OT: Cameras, cameras, cameras.. (was Re: Lightbulb police? ...)

Fred Cisin cisin at xenosoft.com
Sun Jun 13 13:18:44 CDT 2010


On Sat, 12 Jun 2010, Tony Duell wrote:
> The other trick, if you can do it is to fit the lens back-to-front. Most
> camera lenses are designed to work with a larger object than image
> distance. Byu turning it round you reverse this, which is a help for the
> short object distances in close-ups.

I NEVER reverse the lens when photographing anything unless I am going for
a magnification (image larger than object).  When the object is larger
than the image, you are in the realm of "normal" lens design.  Enlarger
lenses, in particular, are designed for ~1" (25.4mm :-) "film", with ~10"
"object"  (print paper).  Direction of photon flow is irrelevant - most
enlarger lenses are designed for about the magnification level that you
would want for photographing a sircuit board, or a sheet of paper.

Also, enlarger lenses are generally designed for FLAT FIELD, which can be
a major plus.

When photographing the innards of a chip, an individual cold solder joint,
postage stamps, coins, or the like, THEN lens reversal becomes worth
considering.


> The problem is that you genrally loose all automatic coupling to the
> lens, which means it's not a lot of use with modern
> electronically-controlled cmaeras. The Praktica PLC/VLC series had a
> special pair of afapater rings to maintain full aperture metering even
> when the lens was fitted backwards, but I've not seen this for anything
> remotely modern.

My micro-four-thirds is the first camera that I have ever seriously owned
where the camera attempted to communicate anything to the lens, (I haven't
unwrapped the Exakta that I was given months ago, andI haven't used the
other SLRs in ~40 years), and shooting in "no lens" mode lets me use my
lenses (manual focus, manual aperture).  If the only prioblem is an "auto"
aperture, there are a few adapters available that let you connect a dual
cable release (similar to that supplied with Visoflex) in order to
"simultaneously" stop down the lens and trigger the camera, or just
duct-tape the stop-down linkage and do it manually.  The lenses for the
4x5 and 8x10 cameras are all manual.


But, I may soon try to disassemble the camera firmware.
I am not sure whether Panasonic's code to refuse to operate with generic
batteries! is really a "safety issue" as they claim, or just greed.

--
Grumpy Ol' Fred     		cisin at xenosoft.com



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