Bokeh!
EOS 350D with a 1917 VPK Rapid Rectilinear f/7.7 (Bausch & Lomb)
Veijo Vilva
(Page under Construction)
VPK Rapid Rectilinear lens remounted in a Helios-44-2 body
simply with two layers of Blu-Tack wound around the RR body,
adjusting the position carefully for infinity focus.
NB. later on, I did remount the lens for use with a macro bellows, see
this page.
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A Project Just Started
A Rapid Rectilinear is supposed to be quite sharp when stopped down, but I want a soft lens with a nice bokeh (I do have many enough very sharp lenses for various purposes, with a so-and-so bokeh - or just plain garish) so I intend to mostly use this lens wide open. However, retaining the integral aperture mechanism will permit experimentation also at smaller apertures.
In the following three photos, I haven't yet actually mounted the lens on the camera. I took the photos through a window keeping the lens (surrounded by a cardboard baffle) in my hand slightly in front of an extension tube mounted on the camera, which means the focusing wasn't any too steady or perfect.
Not too bad for a freely hand-held lens - speak about manual photography!
It would look about like
this
as a 20" x 13" print (1600x1067).
Just look at the car park bokeh!
(a 1024x768 wallpaper)
Some chromatic aberration on the right around the leaves,
maybe the hand-held lens was tilted.
Anyway, the background softness is about optimal.
Rapid Rectilinear Remounted
I finally remounted the lens in the body of an old Helios-44-2, in front of the aperture mechanism, which now provides a certain amount of controlled vignetting.
How's that for bokeh?
A Vignetting Test No vignetting with a fully open lens body aperture, RR aperture at f/11
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The Original: The VPK Rapid Rectilinear lens has a lowish contrast but that can be significantly improved in PS or Gimp using local contrast enhancement.
A Local Contrast Enhanced Version: The lens is quite good considering the realities of the time of its origin. The Vest Pocket Kodak had a frame size of 1 5/8 x 2 1/2 inches (41.3mm x 63.5mm), and the photos were often enlarged to the post card size (3 1/4 x 5 1/2 inches). The above 350D frame sized crop on such a post card would look about like this:
Here the darker grey area corresponds to the VPK frame when the width-to-height ratio is kept constant. If the whole VPK frame would be enlarged as much as the 350D frames on this page have been enlarged, the result would be about 2090 x 1390 pixels in size, and enlarging a 350D frame to 20" x 13" is equivalent of enlarging the full VPK frame to about 57" x 38" (145cm x 97cm). A 350D frame section of a 30" x 20" full frame VPK print might look like this. However, most VPK owners probably had only contact prints made, i.e. something like this but in B&W:
So they just cannot have had any idea of the inherent quality of the lenses of their cameras. |
The Original: Refocused after down-sampling
A 100% Crop:
A Local Contrast Enhanced Version: |
A Local Contrast Enhanced Version: |
Local Contrast Enhanced Photos:
(c.f. a photo taken with a Sonnar 2.8/135)
Observe the well-behaved glitter of the gravel behind the fence.
Also the out-of-focus foreground is quite well-behaved.
(c.f. a photo taken
with a Tessar 2.8/45)
(c.f. a photo taken
with a Tessar 2.8/45)
The background goes gradually softer without any disturbing artefacts.
Some car head lights produce a strange effect,
but mostly the bokeh is very soft and pleasant.
Quite minimal spreading of highlights.
No double lining whatsoever, the details just fade away.
Observe the gradual softening of the decorative arch ending at the
lower right corner.
A crop at 50% magnification
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