In article <5ed6h7$flb@cello.hpl.hp.com>, jacobson@cello.hpl.hp.com says...
>In article <19970218043900.XAA29954@ladder01.news.aol.com>,
>BandHPhoto wrote:

>>Again -- up to the individual & the circumstances. For my part -- every
>>lens I own (Nikon, Leica, Bronica, Mamiya) -- every lens has either the
>>manufacturer's matched hood, or is used with a compendium (bellows-type)
>>hood, depending on the situation.

>That brings up some questions I've been wondering about for a long time.
>What is the current situation regarding compendium bellows?
>1. How do they mount? Are they supported by the filter threads or by
>some other bracket?
>2. What kind of trouble is there with lenses that rotate with
>focusing?
>3. Are the only available ones horribly expensive ones really
>designed for the medium format or movie people, or is there something
>reasonably priced and designed for 35mm work?
>4. As a practical matter, how does one use them, particularly with
>zooms? Do you crank out until you see vigenetting, then back off, or
>are do they have focal length marks or what?
>5. Do they provide noticible improvement over the manufacturer's
>recommended hood?

Hmmm - methinks you probably know the answers to these questions, already,
but...;-):
1. Usually.
2. LOTS! (Or, "BIG!"...;-)
3. No - I have seen cheap ones (e-mail me, if you want one I never use...).
4. Some have FL marks (but the variables make these not reliable). The
alternative of backing off is not very good, if the finder doesn't
show 100% of the film area (though one can fudge a bit...). You can also
use the view-camera trick of looking in through the front to see if you
can see the opposite VF screen corner (but here again, if there isn't
100% screen coverage of the film area, a bit of fudging is required).
Use with zooms, unless you are working VERY slowly (then why use 35mm?),
is too awkward for words...;-)
5. They can, if the lens is particularly sensitive to off-field light, and
the light comes from an area where a round shade doesn't cover (though
a rectangular shade, or a round one with a mask installed, works as well).
Some lenses are best used without shades (PC, some super-wides, macros),
and when necessary, you can cover the sun with a finger, or a broad bright area with a hand.
Hope This Helps