Two Odd Films

I have just bought two lots of film from that auction site and was wondering
if anyone else had any aquainatance with them.

The first was five boxes of Ansco 282. Fortunately there was a info slip
inside the box which suggested a speed of 50ASA which is about right with
the dev time of Ilford FP4. The expiry date on the boxes was May 1960, at
which time I wasnt even born! I think the boxes were kept cold.

The second lot of film was Kodak 4125 Copy Film.
Such Kodak information I have seen suggests that the film might be around
12ASA in daylight and tests seem to suggest such a speed, with a dev time as
for Ilford Pan F.

The Kodak 4125 is ortho film and as such will not penetrate atmospheric haze
which may be a plus point for landscapes.
The Ansco 282 was described as a "high speed panchromatic film. Type 282 is
an excellent choice for studio, commercial & illustrative photography as
well as specialised applications like medical photography".
I suppose that 50ASA was fairly fast by the standards of the time.
I know that the film base is so thick its like putting lino into the holders
and it takes ages to dry as well.

"Neil Purling" wrote in
message ...
I have just bought two lots of film from that auction site
and was wondering
if anyone else had any aquainatance with them.

The first was five boxes of Ansco 282. Fortunately there
was a info slip
inside the box which suggested a speed of 50ASA which is
about right with
the dev time of Ilford FP4. The expiry date on the boxes
was May 1960, at
which time I wasnt even born! I think the boxes were kept
cold.

The second lot of film was Kodak 4125 Copy Film.
Such Kodak information I have seen suggests that the film
might be around
12ASA in daylight and tests seem to suggest such a speed,
with a dev time as
for Ilford Pan F.

The Kodak 4125 is ortho film and as such will not
penetrate atmospheric haze
which may be a plus point for landscapes.
The Ansco 282 was described as a "high speed panchromatic
film. Type 282 is
an excellent choice for studio, commercial & illustrative
photography as
well as specialised applications like medical
photography".
I suppose that 50ASA was fairly fast by the standards of
the time.
I know that the film base is so thick its like putting
lino into the holders
and it takes ages to dry as well.


The speeds may still be the old ASA system. If so the ISO
rating would be double this.
The film should be notched. If you can reproduce the
notch I may be able to identify the film. At a little
earlier date Ansco made three ASA-50 sheet films, one was
orthochromatic so this isn't it. The two others were Isopan
and Superpan Portrait. Isopan had three square notches,
Superpan Portrait a single square notch. Isopan was a
popular film with a medium toe and long straight line
characteristic, Superpan Portrait had a longer toe and "S"
shaped curve, a characteristic once popular for portrait
work. If the films were stored well they may still be good.
I have limited development instructions for these films.
For Ansco/Agfa 17 (similar to D-76) the time for Isopan is
about 12 minutes at 68F, but for a higher contrast then
would be considered desirable now. For Superpan the time for
Ansco 17 is about 11 minutes at 68F for a gamma of 0.9. A
time of around 8 minutes for either film would be closer to
the mark for currently desirable values of contrast. From
the text of the Ansco booklet the time for Superpan may be
long because it was intended that minimum exposures be used
to get most of the image onto the toe. I suspect what you
have is Isopan.


--
---
Richard Knoppow
Los Angeles, CA, USA

Richard Knoppow wrote:

The speeds may still be the old ASA system. If so the ISO
rating would be double this.


Sorry to go off thread topic a bit, but....I wonder if you could expand
a bit on the difference between ASA and ISO and the how the numbers relate?

thanks and cheers

--
regards from ::

John Bartley
43 Norway Spruce Street
Stittsville, Ontario
Canada, K2S1P5

( If you slow down it takes longer
- does that apply to life also?)

Richard Knoppow wrote:

The speeds may still be the old ASA system. If so the ISO
rating would be double this.


Sorry to go off thread topic a bit, but....I wonder if you could expand
a bit on the difference between ASA and ISO and the how the numbers relate?

thanks and cheers

--
regards from ::

John Bartley
43 Norway Spruce Street
Stittsville, Ontario
Canada, K2S1P5

( If you slow down it takes longer
- does that apply to life also?)

Neil Purling wrote:
I have just bought two lots of film from that auction site and was wondering
if anyone else had any aquainatance with them.

The first was five boxes of Ansco 282. Fortunately there was a info slip
inside the box which suggested a speed of 50ASA which is about right with
the dev time of Ilford FP4. The expiry date on the boxes was May 1960, at
which time I wasnt even born! I think the boxes were kept cold.

The second lot of film was Kodak 4125 Copy Film.
Such Kodak information I have seen suggests that the film might be around
12ASA in daylight and tests seem to suggest such a speed, with a dev time as
for Ilford Pan F.

The Kodak 4125 is ortho film and as such will not penetrate atmospheric haze
which may be a plus point for landscapes.
The Ansco 282 was described as a "high speed panchromatic film. Type 282 is
an excellent choice for studio, commercial & illustrative photography as
well as specialised applications like medical photography".
I suppose that 50ASA was fairly fast by the standards of the time.
I know that the film base is so thick its like putting lino into the holders
and it takes ages to dry as well.



Kodak PCF 4125 was a nice film for copywork and also had some uses
pictorially. It is a two-emulsion film IIRC and the contrast was
dependent on both exposure and development because of the different
speeds of the two emulsions.

David Kachel (sp?) claimed you you get N+4 from it. He wrote a series
of articles on using it in his version of the Zone System circa 1990 for
the old Darkroom and Creative Camera Techniques magazine which morphed
into PhotoTechniques. He also had a website at one time so Googling
might turn him up. The speed of the film was very dependent upon the
type of light source but I think it was ISO 50 for Xenon (but I'm unsure
of that recollection - it could have been ISO 12 for daylight as you
suggest). The film was listed in Kodak's Professional Films booklet
until very recently when it was discontinued about 2 years ago. So, if
you can find a copy of that publication pre-2000 or Kachel's article,
they would tell you in great detail all about the specs for the film.

Joe

"Razondetre" wrote in message
...
The speeds may still be the old ASA system. If so the ISO
rating would be double this.

ASA=ISO.

RDE.

No, they are different. The ASA method used until 1958 was
an adoption of the Kodak speed method with the ratings
adjusted to fall between the then current Weston and General
Electric speeds. In addition to this a 2.5X safety factor
was added. In 1958 the ASA adopted the German DIN method of
measureing speed, the same one the ISO currently uses. They
also cut the safety factor in half to 1.25X, which had the
effect of doubling the speed of all films. I don't know why
the very large safety factor was adopted except it was
probably to insure that amateurs got usable images. Kodak
had discovered that the tonal rendition of film stayed about
the same once a certain minimum exposure was given. Minimum
exposures result in finer grain and better sharpness but no
difference in tonal rendition. In thier film booklets Kodak
recommends doubling the speed if lighting and processing are
controlled.
My Ansco data comes from a data booklet dated 1947. The
film probably did not change much over the next decade.
Since the speeds are right my guess is that the film being
asked about was made before the ASA changed its speed
ratings. That would be about right for film which expired in
1960, it was probably about 2 to 5 years old then.


--
---
Richard Knoppow
Los Angeles, CA, USA

"Razondetre" wrote in message
...
The speeds may still be the old ASA system. If so the ISO
rating would be double this.

ASA=ISO.

RDE.

No, they are different. The ASA method used until 1958 was
an adoption of the Kodak speed method with the ratings
adjusted to fall between the then current Weston and General
Electric speeds. In addition to this a 2.5X safety factor
was added. In 1958 the ASA adopted the German DIN method of
measureing speed, the same one the ISO currently uses. They
also cut the safety factor in half to 1.25X, which had the
effect of doubling the speed of all films. I don't know why
the very large safety factor was adopted except it was
probably to insure that amateurs got usable images. Kodak
had discovered that the tonal rendition of film stayed about
the same once a certain minimum exposure was given. Minimum
exposures result in finer grain and better sharpness but no
difference in tonal rendition. In thier film booklets Kodak
recommends doubling the speed if lighting and processing are
controlled.
My Ansco data comes from a data booklet dated 1947. The
film probably did not change much over the next decade.
Since the speeds are right my guess is that the film being
asked about was made before the ASA changed its speed
ratings. That would be about right for film which expired in
1960, it was probably about 2 to 5 years old then.


--
---
Richard Knoppow
Los Angeles, CA, USA

Richard Knoppow, I see that your are acknowledged in Way Beyond Monochrome.
I'm reading it cover to cover. Very good book.

Richard Knoppow, I see that your are acknowledged in Way Beyond Monochrome.
I'm reading it cover to cover. Very good book.

"John Bartley" wrote in message
...
Richard Knoppow wrote:

The speeds may still be the old ASA system. If so the ISO
rating would be double this.


Sorry to go off thread topic a bit, but....I wonder if
you could expand
a bit on the difference between ASA and ISO and the how
the numbers relate?

thanks and cheers

--
regards from ::

John Bartley
43 Norway Spruce Street
Stittsville, Ontario
Canada, K2S1P5

( If you slow down it takes longer
- does that apply to life also?)

The original ASA system, introduced in the mid 1940's was
based on a method developed at Kodak. This method based the
speed point on that part of the toe of the film curve where
the "gradient" or contrast was 1/3rd of the contrast of the
main straight-line portion of the curve. This point was
decided after a very extensive survey of what viewers called
"first excellent prints" from a series of increasing
exposures. The idea was to find the minimum exposure which
had enough shadow detail to result in an "excellent" print.
The reason for using a minimum exposure is that film tends
to be less grainy and sharper when less dense. There were
two problems with this method. One was that it was just hard
to measure since points on two gradients had to be measured.
The second problem was not with the method itself but the
application of it by the ASA. They added a 2.5X safety
factor. Presumably, this was done to insure printable
negatives despite errors in exposure meters, shutters, stop
calibration, film development, etc. Kodak found that the
latitude for over exposure of most film was tremendous.
While overexposed film was not as sharp or grain free as a
correctly exposed negative the tonal rendition would remain
good over a very long range of error.
The safety factor resulted in overly dense negatives.
In 1958 the ASA changed the standard and adopted the DIN
method of measurement. They also dropped the large safety
factor. The DIN method is the one currently used although
there have been some changes in detail over the years. The
DIN standard measures speed from a point where the density
is log 0.1 above the base density and fog to a point where
the density is log 0.8 greater than this for an exposure
range of log 1.2 This corresponds to about the contrast
recommended for contact printing or diffusion enlarging. The
ASA ran a lot of tests and found that the effective speed of
most films came out about the same when DIN and Kodak
methods were compared. The DIN method is much easier to
measure so it was adopted. The biggest effect on published
film speeds was the change from a 2.5X safter factor to a
1.25X safety factor, the same as is spplied now. This had
the practical effect of doubling film speeds. Both sets of
speeds were called ASA speeds but the standard for them had
been changed.
The original ASA speed series was intended to be useful
on the existing exposure meters of the time, mainly those
made by Weston and General Electric. Both companies had
their own methods of speed measurement. The new ASA speeds
were designed so they fell in between the two sets of
speeds. An ASA speed (or an ISO speed) can be used on these
old meters without serious error. For a closer approximation
an old Weston meter, calibrated in Weston speeds, should be
set for the next lower numeber than the ISO speed, for old
G.E. meters, calibrated in the G.E. system, use the next
higher speed. Actually, you will find that Weston meters
underexpose about a stop. Why, well, evidently, Weston
included a safety factor in their speeds which was removed
by the calculator! I find my old Westons agree with modern
meters when half the ISO speed is used. My G.E. meters are
all calibrated in the ASA sytem and work fine with modern
ISO speeds.
The ISO is an international standards organization. The
U.S. member is NIST, or the National Institute for Standards
and Technology. This was formerly the ASA or American
Standards Association, same group. Modern ISO speeds are
directly related to the 1958 ASA and DIN systems.
If you have old Weston speed charts the ISO speeds are
approximately equal to double the next higher Weston speed.
For example, a film rated at Weston 80 would be about ISO
200. Since the speeds are measured by different methods this
is only approximate plus Weston lumped films with similar
speeds into groups with the same published speed.
Kodak published Kodak speeds beginning about 1939. These
have no safety factor. To translate these to ISO speeds
devide 2.5.
I am sure this is more than you really wanted to know.


--
---
Richard Knoppow
Los Angeles, CA, USA