4 Jul
2011
4 Jul
'11
2:44 p.m.
Attached a fiche holder to copy stand with canon camera mounted,
rigged the 50mm lens off the old film eos camera on a cantilever
support over the fiche as a close-up
I cannot cover enough of the digital cameras sensor for easy
readability but it shows promise
http://www.collection.archivist.info/archive/fiche_experiments/50mm_on_stan…
First image is uncropped, then a sequence from the RD53-A manual
then a couple of pics of the experiment done with an old olympus
one either needs to go manual focus or be a little more careful with
the autofocus as one or three are a bit off
the lens was only held by gravity and did shuffle around a bit hence
some vignetting in places
there is some light getting in causing an error
shows it can be done though with simple equipment, now just needs the
process improving a little and
bolting the lens, adding a tube to stop extraneous light, a better
camera (more megapixels)
Dave Caroline
On Mon, Jul 4, 2011 at 9:23 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Tony Im just in the pocess of jury rigging a better close up experiment
http://www.collection.archivist.info/archive/fiche_experiments/50mm_canon_l…
was yesterdays experiment, some exposure error hence noise and also
thats hand held
next is to bolt stuff to a stand so I can increase exposure time and
Some phootgraphic enlargers have the facility to remvoe the enlarger
head/optics leaving a baseboard with a column and a carriag that can be
moved up and down .Such thigns are idea for converting into stands for
setups like this. Normally all you need is a metal bar with a male screw
thread at one end to fit the camera tripod bush (normally 1/4 BSW, may be
3/8 BSW on larger/older cameras) and some way of fixing it to the carriage.
[1] You don't turn down the end of a 2" or so diamater metal bar to 1/4"
and then trhead it, of course. It's much easier to drill a central hole
in the end of the bar ant tap it 1/4" BSW (or whatever) and use a short
length of studding screwed in there to provide the male thread. Either
Loctite it in place, or fit a grubscrew.
reduce shake at the same time
Certainly when photogrpahing small bits of machienry using a film camera,
I use the slowest film I can get (low grain, on a digital camera set the
efective film speed as low as possible to resduce noise) and have the
lens stopped down to increase depth of field. This leads to long
exposures (several seconds in some cases) which are not a problem if the
setup is rigit -- PCBs, etc do not tend to go anywhere.
Depth of field is much less of a problem on a flat subject like a fice
of fiche, of course
-tony