physical sensor size vs print size

[RobC]

Hi
I apologize if this question has been covered elsewhere...

I'm curious about sensor size (aps-c vs aps-h) and print size, image quality, etc.

Let's make a couple of assumptions to simplify things:
- 100 ISO (let's not complicate this with high ISO noise)
- focal length adjusted so both cameras capture the same image
- static subject, same exposure settings, same lens
- ignore the extra "1D Mk III goodies" (like AF & shooting speed)

Since the 1D Mk III and 40D both have 10 meg sensors (3,888x2,592) does that mean that images taken with these cameras should be very similar as far as maximum print size, print quality, etc. are concerned?

I'm currently using a 30D but thinking about upgrading to a 1D mk III in January. I'll be shooting downhill ski racing next March and the extra AF points will be helpful. I used a 30D last winter and it worked fairly well, except when the skiers were doing their "stunts" in mid-air and would suddenly end up missing all the AF points (the smaller skiers were very challenging).

Thanks
Rob

[Jonathan Wienke]

My experience is that the minor (approximately 1/2 stop) difference in DOF and the difference in focal length needed to get the same framing are the only practically relevant factors in such a minor sensor size difference. The other factors, such as maximum frame rate, battery life, viewfinder size and brightness, and faster, more accurate AF with more focus points are MUCH more significant. I have a 1Ds and 1D-MkII, and the sensor size difference between them is pretty much a non-issue. I wouldn't waste time worrying about the physical size of the sensor and focus on camera features relevant to what you shoot.

[Rob C]

Just to clarify:

Rob C is not the same person as RobC; I´m surprised that got through customs control...

Ciao - Rob C

[Eric Myrvaagnes]

Rob C is not the same person as RobC; I´m surprised that got through customs control...
[a href=\"index.php?act=findpost&pid=147578\"][{POST_SNAPBACK}][/a]

That reminds me of the theory that claims that Shakespeare's plays weren't actually written by Shakespeare, but by somebody else with the same name.    

-EricM (I really am EricM, or else a darn good forgery.)
(Not to be confused with Eric_M, or eri_cm, or ...)

[jerryrock]

Larger sensor (physical size) = better image. Larger sensors have larger pixels with greater light gathering ability.  If you cram the same number of pixels in a smaller sensor, the resulting image will be less detailed and not as smooth as the same image created with larger pixels.

Larger pixels = larger dynamic range and less noise than the same number of smaller pixels.

[Jonathan Wienke]

Larger pixels = larger dynamic range and less noise than the same number of smaller pixels.

All else being exactly equal, yes. But given the rapid advances in sensor technology, this is pretty much never the case, as the improved design of a different generation of sensor will make more than the 1/2 stop or so theoretical difference in DOF or DR attributable to sensor size.

[Rob C]

That reminds me of the theory that claims that Shakespeare's plays weren't actually written by Shakespeare, but by somebody else with the same name.   

-EricM (I really am EricM, or else a darn good forgery.)
(Not to be confused with Eric_M, or eri_cm, or ...)
[a href=\"index.php?act=findpost&pid=147636\"][{POST_SNAPBACK}][/a]

Confusion does exist - there is David Bailey of fashion fame, whiter than snow, and another in London of the same name who is not. There has to be a photographic quickie here, but in the interests of international peace and monochrome photography I remain silent.

Rob C

[sanking]

I asked this question on another thread, but it may be more appropriate here.

Can anyone point me to a comparison of image quality between a 12mp point and shoot camera like the Canon G9, which has a fairly small sensor chip,  and a 12mp Canon or Nikon DSLR with larger sensor?

Sandy King

[thompsonkirk]

As Jonathan pointed out above, sensor development, firmware & software rule out a general sort of comparison.  Given a fixed number of pixels, say 10MP, the larger sensor with larger pixels has a better 'signal-to-noise ratio,' resulting in less noise & smoother tonal transitions.  That's the general rule, & for specifics you have to compare images from the two cameras.

In some instances, I'm able to print images from my Lumix LX2 to mix with 5D images in the same portfolio.  A practiced eye can always see the difference in prints, but for the web it matters little.  

If you want to see a specific web example, go to www.dryreading.com/kirkthompson/ & look at the portfolio "Several Messy Gardens."  The images in 16:9 format are Lumix, the 3:2 ones are Canon 20D & 5D.

They go together pretty well on the web, but the prints can't be shown together in any size larger than 9x16" & 10x15", because the 10MP point-&-shoot images just don't 'make it.'

Kirk

[sanking]

Kirk,

Thanks for the comments. I looked at "Several Messy Gardens" but of course could not tell any difference from the web images. Nice work, though.

Sandy King