How do I calibrate my photographic process

A lot has happened since Ansel Adams. As I recall, the specifics about
films and chemicals etc are outdated. I still have the Adams trilogy and
enjoy its insights.

Relative to b&w film development, these two links were helpful to me for
calibrating that part of the process:

http://www.apogeephoto.com/mag2-6/mag2-6mfcalib.shtml Part 1

http://www.apogeephoto.com/mag2-6/mag2-8calib2.shtml Part 2

PSsquare


"Morton Klotz" wrote in message
...
On Mon, 23 Aug 2004 01:52:01 GMT, "Alan Smithee"
wrote:

Where do I start. I want to get a better grip on my whole photographic
process. How do I go about calibrating my camera, development and
printing
process?

Read Ansel Adams' books, especially The Negative and The Print.

"Alan Smithee" wrote in message news:tErWc.199364$gE.111291@pd7tw3no...
"jjs" wrote in message
...

"Hemi4268" wrote in message
...
Where do I start. I want to get a better grip on my whole photographic
process. How do I go about calibrating my camera, development and
printing
process?

With limited funds (under $1000) it really can't be done.
[... snip misunderstanding ....]

There's got to be a _complete_ misunderstanding here, Hemi. He only wants
to
know how to determine his base film speed, and some rules-of-thumb for
printing. He doesn't want to re-engineer the universe of photography.

What I want to know is where is it most important to control the process.
i.e. Camera, Film Developing, Printing.

Have your shutter checked by a repairman. What format are you using?
What brand of camera? What lenses?

Which practices can I use as a means
of eliminating errors from the whole process. Calibrating the shutter speed
and aperture on my camera for example. Is this easy or hard? Is it worth
doing even?

Yes, but this is done by service centers.

How about processing my negs. This seems to me the area with the
most room for error. If my thermometer is out a bit I could be plus or minus
10 to 20 per cent. But how would I even know? What tells me this. A test
image of some sort on the neg perhaps. That's why I was wondering about the
step wedges.

Your thermometer should be accurate within 1/2 degree.

Alan Smithee wrote:

What I want to know is where is it most important to control the
process. i.e. Camera,

I would say in the camera.

First of all, assuming you have set up the camera to include exactly the
field of view you want from the viewpoint you want (otherwise, you took
the wrong picture), what you need is the negative adequately exposed, and
the first step in calibration will determine the effective film speed,
a.k.a., the Exposure Index or EI. It is not normally a great idea to
overexpose the film, but unless you can find some Panatomic X which
shoulders over very rapidly, the worst you can expect from overexposed
film is longer printing times and slightly more grain (assuming
conventional black and white film). A slight benefit that I find
worthwhile is to overexpose by about one stop so I can get better blacks
and slightly more shadow detail.

Film Developing,

This is important to get the contrast right. If your development time is a
little off, you can correct this pretty well with different grades of
paper, but if it is way off, you may as well give up.

Printing.

Printing is normally pretty easy if you have a properly exposed and
developped negative, and almost impossible to do well otherwise.

Which practices can I use as a means of eliminating errors from the
whole process. Calibrating the shutter speed and aperture on my camera
for example. Is this easy or hard?

Calibrating shutter speed is pretty easy if you have a shutter speed
tester, which you can get for around $100 from Calumet. But you will use
it seldom after you have picked a film and calibrated it. So if you are a
technphile as I tend to be, and have a high paying job, by all means get
one. If not, you may be able to join a local camera club and persuade them
to get one. $5 from each of 20 members should do it. But you do not really
need one.

What you really need to calibrate is the light-meter shutter-speed
combination. If you had a lightmeter that read high, and a shutter that
operated correspondingly low, you would be OK.

So if you have a light meter that is linear (and a 10% error probably does
not matter much with B&W negative film), what I would suggest is to expose
some negatives to Zone V with different exposure times, develop for the
time recommended by the manufacturer for the chemistry and temperature you
are using, and compare the density of the negatives, trying to find the
one whose net density is closest to 0.9 (Ansel Adams would have
recommended the one whose density was around 0.75, though his procedure
was a little different). If the light meter had said to expose at 1/125
second for the film speed on the box, and you found that an exposure of
1/30 of a second gives you the desired density, then set the EI on the
meter to 1/4 the speed on the box and you will be close enough.

Otherwise, you can buy a densitometer and measure to your heart's content.
I have a densitometer, but I seldom use it. Here, too, you may wish to
persuade the hypothetical camera club to chip in and buy one. They cost at
least 10x what a shutter speed tester costs.

? Is it worth
doing even?

It is worth doing, but you do not really need the numbers if the shutter
is well-behaved. I.e., if it is 50% slow at all speeds, or 50% fast at all
speeds, you need never know it. (That would be pretty far off, BTW, for
new shutters.) The trouble is that if they are just off different amounts
at all speeds it can be hard to do anything. Even with a shutter speed
tester, you would probably not wish to carry a chart around with the
actual vs. indicated shutter speeds, especially if you had more than one.
For spastic shutters on L.F. cameras, I would either have someone such as
Steve Grimes' merry men do a CLA on the thing, or replace it. For 35mm or
M.F. cameras, I would have the manufacturer do it.

How about processing my negs. This seems to me the area with the most
room for error. If my thermometer is out a bit I could be plus or minus
10 to 20 per cent. But how would I even know? What tells me this. A
test image of some sort on the neg perhaps. That's why I was wondering
about the step wedges.

Here you could buy a precision NBS-certified thermomether, but I would not
bother. I have a Kodak Process Thermometer that used to cost over $60, and
it still costs over that, just more than I paid. I suppose it would be
around $100 now, but I never looked. Since it contains mercury, perhaps
they are unavailable at all.

Now you will find that if you have more than one light meter, or more than
one thermometer, you will go crazy.

What you need is a reliable repeatable thermometer. (This is for B&W:
color is a little more fussy.) When you are calibrating, pick a
temperatu I use 75F because it is difficult around here to get
processing temperatures down to 68F in the summertime, and some
developpers work better at 75F anyway. If you get the contrast you want
when printing most of your new negatives, your development-time, developer
composition and dilution, and development time are OK. It is the
combination of these things that matter.

The numbers in the books and on various web sites are just starting points
anyway. Your water may be significantly different from mine, I may agitate
differently when developping, my enlarger may be more or less diffuse than
yours, etc. It is impossible to know, and you do not need to know.
Calibrating yourself should take care of all that.

THe high price equipment: shutter speed testers, transmission and
reflection densitometers, etc., just make the process a little faster.

About step wedges: I think they are very useful, especially for those
without the high price equipment. I have a Kodak T-14 step wedge which is
fairly small, uncalibrated, cheap (compared with the others), and has
steps of 0.15. I would not waste the money getting a calibrated one. I did
calibrate mine, and the 0 density step has a density of 0.06, and all the
others are 0.15 (very closely) above the previous one.

So if you look at a test negative and it matches step 6 using your
"calibrated eyeball", it will have a density of around 0.9, etc., and this
is close enough for B&W work.

Remember that even if you calibrate to 4 decimal places (not easy), you
will have the problem at the time you make your initial exposu just
what density do I want for this element of the subject? And you will have
enough trouble deciding that to 1/2 a Zone, so while you should not be
sloppy (Murphy's Law says all the errors will be in the same direction to
ensure maximum reduction in quality), there is little point in getting
overly obsessive about this.

So, whith all that, let me repeat your first question:

What I want to know is where is it most important to control the
process.

What I suggest, as a learning tool (you would probably not have the
patience to do this as a routine matter), take a notebook along with you
and make a brief sketch of the subject you want to photograph. Indicate on
it, but using your light meter, what exposures you want for the various
elements of the subject; i.e., what zones you want to place the elements
on. Then try to measure the densities you got when you have the processed
negative. This will help you keep a check on your exposures. Once you are
good at it, you might want to do a few every 6 months or every year to see
if your equipment is drifting around too much. This is easier with simple
subjects and large format negatives unless you have a densitometer.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 09:10:00 up 20 days, 47 min, 4 users, load average: 4.27, 4.18, 4.11

Alan Smithee wrote:

What I want to know is where is it most important to control the
process. i.e. Camera,

I would say in the camera.

First of all, assuming you have set up the camera to include exactly the
field of view you want from the viewpoint you want (otherwise, you took
the wrong picture), what you need is the negative adequately exposed, and
the first step in calibration will determine the effective film speed,
a.k.a., the Exposure Index or EI. It is not normally a great idea to
overexpose the film, but unless you can find some Panatomic X which
shoulders over very rapidly, the worst you can expect from overexposed
film is longer printing times and slightly more grain (assuming
conventional black and white film). A slight benefit that I find
worthwhile is to overexpose by about one stop so I can get better blacks
and slightly more shadow detail.

Film Developing,

This is important to get the contrast right. If your development time is a
little off, you can correct this pretty well with different grades of
paper, but if it is way off, you may as well give up.

Printing.

Printing is normally pretty easy if you have a properly exposed and
developped negative, and almost impossible to do well otherwise.

Which practices can I use as a means of eliminating errors from the
whole process. Calibrating the shutter speed and aperture on my camera
for example. Is this easy or hard?

Calibrating shutter speed is pretty easy if you have a shutter speed
tester, which you can get for around $100 from Calumet. But you will use
it seldom after you have picked a film and calibrated it. So if you are a
technphile as I tend to be, and have a high paying job, by all means get
one. If not, you may be able to join a local camera club and persuade them
to get one. $5 from each of 20 members should do it. But you do not really
need one.

What you really need to calibrate is the light-meter shutter-speed
combination. If you had a lightmeter that read high, and a shutter that
operated correspondingly low, you would be OK.

So if you have a light meter that is linear (and a 10% error probably does
not matter much with B&W negative film), what I would suggest is to expose
some negatives to Zone V with different exposure times, develop for the
time recommended by the manufacturer for the chemistry and temperature you
are using, and compare the density of the negatives, trying to find the
one whose net density is closest to 0.9 (Ansel Adams would have
recommended the one whose density was around 0.75, though his procedure
was a little different). If the light meter had said to expose at 1/125
second for the film speed on the box, and you found that an exposure of
1/30 of a second gives you the desired density, then set the EI on the
meter to 1/4 the speed on the box and you will be close enough.

Otherwise, you can buy a densitometer and measure to your heart's content.
I have a densitometer, but I seldom use it. Here, too, you may wish to
persuade the hypothetical camera club to chip in and buy one. They cost at
least 10x what a shutter speed tester costs.

? Is it worth
doing even?

It is worth doing, but you do not really need the numbers if the shutter
is well-behaved. I.e., if it is 50% slow at all speeds, or 50% fast at all
speeds, you need never know it. (That would be pretty far off, BTW, for
new shutters.) The trouble is that if they are just off different amounts
at all speeds it can be hard to do anything. Even with a shutter speed
tester, you would probably not wish to carry a chart around with the
actual vs. indicated shutter speeds, especially if you had more than one.
For spastic shutters on L.F. cameras, I would either have someone such as
Steve Grimes' merry men do a CLA on the thing, or replace it. For 35mm or
M.F. cameras, I would have the manufacturer do it.

How about processing my negs. This seems to me the area with the most
room for error. If my thermometer is out a bit I could be plus or minus
10 to 20 per cent. But how would I even know? What tells me this. A
test image of some sort on the neg perhaps. That's why I was wondering
about the step wedges.

Here you could buy a precision NBS-certified thermomether, but I would not
bother. I have a Kodak Process Thermometer that used to cost over $60, and
it still costs over that, just more than I paid. I suppose it would be
around $100 now, but I never looked. Since it contains mercury, perhaps
they are unavailable at all.

Now you will find that if you have more than one light meter, or more than
one thermometer, you will go crazy.

What you need is a reliable repeatable thermometer. (This is for B&W:
color is a little more fussy.) When you are calibrating, pick a
temperatu I use 75F because it is difficult around here to get
processing temperatures down to 68F in the summertime, and some
developpers work better at 75F anyway. If you get the contrast you want
when printing most of your new negatives, your development-time, developer
composition and dilution, and development time are OK. It is the
combination of these things that matter.

The numbers in the books and on various web sites are just starting points
anyway. Your water may be significantly different from mine, I may agitate
differently when developping, my enlarger may be more or less diffuse than
yours, etc. It is impossible to know, and you do not need to know.
Calibrating yourself should take care of all that.

THe high price equipment: shutter speed testers, transmission and
reflection densitometers, etc., just make the process a little faster.

About step wedges: I think they are very useful, especially for those
without the high price equipment. I have a Kodak T-14 step wedge which is
fairly small, uncalibrated, cheap (compared with the others), and has
steps of 0.15. I would not waste the money getting a calibrated one. I did
calibrate mine, and the 0 density step has a density of 0.06, and all the
others are 0.15 (very closely) above the previous one.

So if you look at a test negative and it matches step 6 using your
"calibrated eyeball", it will have a density of around 0.9, etc., and this
is close enough for B&W work.

Remember that even if you calibrate to 4 decimal places (not easy), you
will have the problem at the time you make your initial exposu just
what density do I want for this element of the subject? And you will have
enough trouble deciding that to 1/2 a Zone, so while you should not be
sloppy (Murphy's Law says all the errors will be in the same direction to
ensure maximum reduction in quality), there is little point in getting
overly obsessive about this.

So, whith all that, let me repeat your first question:

What I want to know is where is it most important to control the
process.

What I suggest, as a learning tool (you would probably not have the
patience to do this as a routine matter), take a notebook along with you
and make a brief sketch of the subject you want to photograph. Indicate on
it, but using your light meter, what exposures you want for the various
elements of the subject; i.e., what zones you want to place the elements
on. Then try to measure the densities you got when you have the processed
negative. This will help you keep a check on your exposures. Once you are
good at it, you might want to do a few every 6 months or every year to see
if your equipment is drifting around too much. This is easier with simple
subjects and large format negatives unless you have a densitometer.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 09:10:00 up 20 days, 47 min, 4 users, load average: 4.27, 4.18, 4.11

"Jean-David Beyer" wrote in message
...
Alan Smithee wrote:

What I want to know is where is it most important to control the
process. i.e. Camera,

I would say in the camera.

Are you not presuming his meter and metering method is correct? Check first
assumptions first.

"Jean-David Beyer" wrote in message
...
Alan Smithee wrote:

What I want to know is where is it most important to control the
process. i.e. Camera,

I would say in the camera.

Are you not presuming his meter and metering method is correct? Check first
assumptions first.

jjs wrote:

"Jean-David Beyer" wrote in message
...

Alan Smithee wrote:

What I want to know is where is it most important to control the
process. i.e. Camera,

I would say in the camera.


Are you not presuming his meter and metering method is correct? Check first
assumptions first.



If the meter is inaccurate or the method wrong, those errors will be
corrected in finding the true EI -- so as long as they're *consistently*
inaccurate in the same way, there's not a problem, same as with
thermometers (at least for B&W).

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

jjs wrote:

"Jean-David Beyer" wrote in message
...

Alan Smithee wrote:

What I want to know is where is it most important to control the
process. i.e. Camera,

I would say in the camera.


Are you not presuming his meter and metering method is correct? Check first
assumptions first.



If the meter is inaccurate or the method wrong, those errors will be
corrected in finding the true EI -- so as long as they're *consistently*
inaccurate in the same way, there's not a problem, same as with
thermometers (at least for B&W).

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

Alan Smithee wrote:

: "jjs" wrote in message
: ...
:
: "Hemi4268" wrote in message
: ...
: Where do I start. I want to get a better grip on my whole photographic
: process. How do I go about calibrating my camera, development and
: printing
: process?
:
: With limited funds (under $1000) it really can't be done.
: [... snip misunderstanding ....]
:
: There's got to be a _complete_ misunderstanding here, Hemi. He only wants
: to
: know how to determine his base film speed, and some rules-of-thumb for
: printing. He doesn't want to re-engineer the universe of photography.
:
: What I want to know is where is it most important to control the process.
: i.e. Camera, Film Developing, Printing. Which practices can I use as a means
: of eliminating errors from the whole process. Calibrating the shutter speed
: and aperture on my camera for example. Is this easy or hard? Is it worth
: doing even? How about processing my negs. This seems to me the area with the
: most room for error. If my thermometer is out a bit I could be plus or minus
: 10 to 20 per cent. But how would I even know? What tells me this. A test
: image of some sort on the neg perhaps. That's why I was wondering about the
: step wedges.

When done right your film speed tests will take errors in your camera and light
meter into consideration. In my never humble opinion you want to put the bulk of
your effort into getting the best possible negative.

--




Keep working millions on welfare depend on you
-------------------

Alan Smithee wrote:

: "jjs" wrote in message
: ...
:
: "Hemi4268" wrote in message
: ...
: Where do I start. I want to get a better grip on my whole photographic
: process. How do I go about calibrating my camera, development and
: printing
: process?
:
: With limited funds (under $1000) it really can't be done.
: [... snip misunderstanding ....]
:
: There's got to be a _complete_ misunderstanding here, Hemi. He only wants
: to
: know how to determine his base film speed, and some rules-of-thumb for
: printing. He doesn't want to re-engineer the universe of photography.
:
: What I want to know is where is it most important to control the process.
: i.e. Camera, Film Developing, Printing. Which practices can I use as a means
: of eliminating errors from the whole process. Calibrating the shutter speed
: and aperture on my camera for example. Is this easy or hard? Is it worth
: doing even? How about processing my negs. This seems to me the area with the
: most room for error. If my thermometer is out a bit I could be plus or minus
: 10 to 20 per cent. But how would I even know? What tells me this. A test
: image of some sort on the neg perhaps. That's why I was wondering about the
: step wedges.

When done right your film speed tests will take errors in your camera and light
meter into consideration. In my never humble opinion you want to put the bulk of
your effort into getting the best possible negative.

--




Keep working millions on welfare depend on you
-------------------