4 Jul
2012
4 Jul
'12
12:51 p.m.
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
AFAIK mine only does NTSC-rate video (OK, for the pedants, RS170 rate
video), there is certainly no itnernal framestore. (...) there's a disk
with 4 filters (one clear, maybe just a hole) and a stepper motor to
move them. There is some kind of control board, I seem to remember it's
microprocessor based,. maybe even an 8080. And not much more. I don;t
rememebr there being an internal NTSC or PAL colour decoder.
So it must takes RGB component input (no decoder) and you have to feed it a "freeze
frame" video signal, i.e. keep the image content static (no framestore) until the
three exposures have been completed?
(...) it displys TV-rate video on an
internal CRT and photographs it.
There's a colour fitler wheel (red, green, blue and a hole) so it cna
print a colour inamge in 3 goes.
(...) (...) As I mentioned, the optics is a standard, and
not very
good (Soligor, I think) enlarger lese. It's essentially fixed focus
(well evetyhing is at a fixed distance, so that's OK), it's fitted to a
meatl tuve which slites into the camera body and is lcoked by a
setscrew. Presumably you can focus it if necessary when you repari the
unit.
I also got what looks ot be a home-made bracket with it. 'Home made'
meaning not a Polaroid product, I suecpt it was made in the workshops of
the university I got this thing from. This fits in place of the Polaroid
camera. It looks like it would have held a35mm SLR + motordrive (...)
OK, so making a camera adapter in a "normal" workshop is confirmed to be
possible. Apart from interfacing the signals, it looks as if the most complicated part of
it was somehow joining the camera body, the lens and the distance tube in a mechanically
solid and light-tight fashion without messing up the distances between the components as
you go.
Err, yes... I think if I was going to make this, I
would start wit ha
dead electronic SLR, though. On the grounds it has interchagealbe lenses,
a motor to wind the film and solenoids to open/close the shutter. Then
remove the dead electroncis and make my own cotnrolelr. Whether I'd leave
the mirror in palce I don;t know, it might be easier to do so if the
sugger mwchanism depends on it for the corraect sequece.
Seems like a very sane approach. I'll have to see what I can come up with, as I know
for sure I don't have a broken SLR in my junk box...
Well, an enlarger lens is typically used to enlarge
:-). What I mean is
that the distance from the front to whatever (paper in an enalrger) is
longer than the distance from the back to whatver (negative in an
enlrager). So if you put the CRT where the paper would be and the film
(in the cmaera body) where the negative should be, it'll work and
produce a reduced image of the CRT on the film.
That sounds like waht yuu want.
Ahh, I see. I had something backwards but now I can't see what it was...
Thank you so far,
Arno.
5 Jul
5 Jul
12:07 p.m.
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
AFAIK mine only does NTSC-rate video (OK, for the pedants, RS170 rate
video), there is certainly no itnernal framestore. (...) there's a disk
with 4 filters (one clear, maybe just a hole) and a stepper motor to
move them. There is some kind of control board, I seem to remember it's
microprocessor based,. maybe even an 8080. And not much more. I don;t
rememebr there being an internal NTSC or PAL colour decoder.
So it must takes RGB component input (no decoder) and you have to feed
it a "freeze frame" video signal, i.e. keep the image content static (no
framestore) until the three exposures have been completed?
Yes. I got thtis thing along with soem I2S image processor/display units
(high-end (for 1979 [1]) graphics systems for PDP11s and other
minincomputers. It was possibly used for pritnign the output of one of thsoe.
[1] IIRC the resolution is 512*512 pixels. The units have multiple
'byteplanes' of that size, the outputs of which go through programamble
look-up tables, and are then added. further lookup tables the go between
the outptu fo the adder and the DACs (8 or 10 bit per colour). There are
lots of other feautres too, like an overlayed bitplane for text,
historgramming of the displayed data and even somethign called the
'feedback ALU' where planes 0 and 1 becoem a 16 bit accumulator, you cna
then dio the function Acc := Acc Op Another_plane. Where 'Op' is anything
a 74181 can do, and the othee plane cn be arbritratily shifted around.
Oh yes, and unlike the GPU in the Rpi, you get docs. Real docs. There's a
_large_ binder of scheamtics...
(...) it displys TV-rate video on an
internal CRT and photographs it.
There's a colour fitler wheel (red, green, blue and a hole) so it cna
print a colour inamge in 3 goes.
(...) I also got
what looks ot be a home-made bracket with it. 'Home made'
meaning not a Polaroid product, I suecpt it was made in the workshops of
the university I got this thing from. This fits in place of the Polaroid
camera. It looks like it would have held a35mm SLR + motordrive (...)
OK, so making a camera adapter in a "normal" workshop is confirmed to
be possible. Apart from interfacing the signals, it looks as if the most complicated part of it was somehow joining the camera
body, the lens and
the distance tube in a mechanically solid and light-tight fashion
I thinmk it took a noiraml SLR camera (I sould guess a Nikon or a Cannon,
but I am not sure). I susepct it used a lens and extension tubes from
that system, so the back of the lens to the film was easy to keep
light-tight. There woas probably some kind of tebe fro mthe frojnt of the
lens to the vertal part of the bracket, it might be soekthign as simple
as a lens hood.
The bracket is failrly deep from the lense hole ot the horizotnal part, I
suspect it took a camera wit ha motordrive and that the mystery connector
connected to the remote release of that.
[Hacking an SLR onto this]
Seems like a very sane approach. I'll have to see what I can come up
with, as I know for sure I don't have a broken SLR in my junk box...
I have plenty of cameras that I need to repair, but none of them are
electronic (by choice!). But unless you want soemthign exotic, broken
35mm electornci cameras are not that expensive now. You might even get a
working one with an electronic remote release for not too much money.
As for the lens, an elnerger lens would be a good choice I think. You
would have to get ot make an adapter to fit it to the caemra, and get
soem kind of extension tubes, buc such things do exist, or can be made.
-tony
9 Jul
9 Jul
10:29 a.m.
The PCRII takes commands over an IEEE-488 bus. Its a vector graphics display, not NTSC.
The shutter stays open during the write time, the filter wheel rotates to paint each RGB
frame.
The recording time can be several minutes, depending on the speed of the host computer.
I think there were some primitives, like paint polygon, so it did not need the host to
send the whole scan for the shape, just the vector outline and the PCR would do the fill.
Think along the lines (pun intended) of gerber format for PCBs, and photoploters. Similar
idea.
Date: Wed, 4 Jul 2012 21:51:43 +0200
From: Arno_1983 at gmx.de
Subject: Re: Film Recorders (Agfa PCR II)
To: cctalk at classiccmp.org
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
AFAIK mine only does NTSC-rate video (OK, for the pedants, RS170 rate
video), there is certainly no itnernal framestore. (...) there's a disk
with 4 filters (one clear, maybe just a hole) and a stepper motor to
move them. There is some kind of control board, I seem to remember it's
microprocessor based,. maybe even an 8080. And not much more. I don;t
rememebr there being an internal NTSC or PAL colour decoder.
So it must takes RGB component input (no decoder) and you have to feed it a "freeze
frame" video signal, i.e. keep the image content static (no framestore) until the
three exposures have been completed?
(...) it displys TV-rate video on an
internal CRT and photographs it.
There's a colour fitler wheel (red, green, blue and a hole) so it cna
print a colour inamge in 3 goes.
(...) (...) As I mentioned, the optics is a standard,
and not very
good (Soligor, I think) enlarger lese. It's essentially fixed focus
(well evetyhing is at a fixed distance, so that's OK), it's fitted to a
meatl tuve which slites into the camera body and is lcoked by a
setscrew. Presumably you can focus it if necessary when you repari the
unit.
I also got what looks ot be a home-made bracket with it. 'Home made'
meaning not a Polaroid product, I suecpt it was made in the workshops of
the university I got this thing from. This fits in place of the Polaroid
camera. It looks like it would have held a35mm SLR + motordrive (...)
OK, so making a camera adapter in a "normal" workshop is confirmed to be
possible. Apart from interfacing the signals, it looks as if the most complicated part of
it was somehow joining the camera body, the lens and the distance tube in a mechanically
solid and light-tight fashion without messing up the distances between the components as
you go.
Err, yes... I think if I was going to make this,
I would start wit ha
dead electronic SLR, though. On the grounds it has interchagealbe lenses,
a motor to wind the film and solenoids to open/close the shutter. Then
remove the dead electroncis and make my own cotnrolelr. Whether I'd leave
the mirror in palce I don;t know, it might be easier to do so if the
sugger mwchanism depends on it for the corraect sequece.
Seems like a very sane approach. I'll have to see what I can come up with, as I know
for sure I don't have a broken SLR in my junk box...
Well, an enlarger lens is typically used to
enlarge :-). What I mean is
that the distance from the front to whatever (paper in an enalrger) is
longer than the distance from the back to whatver (negative in an
enlrager). So if you put the CRT where the paper would be and the film
(in the cmaera body) where the negative should be, it'll work and
produce a reduced image of the CRT on the film.
That sounds like waht yuu want.
Ahh, I see. I had something backwards but now I can't see what it was...
Thank you so far,
Arno.
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ard＠p850ug1.demon.co.uk -
Arno_1983＠gmx.de -
rdawson16＠hotmail.com