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[OM] Re: [OT] KM 7D for a song

Subject: [OM] Re: [OT] KM 7D for a song
From: Moose <olymoose@xxxxxxxxx>
Date: Sun, 20 Aug 2006 15:25:24 -0700
Chuck Norcutt wrote:
> The appearance to me was that 200 ISO on the 5D was being compared to 
> 800 ISO on the 300D.  The was amplified by seeing the noise in the 300D 
> image.  Am I wrong?
>   
Aaaaahh, the light dawns in my fuzzy head! I didn't understand your 
question before.

You are indeed wrong. Each apparent image is a separate roll-over, with 
the 5D image as default in each case, and the 300D image shown when the 
mouse is rolled over the images.

Both images in the top roll-over were taken at iso 800. Both images in 
the bottom roll-over were taken at iso 200.

To complicate things further, pixel density in the 300D is greater than 
that of the 5D, so a full pixel image from it appears larger than one 
from the same physical area of the 5D sensor. To make the comparisons 
fair, I thought the images should appear the same size. So I downsized 
the 300D image in the upper pair and upsized the 5D image in the lower pair.

You can really see several things from the combo of four images at two isos.
- The major conclusion - in spite of a higher pixel count, 300D images 
are quite obviously fuzzier than the 5D images.
- There is no apparent noise difference between the two cameras at iso 200.
- The 5D is noticeably noisier at iso 800 than at 200 with a flat, white 
subject.
- The 300D is much noisier at iso 800 than is the 5D.

The initial point of this exercise was to find out for myself whether 
I'd been right in my research and calculations. I loved the extra reach 
of the 1.6x factor of the 300D, but also wanted a FF sensor so my 
existing wide angle lenses would be WA again. It appeared to me that 
simply cropping FF tele images to the 1.6x size would approximate the 
results I was happy with out of the 300D. This and the other test I 
posted convinced me that I had been conservative. The cropped 5D images 
are actually better than the 300D images.

It isn't just the sensor, of course, it's the whole imaging system. 
Subsequent experience has show me that performance development in these 
systems has been considerable over the last few years. The overly 
simplistic "megapixel war" has hidden some equally important 
improvements in per pixel sharpness and in noise performance.

So I did  this for my own info. I posted it simply in case it might turn 
out to be of interest and use to others.

Moose

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