On 5 Oct 2003 at 11:14, Henry Posner wrote:

> At 05:58 PM 10/4/2003 +0200, EOS-Digest wrote:
> > >http://www.sigmaphoto.com/Html/12-24.htm
> >
> >My concerns are:
> >- -non-removable hood
> >- -no screw in filter possible
> >- -non HSM (FTM)
> >- -6 diaphragm blades
> 
> I understand your concerns, but this is pretty much SOP for ultra wide
> angle or fisheye lenses. In most cases you couldn't add a front filter
> 'cause the angle of coverage is so wide any filter would vignette.
> Since the depth of field of most fisheyes is almost from the front
> element to the Moon, manual focus override also is not really
> necessary. -- -

But manual pre-focus is, to speed up AF (or avoid the visible red 
focus-patterns from the flash), and even more so to avoid hunting for 
focus....both arguments are more relevant with telelenses of course, 
but still convenient with shorter focal lengths.

That said, according to their site, it *is* HSM....

http://www.sigmaphoto.com/Html/12-24.htm

(just not for MAF & PAF)

Btw, it *is* possible to mount a thin piece of polaroid in/under that 
rear filter slot.
I have been doing this since I owned the old-style Sigma 8mm/f3.5 
(internal screw filter, lens would dismount in 2 parts to give access 
to the filter), then expanded application to a swing lens panorama 
camera, and last year I even succeeded with the new-style Sigma 
8mm/f3.5, by dismounting the upper part of the filter slot, inserting 
the filter, and tightening the screws.
And yes, this is a circular polarizer....:))
(that's why it is much thicker than normal gelatine, and also thicker 
than a linear polarizer (which I do use in my panorama camera btw))

Of course, it's *much* easier with a circular fisheye to adjust the 
polarizer....simply rotate the camera....:))


--                 
Bye,

Willem-Jan Markerink

      The desire to understand 
is sometimes far less intelligent than
     the inability to understand

<[EMAIL PROTECTED]>
[note: 'a-one' & 'en-el'!]


*
****
*******
***********************************************************
*  For list instructions, including unsubscribe, see:
*    http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************

Reply via email to