Ran a film speed test...interpreting results

[BetterSense]

I attempted to run a film speed test by setting up a generic grey card of uncertain origin and metering it with my camera. I then shot it full-frame at the meter reading, reading -+ 1 stop, reading -+ 2 stops, etc. and developed the way I normally do.

I made a test strip in my condenser enlarger to find the minimum time for max black through the film base+fog, using a blank frame on the same roll.

When I use this same amount of time to print through the -4 stops (zone 1?) negative, I cannot distinguish its tone from max black. However, I can print through the -3 stops negative (zone 2?) and get a tone that is distinguishable from max black.

Does this mean I should reduce my EI?

I then tested the over exposed negatives. I was able to print the +3 stops (zone 8?) frame to a tone distinguishable from paper white. But I was not able to print the +4 stops (zone 9) negative to a tone that was distinguishable from paper white. Should I reduce my development time?

Am I making any systematic errors in my test?

 

[OMU]

"When I use this same amount of time to print through the -4 stops (zone 1?) negative, I cannot distinguish its tone from max black. However, I can print through the -3 stops negative (zone 2?) and get a tone that is distinguishable from max black."

I don't know the ISO of your film speed, but from what you are writing; your E.I. is probably between - 4 and - 3, 3,5.

If your film are at 100 ISO your E.I. are either 80 or 64 ASA.

I don’t know hove distinct the black in the – 3 frame is, but perhaps you can figure out from the negatives hove close you are the true black and decide if your E.I is 80 or 64. If not, you have to test ones more.

To test the development time you have to find your E.I first, otherwise your risk testing with the wrong negative. (If you have a E.I at 80 and you test the negative that are exposed at 100 asa, the results will be wrong) (Sorry for my English)

 

[BobNewYork]

I find it easier to set up a "scene" for my testing. I use a black textured camera bag and a piece of white, textured polystyrene. Set 'em up and add a gray card for good measure. I run from -4 to +4 stops in 1/2 stop increments. I'll contact proof the negs, (min exposure / max. black) and select the best looking three or four negs. Then I do full 8x10 prints of those negs, (min exp / max black again). From those I identify the best looking camera bag and on that print look at the polystyrene. If it's blown out I know to reduce my development time; if it's dingy I know to increase my development time. I'll then run the tests again. I find evaluating from a full 8x10 is easier for me, and he fact that I use familiar items improves my visual judgment. The added advantage, is that when I take the frames, I'll calibrate my in-camera meter to my spot meter to my incident meter at the same time so I can interchange them out in the real world. It can be completed in a morning or afternoon. I power dry the negs and the prints - because they're only tests - don't care how much dust etc I have on them!

Bob H

 

[Anscojohn]

.

Does this mean I should reduce my EI?
*********
Yes

I Should I reduce my development time?
*****
Yes

Am I making any systematic errors in my test?[/QUOTE]
*******
No

 

[2F/2F]

I attempted to run a film speed test by setting up a generic grey card of uncertain origin and metering it with my camera. I then shot it full-frame at the meter reading, reading -+ 1 stop, reading -+ 2 stops, etc. and developed the way I normally do.

I made a test strip in my condenser enlarger to find the minimum time for max black through the film base+fog, using a blank frame on the same roll.

When I use this same amount of time to print through the -4 stops (zone 1?) negative, I cannot distinguish its tone from max black. However, I can print through the -3 stops negative (zone 2?) and get a tone that is distinguishable from max black.

Does this mean I should reduce my EI?

I then tested the over exposed negatives. I was able to print the +3 stops (zone 8?) frame to a tone distinguishable from paper white. But I was not able to print the +4 stops (zone 9) negative to a tone that was distinguishable from paper white. Should I reduce my development time?

Am I making any systematic errors in my test?

Your analysis of what you reported in paragraph three is correct. What you are seeing is that you need to use a lower EI in order to be able to accurately place a zone I density.

Your current test puts you at half box speed. However, IMO, you should shoot again with more precision than one stop. You may have an EI somewhere between box speed and half box speed.

Testing the separation of whites between zones IX and X is more difficult, IMO; harder to see the differences there than in the blacks. These ones are also the most sensitive to minor development changes. Usually zones V - VIII are used as "targets" for deciding development times, and IX and X are allowed to fall where they may, as they contain no detail anyhow. I would worry about it after you get a working EI. However, I would say, based on your description, that you may need to reduce developing time a bit.

After finding an EI based on zone I, and finding a normal development time, you may also want to consider retesting for an EI that gives you a predictable placement of zone II - III rather than a zone I, as some films are not yet onto the straight line right above 0.10, and placements other than a dead-on zone I may fall below their "expected" densities (if it was a perfectly linear scenario). This is part of the "look" of certain films, you get to know what to expect rather quickly, and it works just fine, but even so, I now calibrate to zones II and III myself. This means that I test for the EI that most closely renders a zone II placement at 0.20 above FB+F and a zone III placement at 0.40 above FB+F to start. (It always has to be backed up by real-world printing to find the "actual" densities that print to these zones, and it will change with each paper, but these are the theoretical starting points.) I let anything below zone II fall where it may. I am more concerned about being able to perfectly place the zone II - III tones. That way, if anything is not falling right where I expect it, it is a zone I falling too high, which is far preferable to a zone II or III falling too low.

 

[Lee L]

This means that I test for the EI that most closely renders a zone II placement at 0.40 above FB+F and a zone III placement at 0.70 above FB+F to start.

So you're aiming for a CI/gamma of 1.0, even in the shadows with long toed films?

Lee

 

[2F/2F]

So you're aiming for a CI/gamma of 1.0, even in the shadows with long toed films?

Lee

The numbers are wrong...obviously...Tech Pan is discontinued. heh At 5 a.m. I am confusing things, and making the standard mistake of treating it like ND filters. It is zone III I aim to get at around 0.40, zone V is around 0.70. I changed it now, thanks to you catching it. The numbers I put aren't half bad for an N+2, however. It is the same exact mistake I would make when I was first learning the zone system. I was wondering why the hell I needed to develop so darned long to get my zone VIII, yet my negs looked bulletproof.

 

[BetterSense]

This means that I test for the EI that most closely renders a zone II placement at 0.20 above FB+F and a zone III placement at 0.40 above FB+F to start.

OK this makes sense, supposing I have a densitometer this is all well and good and makes sense

(It always has to be backed up by real-world printing to find the "actual" densities that print to these zones, and it will change with each paper, but these are the theoretical starting points.)

I don't quite understand "printing to these zones"; is it a fact that transmissive and reflective densities can be correlated, so that if you have a negative of density .4, then it will (or should) print a .4 reflective density onto the paper?

 

[2F/2F]

OK this makes sense, supposing I have a densitometer this is all well and good and makes sense



I don't quite understand "printing to these zones"; is it a fact that transmissive and reflective densities can be correlated, so that if you have a negative of density .4, then it will (or should) print a .4 reflective density onto the paper?

Remember that a zone is a print tone, not a negative density. You can print various negative densities to various zones via manipulation. Where certain densities print to with "normal" printing varies depending on the enlarger, and all papers are not the same either. What works for me on my B22 with condenser head does not work exactly the same on my friend's Beseler 45 with a color head. Since this is the enlarger I usually use for printing 4x5, and with which I tested for all my 4x5 times and such, I develop my 4x5 negs to slightly different contrast than my smaller negs.

As for the reflective value correlating to a transmissive value...I really don't know. I am not incredibly techie about this beyond the basic level. I took a zone class at school because it was required, and they did not go into any detail about reflected values...just lots and lots of "practice" printing! We did not even have a densitometer until AFTER the class was over...go figure.

 

[Anscojohn]

I don't quite understand "printing to these zones"; is it a fact that transmissive and reflective densities can be correlated, so that if you have a negative of density .4, then it will (or should) print a .4 reflective density onto the paper?[/QUOTE]

*******
I don't know.

 

[BetterSense]

Ok this has all be reassuring. Not to overthink it, I think I will shoot my next roll at 200 instead of 400, develop for 8 minutes instead of 9, and perform the test again. I had already started creeping my EI down from 400 for normal rolls because I could tell from my contact prints that the images were pretty dark.

I mostly wasn't sure if zone I was supposed to be printable or not; some of the explanations of the zone system that I have read have said that zones 1 and 10 are equivalent to dmax and dmin and are basically the same as nothing at all.

 

[2F/2F]

Ok this has all be reassuring. Not to overthink it, I think I will shoot my next roll at 200 instead of 400, develop for 8 minutes instead of 9, and perform the test again. I had already started creeping my EI down from 400 for normal rolls because I could tell from my contact prints that the images were pretty dark.

I mostly wasn't sure if zone I was supposed to be printable or not; some of the explanations of the zone system that I have read have said that zones 1 and 10 are equivalent to dmax and dmin and are basically the same as nothing at all.

Zone I is a hair above max. black on your paper. The tiniest hints of tone above black, but it is flat tone, with no texture and no detail. It's equivalent on the other end of the scale would be zone IX. Zone X is paper white, and is equivalent to zone 0 on the other end of the scale. What a zone X density is on your negative will depend on your enlarger, paper, etc. IMO, it can all only be so exact without actually printing. It is really only able to be refined once you start printing. At that point, there is no such thing as a good enough negative (close is good, however), and the biggest part of getting things just right depends on printing ability. All the technical work that goes into making the negative simply serves the, IMO, far less technical art of making the print.

 

[Lee L]

I don't quite understand "printing to these zones"; is it a fact that transmissive and reflective densities can be correlated, so that if you have a negative of density .4, then it will (or should) print a .4 reflective density onto the paper?

No, 0.4 transmission density in a negative isn't supposed to produce a reflective density of 0.4 in a print. Transmissive and reflective densities from a resulting print are a generally inverse relationship, but neither is always linear, so you're summing two curves.

0.1 transmission density in a negative is approximately Zone I, very dark, and reflection density of 0.1 on a print is a light gray. Reflection and transmission densities are equal at some point near the middle of the useful ranges.

You have to account for the interactions of the film (H&D) curve and the response curve of the paper to know where things will fall on the print.

I'd suggest a good book, The New Zone System Manual, by White, Zakia, and Lorenz. You can get a good used copy for under $5 from Amazon. It explains all these relationships in a comprehensive and understandable way with lots of good illustrations and graphics, and alternate ways of thinking about the process.

I've attached a table from that book relating negative densities to print tones, with densities suggested for different formats.

Lee

 

[BobNewYork]

........

I'd suggest a good book, The New Zone System Manual, by White, Zakia, and Lorenz. You can get a good used copy for under $5 from Amazon. It explains all these relationships in a comprehensive and understandable way with lots of good illustrations and graphics, and alternate ways of thinking about the process.

Lee

Absolutely!

Bob H

 

[Gene Crumly Photo]

Being new to black and white (always processed colored slides) and being the type that builds the bike first then looks at the instructions, I knew I needed some technical information. The 2 things that has made black and white easier for me has been Frd Picker's book and video. The book Zone VI Workshop can be found on ebay under zone VI or Fred Picker $5 to $10. The video named Black & White Film Photography - Fred Picker's Clasic Trilogy, is the 3 VHS tapes put on DVD by Calumet. This can be found on ebay with the title or type Calumet and search within (store), $29 with buy it now, or go to Calumet on the web to buy it. You will see in the book and DVD what everyone has been posting here, and find it is an easy process layed out clearly.

 

[Doremus Scudder]

Better Sense,

You seem to be doing everything correctly and making the correct assumptions. If your Zone I "proper proof" is indistiguishable from maximum paper black, you are probably underexosing. Changing your E.I. by a stop and repeating the test will give you a substatially different result and enable you to tell immediately if your proper E.I. is somewhere in the middle. Then you can just choose one and work. One-third of a stop is not a big deal.

Make sure, however, that you are not overexposing your paper, i.e., that your "proper proofing time" is not too long. Do a a couple of proofs with slightly less exposure than your "proper-proofing time" just to make sure (for me, zeroing in on "black" was a real learning process when I first began.)

When you are fairly sure your proofing time is good and have a new E.I. that is within a stop, then you can repeat the test a time or two to zero in on your developing time. Wait on tweaking development till you have your E.I. fairly closely established. It is always best to change one variable at a time.

If you have to change your developing time by 20% or more, you should start the whole process over and re-establish your E.I. since the development change will affect that to a certain extent.

Once you are within about 2/3-stop from ideal, you can just go shoot, keeping careful notes for a while and fine tuning the process as you go. The main thing for roll film is to make sure you are exposing properly and not overdeveloping, so err on the side of these things.

One more thing. You need to decide what your Zone VIII and IX will be. In my (and the original Adam's) system, Zone IX is pure paper white, while Zone VIII shows the slightest grey and a little (but not full) detail. Zone VII would be greyer and fully textured (e.g. a brightly lit rough concrete wall). Many use a variant of the system in which Zone IX is just a bit darker than paper white, but not textured, and Zone X is "max white." This latter often results in slower E.I.s and shorter developing times.

You seem well on your way, so "full speed ahead" and have fun.

Best,

Doremus Scudder
www.DoremusScudder.com

 

[BobNewYork]

....... sure (for me, zeroing in on "black" was a real learning process when I first began.)
l

I had the same problem - distinguishing which was the first maximum black in my test strips. Now, I use a slightly wider test strip and, once exposed I firmly cover half of it (lengthwise) and turn on the room lights for a few seconds to ensure fogging.

It gave me two advantages: (a) I can confirm that the range of exposures given have, indeed given a maximum black and; (b) I have a direct, side-by-side comparison of each step to a known maximum black. It took me from a lot of "umming and aahing" and second guessing to a three second decision.

Bob H

 

[Doremus Scudder]

Bob,

I do the same. Realizing that true D-max is rarely, if ever, achieved when actually printing was the "ah-hah" moment for me. I now work for the deepest usable black in printing to compare to for film-speed tests. This is precisely what Phil Davis in his BTZS designates as ID-max, or maximum image density, which he pegs at 90% of D-max. For me, getting acceptable blacks in the print is balanced by getting the shadows off the shoulder of the paper as much as practical. The separation vs. blackness compromise is subjective and highly individual (and varies from paper to paper), so I would hesitate to try and quantify what I find a usable black it quite so precisely.

Furthermore, blacks can be supported and enriched by toning and selective burning in of key areas while keeping the other "blacks" in an area of the film's curve that yields more separation. I find that trying to match Zone I to the papers true D-max requires way too much overexposure of the film (i.e., a really big difference between the Zone I density and fb+f density) to be practical. The visual evaluation method using a "proper proof" that I recommend requires a bit of getting used to the different ideas of black and rethinking what one really wants in the blacks of a print, both things I think are good to engage with and which make one a better printer.

Best,

Doremus Scudder
www.DoremusScudder.com

 

[Stephen Benskin]

The 90% of D-Max actually comes from the ISO standard for determining the log exposure range (LER) of the paper. The ISO standard is derived from a paper by Loyd Jones. 90% of D-Max can be assumed to be the paper's Zone I tone.