Hi--

 

Well, I've been in photography for 40 years, and this term is a new one for me - and it

makes no sense. As I said (and have pointed out many times on the NGs) there is

little correspondence between lens physical size and relative aperture - and even

among lenses of the same FL and relative aperture, physical size (and front element

size) can vary radically. Among simple designs (as for very old view cameras, with

consistent relative apertures), the correlation is stronger, but it still fails as the FL

changes. It is time to do away with a misleading term...

 David Ruether

 d_ruether@hotmail.com

 http://www.David-Ruether-Photography.com

 Hey, take a gander at www.visitithaca.com, too...!

 

----- Original Message -----

From: "RGBaker" <gb@bakerfilms.com>

To: "David Ruether" <rpn1@.cornell.edu>

Sent: Monday, July 14, 2003 2:25 PM

Subject: RE: Why would a large sensor give better low light performance?

 

 

> In photography, a 'large lens' is one with a lower maximum aperture

> regardless of the physical size of the lens.  A 100mm F1.8 is a 'larger

> lens' than a 100mm F2.4 ...

>

> I'm happy to stick with terminology everyone understands ... but the 'large

> lens' reference is older even than I am!

>

> GB

>

> -----Original Message-----

> From: David Ruether [mailto:rpn1@no-junk.cornell.edu]

> Sent: Monday, July 14, 2003 2:03 PM

> To: RGBaker

> Subject: Re: Why would a large sensor give better low light performance?

>

>

>

>

> "RGBaker" <gb@bakerfilms.com> wrote in message

> news:7mmQa.1260$104.90832@news20.bellglobal.com...

>

> [...]

> > > Ok, that makes more sense. But then it isn't the size of the sensor

> > > that counts, but the size of the lens, right?

>

> > The lens is clearly a factor, but all else being equal ... means that all

> > else is equal.  Larger CCDs are better at gathering light.  Large lens are

> > better at gathering light.  Large CCDs and large lens are better still ...

>

> Uh, please lose the "large lens" thingy, since it adds nothing, and is

> misleading... It is perfectly possible to have a lens with a front the size

> of a dinner plate that lets in less light intensity than one of the

> tiny-fronted

> zoom lenses on a Mini-DV camcorder. Lens "size" indicates little of

> value, but the relative aperture and area of coverage may...

> Best to stick with the "all else being equal" premise, and just change the

> CCD size and/or pixel count for this discussion...;-)