AA's Value I density targets

[john_s]

As I suggested in an earlier post, the Zone VI Pentax spot meter might have influenced your conclusions. Mine gave me similar results that did not coincide with all other meters. My two are for sale, if anyone wants inaccurate meters.

 

[markbau]

As I suggested in an earlier post, the Zone VI Pentax spot meter might have influenced your conclusions. Mine gave me similar results that did not coincide with all other meters. My two are for sale, if anyone wants inaccurate meters.

After reading your post I've just gone outside and checked my spotmeter against a fairly new Sekonic L-308S. We have a cloudless blue sky here today and the meters agreed perfectly, (metering the blue sky), I then metered a dark card in open shade, again the meters agreed. Maybe your meters are defective but mine appears to be working perfectly.

 

[Bill Burk]

The film was hand developed in D76 1:1 for 9 minutes, 30 second agitations.

Sorry didn’t mean to insult you. I am actually embarrassed at my gaffe.

My time to develop Tri-X to meet ASA parameters in D-76 1:1 is 13:30

You developed for four minutes less time than I would.

It’s good to develop for 9 minutes 30 seconds, especially if you are using EI 200. So I don’t suggest you change the time. I just think the time explains the low Zone I density you got.

 

[Sirius Glass]

That's a slightly insulting question, having developed films for 40+ years including 10 working in a pro lab. I live in Australia where it is the middle of summer although I'm not sure what the season has to do with film development temperature. I measure film developer 3 times, once just before it goes in, mid way through development and then after it is poured out, the drift is usually 0.5 Degree C.

As I suggested in an earlier post, the Zone VI Pentax spot meter might have influenced your conclusions. Mine gave me similar results that did not coincide with all other meters. My two are for sale, if anyone wants inaccurate meters.

After reading your post I've just gone outside and checked my spotmeter against a fairly new Sekonic L-308S. We have a cloudless blue sky here today and the meters agreed perfectly, (metering the blue sky), I then metered a dark card in open shade, again the meters agreed. Maybe your meters are defective but mine appears to be working perfectly.

I have several light meters:

• Built in Nikon N75
• Built in Nikon N80
• Built in Nikon F100
• Hasselblad PME [prism]
• Sekonic L308-S
• Pentax Digital Spot Meter

They had mostly agreed but I sent them all to be calibrate at once. All were done by the same person except the Hasselblad which had to go to Hasselblad in New Jersey. Now they all agree with each other and all the photographs are exposed exactly the same way. It was well worth the expense. No since George at Quality Light Metric [the go to guy for the Hollywood movie industry] retired, I do not have a calibration lab to recommend.

 

[takilmaboxer]

Yes but usually you leave that whole a lot smarter than you entered it.

Very Very True!
To address the OP, light meters are supposed to "see" whatever they are pointed at, as 18% grey. If you use a black target for calibration you must adjust accordingly. I calibrated all my equipment using a Pentax spot meter that agreed with my other meters. The spot meter has since died but the other meters live on.
I never use a grey card any more. The spot meter taught me that the blue sky in New Mexico is EV 14 and my hand is EV 15. The brightest reflections on our typical cumulus clouds can reach EV 16. Those are my reference values nowadays...and I worry a lot more about the slope of the "curve" than its knee point. I always bracket any ways, just in case. One never knows when the shot you didn't really think about turns out to be important.

 

[bernard_L]

the blue sky in New Mexico is EV 14 and my hand is EV 15

Technically, LV, not EV. A scene (object+lighting) spot has a definite LV (luminance). Which corresponds to diverse EV values (speed-diaphragm combination) depending on the film speed. The two coincide numerically for ISO 100 film.
Outdoors in sunny weather I can also dispense with a meter (let alone spot meter): I use the inside flap from an old film box. But under deep tree cover, even summer noon, is another story.

 

[Bill Burk]

Adding development time is appropriate. That literally is what Zone System testing “asks” you to do when Zone I density is low (as you found).

But you do not want to try to get 400 EI by Zone I reading. I would say no more than what it takes to bring 200 to 250 EI Zone I reading up to 0.10 above base plus fog. Because EI 250 means full 400 speed. And EI 200 will mean traditional Zone System N contrast.

 

[Stephen Benskin]

Hard to believe people used to think this method of testing produced "true" speeds.

 

[Doremus Scudder]

I don't know about your meters, but all three of my Pentax digital spot meters (modified and unmodified) have fairly significant flare that will skew the meter reading for a dark object when there are brighter things around. This could easily be the cause of the underexposure the OP has. I have to be careful of this in the field, often compensating for possible flare by adding a bit of exposure. A lens hood on the meter helps a bit, but doesn't solve the problem entirely. FWIW, my modified meter tends to flare more than the unmodified (maybe all the filters added scatter more light?).

There are a number of other things that might influence the test results as well: faster shutter speeds than expected, inaccurate densitometer readings, development times that are on the short side, developer exhaustion or formulation not as expected (e.g., I had a batch of PMK that was inexplicably weak for no apparent reason), etc., etc.

My advice would be to err a bit on the overexposure side, go out and make some exposures and see how they print, paying special attentions to the shadow detail desired. Basing exposure on a Zone III or IV placement is a lot different that metering for Zone I and eliminates a lot of the flare problem.

I used to do a lot of film-speed testing, but these days just rate my film 2/3 stop slower than box speed to start, keep good notes and modify as I go. More important is finding a good "normal" development time that allows the maximum contrast control in the darkroom. Again, keeping notes and adjusting as I go works well for me.

Best,

Doremus

 

[Deleted member 88956]

I don't know about your meters, but all three of my Pentax digital spot meters (modified and unmodified) have fairly significant flare that will skew the meter reading for a dark object when there are brighter things around. This could easily be the cause of the underexposure the OP has. I have to be careful of this in the field, often compensating for possible flare by adding a bit of exposure. A lens hood on the meter helps a bit, but doesn't solve the problem entirely. FWIW, my modified meter tends to flare more than the unmodified (maybe all the filters added scatter more light?).

There are a number of other things that might influence the test results as well: faster shutter speeds than expected, inaccurate densitometer readings, development times that are on the short side, developer exhaustion or formulation not as expected (e.g., I had a batch of PMK that was inexplicably weak for no apparent reason), etc., etc.

My advice would be to err a bit on the overexposure side, go out and make some exposures and see how they print, paying special attentions to the shadow detail desired. Basing exposure on a Zone III or IV placement is a lot different that metering for Zone I and eliminates a lot of the flare problem.

I used to do a lot of film-speed testing, but these days just rate my film 2/3 stop slower than box speed to start, keep good notes and modify as I go. More important is finding a good "normal" development time that allows the maximum contrast control in the darkroom. Again, keeping notes and adjusting as I go works well for me.

Best,

Doremus

Except OP was satisfied with his negatives up until tests second guessed that. Not that negatives prior to that changed in the sleeves. And OP still stated he was not going to change anything. But with all follow up posts he ma have no choice. Seems like sure way to take all the fun out of shooing pictures.

 

[Stephen Benskin]

There are some exceptions to the EI/ISO problem, however this is because the manufacturer misuses the ISO designation.

Curious. How so?

 

[Stephen Benskin]

Some of the Foma films, for example. They are branded as ISO xxx however the data in the technical sheets contradict this. They also clearly mis-label EIs as ISO in these documents.

Did not know that. Thanks.

 

[markbau]

Hard to believe people used to think this method of testing produced "true" speeds.

Oh please, grace us with your method for finding your EI. Or is it just "sunny 16 rule" for you and hope for the best?

 

[markbau]

Used to? Many people still do. And it goes further than that. They still believe finding this EI is critical to improving print quality. Further still, they believe minus/plus development is a much more effective control than it really is, in the context of print quality. Basically, people see what they want to see.

There are some exceptions to the EI/ISO problem, however this is because the manufacturer misuses the ISO designation.

Well it sort of is crucial for print quality. Not giving enough exposure, which will almost certainly occur if you rate TX @400, will result in shadows that print pure black. If that's your cup of tea, go for it!
Regarding plus or minus development, not long ago I had a very low contrast scene, I exposed two sheets. The sheet that got 25% more development printed much better than the one that got normal development. I'm glad you are so happy with your film exposure/development regime, but there is no need to poo poo others methods, whatever works for you.

 

[Deleted member 88956]

Well it sort of is crucial for print quality. Not giving enough exposure, which will almost certainly occur if you rate TX @400, will result in shadows that print pure black. If that's your cup of tea, go for it!
Regarding plus or minus development, not long ago I had a very low contrast scene, I exposed two sheets. The sheet that got 25% more development printed much better than the one that got normal development. I'm glad you are so happy with your film exposure/development regime, but there is no need to poo poo others methods, whatever works for you.

Since there are tons of photographs printed with great brilliance and detail (which is what ZS user are after), but with no testing of any kind, how does that fact tie into the need for all testing, targeted development etc.? I have no problem with anyone who wants to spend all that time on testing rather than actual photograph making, but I see your thread here showing the exact dangers of not seeing that others are able to do without.

Kind of interesting how you stated "I'm fine with my negatives and do not intend to change anything" which was then followed by a number of posters suggesting how you DO need to make changes based on that test, or suggesting the test itself was done incorrectly, or whatever else said since. All theories, some based on science, hardly any on actual impact on final print.

I wish I could post a photo that's been hanging on my wall since 1991, but so far that print in scanned version does not seem to show enough of proof of what it looks like. It is a winter scene from streets of Bristol CT, with classic colonial house & white clapboard siding, trees & shrubs around, sunny day, deep shadows. In other words about 9 stop range. Shot with Pentax 645 on Tmax 100, developed in Rodinal 1:25, just one area in mid shadows spot metered, film/developer never tested for any ZS implied issues. It printed with ease with some pretty mundane burn & dodge. Brilliance in whites, details in deep shadows. How was that scene possible to be that easy to print and come out the way it did, with none of the testing or lengthy multi-spot metering?

I am not completely discounting the need to get more intricate with technical side ( and I like getting technical), but I do also think that a lot of people never give the simple way a good enough try, just go full on with the ZS parlance and practice, without a second thought. Good for anyone who is having success AND fun making photographs this way, it is just not the only way. No need to make it all sound as complicated as some make it look, it is not, or at least does not have to be most of the time.

 

[john_s]

As I suggested in an earlier post, the Zone VI Pentax spot meter might have influenced your conclusions. Mine gave me similar results that did not coincide with all other meters. My two are for sale, if anyone wants inaccurate meters.

Further to my posts about my inaccurate Zone VI modified Pentax spot meters, have a look at post #6 at this recent thread:

https://www.photrio.com/forum/threa...-110v-to-220v-conversion.188506/#post-2498971

Richard Ritter did the modification to the meters for Zone VI as well as some/all of the setting up of the Zone VI Compensating Timer and its associated light sensors that were installed in the cold light heads. If they used a bit of black marker to adjust the sensitivity of the sensor, it may well be that my Pentax meters just need a bit of black marker! I'm not equiped to do that kind of work unfortunately.

It's good that the OP's meter is accurate.

 

[Stephen Benskin]

Oh please, grace us with your method for finding your EI. Or is it just "sunny 16 rule" for you and hope for the best?

You should really be less defensive. I was talking about The Zone System. In fact, I was referring to the people who believe the Zone System methodology is more accurate than the ISO standard. How it's more of an illusion of precision in most cases.

If you want to know how I do it, you can search the site for my posts. I use a sensitometric approach and have written extensively about it.

 

[Bill Burk]

Oh please, grace us with your method for finding your EI.

I will explain what I learned from Stephen.

For film with unknown properties (e.g., Tri-X expired in 1974)… Expose film on a calibrated sensitometer and develop to ASA parameters. Index to the exposure corresponding to density 0.1 above base plus fog.

For fresh film, trust the speed indicated by manufacturer. Develop to ASA parameters and calibrate the sensitometer to the density 0.1 above base plus fog.

 

[Bill Burk]

@markbau add a couple minutes developing time to your next run… write the new time on a Post-it and if it works use the new time from now on.

I would trust film, camera, meter, thermometer, D-76 all being good before I would trust published processing times or the Massive Dev chart times.

They usually do not provide contrast aims for the times they recommend.

 

[Bill Burk]

If you want to know how I do it, you can search the site for my posts. I use a sensitometric approach and have written extensively about it.

@markbau let me introduce my good friend Stephen Benskin. His background is as consultant for photolabs in the Los Angeles area during film’s heyday. He knows how to get good lab control.

Mark has 40 years processing and lab experience, so he knows his stuff too.

My background is a bit more dubious. For my 50th birthday my wife bought me an expensive camera that I promised her would be the last one I will ever need. The manufacturer of that camera was getting trolled here so I joined as a shill for Littman. And I’ve just been writing obnoxious posts ever since.

 

[DREW WILEY]

Yep, cowboys, taint nuthin quite like hollerin over to ole Ansel n' askin him what length harness he attached to the horns of his Triceratops, so thet you kin cipher how long a harness you need on your quarter horse. Even the Tri-X he used taint the same as the one under question here. Furthermore, not all films are the same today with respect to how much above fbf you need to be to start distinct shadow separation. Not all have identical toes (if you aint shot em off first playin quick draw). And that itself varies according to specific development. Some dern things ya just have to figger out for yersalf, doing yer own roping in the corral, and if ya gots one, yer own densitometer plottin.

Or yer could ride into Dodge City and ask Sheriff Barnbaum, and he'd tell ya to base everything on Zone 3 instead, with a neg so dang thick than even yer .44 magnum cain't penetrate the density. Maybe thets why he done orders up Farmers Reducer by the freight wagon load, to clear the shouldered-off blocked-up highlights. No thanks. I prefer to raise my own cattle my own way.

 

[DREW WILEY]

Doremus and others, per meters. Flare is easily controlled. You can put a rubber lens shade on a Pentax spotmeter just like a camera lens. It's an odd but available size, 40.5mm if I recall correctly.

 

[Sirius Glass]

Doremus and others, per meters. Flare is easily controlled. You can put a rubber lens shade on a Pentax spotmeter just like a camera lens. It's an odd but available size, 40.5mm if I recall correctly.

Maybe I am lucky and others are unlucky but I have not had a flare problem with my spot meters. I have even looked for them.

 

[Stephen Benskin]

I will explain what I learned from Stephen.

For film with unknown properties (e.g., Tri-X expired in 1974)… Expose film on a calibrated sensitometer and develop to ASA parameters. Index to the exposure corresponding to density 0.1 above base plus fog.

For fresh film, trust the speed indicated by manufacturer. Develop to ASA parameters and calibrate the sensitometer to the density 0.1 above base plus fog.

Bill, I had hoped I had more to contribute.

I had to cut the last post short, but Bill, you've hit on a key point with the film of unknown properties. If the OP didn't know what the scientifically tested ISO value was, would he have questioned the results? It's about the level of confidence that can be attributed to the results. All the excellent insight proposed by everyone\s evaluation is a strong indicator that the confidence level is low. How do you know what you got is what is real? You still get a result whether it's from good or bad testing methodology.

Equally important is good interpretation of the results. I believe Bill just short handed his answer using 0.10 density, but a fixed density is not a accurate way to determine film speed. Density alone, and Jones would say at all, is not a valid indicator of image quality. I use the Delta-X Criterion, which is what is used in the black and white ISO standard. An important step to interpretation is to have an indepth understanding what the speed value means. I believe one of the reasons ZS practitioners have a repetition for incessant testing or obsession with 0.10 is that the system gives an aim without context or proper theory.

 

[DREW WILEY]

Well, I've spent my whole adult life taking pictures in extreme glare and contrast settings, like shimmering glacial ice adjacent to deep dark high altitude rock shadows. Used those Pentax spotmeters all along, with complete reliability. The real deal Pentax ones have a good multicoating on the lens (versus later and cheaper imitation spotmeters), and that probably helps. Otherwise, just common sense avoiding aiming directly at the sun or a sun reflection in the water, and if necessary attaching a supplementary lens hood.

Like other photographic items in the mountains, these can get temporarily fogged with condensation if you don't allow year gear to equalize to cold outdoor temps first, or if your own breath fogs it up. Worst case is when ice crystals instantly form due to your breath. Been there, done that. It's really a nuisance when it forms on a view camera ground glass. Take a long a cold weather "snorkel" hat when things get that bad.