Date: Sat, 06 Apr 2002 08:24:31 +0000 From: "Matthew Hanson" <[EMAIL PROTECTED]> Subject: Re: [LIB] [OT] RE: Digital cameras (danger Matt/Ray length exposition :)
>From: "neil barnes" <[EMAIL PROTECTED]> > >>Date: Fri, 05 Apr 2002 18:06:01 +0000 >>From: "Matthew Hanson" <[EMAIL PROTECTED]> >>Subject: Re: [LIB] [OT] RE: Digital cameras (danger Matt/Ray length >>exposition :) >> >>This is all very informative and interesting indeed. But you're going to >>have to hammer at me a bit more here (where's that BFH?). Raymond asked >>this question, and got the reply that follows from David: >> >>>>From: Raymond <[EMAIL PROTECTED]> >>>> >>>>OK you got me curious ... why is the LACK of a fast lens an advantage? >>> >>>From: David Chien: >>>Lots of depth of field with slow lenses, thus no worry or thinking at all >>>about is that in focus or what f/stop do I use. Can't do it = don't >>>think about it = less to think about in the field.<<< >> >>Is it me, or is there something that isn't computing here when David says, >>"Lots of depth of field with slow lenses..." And then goes on to say, as >>my feeble reckoning abilities manage to grasp, that there will be less >>worries about focusing because of the slow lense... which again, seems to >>have, "Lots of depth of field..."<< >> >>Did I mention that it seems that it appears David is saying that slow >>lenses have lots of depth of field? :-D<< >> >>Shmatt... >I think David is mistaken or has mistyped. With a slow lens you have lots >of depth of field *control*: the depth of field is small which means you >can use it to isolate elements of the composition. < Aw shoot... Just when I thought I had David's explanation down, now I have to get the broom and clean up these shattered pieces of comprehension I was so confident with a few minutes ago. It made sense when David said: "Slow lens is a lens with a large aperture value when set wide open (when the lens lets in as much light as it can), eg. f/5.6.A fast lens is a lens with a small aperture value, eg. f/1.8." If the definition of a "slow lens" is as David describes, then I can see where such a lens would be limited to slower shutter speeds when the lens is wide open, compared to the higher shutter speed capability of a wide open lens with a f/1.8 aperture value. And it made sense that if a lens is only capable of the highest aperture value of 5.8 or greater, then I'd think that it WOULD in fact be limited to the larger f/stops with higher depth of field. No? >However, you must have good control of the focus to achieve this. Not what >you want for point and click, and not what you want when you can't see a >viewfinder image with the same resolutiuon as the final image.< > >Of course, one point I didn't mention - the depth of field is also >proportional to the resolution of the image sensor - if that is low, then >the depth of field is effectively increased, in that the image is equally >soft either side of the focus point.< Let's see... if the image sensor resolution is low, then depth of field is high. You getting this Raymond? Off to try to slow down these spinning wheels... Matt _________________________________________________________________ Join the world�s largest e-mail service with MSN Hotmail. http://www.hotmail.com ************************************************************** http://libretto.basiclink.com - Libretto mailing list http://www.silverace.com/libretto/ - Archives -------TO UNSUBSCRIBE------- Reply to any of the list messages. The reply mail should be addressed to: [EMAIL PROTECTED] - Then replace any text on the message's subject line: cmd:unsubscribe --------TO UNSUBSCRIBE DIGEST------ Do above but with this on subject line: cmd:unsubscribe digest **************************************************************
