4/3

What do they mean by 4/3 inch ? What does it have to do with the pixel count ? Does 4/3 inch mean that the longer side of the ccd is 4/3 times longer then it is in 35mm cameras ?

Could anyone explain ?

Thanx

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Adam Novak

I can't explain where 4/3 inch comes from, but 4/3 refers to the size of the sensor. It is a 4/3 inch sensor, but there is no 4/3 inches anywhere, the chip manufactures do some weird math to get the numbers.

The real size of the lens is 13.5 x 18 mm with a 22.5 mm diagonal. 35mm is 36 mm x 24 mm with 43.3 mm diagonal.

4/3 is also the aspect ratio, while 33 mm uses a 3/2.

See here for more info :
http://www.dpreview.com/news/0210/02100402sensorsizes.asp

One thing that's convenient, with the 4/3 sensor size, lens sizes are equivelent to about twice the size on 35 mm, i.e., a 100 mm lens gives the same image a 200 mm lens gives on a 35 mm camera (sort of - there are difference with depth of field etc.).

Adam Novak said:

What do they mean by 4/3 inch ? What does it have to do with the
pixel count ? Does 4/3 inch mean that the longer side of the ccd is
4/3 times longer then it is in 35mm cameras ?

Could anyone explain ?

Thanx

--
Adam Novak

Click to expand...

According to the chart posted in the link below, 4/3 = 33.867 mm which is very close to 1 1/3 inches. Since the irregular fraction 4/3 is a translation of the regular fraction 1 1/3, I am betting that this is answer to the mystery. I have too much time on my hands.

TrentMcD said:

The real size of the lens is 13.5 x 18 mm with a 22.5 mm diagonal.
35mm is 36 mm x 24 mm with 43.3 mm diagonal.

4/3 is also the aspect ratio, while 33 mm uses a 3/2.

See here for more info :
http://www.dpreview.com/news/0210/02100402sensorsizes.asp

One thing that's convenient, with the 4/3 sensor size, lens sizes
are equivelent to about twice the size on 35 mm, i.e., a 100 mm
lens gives the same image a 200 mm lens gives on a 35 mm camera
(sort of - there are difference with depth of field etc.).

Adam Novak said:

What do they mean by 4/3 inch ? What does it have to do with the
pixel count ? Does 4/3 inch mean that the longer side of the ccd is
4/3 times longer then it is in 35mm cameras ?

Could anyone explain ?

Thanx

--
Adam Novak

Click to expand...

Click to expand...

Adam Novak said:

What do they mean by 4/3 inch ? What does it have to do with the
pixel count ? Does 4/3 inch mean that the longer side of the ccd is
4/3 times longer then it is in 35mm cameras ?

Could anyone explain ?

Thanx

--
Adam Novak

Click to expand...

This is from http://www.dp-now.com:

"What does Four Thirds really mean?: The sensor chip ‘size’ of 4/3rd inch. The actual physical dimensions of the chip are 13.5x18mm, with a 22.5mm diagonal. This is smaller than the APS size chip used several other DSLRs, but larger than the chips used in the Olympus E-10/20. The aspect ratio is 4:3, but the Four Thirds moniker refers specifically to the sensor size as the whole new lens system revolves around this."

Ian Burley (the proprietor of the site,) got this answer from the Oly reps at the booth at PMA.

--
Todd Walker
Olympus: E20N, FL40, RM-CB01, FL-CB05, MCON-35, Stroboframe Quickflip 350
Canon: G2, Vivitar 285HV
http://twalker.d2g.com
Galleries:
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