[LargeFormat] Bausch and Lomb Portrait Lens

[Les Newcomer]

> From: Clive Warren <cocam@blueyonder.co.uk>
> Reply-To: largeformat@f32.net
> Date: Sat, 13 Apr 2002 18:02:12 +0100
> To: largeformat@f32.net
> Subject: Re: [LargeFormat] Bausch and Lomb Portrait Lens
> 
> 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


"the efficiency of a country shutter." <giggle>   sounds like an MIT masters
thesis if I every heard one.

I got the term from another photographer. don't know where she got the term
from, but I've heard it from seperate sources.  There has to different names
for this thing, and it's the one item that was so readily usable that I've
never seen marketed on a commercial basis.

I don't think there's a major problem with uneven exposure.  Use POP and
print through it!!  *->

For the one I build for the Unar I made 5.5" wide as the lenscape was 4.25"
I also made the far edge a bit deeper with a bead on the inner lip. This way
i can hang the shutter on the lens and it won't fall off while I pull the
darkslide.  All way over built, but once in awhile I like to see what the
wood working tools can do besides make sawdust.