RCA camera
16 messages in this thread
C mount lenses were q uite common for the 16mm amateur and
professional cameras for a long time, and Cmount is still in some use these
days on video cameras by a number of manufacturers. It's a screw-thread
thingy, not a bayonet.
I've been looking for a source of C mount lenses for my own Panasonic
WV1410, but I havent had time to get down to serious scrounging yet.
You can also buy Cmount to <something else> adapters which will permit
using such things as SLR lenses on your WV1410. most of these introduce
lens extension, which limits the infinity-focus of the camera, but infinity
focus is not a consideration on a copy stand.
The king of adapter sources is Spiratone, but I've been busy and haven't
had time to chase the artricles down exactrly.
Many lenses for those ol' 16mm projectors are Cmount, too, and they're
mostlyoptimized for flat-to-flat reproduction, which the Panasonic lens is
definitely not.
A projection lens is sposes to take flat field things and render them flat
on projection. The one on the camera as supplied (to me!) has serious
curvature of field and vignetting. I call it the Bluromat.
My husband has been a camera fan for many years, but I have not. Since I
wanted to use Digi-View, I've had to acquire a bit of knowledge about cameras,
but I mostly depend on his knowledge. However, he had not mentioned the
possibility of the adapter. He has some very fine lenses for some of his
cameras, so the adapter might be all I would need.
It was he who suggested the pawn shops. He said that the C-mount cameras were
no longer very popular and that the most likely place to find those lenses
might be at pawn shops and camera-oriented flea markets.
Thanks for the information. I'd really like to get better quality from
Digi-View so I'll be looking around. Oh – if I find his Spiratone catalog,
I'll let you know about adapters.
Well, I spent many long and pleasant years as a high-end professional
commercial photographer, and I made it a habit to keep up with such minutae
as lensmounts. Unfortunately, my knowledge is getting old and dated, but
it do come in handy now and again. The lens you want is as short a focal
length as possibe while still maintaining flat field. On 35mm cameras,
that's probly one of the "macro" lenses. I use Canons, and theirs is 55mm
(mine is ancient!). Nikon is 50mm, I think.
The focal length will be a problem, as you'll be in superclose mode on the
video camera. I'm going to figure all this out hands-on but haven't had time
yet. I get most acceptable results with my DigiView as is.
Oddly, when i bought the thing, I had visions of installing my outrageously
sharp and expensive enlarging lenses on the thing (they fit the Cthread enough
to work). Unfortunately, they have no helical for focusing, though. Well,
live and learn.
They do sell minibellows for enlarger lenses (and I agree, the little buggers
are too d*** expensive for what you get 8) I've seen them advertised for
macro/copystand work by, of all people, Spiratone. They have a variety of
mounting systems (c-Nikon, c-Minolta, etc.)
As with you, this is dated information. I do remember seeing one for video
work somewhere <suspiciously eyeing large stack of 'Popular Photography'
teetering over in corner of room> but can't remember the specifics.
My instinct is that a bellows will introduce far too much extension. The
back focus of the lens is not accustomed to being more than an inch, and by the
time you add bellows, adapter, etc., the result is likely to be much to long.
I'd have to luck onto one of the things in a real store, where I could touch it
and feel it before I invested.
J:
Jay,
The easy solution is to use a longer-than-"normal" enlarging lens. This
will also have the added benifit of increasing the distance between the lens
and the object being digitized.
I couldn't get the Panasonic WV1410 to focus (even with adjusting the back
focus knob) using either the 50mm S-Componon or the 80mm one. They both fit
well enough in the thread, but would not focus.
I hjaven't given up, just temporarily set back. :I spose I really
shoulddevote energy to making the Componons work, because of their copying
optimization.
J:
Jay,
If my memory is correct, I belive a 'normal' lens for a video camera is
in the 35mm range.
Don
"Normal" focal length for a video camera should be approximately the dsame
as for a 16mm one, maybe a bit longer. The 16mm range is pro probably slightly
wideangle on the Panasonic.
I'll look through my photo doodads and see if I can pinpoint this. It's an
interesting question.
Jay,
I'd be interested (just curiosity…I don't have a video camera) in
what you find out. Like I said, my memory tells me it's 35mm, but I could
easily be wrong. I am fairly sure that for a video camera, the focal lenght is
shorter than for a 35mm SLR, and normal for them is about a 50mm lens.
If you're into mathematics, the "normal" focal length for a format is
defined as the DIAGONAL of the format. With 35mm, that's approx 50mm, 'cause
35mm film format (picture size) is 24mm x 36mm. Thereabouts.
My confusion on the issue is that i don't know how to measure the format
size of the video camera. Does a 2/3" Plumbicon mean the format is 2.3"
square?
J:
Well…I presume that's a 2/3" diameter circle…and thus would
hold a rectangle with a 2/3" diagonal…or about 18mm.
How about this: take a 35mm SLR and look thru the viewfinder, now
set up a video camera beside it and zoom in or out until you have the same
field in the viewfinder (or as close as you can get depending on the aspect
ratio) and then read the focal length off the zoom? That ought to give you
and idea what a normal lens for a video camera should be. (Oh…forgot to
mention, put a 50mm lens on the SLR)
I think our best lenses were for his old Miranda. He could focus that
thing on a postage stamp and make a full-size slide from it. Used it to
make slides for classroom presentations, mostly. He could take a picture
of any little diagram he could find, then project it for the class to see.
Very, very old now – but quite good. I don't know the brand of the lenses
themselves.
Several yearsago, he took pictures of very faded old family pictures and
made them sharp and new (with various filters). Quite a few relatives
were extremely happy with the pictures he gave as Christmas presents that
year!
Betty, That's one of the advantages I've found with the C-Mount adaptor on
the Pan. camera with DigiView. I'm using a Cannon 50mm lens w/C-mount
adaptor. I can focus on a object half an inch from the lens. You can
blow-up a pin head to full screen, and still have the ability to
digitize a full 8 1/2 x 11 mag page. Dale
WHO'S GOT THAT MIRANDA?!! I thought I was the only one that still had one!
Mine's an old DR 1.9 that I bought from a fella who bought it in (believe
it or not) Dallas, November 22, 1963. I've still got it, and use it on
occasion on my 10" Newtonian telescope. Put a nifty cold pack back on it,
hyper the film, push process it (the film is normally 200 speed), and
Voila! The Trifid nebula in full color with a 22 minute exposure. Not bad
for such an antique!