Dear dreammoose,
Thanks for the correction.
tOM
On Monday, September 16, 2002 at 14:48, dreammoose
<olympus@xxxxxxxxxxxxxxx>
wrote re "Re: [OM] hoods" saying:
> Whoa, whoa, wait a minute here.
> 1. The 'tulip' shape is exactly equivilent to a rectangular, full-length
> hood, but physically smaller and less obtrusive. Do the 3-D geometry on
> your CAD program. It doesn't matter whether the light path is
> interrupted close to or far away from the lens. Whether that light ray
> to the far corner of the image sneaks past a corner of a rectangular
> hood 4" away from the glass or through a curved notch 3/8" from the
> glass, the effect is the same. I assume tulip hood designs became common
> after is became relatively easy to design them with computers.
>
> 2. The 'tulip' shape is no more effective at longer focal lengths on a
> zoom than any other hood design.
>
> also
> 3. They are sexy for the same reason that flowers and Julia O'Keefe's
> paintings of them are sexy, flowers are sex organs and many are
> reminiscent in form to human sexual organs.
>
> om@xxxxxxxxxxxxxxxx wrote:
>
> >Actually, hoods don't "HAVE" to be petal shaped for a zoom. But if they
> >weren't, the lens designers would have to design a hood that was optimized
> >only for the wide-angle setting of the lens. Any telephoto-designed hood
> >would vignette at the wide-angle setting. So they opt for a compromise.
> >
> >Skip
> >
> >
> >Original Message:
> >-----------------
> >From: Tom@xxxxxxxxxxxxx
> >
> >They have to be petals for zooms.
> >
> >Every little bit of shade helps, especially with zooms.
> >
> >Besides, they're sexy.
> >
>
>
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>
>
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