Ken,
Yes the compendium hoods that cinematographers use are ideal for
coverage and protection, but not ideal, from cost, complexity and ease
of use. These are mostly used in studio conditions even by still
photographers (most large-format cameras have compendium hoods available
as did Hasselblad). There are a few 3rd party compendium hoods for
35mm. The only one I've used is the Ambico, but I'm not very happy with
it (it's pretty flimsy).
The round funnel or round tube designs are the easiest to design and are
very compact (rubber round funnel collapses, round tube can either
retract or be reversed on the lens).
For wide angle lenses the round hood must be made very short to avoid
vignetting the corners of the frame.
One way to get a more effective hood for a wide-angle lens is to use the
round funnel or tube design and cut back the corners making the petal
design.
Someone said that a lens was round so the hood must be round as well,
that's not really correct. Lenses are round as is the image they
produce (and the section of the world that they see. But, and it is a
big but, our cameras crop a 2:3 rectangular piece out of that round
image. So the hoods are best rectangular.
The best hood, sort of a compendium would be a rectangular pyramid with
the lens stuck through the small end. There's a cute one up on eBay:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1236279414
It's not really easy to see the picture, but the hood is pretty
effective for the lenses covered. It works for both 50mm and 35mm,
because the Retina's 35mm lens' front element is closer to the edge of
this particular hood (the 50mm front element is recessed into the hood).
I do agree, that a rectangular hood would take up a lot of space in a bag.
Also, hood don't do anything but act as bumpers if the light source is
not beside or in front of you. If the light is behind you, the hood is
not doing anything optically.
As far as I'm concerned the Canon FD hoods were about as good as you can
get. The EF hoods are a pale imitation for durability, coverage, ease
of use and storage. It's almost as if Canon said, we must obsolete
EVERYTHING with this new line of cameras. Our customers must not be
able to make use of ANYTHING they already own.
Mr. Bill
Ken Durling wrote:
>
> Again, pardon my ignorance, but do you mean like a very wide-mouth
> funnel? I'm picturing some of those huge cinema camera hoods...
> would you characterize them as "optimal?"
*
****
*******
***********************************************************
* For list instructions, including unsubscribe, see:
* http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************
