The 1DX may have higher resolution than the 1Ds III in the real world...

[Radiating]

I just thought I'd post an interesting piece of info for everyone that's bothered by the reduction in megapixels for the 1DX.


Mathematically speaking the noise in an image actually contributes to a reduction of resolition of an image. You can't make out individual specs of sand on a picture of a beach when there are grains of noise for example. In less technical terms if you look at the MTF50 of a high noise image versus a low noise image of an identical test chart, the resolution is lower for the high noise image. Noise reduction suppresses the distraction of noise, but cannot improve the physical signal to noise ratio. This is why high noise images lack fine detail.

So while technically the 1Dx has a maximum resolution of 18 megapixels, if the reduction in noise on the 1Dx compared to the 1Ds is a bit over one stop the 1Dx would practically and technically speaking have superior or equal resolution at anything above 400 iso.

This is just something to consider for those that think it's a downgrade in resolution. The reality might be that it's identical or superior in practical terms, although anything above a 1 stop increase in noise handling is very unlikely.

 

[dougkerr]

Hi, Rad,

Mathematically speaking the noise in an image actually contributes to a reduction of resolition of an image. You can't make out individual specs of sand on a picture of a beach when there are grains of noise for example.

An important notion, of fundamental importance in the telecommunications world (as revealed in the work of Shannon and Hartley, for example).

But in the digital camera case we must note that the signal to noise ratio varies with the luminance of the specific pixel (duh!) .

Thus, except in the "shadow" areas of the scene, a decrease in noise will not lead to a "measurable" improvement in resolution.

So the point you make is important with regard to "resolution in the shadow areas", but not much elsewhere.

Best regards,

Doug

 

[Radiating]

I appreciate the response Doug and you make a valuable point. I used middle gray as a fair point of comparison. As you said the noise is not constant but depends on luminance, so the effect is more prominent in the shadow areas than the highlights. In other words your mileage may vary.

The argument is just useful information. For me as a studio photographer that shoots hand held at 400-800 iso it's useful to consider.

 

[GMCPhotographics]

I've been using a 7D in conjuction with a pair of 5DII's for a few years and I have to say that there is little real world difference between 18mp and 21mp. Sure there's a world of difference between the two formats and relative pixel density, but like for like photos....thre's little real world diffferance.

I doubt that I can afford a 1D-X, I can get a pair of 5DII replacements for that kind of price. But the 1D-X is one hell of a camera and would offer amazing professional performance for a long long time...I mean who actually needs more that 18mp? This is easily Canon's most versatile DSLR to date.

 

[kennykodak]

pre-ordered one. hope to have it by the next wedding season.

 

[Orion]

I just thought I'd post an interesting piece of info for everyone that's bothered by the reduction in megapixels for the 1DX.


Mathematically speaking the noise in an image actually contributes to a reduction of resolition of an image. You can't make out individual specs of sand on a picture of a beach when there are grains of noise for example. In less technical terms if you look at the MTF50 of a high noise image versus a low noise image of an identical test chart, the resolution is lower for the high noise image. Noise reduction suppresses the distraction of noise, but cannot improve the physical signal to noise ratio. This is why high noise images lack fine detail.

So while technically the 1Dx has a maximum resolution of 18 megapixels, if the reduction in noise on the 1Dx compared to the 1Ds is a bit over one stop the 1Dx would practically and technically speaking have superior or equal resolution at anything above 400 iso.

This is just something to consider for those that think it's a downgrade in resolution. The reality might be that it's identical or superior in practical terms, although anything above a 1 stop increase in noise handling is very unlikely.

Here is an interesting piece on this issue also, from (just scroll down a a notch till you get to 1Dxheadline) :
http://www.the-digital-picture.com/News/