----- Original Message -----
From: "Lex Jenkins" <lexjenkins@xxxxxxxxxxx>
To: <olympus@xxxxxxxxxxxxxxx>
Sent: Thursday, August 03, 2000 3:40 AM
Subject: Re: [OM] Airplanes -Reply
> Vunderblochen SLRs typically use passive AF and, as you mentioned, need some
> kind of contrast for best results. Focus assist lights have very limited
> range and would be useless on subjects like planes flying overhead.
>
> Oddly, some P&S cameras have more sophisticated AF systems. Pentax, and
> possibly others, have combined passive and active systems for reliability.
> But, again, the range is limited.
>
> The trick is to find a surface the AF can lock onto, then recompose along
> the same focus "plane." ;) The Olympus ZLRs seem to be very good at this.
> My mom's iS-2 can focus on a blank white wall out to reasonable distances by
> projecting a red beam of vertical and horizontal lines from the focus assist
> light.
Yes, this is used on the advanced line of iS cameras, but the simple line use
the built-in flash as
focus assist light. Don't know which is best though. I imagine the flash light
would be more
annoying if you're shooting a person or an animal. Incidentally the CMOS sensor
of the iS-30(0) is
reported to be able to focus down to EV 1 without assisting light, so I presume
at least this camera
wouldn't be needing the assisting flash light very often.
Per Nordenberg
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