average of around 1.41. Interestingly that's a ratio of SQRT(2):1, which is the basis of ISO paper size ratio.

Some photographers like the opportunity to clearly differentiate between portrait and landscape composition whilst taking the photo. A ratio like 1.5 will give you a more definitive portrait composition than a 1.33 ratio. A 16:9 ratio gives an even more panoramic/landscape format.

Unless you are prepared to work with circular images, square format film or sensors use as much of the image produced by lenses as possible but what I found when working with square format I nearly always cropped to standard landscape or portrait paper sizes.

thanks everyone!

would it be offtopic to ask how large I could print an image from a 20D shot in Raw. At best quality obviously.

Take it to the Post Processing section of the forum if you wish. The same question gets asked there once a week. There is no precise answer unless you define "best quality."

---Bob Gross---

"how large I could print an image from a 20D shot in Raw"

I routinely print 8MP images from the 350D/XT at 12" x 18" and they are as good as or better than anything I ever produced with (equally good) 35mm equipment. Even good 6MP images from my previous 300D have printed beautifully at that size. So I would be happy to print considerably larger than that, given an optimal image (8MP, uncropped, in focus, no camera shake, minimal or no noise, no sharpening artefacts), say 24 x 36", and would resample to 200dpi. You won't normally view a print that large from as close as the 12x18, of course.

I still want to move to a 5D, however.

thanks for the input!