Zone System and filmtesting

[erik_reitan]

I have just started to dip into the Zone system and are doing a

calibration of my system: F90x (N90s), APX 100, Rodinal 1+25, colour

enlarger and Agfa multicontrast semi matt paper. I have based my test

on Michael Fulks' test as described on the apoggee site (with

modifications): I use a kodak grey card outside (under uniform

lightning) and fill the frame completely, focusing to infinity. I

then set the aperture to f/8 and adjust the shutter time according to

the light meter (built-in spot), and change the aperture to shoot all

9 zones from I through X. I develop according to Agfa's

recommendation (8 mins, agitation every 30 seconds), and using

minimum printing time (12 secs, f/8, 55cm)I expose a test strip for

each frame. I have done this at E.I. 80, 100 and 125, and 80 seems to

render the best zone I. My problem is that at this speed, zone V

looks at least one zone brighter than the grey card (so does it at

the other speeds as well), and all zones above VI become completely

white. Why? Is my meter off? If so, should I change the meter

setting, or the development? Fulks says in his article that he has

never had to lower zone V, so i'm getting kind of confused...

[dhananjay_n]

Its probably because you're ending up developing the film to a higher contrast i.e., given your working conditions (agitation method, meter, shutters, alignment of the stars, precession of the equinox etc), you're developing your film to a higher gamma than you would like. Try developing for about 15-20% less time, you zone 1 should remain pretty much unaffected whereas your higher zones should drop into place. Cheers, DJ

[gphoto2]

Erick, Sounds like your doing most right. As previously mentioned back on the development a bit. Also Zone one should be pure black and you should begin to see detial(gray) in Zone 2-3. If your Zone 5 is consistently too bright you may want to increase your EV back to 100 from the 80?<div></div>

[john_stockdale2]

As Dhananjay said, you are developing too much. The stages in testing are basically:

 

1. Find film speed through exposure tests (Zone I)

2. Find development time by testing the higher zones. You have just found that your Zone V is too dense. In my limited experience, manufacturers' development times are usually too much. I believe that Agfa's times are based on a contrast index that is higher than most experienced users prefer.

 

Incidentally, Zone I on the print should be a fraction paler than maximum paper black.

[pete_andrews]

IMHO, Rodinal is a vicious developer at 1+25 anyway, with a tendency to block highlights at the slightest provocation. You might want to try a developer more in tune with modern film emulsions, or use a higher dilution of Rodinal to tame the highlight density.<p>If you're not using an acid stop bath after the Rodinal, then development will almost certainly be continuing in the water rinse, giving you overdevelopment. And if you use that faddy alkaline fixer, then development might even continue in the fixing bath!

[chris_waller]

I use Rodinal at 1:50. For example, I rate TMX at 50 ASA and dev in Rodinal 1:50, 20 C for 7 minutes inverting the tank once every 30 seconds. If the light is very contrasty then I reduce the agitation to once per minute and dev for 8 minutes.

[don_sigl]

Erik:

I'm not familar with Michaels process, but It looks like your development time is too long and/or your developer is too aggessive. I establish film speed based on zone I negative density and tweak development to give me a zone V density of .65+B+F. It sounds like your zone V negative density is considerably higher, you would probably need to reduce development to the point where your zone I was significantly affected.

The first thing I would try would be to use a less agressive developing agent, and see if contrast in the middle zones could be reduced.

 

Don

[justthings]

I read this thread with interest and I'm curious about the recommendations for Erik to use a different developer or dilution than what he's using. Isn't the point of this testing to calibrate your film, exposure system, and processing (including specific chemistry)combine to give the results you want? The responses that suggest he alter his developing time would seem to me to be more fitting giving the testing he's doing. Am I off base here? Zap me if I need it!

[erik_reitan]

Thanks for your responses, people. I'm getting very close now; I decided to dillute 1+50 instead of 1+25, since I would then probably end up with a developing time less than five minutes, plus I've heard that rodinal yields slightly less grain at this dillution. At this dillution Agfa recommends an E.I. of 125/160, so I ran a test at 100,125 and 160, reducing developing time by 35%(11 mins) and agitation by 40%. At 100 this gave almost a perfect grayscale, with tonality at Z II, texture at Z III (I used a yellow fabric and foucused this time) and likewise at Z VIII and IX. Zone V ended up slightly darker than the gray card. However, It was hard to see any difference between Zone 0 and I, but I imagine that these deviations might be solved by returning to my normal agitation routine (continously the first minute, than every 30 sec.) I know that zone I is basically determined by the EI, but i'm exited to see how agitation will fit into the equation. Hmmm, complicatetd stuff this zone system (and I haven't even begun with metering, placement of values etc) but with this film testing business i've learned more about the process than I've done in the past 2 years shooting B&W. I'm eager to learn more, so if you people have any other hints i'm greatful to hear them.

[pat_krentz]

Read The Zone VI Workshop by Fred Picker, you can get it through your local library or buy it at B/N, very simple and easy to understand. Pat