[LargeFormat] Bausch and Lomb Portrait Lens
Clive Warren
largeformat@f32.net
Sat Apr 13 12:59:01 2002
At 9:05 am -0700 13/4/02, Les Newcomer wrote:
snip
>
>"And the soft edge effect just gets better with age!! "No wiry sharpness
>around the edges on images from this lens!"
snip
>
>there were focal plane shutters designed for the rear of the camera
>And then there were the Ilexpo shutter boxes, or shutter boxes with a
>packard on them, so (in theory) he could change lenses without changing
>bulbs and hoses. But even in the twenties, having more than one lens was
>uncommon. I suppose a short lens for doing full or 3/4 lengths and this for
>doing busts and head shots.
>
>Nobody, not even me, has attempted to document the evolution of the country
>shutter, but I'm sure they were around. A country shutter is nothing more
>than a small box on a stick. I've made one out of mahogany and flocked the
>interior with box jointed corners and dovetailed the handle. But in truth
>most are made of a 4x5 film box stuck to a stainless steel ruler with gaffer
>tape. The idea is the same as the lens cap but with a much faster exposure
>as a 'flick of the wrist' is all it takes. Just for fun I played with my
>Calumet digi-tester and my shutter. It varied a bit but the times were 1/8
>to 1/15 of a second.
>
>I've also used this when doing multiple pops with a flash. Open the lens
>and stick the shutter as close as possible without touching. Flick open and
>flash, then close. Wait for the flash to recharge. Flick open and flash.
>This way the flash can build up without the danger of moving the camera
>recocking the shutter.
Les,
You're right about the soft focus - never mind the edges, it's all
soft! Just checked out the ground glass with a head sized object and
tried stopping down. There seems to be a bit of focus shift which is
what you may expect with a protar. Stopping down down to the point
where you can't really tell much about the image it does seem to get
sharper but probably is never going to make your eyes bleed.
This lens could make a lot of women very happy ;-)
I like your country shutter - is it you who coined the term? I
remember you mentioning the technique previously on the list. The
Plastigmat would need a 5x7 film box as the OD is around 4" at the
business end. I have been trying to wrap my head around the idea of
what would be happening to the film exposure as the box is moved.
Seems to me that the top of the film would receive more exposure
which may or may not be significant depending on the "shutter speed".
A chap recently demonstrated a really old brass shutter to me that
was powered by a rubber band that moved a circle of metal with a
quadrant cut out across the front of the lens. The little Olmpus Pen
shutters used this design but their metal disks were made of titanium
to achieve higher speeds with the lower mass.
I have visions of a large matt black cardboard circular disk with
quadrant cut out, on a spindle and a large rubber band.... hmmmm....
might work for slower shutter speeds if it moved fast enough to avoid
differential exposure across the film plane.....
The box would be a lot easier though :-)
Cheers,
Clive