Photography - Making sense of the sensor size?

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Making sense of the sensor size?

Could somebody please explain the jargon used to denote the sensor size?
I mean numbers like 1/1.7. How does this translate to actual size
(dimensions or area)?

What is the typical size for DSLR?
For ZLR?
For good P&S?

Thanks.

Making sense of the sensor size?

RPS wrote:
Could somebody please explain the jargon used to denote the sensor
size? I mean numbers like 1/1.7. How does this translate to actual
size (dimensions or area)?

What is the typical size for DSLR?
For ZLR?
For good P&S?

Thanks.

See:

http://www.dpreview.com/news/0210/02...ensorsizes.asp

David

Making sense of the sensor size?

Gisle Hannemyr wrote:
This designation has clearly stuck
(although it should have been thrown out long ago).

I suspect the manufacturers are happy for the
size to be obscure, since people
might find the actual sizes disconcerting.

There's nothing to stop manufacturers
putting sensor dimensions in
"normal units" in their brochures, advert
or manuals, and yet they don't.

BugBear

Making sense of the sensor size?

On Wed, 29 Aug 2007 10:28:15 -0500, RPS wrote:

Could somebody please explain the jargon used to denote the sensor size?
I mean numbers like 1/1.7. How does this translate to actual size
(dimensions or area)?

What is the typical size for DSLR?
For ZLR?
For good P&S?

Thanks.

I'm not familiar with ZLR and P&S's, but for DSLRs, unless the
manufacturer says the sensor is "full frame", they're usually in the
range of the reciprocal of 1.5 to 1.7... meaning they are smaller
than the standard 35mm from film days. You'll also hear of "APS"
size sensors, a size of film also smaller than 35mm.

That should help you some...

Jim

Making sense of the sensor size?

bugbear wrote:
Gisle Hannemyr wrote:
This designation has clearly stuck
(although it should have been thrown out long ago).

I suspect the manufacturers are happy for the
size to be obscure, since people
might find the actual sizes disconcerting.

There's nothing to stop manufacturers
putting sensor dimensions in
"normal units" in their brochures, advert
or manuals, and yet they don't.

BugBear

I suspect your suspicions are accurate. Attempting juggle sensor size,
zoom range, noise and mp value is something they probably prefer to do
behind closed doors where they can better balance value vs hype.
Dave Cohen

Making sense of the sensor size?

"RPS" wrote in message
...
Could somebody please explain the jargon used to denote the sensor size?
I mean numbers like 1/1.7. How does this translate to actual size
(dimensions or area)?

It actually doesn't translate very well at all, and is a goofy system that
should have been abandoned long ago. The fraction refers to the old video
tube size in inches, which is the way such sensors are traditionally sized
but obviously has nothing to do with digital still cameras.

What is the typical size for DSLR?

Those are not described in that way; only compact cameras use the fractional
inch method. Nikon and some other DSLRs mostly use a sensor of either 23.7 x
15.6 mm or 23.6 x 15.8 mm, in either case roughly the same as the full APS-C
format and often referred to by that term. Most Canon DSLRs s have a
slightly smaller sensor than that, some other makes are smaller still, and a
very few are larger.

For ZLR?
For good P&S?

Both of those types use sensors in the fractional inch sizes, though often
the "inch" is omitted and "type" is substituted. So for example one
manufacturer may call a particular sensor "2/3 inch" and another may call
the same sensor "2/3 type."

Whatever it's called, the 2/3 type is the largest sensor generally found in
any digicam. Its actual size is about 6 x 8 mm.

Other common sizes are 1/1.8 and 1/2.5 -- there are several other sizes as
well, but those appear to be the ones most often used today. I have read of
sensors as small as 1/3.2 but have never owned a digicam with that small a
sensor myself.

In high-end compact cameras of the type you call ZLRs, such as the Nikon
Coolpix 8800, the 2/3 type was common. Most of today's superzoom ZLRs use
much smaller sensors than that, however.

For a very good but more compact camera such as the Nikon P5000, the 1/1.8
type is used and is undoubtedly the best choice. Smaller sensors than that
are more likely to give problems with noise at the higher ISOs, all else
being equal. But where extreme compactness is important it's usual to see
sensors of 1/2.5 type or smaller. Also, many of the superzooms today use
1/2.5 type sensors. It is adequate for most ordinary use.

Camcorders of course have much smaller sensors than these.

Neil

Making sense of the sensor size?

"Neil Harrington" wrote in message
...

Whatever it's called, the 2/3 type is the largest sensor generally found
in any digicam. Its actual size is about 6 x 8 mm.

Correction, that should be about 6.6 x 8.8 mm.

Neil

Making sense of the sensor size?

Neil Harrington wrote:

Those are not described in that way; only compact cameras use the fractional
inch method. Nikon and some other DSLRs mostly use a sensor of either 23.7 x
15.6 mm or 23.6 x 15.8 mm, in either case roughly the same as the full APS-C
format and often referred to by that term.

...

Whatever it's called, the 2/3 type is the largest sensor generally found in
any digicam. Its actual size is about [6.6] x [8.8] mm.

Other common sizes are 1/1.8 and 1/2.5 -- there are several other sizes as
well, but those appear to be the ones most often used today.

What are the actual physical dimensions of 1/1.8 and 1/2.5 sensors? Do
DSLR sensors really have more than six times the area of a 2/3 sensor? Wow.

Thanks for the informative article.

--
Dave Sill

Making sense of the sensor size?

"Dave Sill" wrote in message
...
Neil Harrington wrote:

Those are not described in that way; only compact cameras use the
fractional inch method. Nikon and some other DSLRs mostly use a sensor of
either 23.7 x 15.6 mm or 23.6 x 15.8 mm, in either case roughly the same
as the full APS-C format and often referred to by that term.

...

Whatever it's called, the 2/3 type is the largest sensor generally found
in any digicam. Its actual size is about [6.6] x [8.8] mm.

Other common sizes are 1/1.8 and 1/2.5 -- there are several other sizes
as well, but those appear to be the ones most often used today.

What are the actual physical dimensions of 1/1.8 and 1/2.5 sensors? Do
DSLR sensors really have more than six times the area of a 2/3 sensor?
Wow.

Yep. Compact digicam sensors really are tiny compared to DSLR sensors.

The 1/1.8 type is about 5.32 x 7.18 mm, and the 1/2.5 type is 4.29 x 5.76
mm.

You can find the *approximate* size of any sensor if you know the actual
focal length of the camera's lens and its 35mm equivalence, both best taken
at the long end of the zoom for the sake of better accuracy. Dividing the
latter by the former will give you the digicam's lens factor. Dividing the
diagonal of a full 35mm frame (about 43.2 mm) by the lens factor should give
you the diagonal of the digicam's sensor. However, this is a rough method
(because the camera lens's stated focal length may not be precise) and may
not give you exactly the figures above.

More sensor sizes are given he
http://www.dpreview.com/learn/?/Glos...r_sizes_01.htm

Thanks for the informative article.

You're very welcome.

Neil