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From: smh@mhuxl.UUCP (henning)
Newsgroups: net.rec.photo
Subject: Re: Tripods
Message-ID: <424@mhuxl.UUCP>
Date: Sun, 5-Jan-86 13:32:48 EST
Article-I.D.: mhuxl.424
Posted: Sun Jan  5 13:32:48 1986
Date-Received: Mon, 6-Jan-86 03:45:46 EST
References: <1742@trwrba.UUCP> <574@harvard.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 24

> An interesting exercise is to take pictures of resolution charts at
> various shutter speeds hand-held. Then do the same with a really
> sturdy tripod.  I found that I needed a speed of 1/250 to come close 
> to the tripod mounted speeds. If I really concentrated I could go down
> to 1/60 with only slight degradation, but for quick shooting 1/250 was
> the slowest.

****                                                                 ****
From the keys of Steve Henning, AT&T Bell Labs, Reading, PA mhuxl!smh

Assuming that Marty was using a 50mm lens on a 35mm camera this translates 
into the following:
25mm lens use 1/125 or faster
50mm lens use 1/250 or faster
100mm lens use 1/500 or faster
200mm lens use 1/1000 or faster
400mm lens and longer use a tripod.
Actually, most pros recommend using 1/xth of a second with a xmm lens.
In other words use 1/50th of a second with a 50mm lens.  But this is
the absolute slowest exposure you should try to get away with.  For
normal landscape photography the affects of hot air movement and other
differences in air density just about have the same affect as blur
at that speed.  Of course for close work like resolution chart 
photography higher speeds are necessary.