Testing and evaluating KODAK T-MAX P3200 and Ilford Delta 3200

The Wedding

D
The Wedding

  • 0
  • 0
  • 7
Rockwood Bungalow

A
Rockwood Bungalow

  • 0
  • 0
  • 49
Posing

D
Posing

  • 0
  • 0
  • 50
Saab 99LE

A
Saab 99LE

  • 3
  • 0
  • 73
Fall

A
Fall

  • 1
  • 1
  • 64

Recent Classifieds

Forum statistics

Threads
180,481
Messages
2,490,201
Members
95,085
Latest member
rasicjoy
Recent bookmarks
0
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
But I am interested in Tmax 3200 and Ilford Delta 3200 both @Iso 3200developed in XTOL and replenished XTOL. That is where the rubber meets the road.
Awesome. Do you happen to know how I can get to replenished XTOL fairly quickly, without having to go through several films before it becomes properly replenished? Is there such a thing as an XTOL starter? I'd love to try both XTOL stock and replenished with those ISO 3200 films.
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
40,390
Location
Delta, BC, Canada
Shooter
Multi Format
Is there such a thing as an XTOL starter?

Yes, but it isn't made any more.
Here is what the X-Tol datasheet says, remembering of course that the availability of each of these is problematic, and catalogue numbers are dated:
You can also “pre-season” fresh XTOL Developer by adding one of the following:
• 6.5 mL of KODAK Developer Starting Solution (CAT 146 6382) per litre of developer
• 1 mL of KODAK EKTACHROME R-3 First Developer II Starter (CAT 869 9795 [U.S. and Australia] or CAT 524 0007 [Europe]) per litre of XTOL Developer
• 1.2 mL of KODAK PROFESSIONAL First Developer Starter, Process E-6 (CAT 167 1577 [U.S.] or CAT 526 2670 [Europe and Asia]) per litre of developer

The second item is long gone.
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
42,494
Location
Southern California
Shooter
Multi Format
Awesome. Do you happen to know how I can get to replenished XTOL fairly quickly, without having to go through several films before it becomes properly replenished? Is there such a thing as an XTOL starter? I'd love to try both XTOL stock and replenished with those ISO 3200 films.

What I do is the fastest way. From the first roll developed, pour 70ml/roll into the new replenished bottle, then add the rest of the developer from the tank. From then on replenish for the rolls developed and continue using without worry nor guilt.
 

Moose22

Subscriber
Joined
Jul 1, 2021
Messages
898
Location
The Internet
Shooter
Medium Format
Isn't it just develop half a dozen rolls normally and then start replenishing?

That's what I did. Not "instant" seasoned, but it got me in the ballpark with a couple rounds in my 3 roll paterson tank.

So, if you've been using xtol full strength already, you're likely already there with one of your working bottles, right? Or have you been going one shot?
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
40,390
Location
Delta, BC, Canada
Shooter
Multi Format
Isn't it just develop half a dozen rolls normally and then start replenishing?

This is the easiest.
Do tests first with stock X-Tol and keep the used developer afterwards.
If you do six of those, you will have enough byproducts in the used stuff that, when you add it back to the unused stuff, you will be very close to the steady state.
 

Steven Lee

Member
Joined
Jul 10, 2022
Messages
232
Location
USA
Shooter
Medium Format
@aparat Careful with replenished Xtol. Delta 3200 has a hard time building density in it so don't put anything of importance on your first roll. It works far better in DD-X and Microphen.

To quickly season a small amount of Xtol, say 300ml, you can develop a short strip of 100% exposed roll first. Just cut it from the test roll. To determine the length, look at the relevant data in the datasheet:

* Find Kodak-recommended development time for Xtol-R and note % delta vs stock
* Find "Time compensation" table for reusing stock developer and see how many rolls in 1L require the same % delta compensation
* That table uses the 18% grey assumption and 1L, so you can do the math for how much of 100% fogged film you need to season 300ml
 
Last edited:

albada

Subscriber
Joined
Apr 10, 2008
Messages
1,621
Location
Escondido, C
Shooter
35mm RF
I have a few questions about @aparat 's graph in posting #20, which shows how zones on a negative are changed to zones on a print using the paper's H-D curve.
  • AA's definition of zone V is middle gray, so I would expect 18% to be in the middle of the range for zone V on this graph. But on the right side of this graph, 18% is at about the three fourths point of the zone V range instead of its middle. Why?
  • Are there standard definitions of the midpoints or range-boundaries of the zones? On page 116 of Way Beyond Monochrome (2nd ed), Ralph Lambrecht provides a table of densities for the zones. I presume these are midpoints of those zones. He states that these are "standard Zone System values", implying that such a standard exists.
  • On the lower-right corner of the graph, print density of 0 corresponds to Dmin. But no paper can achieve a density of 0. Is this an error?
  • On the lower-right corner of the graph, zone IX is shown as extending down to density of 0. But that's impossible because the definition of zone IX is "slight density without texture", which means density is nonzero. No density (paper-white, Dmin) is the definition zone X. Is this a mistake?
Well, that's four questions.
I implemented zones in my LED-head controller, giving the user the ability to place an element on the easel on a zone. The answers to these questions will ensure I got the details perfect.
 
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
I have a few questions about @aparat 's graph in posting #20, which shows how zones on a negative are changed to zones on a print using the paper's H-D curve.
  • AA's definition of zone V is middle gray, so I would expect 18% to be in the middle of the range for zone V on this graph. But on the right side of this graph, 18% is at about the three fourths point of the zone V range instead of its middle. Why?
  • Are there standard definitions of the midpoints or range-boundaries of the zones? On page 116 of Way Beyond Monochrome (2nd ed), Ralph Lambrecht provides a table of densities for the zones. I presume these are midpoints of those zones. He states that these are "standard Zone System values", implying that such a standard exists.
  • On the lower-right corner of the graph, print density of 0 corresponds to Dmin. But no paper can achieve a density of 0. Is this an error?
  • On the lower-right corner of the graph, zone IX is shown as extending down to density of 0. But that's impossible because the definition of zone IX is "slight density without texture", which means density is nonzero. No density (paper-white, Dmin) is the definition zone X. Is this a mistake?
Well, that's four questions.
I implemented zones in my LED-head controller, giving the user the ability to place an element on the easel on a zone. The answers to these questions will ensure I got the details perfect.

I can take a stab at these. One, Zone V is the perceptual / psychophysical middle. Two, Zones aren't real and don't have any definite value (except for maybe Zone V). They are a visual tool. Some produce a reference scale. Three, it appears the measurement and consequently the scale is zeroed on the paper base - ie 0.04 over Pb+f. That should also answer number four.
 

albada

Subscriber
Joined
Apr 10, 2008
Messages
1,621
Location
Escondido, C
Shooter
35mm RF
I can take a stab at these. One, Zone V is the perceptual / psychophysical middle. Two, Zones aren't real and don't have any definite value (except for maybe Zone V). They are a visual tool. Some produce a reference scale. Three, it appears the measurement and consequently the scale is zeroed on the paper base - ie 0.04 over Pb+f. That should also answer number four.

Stephen, thanks for replying. Especially because it's late in the evening.
If the scale is zeroed on the paper base, then the scale is relative and not absolute. But the scale ends at 2.1, and for a Dmin-relative scale, I'd expect it to end at 2.1-0.04=2.06. But the graph becomes flat at 2.1 (relative), which is 2.14 (absolute), which looks like a mistake because 2.1 is the typical absolute Dmax I see in most places. Anyway, I think it would be clearer to use absolute paper-densities everywhere, as is done with negative-densities.
 
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
I have a few questions about @aparat 's graph in posting #20, which shows how zones on a negative are changed to zones on a print using the paper's H-D curve.
  • AA's definition of zone V is middle gray, so I would expect 18% to be in the middle of the range for zone V on this graph. But on the right side of this graph, 18% is at about the three fourths point of the zone V range instead of its middle. Why?
  • Are there standard definitions of the midpoints or range-boundaries of the zones? On page 116 of Way Beyond Monochrome (2nd ed), Ralph Lambrecht provides a table of densities for the zones. I presume these are midpoints of those zones. He states that these are "standard Zone System values", implying that such a standard exists.
  • On the lower-right corner of the graph, print density of 0 corresponds to Dmin. But no paper can achieve a density of 0. Is this an error?
  • On the lower-right corner of the graph, zone IX is shown as extending down to density of 0. But that's impossible because the definition of zone IX is "slight density without texture", which means density is nonzero. No density (paper-white, Dmin) is the definition zone X. Is this a mistake?
Well, that's four questions.
I implemented zones in my LED-head controller, giving the user the ability to place an element on the easel on a zone. The answers to these questions will ensure I got the details perfect.
All good questions. First of all, I must apologize for the confusion. I did not mean to include that plot in #20 toward our discussion of the Kodak and Ilford ISO 3200 films. It took the discussion off course. It was just an example of how Phil Davis chose to depict the division of the "Print Zones," 2 through 8, and how it depends entirely on the contour of the selected paper curve when matched to a particular film curve. So, I guess, the short answer is to just disregard that plot :smile:. The gradient shown is not meant to accurately convey the density of the print but instead serves as a visual reminder of how subject luminance is translated into negative density. As I mentioned earlier in the thread, it is not my favorite way of showing the relationship between negative and print.

I found the discussion of Zones and tone reproduction on p. 49 in my copy of Beyond Monochrome. The author did say that "The development of these numbers was based on a few material and equipment assumptions, and they may not be completely valid for all photographers and their material choices." In other words, while these values aren't completely arbitrary, they do not really represent a standard. I've seen this type of generalization in other sources, as well. Some photographers have a very specific sensitometric definition of the important values, e.g., "I want my Zone VIII to be 1.2 over B+F," etc., but these are all based on personal preference, rather than standard values.

I don't know exactly how Win Plotter calculates their 18% value, but, in BTZS theory, it needs to be " near the middle of the normal Zone V range." It's possible that it's simply log10(1/0.18).

Again, sorry for including that plot.
 
Last edited:
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
albada, after taking a closer look at how Davis set-up the exposure Zones, he has begun and ended the range at the extremes. I see your point. No real standardization is a problem with made up systems. From my perspective, since Zone V is the metered value, Zones should fall like:

1668926034652.png


In addition, if you take a close look at the size of the Zone ranges along the bottom of Davis' graph, he has incorporated compression due to flare. Zone II is smaller than Zone VIII. This can also shift placement from the "Ideal."

This is how I do it with my plotting program when using Zones. The guidelines are set at the middle of each Zone range.

Zone V as 12% - 4 quad.jpg

And this is from Way Beyond Monochrome:

Zone Density comparison - no flare.jpg


The values pretty much agree except that the camera image is with out flare, which is unrealistic. The curve is rather linear. What about a long toed curve? Won't the results be different? There's also the question of what Zones were meant to be to begin with. Equally spaced tones do not look equally spaced to the eye. Darker tones tend to look compressed. If the idea is to visualize a gray scale from black to white, it's usually equally spaced in our mind's eye. What about the Munsell scale values then?

Note: The Zone System uses 7 stops, so the extra 1/3 stop at the bottom should be ignored in this example.
 
Last edited:
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
@Stephen Benskin Thank you for the thorough explanations. I am impressed with your program. It gives a very flexible and highly informative view of tone reproduction. And thank you for the papers you wrote and generously shared here. They contain a lot of detail that is otherwise scattered over a number of, by now obscure, journal articles. I really appreciate it. Edit: Quick question, in Q1, your mcs value of 0.067, is that for a film of about ISO 125?

When I was calibrating exposure for my test of KODAK T-MAX P3200 and Ilford Delta 3200, I exposed and processed P3200 (in blue) along with 400TX (in red) for 8 minutes in D76 at 20C. This is not meant to be part of my analysis of T-MAX P3200, nor is it meant to provide conclusive measurements. It's only meant to illustrate the relative difference in film speed. According to this test, KODAK 400TX is over 2.5 stops slower (comparing theoretical curves with =0.62). Since a lot of people routinely push 400TX to EI 1600, I thought I'd include this comparison.

Also, note the relative difference in B+F density. I found both my samples of P3200 to have somewhat high levels of base fog, at least with D76, ranging from 0.3 to 0.39, while this particular sample of 400TX is more reasonable at 0.27. I wonder how this impacts scanning and printing. Does anyone have experience they'd like to share?

tmz2_400TX_curves.png
 
Last edited:
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
This is the easiest.
Do tests first with stock X-Tol and keep the used developer afterwards.
If you do six of those, you will have enough byproducts in the used stuff that, when you add it back to the unused stuff, you will be very close to the steady state.
Yes, this does sound much easier. I will mix 5 L of XTOL, then I will put aside 1 L for "tank solution" and 4 L for "replenisher." I will then add 70 mL of replenisher XTOL to the tank solution or each roll. How does that sound?
 

Paul Howell

Subscriber
Joined
Dec 23, 2004
Messages
7,345
Location
Scottsdale Az
Shooter
Multi Format
When I took the summer seminar from Minor White in the 60s, he was clear as was AA that the zones of system are not a quantitative values, in the 1968 edition of the negative Adams states that Zone V is a emotional value. Adams and Archer decided on 10 zones as the Weston meter of day had a dial that was easily matched to the 10 zones. I have not spent much time studying Beyond the Zone System, it seemed to me that David was applying a more rigorous approach to improve the quantitative aspect, yet it still based on the Zone System and the Weston dial of 1938. I understand that some have used the Stuffers (sp?) Step Wedge used in the printing trades to calculate a films curve, John Schaefer in his Ansel Adams Guide comes to mind.

Even using a step wedge or printers scale visualizing the 10 zones devised by Adams and Archer is used, 10 zones were thought to be manageable, visualizing the 28 zones of the step scale would be difficult.
 
Last edited:

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
42,494
Location
Southern California
Shooter
Multi Format
When I took the summer seminar from Minor White in the 60s, he was clear as was AA that the zones of system are not a quantitative values, in the 1968 edition of the negative Adams states that Zone V is a emotional value. Adams and Archer decided on 10 zones as the Weston meter of day had a dial that was easily matched to the 10 zones. I have not spent much time studying Beyond the Zone System, it seemed to me that David was applying a more rigorous approach to improve the quantitative aspect, yet it still based on the Zone System and the Weston dial of 1938. I understand that some have used the Stuffers (sp?) Step Wedge used in the printing trades to calculate a films curve, John Schaefer in his Ansel Adams Guide comes to mind.

I use Zones as an approximation exposure to for printing.
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
40,390
Location
Delta, BC, Canada
Shooter
Multi Format
Yes, this does sound much easier. I will mix 5 L of XTOL, then I will put aside 1 L for "tank solution" and 4 L for "replenisher." I will then add 70 mL of replenisher XTOL to the tank solution or each roll. How does that sound?

Sounds good - assuming of course you are discarding some of the used developer each time - usually to keep the "tank solution" volume constant.
FWIW, I usually refer to the "tank solution" as "working solution".
For consistency, it is best to always use the same amount of developer in your developing tank each time, so if you sometimes develop one roll at a time, but other times develop more, it is best to always use the volume that you will use for the full developing tank.
Most of us add 70ml/roll of replenisher to the "working solution" container while the film and developer are in the developing tank, and then when the development is finished, pour enough of the used developer back into the "working solution" container to bring it up to the full volume, and discard the rest.
In a fully controlled replenishment line, you would also employ control strips and a densitometer, and adjust the 70 ml amount accordingly. But for your purposes, over the time you are making these tests, the 70 ml replenishment rate should suffice.
 
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
@Stephen Benskin Thank you for the thorough explanations. I am impressed with your program. It gives a very flexible and highly informative view of tone reproduction. And thank you for the papers you wrote and generously shared here. They contain a lot of detail that is otherwise scattered over a number of, by now obscure, journal articles. I really appreciate it. Edit: Quick question, in Q1, your mcs value of 0.067, is that for a film of about ISO 125?

Sharp eye. That is one of the quirks of my program. While the camera image can be generated for any exposure, the alignment with the film curve is relative. I tend to leave the exposure on Sunny 16 for 125 speed film because it's the only standard film speed that has a corresponding shutter speed - f/16 / 1/ISO (shutter speed). And because of that, it's the one I used most when studying exposure theory, so I am most familiar with the values.

4 Quad with details 1.jpg
 
Last edited:
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
@MattKing Thanks for the instructions. I will follow the replenishment regime you describe. I happen to have four 32 oz amber bottles available so I will use them for the replenisher. Who knows, I might even end up liking XTOL better than D76.

@Stephen Benskin Your program looks very sophisticated! I particularly like the tabbed UI. Currently, all my constants, settings, and options are in a flat text file, so it's easy for me to miss things when I run the analysis.
 
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
@Stephen Benskin Your program looks very sophisticated! I particularly like the tabbed UI. Currently, all my constants, settings, and options are in a flat text file, so it's easy for me to miss things when I run the analysis.

Thanks. I wanted options. Most have to do with the camera image and the choosing a sensitometric or Zone System analysis.

One of the things I did was to compare up to 6 tests. The three tests below are from a 9 stop luminance range. The test compares compensating with development vs paper for higher luminance values. It uses same film but developed to a different CI. The paper's LER matches the NDR as closely as I could. In the comparison window, quad 4 is chosen and the gradients from each step can be compared. Reflection density for the paper, Density of the film, or exposure can be compared for each of the respective quads.

1668983907812.png


Here are the results of a single test (Zone analysis using 12% as Zone V - the meter reading). The data points are from the guidelines. Please note the higher than 1.10 gradients in the reproduction curve?

1668984952623.png
 
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
Thanks. I wanted options. Most have to do with the camera image and the choosing a sensitometric or Zone System analysis.

One of the things I did was to compare up to 6 tests. The three tests below are from a 9 stop luminance range. The test compares compensating with development vs paper for higher luminance values. It uses same film but developed to a different CI. The paper's LER matches the NDR as closely as I could. In the comparison window, quad 4 is chosen and the gradients from each step can be compared. Reflection density for the paper, Density of the film, or exposure can be compared for each of the respective quads.

Here are the results of a single test (Zone analysis using 12% as Zone V - the meter reading). The data points are from the guidelines. Please note the higher than 1.10 gradients in the reproduction curve?
This is very, very cool. I really like how it ties all of these variables together into a coherent and meaningful display of numerical values and graphical elements. Are all the UI elements reactive? So, say, you enter a different LSLR value in its box, does the display automatically redraw with all the new values calculated? I'd love to be able to do something like that, but in a web browser.

I read your Delta X article and found it very informative. I had previously implemented Fractional Gradient and Delta X based on the Nelson and Simmonds (1955) article, but your paper helped tie it all together, esp. with how the Delta X criterion is "hiding" in plain sight. I added a Delta X calculation for the theoretical ISO curve (dotted line) and displayed it next to the ISO speed (I am having trouble getting Unicode characters to print reliably).

I am using absolute exposure values here, so they may not be very accurate, as my setup is not calibrated. However, the DIY setup allows me to change exposure very easily, which I cannot do with my sensitometer. I can change shutter speeds and add or remove ND filters, as needed. Here's a recalculated curve family, including Delta X speed.

kodakTmaxP3200_DeltaXSpeed.png
 

albada

Subscriber
Joined
Apr 10, 2008
Messages
1,621
Location
Escondido, C
Shooter
35mm RF
I wanted options.

One option might be to add another quadrant, which I guess would make them "pentants".
Would it be helpful to add a quadrant/pentant for enlarger-flare? An enlarger adds flare:
  • In the chamber between negative and lens;
  • In the lens itself;
  • From the enlarger's light-leaks finding their way on to the paper.
The Beseler 45M-series tends to leak light horizontally at the neg-holder, emitting a ring of light hitting all four walls, some of which lands on the paper. OTOH, perhaps this source of flare has been found to be insignificant and thus not worth including in quadrant graphs. But I thought I'd mention it.
 
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
So, say, you enter a different LSLR value in its box, does the display automatically redraw with all the new values calculated?

It redraws the diagram to respond to any change. You can move the camera exposure up or down and all the guides will redraw. Film and paper data is just the beginning. A film curve doesn't mean anything until you interpret it.

One of my favorite sensitometry / Zone System incongruities is the aim negative density range. For the same seven stop range, the ZS has 1.15 - 1.25 as its aim for a grade 2 paper printed on a diffusion enlarger, while sensitometry has it as 1.05. Now there are lots of reasons why this difference might not be noticeable in practice, from a theoretical standpoint, it's a problem. Here's the answer.

Zone Placement and Flare.jpg


The answer is testing methodology. The above example uses the same film curve. Zone testing doesn't incorporate flare, sensitometry does with interpreting the curve. There wouldn't be a problem if the Zone System was aware and incorporated flare at some other time, but it doesn't. Since flare exists, the flare example is in better agreement with reality, and since the different testing methods both indicate the same CI, the resulting negatives in practice will necessarily have the same NDR. The difference is one method reflects reality and one doesn't. Like I said, the film data is just a starting point.

Your family of curves looks good. May I suggest adding a Time/CI curve from which you can determine development for any set of conditions. I've written a paper on determining a developmental model if you're interested. Something not well know is the gradient of the time/CI curve and point of gamma infinity can help determine the uses of the film, like if it's a good film for pushing for speed or how forgiving it is in development.
 
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
One option might be to add another quadrant, which I guess would make them "pentants".
Would it be helpful to add a quadrant/pentant for enlarger-flare? An enlarger adds flare:
  • In the chamber between negative and lens;
  • In the lens itself;
  • From the enlarger's light-leaks finding their way on to the paper.
The Beseler 45M-series tends to leak light horizontally at the neg-holder, emitting a ring of light hitting all four walls, some of which lands on the paper. OTOH, perhaps this source of flare has been found to be insignificant and thus not worth including in quadrant graphs. But I thought I'd mention it.

I've seen diagrams that go on forever. Jones included viewing conditions and perception in some of his. My print quadrant does incorporate flare. Since the paper tests use the enlarger I plan to print with, I don't contact the step tablet but enlarge it and allow some clear area around the tablet to introduce flare.

1668999063748.png

1668999137286.png
 
OP
OP
aparat

aparat

Member
Joined
Sep 5, 2007
Messages
695
Location
Saint Paul,
Shooter
35mm
The answer is testing methodology. The above example uses the same film curve. Zone testing doesn't incorporate flare, sensitometry does with interpreting the curve. There wouldn't be a problem if the Zone System was aware and incorporated flare at some other time, but it doesn't. Since flare exists, the flare example is in better agreement with reality, and since the different testing methods both indicate the same CI, the resulting negatives in practice will necessarily have the same NDR. The difference is one method reflects reality and one doesn't. Like I said, the film data is just a starting point.
I think maybe the Zone System was complicated enough, at least as a marketing construct. Companies like Zone VI needed to keep it relatively simple for photographers to buy in. But, of course, you're right, these incongruities do exist in various text books. The Zone System can be a bit dogmatic at times. I think the younger crowd are not very keen on using it from what I've seen on this forum. Maybe that's a good thing. People can get great results developing film in coffee, using decades expired film, shooting with toy cameras, etc.
Your family of curves looks good. May I suggest adding a Time/CI curve from which you can determine development for any set of conditions. I've written a paper on determining a developmental model if you're interested. Something not well know is the gradient of the time/CI curve and point of gamma infinity can help determine the uses of the film, like if it's a good film for pushing for speed or how forgiving it is in development.

You mean like these two plots? Or do you mean something else entirely? Yes, I'd be interested in your paper on the developmental model. Thank you!
time_ci.png time_G.png
 
Joined
Jan 7, 2005
Messages
2,252
Location
Los Angeles
Shooter
4x5 Format
I think maybe the Zone System was complicated enough, at least as a marketing construct. Companies like Zone VI needed to keep it relatively simple for photographers to buy in. But, of course, you're right, these incongruities do exist in various text books. The Zone System can be a bit dogmatic at times. I think the younger crowd are not very keen on using it from what I've seen on this forum. Maybe that's a good thing. People can get great results developing film in coffee, using decades expired film, shooting with toy cameras, etc.


You mean like these two plots? Or do you mean something else entirely? Yes, I'd be interested in your paper on the developmental model. Thank you!
View attachment 322334 View attachment 322335

Those are them.

Personally, I don't think people knew. Adams writes that because the test is done with a camera it automatically incorporates flare. Which it doesn't. Without using curves, the idea of gradient and density is hard to evaluate. Same basic problem with Zone System vs ISO speed.
 

Attachments

  • What is Normal.pdf
    311 KB · Views: 16
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab
Top Bottom