Olympus-OM
[Top] [All Lists]

Re: [OM] OM: Extension tubes and focusing distance

Subject: Re: [OM] OM: Extension tubes and focusing distance
From: Gary Edwards <edwardsg@xxxxxxxxx>
Date: Sun, 21 Nov 1999 20:52:19 -0600
John, what are your other half's interests?  My wife is an organic gardener.
She loves butterflies and beneficial insects (most are).  It was easy to sell
her on a macro lens.  When she needed duplicate slides for a professional talk,
I got an autobellows, 80/4 macro, and a slide copier.  After we drove 400 miles
so she could see the sandhill cranes wintering in the Texas panhandle, I got a
Tamron 400/4.  Get the picture?  ;-)

Gary Edwards

"John A. Lind" wrote:

> At 14:39 11/21/99 , Ron & Mary Spolarich wrote:
> >Goin' to school! <g>  Thanks for the great explanation Chuck. Though I've
>
> A couple things Chuck left out:
>
> 1.  Extension tubes are generally thought to be better than using screw-on
> close-up lenses on the lens filter ring, but lesser than a macro lens which
> has optics designed for extremely close focus.  Tubes do not add any glass
> to the light path.  Screw-on close-up lenses do, and you are at the mercy
> of how good (or poor) they are.
>
> 2.  Close-up lenses screwed onto the filter ring will not change exposure
> settings, but an extension tube will!  There are tables that show the
> exposure adjustment required if you ever use tubes on a *non-TTL* metered
> camera.  However, TTL metering compensates for it just as it does for
> filters.  Just remember with an extension tube on you do lose some light,
> the longer the tube, the more light lost.  This might affect choice in film
> speed.  Kodak's Pocket Photoguide (the little pocket bible many photogs
> have in the bag; used to be called the Master Photoguide) has tables in it
> about the effect of tube extensions on exposure.
>
> -- John
> (who hasn't come up with a story good enough to ustify the cost of a macro
> lens to his other half yet!)
>
> < This message was delivered via the Olympus Mailing List >
> < For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
> < Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz