Pixel density - WOW!

Willid1

Willid1

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David Williams
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After struggling with my S95 at a concert the other night I wondered just how many pixels it had per mm squared on the sensor compared to my 40D

Hopefully the S95 info is correct (not stated in the instruction book :shrug:)

Here you have a go

40D
sensor size in mm 22.2*14.8
area 328.56mm square
10 MP
0.034 MP per mm square

or 30435 pixels per mm square !!!!!!

If you thought that was a lot try this

S95
sensor size in mm 7.6*5.7
area 43.3mm square
10 MP
0.2309 MP per mm square

or 230946 pixels per mm square!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You can draw a mm square with a sharp pencil, but fit in 230 thousand pixels, all individually connected to the camera processor. I wonder how many are dud and mapped out in the manufacturing process??

My brain is now going :eek::eek::eek::eek:

D
 
Willid1 said:
You can draw a mm square with a sharp pencil, but fit in 230 thousand pixels, all individually connected to the camera processor. I wonder how many are dud and mapped out in the manufacturing process??

My brain is now going :eek::eek::eek::eek:

D
Click to expand...
I have never thought of it like that and yes it is totally mindblowing when can be achieved. :eek:

I wonder what the numbers are for a 7D with 18MP packed onto a 1.6 crop sensor?

Andy S
 
You can make very, very small structures on silicon these days. Small pixel and sensor sizes means less area to catch light which means lower signal/noise ratio. This is the main reason why small sensor cameras don't perform as well as larger sensors...
 
arad85 said:
You can make very, very small structures on silicon these days. Small pixel and sensor sizes means less area to catch light which means lower signal/noise ratio. This is the main reason why small sensor cameras don't perform as well as larger sensors...
Click to expand...

It's more to do with absolute area than area of the individual pixels - the electronics do take a significant proportion of the area on mobile phone sensors, but that's falling all the time. The real marker of difference in noise at any given ISO is in total sensor area.
 
ausemmao said:
The real marker of difference in noise at any given ISO is in total sensor area.
Click to expand...
... assuming a well exposed image ;) If you don't have well exposed, pixel size is the dominant...
 
EMA747 said:
I have never thought of it like that and yes it is totally mindblowing when can be achieved. :eek:

I wonder what the numbers are for a 7D with 18MP packed onto a 1.6 crop sensor?

Andy S
Click to expand...

7D is still only 54784 pixels per square mm

I saw a news story recently where Canon had produced a sensor with some unimaginable number of pixels, I can see how they did it now.

Using my numbers and making a S95 pixel dimension 40D/7D size sensor you would get 75MP.

David

Still going :eek::eek::eek::eek::eek:
 
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