Zone System Calibration - Change in EI with change in HC-110 Dilution

These are detailed questions, I know, but I would REALLY appreciate

any help with this.

 

I started my Zone System tests for HP5 (4x5) in HC-110, dilution B,

in a Jobo processor. I mix directly from syrup, 1:31 and develop at

68F. The EI for my 90mm Super Angulon came out to be 200. Testing for

normal development, at 4'15", Zone V was 0.74, Zone VIII was 1.17

(after subtracting fbf). Adams gives values of between 0.60 and 0.70

for Zone V and between 1.15 and 1.25 for Zone VIII. So my Zone V

seems a little high but the Zone VIII seems just fine. As I used to

say when tuning my guitar, is this close enough for rock and roll?

 

Second question. The EI on my 150mm lens is 320. At 4'15", both Zone

V and Zone VIII are too high (V=0.76, VIII=1.31). However, I have

been told that development times below 5 minutes are already a little

iffy so rather than further shortening development, I should change

dilution. Does this mean that I need to recalibrate the EI at the new

dilution? Can anyone suggest a proper dilution (maybe D?). Also, I

can only put so much in the Jobo drum without putting too much of a

load on it but I am worried that at higher dilutions, I won't have

enough syrup in the mix. I read that I should have at least 3ml of

syrup for each 135 or 120 roll. I develop 4 sheets at time in my

drum. Dilution D (1:39) with 12 ml of syrup would give me 480 ml of

developer which is not too much for the tank (model 2523). Is that

enough syrup for 4 sheets of 4x5?

 

Finally, are there any charts out there of recommended values for 4x5

sheet film for the Zone densities?

 

Thanks,

 

Don Wallace

Don: Since your question has been lingering out there for a few hours unanswered, let me take a stab at it. It would be helpful to know how you performed the exposures for your film speed test. I assume, but want to be sure, that the film speed you use before you work on the development time test is accurate for your meter and processing method. It concerns me that you have different film speeds from lens to lens. Why is this? Do the test with a lens you know to be in the right shutter with an accurate scale and with shutter speeds that are accurate in the range you will use in the field. Something is wrong with how you did the test, or one or both shutters are off on speed, or you have a misapplied aperture scale, so get that sorted out or you will never know what is what. The film speed is what it is with your meter and your processing but without that step nailed down you can waste a lot of time. If you don't want to get the faulty shutter fixed, you can test it and adjust for its actual times, but the logic of applying different film speed from lens to lens I don't follow. And shutters run fast on some speeds and slow on others so you end up with different film speeds for each shutter and each speed? Anyway, assuming that issue is behind you, we move on to the development time test. I know that Adams and some others publish numbers for what a Zone VIII density should be over and above b+f. My experience has been that it is better to determine the development time by putting away the desitometer, determining what level of exposure gives you maximum black through developed and fixed unexposed film, and then adjust development time until you see a Zone VIII which is what you with that level of exposure. As long as you know what you want that VIII value to look like, and you test until you develop it to what you want, you will be fine. Use the paper and developer you think you are going to print on and with because it can make a huge difference in the outcome. My favorite paper at the moment is Seagull fiber based VC. If I develop film to a Zone VIII density above .95 to 1.0 -- into the range you suggest -- then with a development time test those Zone VIII exposures will be pure, blank white, not a proper Zone VIII. If I have them at 1.25, for example, then when it comes times to print a real negative I am going to end up overexposing the paper to get the Zone VIII to where I want it, which is a slight hint of texture and substance. If I do that (and I did it for several years because I made the mistake of using paper for the development time test which was not what I printed on but which was quick and easy and cheap) then I will along the way give my lower Zones too much exposure and drive the Zones II and III down to black, which can pretty much suck the life out of some negatives. So I question using the densitometer to determine the length of development and don't recommend you do it. Once you know what Zone VIII density gives you Zone VIII print values at an exposure which is the minumum exposure for maximum black on your paper, you can use the densitometer to tune to that number with different flim/developer combinations, but I think starting off trying to reach a numeric goal isn't the way to go. I'm not sure tuning the development time test to the mid Zones is productive. If, as you say, your "Zone V seems a little high" when you think the Zone VIII is right then this is a function of the scale of your film, in your developer, and your paper and your print developer and trying to futz around to make minor moves in the middle zones by altering development times will throw everything off. The close zones tend to move in lockstep with changes in development time, relatively speaking. Regarding capacity, my experience with HC110 (albeit more with Tri-X than HP5) is that one ounce of syrup can develop 6 4X5 sheets. Given my lack of experience with JOBO's I can't get much further than that with your second question. To answer the title of your question, I would get things calibrated at a normal dilution and have film speed and Zone VIII established. Then I would go with a greater dilution for a longer development time and adjust time until my diluted developer have me the Zone VIII density I had with the more concentrated developer. If you use that time to repeat the film speed test I think you will find it very close or exactly where it was when you started. This can all get rather circular if you carry it too far. When you make good prints quit while you're ahead. Good luck.

Don't know if you have seen this:

 

http://www.covingtoninnovations.com/hc110/

 

FYI

Whether or not the Kodak published times for HC-110(B) are correct or in error (as Covington claims) is irrelevent if one does their own film speed and development testing.

 

Yes, if you change the dilution you should retest the film speed and retest the development time.

 

HC-110 can withstand very high diltuions before becoming exhausted. But try it and see what happens.

Hi Don. I'm not a zone guy, so maybe you don't want to hear from me. On the other hand, I've had substantial sensi testing experience, and the zone system is, after all, a simplified application of sensitometry. So I'll toss out a couple opinions and let you weigh them yourself.

 

I'm working on the assumption (like I said, I'm not a zone guy) that each zone represents a doubling of the light in the scene; ie, just like a full f-stop exposure change. On that basis, each zone is also exactly like a "log exposure" change in a "characteristic curve". And I'll presume you have a well behaved film response that is a reasonably straight line on such a curve.

 

First, you got these results: "�Zone V was 0.74, Zone VIII was 1.17�". The difference of three zones corresponds to a log exposure change of 0.90. The density difference divided by this is about 0.48. Therefore, you are working with a film "gamma" (this describes how "contrasty" the film is) of about 0.48. I emphasize that this is based on the presumption of a reasonably straight line response.

 

Then you said, "Adams gives values of between 0.60 and 0.70 for Zone V and between 1.15 and 1.25 for Zone VIII.". The same calculation on Adams' aims gives low/high extremes of 0.50 to 0.72, with an average of 0.61.

 

Therefore, I would say that your gamma ("contrastiness", if that is a word) is just on the low side of Adams' recommendations. So if you want to center on his recommendations, you probably ought to increase development a little. Then, both of your density values will be on the high side (as per Adams' recommendation); what this means is that you are overexposing a little (with respect to Adam's numbers) and should therefore lower your exposure index a bit.

 

On your second question, "�both Zone V and Zone VIII are too high (V=0.76, VIII=1.31).", the calculated gamma is 0.61; right in the middle of Adam's range. So the amount of development sounds right; it's just that there is a little too much exposure. If you'd like, I can make a rough calculation of the exposure error.

Don, your short development time sounds uncomfortable to me. I've never used a Jobo (I use trays). My guess is the short time may be related to constant agitation.

 

The world does not end at Zone VIII. I have occasionally printed through some "bulletproof" Tri X negs. I don't recommend it, but it can be done. I would try diluting the HC110. A longer development time is more easily controllable. As already noted, changing the dilution shouldn't have much impact on the lower values (speed).

 

I second Kevin's thoughts about zone determination by printing. Try diluting 1:47 and/or 1:63. See how your negatives print. Keep us posted.

If you don't already have it, Steve Anchell's book on film developing should be part of your much used library.

Don,

 

Bill's answer above seems right on to me (I am a "Zone System Guy"). I would, however, also like to advocate the materials-oriented approach to calibrating espoused above. There are so many differnt variables that it is more accurate in practice to calibrate using the shutters, films, papers, developers, agitation schemes, etc. that one uses in the field/darkroom.

 

The basis of this is "Proper Proofing Time", the minimum time it takes to print maximum paper black (D-Max) through the film-base-plus-fog of a properly developed negative. Make a contact test strip on the paper you plan to use for most of your printing and at the contrast you are calibrating for through an unexposed but developed neg and find where an acceptable maximum black is. This is not as easy as it sounds since small differences in black are difficult to discern, and, to make things more complicated, depend on the light level you are observing under. In sunlight you will see many more stripes of black than in normal room light. My recommendation is to observe under the brightest viewing light you expect for your prints and to choose a black that is an acceptable "base black" for your work. Choosing too black a black can result in unnecessary overexposure (more later). This resulting exposure time for your contact print is your "proper proofing time" provided that the light intensity of your enlarger remains the same. This means that for further testing, the enlarger head, lens, filtration (if any) and light source (and intensity if you have a control for that) must remain the same.

 

Once you have established your "PPT", contact print your test negs at this time and evaluate them to find proper film speed and development time. Again, this is somewhat subjective, but gives you values that you imagine as Zone I, Zone VIII, etc. and can use to visualize the final result. Zone I for me is the first discernable difference from my "base black". Therefore, it is useful to compare it side-by-side on the same neg. The clear border or an unexposed portion of the film should be right next to the densities to be tested. The film speed for the chosen value determines your film speed. I should add here that it is the contact print made at "PPT" that is being evaluated here, not the negative. This includes your choice of paper in the test and eliminates an entire range of paper tests.

 

Zone VII, as mentioned above, is the first white under maximum paper white that shows adequate detail (texture). Again, the look of this texture is up to you. Using your previously determined film speed, make several Zone VIII negs of a textured surface (evenly lit, of course) and develop for various time around your best estimate of where the proper developing time is. The chosen Zone VIII value determines your Normal developing time for your equipment and materials (i.e. film/dev/paper/shutter/camera flare/lens/etc).

 

Similar tests for plus and minus developing times, different films etc. will give you those data. Using such subjective means of evaluation may seem "unscientific", but actully give better results since the process takes into account your personal expectations and visualization techniques as well as the variables at all stages of testing, which would all have to be tested separately and then somehow figured together.

 

I often find it useful to make "Zone Rulers" (one sqare of each Zone from 0-IX) to see just how the characteristic curve of a given film/dev combination distribute the middle zones. This can vary markedly depending on film and developer.

 

Some things to keep in mind when calibrating: 1.)Choosing a higher a Zone I density (there is some leeway here) requires more exposure (i.e. lowers effective film speed) and moves the shadow values up the film curve. This can be beneficial in that the shadow values recieve more separation this way and is a built-in advantage of the Zone System that many do not realize (many sheet-film users routinely overexpose even more when they need extra separation in the shadows for this very reason). 2.) Greater expansions or contractions will change the fb+f and require a different "PPT" for the most precise calibration. 3.) Increasing or decreasing development time, or changing developer, will result in a different effective film speed (EI). These I usually think of as "exposure factors" for N+ and N- developments.

 

To minimize differences and inaccuracies in shutters, try to use the longest shutter speeds possible and use the aperture you do most of your taking with. If you suspect a shutter of being inaccurate, have it tested and find out the actual speeds (it's easy to convert from milliseconds). If your shutter is consistent, just tape the real values to the lens (1/400 = 1/125, etc.). If you use older, uncoated lenses, flare can be a factor and result in a loss in contrast. This I deal with by applying a "development factor" to low-contrast lenses (i.e. this lens needs 15% more develoment time. The result is something like "N+1+15%).

 

Now, finally, to answer your question about HC-110 dilutions. I have used this developer in many dilutions and now use it primarily in Dil. B (1:31) and at twice that dilution, 1:63. Contrary to the above posts, I have found no difference in EI for the different dilution, just the expected difference in development time.

 

I'd be happy to elaborate more if you like, but this is long enough already, so I'll stop here. Hope this helps.

 

Regards, ;^D)

 

 

Don: here is a link to my site where there is data for HC110. I do not use it anymore but you can see I did use it at various dilutions from stock, not syrup. just FYI <html>

<a href="http://home.att.net/~shipale/index.html">phil sweeney's website</a>

</body>

</html>

Much thanks for all of these responses. I am starting by taking the suggestion about getting equipment checked and getting all my shutters and light meter tested tomorrow. Then I am going to take another whack at it this weekend.

 

I love this forum. Thanks again guys.

 

Don

You might consider letting The View Camera Store do the testing for you. It will cost about $40 but it wil be done with no hassle to you other than developing the exposed film they'll send you and shipping it back to them. A week or so later you'll have charts and graphs that will give you developing times for normal, plus, and minus development plus your effective film speed at those development times. They will also tell you more than you ever wanted to know about your film and your developing system.

 

The last time I tried doing my own zone system tests I was driven nuts by inexplicable variations from one test to another and by the fact that I would come up with an EI based on .10 or thereabouts log units above FB+F but then when I'd do the development tests my FB+F was different than it had been when I did the EI tests. I went through a box and a half of film without ever feeling confident that I had accomplished anything worthwhile and I have a densitometer so I wasn't relying on the eyeball method.

Don, your equipment sound "in tolerance" to me. How much 4x5 work have you done? I get the feeling that what you need is a few hundred more negatives. You'll develop a feel for things. Don't get discouraged!

I tried the same combo as you and gave up on it. HC-110 develops too quickly in a Jobo to get minus development. Try D-76 1:1.

A little off the subject but I would question using a Jobo for zone development. The constant agitation and thin emulsions of modern films will make it difficult to get good n-x compression in the negative I would think. But, I don't have much experience with jobo processing.