William Curwen wrote

> For example, a 300mm standard lens on a 10x8in camera has the same depth of
> field as a 300mmm telephoto lens on a 35mm camera.

But...

To get the same field of view on a digicam as i do on 35mm, I have to use
wider angle lenses... (which have greater field of view)

>Digicam lenses have a
> minimum aperture of around f8/11 due the small circular field of
> illumination necessary to cover a typically small sensor. Any smaller and
> all manner of lens abberations begin to creep in.

But if I look at the middle portion of a 35mm tranny shot at f22
(approximating to the area covered by the small sensor), I do not see all
manner of lens abberations? So I can't see why couldn't I use f22 on a
digicam?

Or is it that compact digicams have crap lenses placed very close to the
'film' plane, thus exacerbating abberations?

I guess that I should find out whether (say) a 17mm lens at f8 (field of
view x, min aperture) has more or less d.o.f than a 28mm lens at f22 (min
aperture for 35mm slr at same field of view) (I would imagine less).

Giles Stokoe

photographer/photojournalist. See some images at http://www.stokoe.co.uk


> From: "william.curwen" <[EMAIL PROTECTED]>
> Reply-To: [EMAIL PROTECTED]
> Date: Thu, 29 Jan 2004 15:22:57 +0000
> To: <[EMAIL PROTECTED]>
> Subject: Re: [PRODIG] digital focal lengths
> 
> Focal length dictates the depth of field that a lens can achieve.
> 
 
> 
> Hope this helps
> 
> William Curwen
> 
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