If that is the way the film was intended to be, you'd think that is the way CatLABS would have marketed it. But I don't know much about marketing, other than it is the practice of psyops on the consumer.
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Testing and evaluating CatLabs "X Film 320 Pro (2022 version)
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If that is the way the film was intended to be, you'd think that is the way CatLABS would have marketed it. But I don't know much about marketing, other than it is the practice of psyops on the consumer.
Interesting. So you are saying that people that like that sort of films are definitely not the "new kids" (they wouldn't be flocking from digital to film to get the same digital look, right?), but people working with film (probably all their life) and only now discovering that they can get the digital look with some "new" aerial films?
MattKing
Moderator
mea culpa
With that in mind, perhaps we can get back to posting about what the existing film can actually do.
There is already one train wreck thread about marketing films - we don't need two.
With that in mind, perhaps we can get back to posting about what the existing film can actually do.
There is already one train wreck thread about marketing films - we don't need two.
There are always new people showing up so things have to be re-taught over and over. Usually the same stuff since Jones and Nelson.
What can be new is computer analysis and interpretation, which is why I'm interested in this thread. For example my spreadsheet was created over ten years ago and is cumbersome to use.
I outlined my testing procedure here, just the usual stuff: https://www.photrio.com/forum/threads/testing-some-new-film-shanghai-8x10-how-i-do-it.171836/
What we have done in the past is share the datasets, so others can corroborate the results. Wether plotting by pencil and paper or using custom computer analysis there will be small differences in the results.
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OP
OP
Yeah. I remember reading in an old Nelson paper about the prospect of using an automated densitometer that feeds data directly to an analysis program. It's 2022 and I still jot down densitometer readings with a pencil.
MattKing
Moderator
Some might be surprised - they seem to think that people who do these sorts of analytical things must still use quill pens!
Yes, and it only consisted of 1.5 lines. Not a great whole to read...
Furthermore my reply was meant to be generic, not referring to Aparat's graphic, which I found enigmatic. Sorry for making this not clear.
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OP
OP
Well, I wasn't going to say anything but here's a shot of part of my desk at this very moment.Some might be surprised - they seem to think that people who do these sorts of analytical things must still use quill pens!
OP
OP
Okay, to bring this thread back to its original topic (I apologize for my earlier departure), I have a first curve with, what seems to be, the right amount of exposure. The toe is what I intended, which means the first two steps of the step tablet are B+F density, and then it starts climbing. This was 8 minutes in D76 (Kodak) 1+1 at 20C in a rotary processor. This is just raw data, no analysis, yet. This is it from me for now. More, hopefully, next weekend.
You're a champ. And is your estimated film speed still ~80?
You might consider doing this test with a properly developed negative, rather than a 20% underdeveloped one
Are the developing times specified on your website intended for a rotary processor?You might consider doing this test with a properly developed negative, rather than a 20% underdeveloped one
I have a small collection of various sensitometers and densitometers. I do have a X-Rite 890 Densitometer that will suck in the strip and read all the steps automatically, but it needs a special leader exposed to the front of the strip. Maybe someday I'll get around to making a single leader I can tape to any strip to get it to read.
You can read the book online (free, but requires an account):
CatLABS does not specify the mode of film processing. The development times shown are for the film shot at "EI 320". Just as with film speed, there is no explanation of the methodology CatLABS used in arriving at its recommended times for development in the various developers.
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And this is exactly why people need proper technical information provided by the film manufacturer!
OP
OP
So I guess you are joking again, judging by the smiley face. I should probably just ignore this, but there are other forum members reading this thread so I will reply.You might consider doing this test with a properly developed negative, rather than a 20% underdeveloped one
You probably did not read this thread, including my earlier posts regarding film testing. You would know that this is the first curve in a series (of five). In a conventional film test, the choice of developing time is, mostly, arbitrary. You want to have a decent spread, say, from around 4 minutes to maybe 16 or 20 (for D76 1+1, anyway), depending on the film, developer, temperature, agitation, etc. The point of the test is to arrive at a series, a progression if you will, which will allow the photographer to choose whichever time they prefer for whatever purpose (e.g., to pull, push, etc.). The data will indicate which time will do what to the film curve, and, thus to the negative, without much guesswork. Tone reproduction analysis, which will follow, includes the final print.
Also, if this film is underdeveloped, as you say, then the "correct" development time will likely produce a challenging negative. This one, I am guessing (I have not yet done the analysis) has the Contrast Index well above 0.6, which is already, for most people with a condenser enlarger, not ideal, at least for a conventional silver gelatin print. Twenty percent more development is likely to push CI to well over 0.7, and that would be hard to print, even on grade 1. It would also be hard to scan because the highlights would likely contain very little information (I am talking about a typical outdoor scene, with a typical luminance range). It might be the "right" time if one wishes to push-process the film, or for negatives containing a low-contrast scene. I am guessing you're also talking about a typical scene, though, yes?
So, yes, I know you're just joking, but the others deserve clarity.
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Based on this graph, the CI between zones 2 and 8 is about 0.71, so it appears that the roll was overdeveloped, because ISO CI is 0.58 (IIRC). Interpolation of CI-values suggests that 6.5 minutes will yield a CI close to 0.58.
Also, I presume your step-tablet has 0.15 steps, but the red dots in the graph are spaced slightly closer together. Any idea why?
OP
OP
Thank you!
The step tablet is not perfectly linear, so they dots are not spaced exactly .15 apart, and the densitometer has some inherent error. Once the analysis is done, the cruves will be modeled statistically and all those non-linearities will be accounted for.
Well, I did my version of a film test yesterday. I divided up a 35mm roll into three cannisters and shot one roll using the method of determining ISO in the John Finch video linked to earlier. But I don't have any paper on hand to run that test so that will have to wait. Then I shot a sequence of what I thought would be a wide range of light values in one image. It was a lightly overcast day with occasional moments of direct sunlight. The scene is on the shaded side of the house with the post at the bottom of the stair in direct sunlight. All photos were taken while the sun was shining directly on the stair post.
I set my ISO manually to 200 based on the recommendation in the box label for use with HC110 and used the compensation dial on my Pentax ZX5n to go from a -.5 to a +3 in half stop increments as shown in the photos below. The Pentax was set for matrix metering. I developed the film in HC110 for 10.5 minutes as recommended.
Notable colors in the scene: The sky is lightly overcast, so mostly white. The house is a medium blue. The house across the street is a dark brown. The tree on the left has turned a bright yellow. The chair behind the railing gate is dark brown, with a woven texture that is visible starting with the 200 ISO setting. The railing is a smooth white pvc plastic.
I scanned the negatives on an Epson v850 with no adjustments. I find I like the moodiness of the 200 ISO shot, but the 200 +.5 is probably most accurate. The longer exposures have blown out highlights and darker elements such as the house across the street are too light. Of course, everyone's monitor is different, so you may come to a different conclusion. In fact, now when I view these on my phone, I would choose the 100 and 100 +.5.
After reading what Matt wrote about more exposure and less development, and watching the second John Finch video, I wish I had also shot the last third of a roll and developed with a shorter time.
ISO 200 -.5
ISO 200
ISO 200 +.5
ISO 100
ISO 100 +.5
ISO 50
ISO 50 +.5
ISO 25
I set my ISO manually to 200 based on the recommendation in the box label for use with HC110 and used the compensation dial on my Pentax ZX5n to go from a -.5 to a +3 in half stop increments as shown in the photos below. The Pentax was set for matrix metering. I developed the film in HC110 for 10.5 minutes as recommended.
Notable colors in the scene: The sky is lightly overcast, so mostly white. The house is a medium blue. The house across the street is a dark brown. The tree on the left has turned a bright yellow. The chair behind the railing gate is dark brown, with a woven texture that is visible starting with the 200 ISO setting. The railing is a smooth white pvc plastic.
I scanned the negatives on an Epson v850 with no adjustments. I find I like the moodiness of the 200 ISO shot, but the 200 +.5 is probably most accurate. The longer exposures have blown out highlights and darker elements such as the house across the street are too light. Of course, everyone's monitor is different, so you may come to a different conclusion. In fact, now when I view these on my phone, I would choose the 100 and 100 +.5.
After reading what Matt wrote about more exposure and less development, and watching the second John Finch video, I wish I had also shot the last third of a roll and developed with a shorter time.
ISO 200 -.5
ISO 200
ISO 200 +.5
ISO 100
ISO 100 +.5
ISO 50
ISO 50 +.5
ISO 25
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OP
OP
Thank you! I also found it at a public library website, so should be able to borrow a copy. It promises to be a great resource.You can read the book online (free, but requires an account):
Wow. I think I've seen one of those on eBay some time ago. Mine (X-Rite 810) has what looks like an old serial port connector at the back, but I doubt I could connect it to a modern PC.
You guys have to explain something to me. From the little I understand in this thread, tests you're doing show this film to have a film speed around 80, but my experience with it in the street gave me perfectly workable negatives at 200, developed in XTOL at the recommended time. I know one user's experience is anecdotal, but yet, still begs the question: if the science doesn't match the experience, surely, the science must be wrong, no?
MattKing
Moderator
Me too
.But thankyou for what you did post, because it too was very interesting - particularly the mid-tones in the 100, 50 and 25 examples.
And for clarity and a reminder, we also would like to see simply interesting photos, in addition to photos done for the purpose of testing. If they can be accompanied with exposure/metering and development info as well, all the better.
No, not necessarily. After all one can rate Tri-X at 800, push process and get "a workable negative" even though the science says it is an ASA400 film.
OP
OP
I asked this very question earlier in the thread. People much smarter than me answered this question long ago, because this "problem" has existed in photography forever, really. Industry standards, such as the ISO 0.1 over B+F film speed criterion, are very specific, which is, partly, what makes them standards. How they reconcile with real-world experience is up to each individual photographer to figure out. But, crucially, these are not mutually exclusive.
I will quote Fred Picker on this very subject - I do this from memory so I apologize if I misquote him. By the way, he found Kodak Tri-X to be EI 140: "Film speed is based on exposure for Zone I, which is minimum printable density or 0.1 over film base + fog. Manufactures have determined that it is best for the world out there, but experienced photographers want to control their exposures better."
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