Testing J&C Classic 200. Same as BPF 200?

[sanking]

Let me add to the previous message that stand develoment is more appropriate for printing with reglar silver gelatin papers than with AZO. I doubt very much that you would be able to get a high enough CI for AZO using a 3:3:600 dilution of Pyrocat-HD with stand development.

I am really not sure what you hoped to achieve with this extreme dilution, assuming the final objective is AZO printing. My tests would indicate that you could handle an SBR of 9 with the 2:2:100 dilution of Pyrocat-HD with a development time of around 7-8 minutes. This should give you a negative with a DR of about 1.3 (Visual) or 1.6 (Blue) that would be just about right for AZO.

 

[Francesco]

My metering method: I use a 1 degree spot meter to measure the Exposure Values of those areas in the scene important to me. The lowest and highest EVs give the scene's SBR. In this particular case where the SBR = 9, the lowest EV value was 10 and the highest 14. I exposed at f. 45, 2 seconds (I would think that this is quite a reasonable amount of exposure). It was a very sunny day and the scene was a cluster of trees in a dense forest. It is that time of the year when I am inspired to take bright sky scenes together with deep shadowy tree formations.

It seems that I have been encountering wide SBRs of late. Over the last month or so I have typically been developing negatives with SBRs of 9 and 10. Twice I have tried a negative with an SBR of 11 and 13. Maybe I measure the scene overzealously while at the same time overestimating the exposure range capabilities of the film.

As regards the extreme dilution, I was just curious as to how effective or potent PYROCAT HD would still be (target negative = silver printing). I am quite happy with the 1:1:100 and 2:2:100 dilutions, which are quite economically already. Just pushing the envelope even further on such a versatile developer.

 

[Donald Miller]

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[Francesco]

An SBR of 4 would imply an extremely low contrast scene. The scene I have referred to above was definitely contrasty, much more than normal. Even without using a meter I can observe (and remember, as I shot this scene yesterday) that there was a significant difference between high and low values.

As regards my technique, I have been using this metering method since taking a BTZS workshop back in 1996. It has not let me down yet. Recently I have decided to switch to Pyrocat HD and Efke and Classic. But rather than play with a densitometer I thought it would be more fun to take actual pictures (2 to 4 shots same scene, same exposure) and experiment with dilutions and times. This is why I have been interested in specific instances of high SBRs (plus the fact that Stockholm archipelago is quite contrasty during clear, sunny days). I initially started with extensive BTZS tests for TMX and HP5. Using this metering method together with the data and charts for development times and SBRs matches well the rule of thumb ("...plus 5") that you mentioned.

I just do not see how what I saw yesterday translates into an SBR of 4. Not with that kind of sunlight.

 

[Jorge]

Hmm...seems to me you have modified the BTZS method to fit your particular way of working. Other than using Phil's formula to translate "zone" readings into SBR readings I have not heard of another useful method.

Is this how you ar egtting your SBR readings? by converting zone readings with Phil's formula?

 

[sanking]

Hmm...seems to me you have modified the BTZS method to fit your particular way of working. Other than using Phil's formula to translate "zone" readings into SBR readings I have not heard of another useful method.

Is this how you ar egtting your SBR readings? by converting zone readings with Phil's formula?

A few points.

I use reflected readings for calculating N values but only incident readings for calculating SBR values. Calculating SBR values from reflected readings or N values from incident readings might work with some subjects but with most scenes it would involve some type of conversion factor that would make exposure determination very complicated and prone to misinterpretation. Which is one of the reasons I use the Expo/Dev program for figuring exposures -- you choose either the SBR or N system and the program does the rest.

About the SBR of 4, there is no such thing. All subjects that are evenly illuminated (assuming no glare or flare) will fit into a five-stop luminance range, which is two stops less than the normal SBR of 7. Thus, for all practical considerations an SBR of less than five is impossible. Even a real five is highly unusual as in even the flattest of lighting situations I rarely encounter scenes with SBRs of less than 5.5.

Finally, one of the dangers in working with either the N system of SBR sysem is misinterpretation which can lead to an exaggeration of the difference in luminance in the scene and to inflated values, both high and low. A typical example with the SBR system, for example, would be in an outdoor scene in full sun but with some deep shadwos( as in say a recess in a boulder). If you were to meter the deepest shadows of the recess your readings would provide a SBR that is greater than it should be and this will cause you to both over-expose and under-develop your film.

 

[Francesco]

Yes I do modify my readings a bit (because I use a spot meter to get to my SBRs) in order to avoid wrong exposure. It depends on the absolute values that I get. To give one example: I would expose differently for an EV range of 11 - 15 as opposed to 7 - 11. If I were to give both scenes the same exposure I find that I overexpose (still, better than underexposure) on the latter. I would give the first one an SBR of 9 and the second one an SBR of 7. I adjust my SBRs based on the overall level of contrast in a scene. It is not fool proof but that just makes it more fun.

Sandy, how do you avoid this misinterpretation of inflated values? Is it simply a matter of careful selection of the high and low areas?

 

[Francesco]

In any case, my original mistake was using an extremely low dilution of Pyrocat HD on Classic 200 for a scene that really did not need it. I also underestimated the time needed for the film to develop at such an extreme dilution. So far it seems that Classic 200 likes the 2:2:100 dilution much more than the others I have tried (1:2:100, 1:1:100). Does this mean that Classic 200 is an excellent film for PtPd?

 

[Francesco]

Just tried Classic 200 (rated 200) on a neg exposed for SBR = 10 and Pyrocat 2:2:100. I used very gentle agitation on BTZS tubes for 5 mins and the results were stunning! Also did SBR = 9, 6m30s and had same success.

Thinking of giving Classic 400 a shot using the same guidelines. Any thoughts or experiences?

 

[sanking]

Just tried Classic 200 (rated 200) on a neg exposed for SBR = 10 and Pyrocat 2:2:100. I used very gentle agitation on BTZS tubes for 5 mins and the results were stunning! Also did SBR = 9, 6m30s and had same success.

Thinking of giving Classic 400 a shot using the same guidelines. Any thoughts or experiences?

For the same conditions try increasing development time with the Classic 400 about 15%.

 

[Francesco]

Thanks Sandy. Will do. I will expose for the rated film speed of 400. I love the way Pyrocat allows for the use of the rated film speed.