Agitation Question

[N Dhananjay]

I like my negative to be developed as close to a straight line as I can. It is rare for me to deal with photographs where the highlights are small and fall out of the scale of the paper. Usually, if the highlights of the negative falls out of the range of the paper, I prefer to rely on dodging and burning. My reason for this is that the local contrast stays even through as much of the scale as possible (i.e., the toe and shoulder are minimized as much as possible). Its just the way I like my prints to look. Keep in mind that I contact print.

Getting this to wrk has been difficult. HD curve shape appear to be primarily an emulsion characteristic. I've never had much luck with changing the curve shape in any significant way, although from various reports, it sounds as though older film such as Super XX were probably more responsive in this respect. The TMax 400 was mostly all straight line, but most modern films were pretty good - their Dmax was so high that the shoulder was a non-issue and you could choose based on toe shape and other things you cared about. I did some tests a long time back with different agitation schemes and read the densities and did not see much evidence of changes in curve shape - it was just the slope of the curve which changed. So, I concluded that there was not much to be gained by this because if the look of the final print is a combination of two slopes (the slope of the film and paper curves), lowering one while increasing the other (N- film development with higher contrast paper) would be a wash (barring any minor changes due to the inevitable changes in the toe and shoulder). I can see that some prints might be impossible to dodge and burn (although dodge burn masks used with a pin registration system can be pretty accurate) but for the most part, I decided it was simply not much use for my work. However, to a certain extent, I am exaggerating. Its not straight line HD curves per se - developing to a somewhat high contrast and using contact printing processes (with a paper capable of holding a longer range of negative densities) minimizes the area of the toe and shoulder. The problem I usually have is the fact that I cannot get to higher contrast negatives (N+ developing) since modern films appear to have lower gamma infinities.

I hope the clarifies the meaning of my earlier post. Cheers, DJ

[N Dhananjay]

I also wanted to add (as pointed out by Steve and Doremus) that any curve shape due to agitation requires careful massaging - it will only work if you restrain highlights while allowing shadows to develop to completion. Usually this requires considerable increase in exposure to support the shadows and fairly extreme reduction in agitation. My guess is that some of the creative control has been 'removed'/reduced by manufacturers to ensure repeatable results for people with less than perfect process control - it ensures that most people get repeatable results.

Also note that most people appear to use these techniques to control subject brightness range (SBR) whereas they are actually techniques to control local contrast - increasing local contrast in the shadows while reducing it in the highlights - what I have come to regard as a robbing Peter to pay Paul game since it appears to complicate my life unnecessarily. If you have a long SBR, you can do an N- development but that will result in lower contrast throughout the scale - in effect you steal a bit of local contrast through the entire scale and use it to accommodate some more tones at one end of the scale. I have never had much luck getting satisfactory (for the way I want my prints to look) results this way. I prefer trying to use filtration to control contrast where I can and with judicious dodging and burning.

This is not a technical issue but an aesthetic one. Any medium has a limited range and cannot accommodate the huge SBRs we encounter in the real world - painters have it worse, their material can probably accommodate only a range of about 1.5 D compared to the 2 D and higher ranges photographic material can accommodate. They have come up with clever ways around this - playing sophisticated games with local contrast, adjacency effects and the like. Those are lessons we might be well served by studying.

Cheers, DJ

[Steve Sherman]

Sp picking up on what people are saying... In an opposite scenario (Flat lighting very low subject brightness range) using a semi-stand type development with little agitation is going to be of no use what so ever, in fact, it may produce even flatter looking negatives ?

Actually, and respectfully submitted the reasoning you suggest is exactly opposite of what I find to be the benefits of any Minimal Agitation forms of processing film. I am going to expand on my reasoning in a general post right now at the end of what has currently been offered by those participating in this thread.

[Steve Sherman]

There has been a lot of opinion and reasoning offered in this thread and I believe where the thread has gotten off track and is confusing to those possibly not as versed in Minimal Agitation forms of development is in terminology.

Reduced Agitation we all know effects the highlights first and to the greatest degree. So it is natural to assume that Semi-Stand is a form of reduced agitation, no debate. What gets left out of that "general" reference is True Semi-Stand or Extreme Minimal Agitation forms of development go well beyond just reducing the densities of the most highly exposed areas of the negative, S-S and EMA forms of development are designed so a delicate balance of Dilution, Agitation Infrequency and Length of time in the Development stage rely on the Developer exhausting at some point during the "standing" portion of the development time. Only when Developer exhausts can Adjacency Effects happen, they happen in varying degrees dependent on the ratio of strength ( how dilute ) length of time between Agitation cycles which are usually only 10-20 seconds and how often this developer exhaustion can happen during the total processing time. Once Adjacency Effects happen the Lower and Mid Tone densities take on an exaggerated separation or some would say the "Impression of higher Acutance" There in lies the exact reason why with very flat lighting and a low contrast scene the very best way to expand the final contrast appearance in the print is to exaggerate the Mid Tone separation and resulting contrast. So, while the amount of tonalities actually sitting on the straight line or slope of the films curve may not make up much difference from the lowest to highest, S-S and EMA forms of film development when the developer is by design allowed to exhaust the actual straight line or slope of the H&D curve is altered, the slope becomes steeper and it most clearly seen in the Low to Mid Tone contrast.

So in summation, if the very low contrast scene's lowest values are placed on the very beginning part of the straight line of the film's curve and the actual highest measured density of the scene is controlled to fall within the end processes capability to render tone in the highlights the Mid Tones are exaggerated to the point where the print becomes a full range print with deep shadows and well controlled highlights and the Mid Tone relationships are a result of Adjacency Effects that are a direct result of Developer exhaustion. Each scene's actual contrast will dictate how to process the film but ultimately the Highlight must stay in a printable range for your final medium, whether it be Silver or Pt. / Pd. As I stated in an earlier entry, I just released a 20 minute video that will explain in detail with side by side comparisons of 7x17" negatives, one tray agitated the other Semi-Stand processed for 45 minutes There are scores is not 100's of photographers talking about Semi-Stand or EMA forms of development, very rarely do I hear any reference whatsoever to the single most important part of the technique, that the Developer must exhaust for any Adjacency Effects whatsoever to happen.

I hope this clarification on terminology is helpful.

Steve Sherman

[Pere Casals]

Actually, and respectfully submitted the reasoning you suggest is exactly opposite of what I find to be the benefits of any Minimal Agitation forms of processing film. I am going to expand on my reasoning in a general post right now at the end of what has currently been offered by those participating in this thread.

Hello Steve,


I find very interesting your point of view. You make clear that agitation is a major tool in certain conditions.





I wanted to know how your processing modified images and I took an screenshot and compared histograms, well, IMHO difference is great and non trivial.

We can modify the second image with PS to make it match to the first one. It can be done, but it's difficult to obtain a really perfect match. Also IMHO microcontrast if different.

So now I see minimal agitation as a power tool to obtain nice pure optical prints. I'll add that to my learning program, with CRM/SCIM.


Thanks.

Best Regards

[Steve Sherman]

Hello Steve,


I find very interesting your point of view. You make clear that agitation is a major tool in certain conditions.





I wanted to know how your processing modified images and I took an screenshot and compared histograms, well, IMHO difference is great and non trivial.

We can modify the second image with PS to make it match to the first one. It can be done, but it's difficult to obtain a really perfect match. Also IMHO microcontrast if different.

So now I see minimal agitation as a power tool to obtain nice pure optical prints. I'll add that to my learning program, with CRM/SCIM.


Thanks.

Best Regards

Thank you Pere, I'm not much of a PS guy, I know enough to get my images up to the web but am grateful that even on a computer screen the difference in Mid Tone or Micro Contrast whatever one chooses to call is detectable and has been borne out by your test !

Many thanks, SS

[IanBarber]

Thanks to everyone for their input, much appreciated and informative.

Enjoyed your video Steve about your process

[Steve Sherman]

Thanks to everyone for their input, much appreciated and informative.

Enjoyed your video Steve about your process

Thank you Ian for your kind words, and I will again thank Pere Casals for the Histogram analysis he provided as I believe this provides clear validation for the Minimal Agitation process is in fact a powerful technique and will begin to validate for the Non Believers who still remain. It's my hope that the entire thread has been a reward for all who have participated

Cheers !!