PDA

View Full Version : Reciprocity, Contrast & Adjacency



Annie M.
16-Aug-2004, 10:46
I often photograph B&W in conditions of extreme low light... usually my local briny portals to the underworld... sea caves... the realm of reciprocity. I know my prints of this subject are lacking something and I believe it is to do with tonal separation and distribution. I think that my negatives are being skewed by reciprocity. So I am wondering that during exposure when reciprocity increases the contrast of the negative is it doing so in a uniform manner from shadows to highlights?

Also, it is my usual procedure when dealing with reciprocity to develop my negatives to compensate slightly for the increased contrast.... This usually consists of stand development in 2 separate developer dilutions ...I like to boost the concentration with agitation for the first minute or so to give the shadows and opportunity to present themselves (at least I hope that is what is happening). I also assume that I am gaining some adjacency effect from the stand development (does the adjacency effect favour specific areas of the tonal scale?) Is my method totally off the mark for the situation?

I believe my final prints are begging for more mid-tone separation and I am wondering where to begin to modify them while still supporting vigorous shadows (let the highlights fall where they like... they are routinely specular). Are there papers that are more enthusiastic about the mid-tones? Presently I am using Museum Classic (graded) and Agfa Classic. Should I be using a different film developer combinations of TriX/HC110 J&C200/A49? Any thoughts or suggestions on cranking open the mid-tones would be sincerely appreciated.

Cheers Annie

paulr
16-Aug-2004, 11:57
Hi Annie, I don't know for sure what you're seeing, so I'll just throw out some thoughts ...

Of the films you could be using, the ones that would likely give the most ajacency effects are the older, traditional emulsion films. But the ones that would have the best reciprocity characteristics (and the highest effective speed because of this) are modern emulsions (t-max, etc.) This may just be a tradeoff that you're faced with, unless someone else can offer a specific film suggestion.

The stand development you're using (which gives lots of compensation, to keep your highlights from blocking up) works its magic at the expense of midtone separation. Basically, you're expanding the scale in the shadows and lower mids, and compressing it in the upper mids and highlights. Adjusting the internal shape of the scale is tricky, and it can be hard to tell exactly what you're looking at. I'm assuming that spending weekends with test wedges and a densitometer is NOT your idea of a good time.

My first reaction would be to try a film that does significantly better in low light, and then try to develop with a less radical kind of compensation than stand development. A more standard compensating developer at a weaker than normal dilution would be a good place to start.

It's possible to get very beautiful results from t-max, although I find that standard developer formulas (including t-max developer) don't really do it justice. I have some thoughts on how to get a nice compensating scale from t-max, if you're interested, but you'll proably have the time working with materials you're familiar with.

John Cook
16-Aug-2004, 13:01
Having spent most of my life in a commercial advertising studio, reciprocity characteristics are obviously not my forte. However, I do have one or two general suggestions.

You seem to be mixing materials from several different manufacturers and indulging in some unusual, possibly unproven, processing techniques. This creates too many variables to easily solve your problem.

If it were me, Id return to conventional middle-of-the-road materials and techniques. And Id stick with one manufacturer so that I could legitimately bug them for advice. For me personally, that would be something like HP5 Plus developed in ID-11, printed on Multigrade or Galerie paper developed in Bromophen. I would download the pertinent technical pdf files from the Ilford website and follow their instructions to the letter. Then I would begin driving their David Carper nuts with questions.

Or you can listen to us, giving you all sorts of artistic advice. For example, my favorite technique for this kind of photography is to gargle prune juice and spit on the lens just after making the exposure ;0)

Annie M.
16-Aug-2004, 13:33
Looks like my dirty little secret is out.....it is true I lack disciple with my process... making the long exposures for what 'seems' about a minute (I don't own a watch), and indeed I do not get particularly upset if I forget my lightmeter, I just put my finger to the air and use apparent wind speed (results so far seem about the same), if printing is not going well I just slop a little straight Dektol into the mix no matter what developer I started with & I like stand development because I can go and walk the beach while the film develops itself... and if on quick inspection it is not quite right well what the heck, I slop a little drop of Dektol in there too.... And I may as well confess also that I have used pretty well everything that will transmit light as a lens... Including one I carved from ice.

However, I now think I am crossing a threshold .... My work is beginning to sell (really sell not the usual situation where a dinner guest has a bit too much wine during the main course, grabs a print off the dining room wall and tries to stuff an exorbitantly inappropriate amount of cash under the dessert plate) and I have finally begun to really 'see' my prints and I know they can be so much more luminous than they are.

It seems possible that I may be working against myself with the procedures I have been using... but I wish to improve.... perhaps my question should have been what film/developer combination will best support the mid-tones when reciprocity is a consideration. I would certainly be interested in Paul's thoughts on a strategy to get a nice compensating scale from T-max... And I have no problem with going back to basics if that will take me where I need to go.

Thanks, Annie

John Cook
16-Aug-2004, 13:54
Over the last forty years I have, like many of us, spent (wasted) untold thousands of dollars and thousands of hours searching for that magic, secret film and developer combination which will make my prints just sing and glow right off the wall. I have never found it. Now I see the new kids enthusiastically carrying on the tradition.

And yet, I have viewed many hundred-year-old prints made with crummy lenses and crummy film souped in crummy developer which look infinitely better than mine.

You wouldnt suppose its something to do with the technique, not the materials?

paulr
16-Aug-2004, 14:14
I think we're all trying to answer this without knowing what your negs look like or what you want them to look like, so we're pretty much guessing. Before suggesting even more formulas and combinations to throw into the mix, I'll ask this ... are you able to get results that you like when shooting in more normal situations? With some level of consistency? I'm asking just because it's hard to work with too many variables or new tricks at a time and expect to get anywhere.

It's great that you photograph more like a chef than like a propellerhead. Keeps life interesting. There are some areas, though, where a chef needs to button up the technique and do things systematically ... pastries come to mind. When you're trying to fix issues like reciprocity departure and the internal shape of your film's scale, it might be a time to take a deep breath and get more systematic with your approach. It can feel like a drag when what you really want to be thinking about is your work, but in the end it can save a lot of time and grief.

Anyway, if you're open to mixing your own developer solution, I can give you a formulat that has worked for beautifully for me with T-max for a wide range of contrast situations. If not, I'd suggest liquid concentrate developers that lend themselves to high dilution, like rodinal (friends have had amazing results with this) or maybe even HC110.

Another resource is Bud at Photographer's Formulary (photoformulary.com). He often has good tips.

Ben Calwell
16-Aug-2004, 14:24
Annie, you sound like my kind of photographer. I can't speak with the same "tested to the 'enth degree" precision that some of the other more learned posters can, but in my experience, for really long exposures of a minute or more, I've used HC110 diluted 1:31 (from the stock, not the syrup) and given my Tri-X 4x5 about 20 minutes with agitation every three to four minutes (ala Ansel Adams in his book The Negative). I use this development scheme when I desire great shadow detail in a scene in which there are also important high values that would blow out with "normal" development. I've also learned through trial and error that even if exposures are really long, if the scene brightness range is really quiet and low, you can develop with a full strength developer and maybe cut back just a minute or two. As an example, I once photographed a landscape that was illuminated just with the light of the Western sky after sunset. As I recall, the exposure was in excess of several seconds, but the SBR was pretty low, as I recall. In spite of the long exposure, I used my HC110 full strength and just cut back on the time a little. It gave the negs the added punch they needed in that subdued light. You mentioned that your highlights are specular, so there's no point in trying to reign them in with stand development. Even if your exposures are long, you might get the better mid-tone separation if you try a more "normal" development procedure. It could be worth a try just to see.

Ole Tjugen
16-Aug-2004, 14:30
My "Standard Magic Bullet" is traditional film (APX100 - still have a few boxes left, EFKE PL100, Ilford FP4), developed in half-strength FX-2. I use a JOBO25something, and let it sit for up tp an hour: Presoak 2min, one minute with agitation, sit for 20 minutes, 30 sec agitation, then leave it until it's done.

So far this has given me good compensation without flattening the midtones.

Another way is to use a compensating developer like Windisch' Pyrocatechin or Maxim Muir's "modernised" version. I use that for extreme contrast range - one case was a partial solar eclipse. I got detail in the foreground as well as visible sunspots!

Annie M.
16-Aug-2004, 15:12
Paul... My negs are quite consistent and all the information seems to be there.... no gaping holes in the shadows and no major pileups in the highlights. My prints do not scream 'genius' and the curators of the MOMA are not breaking down the door....but the prints are interesting ($500 worth of interesting to some) and I have progressed beyond mud in the middle tones. At this time I am struggling with the particular problem of reciprocity and midtones... I just do not have the experience (I have been photographing for less than 2 years, learning on my own) to know how to augment the process to maximize the middle. I have a cupboard full of the usual chemistry in the darkroom so I am sure I can mix up most formulas (except Pyro).

Thanks for the other suggestions..... I will expose a stack of negatives and test your development ideas... It would be wonderful if I could push this particular subject into something sublime. Thanks again for taking time to assist me.

Annie

...... You know I am thinking it might be time to take my stuff to a workshop and get some input.

Donald Miller
16-Aug-2004, 15:42
Hi Annie,

My thoughts on your situation are these. The effects of the lengthy exposures one encounters in low light situations is favoring an increased density to the hightlights. This builds contrast. Typically in low light situations one would increase exposure to support low values and then compensate by reduced development. The reduced development will affect the negative high density regions first.

What I am thinking that you are experiencing is a reduction in local contrast when you are attempting to bring overall contrast into the realm of the paper's exposure scale. This is nothing new. In an attempt to achieve the elusive "glow" in our prints we are continually struggling with achieving desireable local contrast while attempting to hold overall contrast.

There are several ways to accomplish this. The first is by pre-flashing the paper. This will compress highlight values downward...allowing a higher paper grade or filtration and hence increased local contrast.

The second way is sharp shadow masking of the negative. This compresses shadow tones upward and once again leads to the ability to use higher contrast printing materials. Hence increased local contrast.

The third method is to unsharp mask the negative at the printing stage. This collapses the overall contrast of the negative and once again allows for the use of higher contrast printing materials. This method will also provide increased apparent sharpness akin to the adjacency effects that you enquired into.

My thoughts are that normal human visual acuity is more discerning of proper highlight separation then of proper shadow separation. This leads me to favor shadow or unsharp masking at the printing level.

As others have indicated, the adjacency effects that I have experienced with minimal agitation procedures have been most pronounced with old emulsion films. In my experience Efke PL 100 in combination with Pyrocat HD 1-1-150 is incredible in this regard.

Good luck, Donald Miller

Sal Santamaura
16-Aug-2004, 15:46
One approach to dealing with reciprocity problems is using a film that's virtually immune to them: Acros. Fuji specifies no exposure correction at all up to two minutes, then a mere 1/2 stop increase from 120 through 1000 seconds. Development adjustment is not required.





I posted Acros development/printing information in a recent thread (http://largeformatphotography.info/lfforum/topic/498673.html). Tonality is satisfying to me with this combination, but only you can decide if it's what you're looking for.

Andrew O'Neill
16-Aug-2004, 15:50
Hi Annie,

Maybe you should get a good grip on the reciprocity characteristics of your film of choice. Test it. From what I remember years ago using Tri-X it loses a lot of speed and its contrast increases with long exposures. I never really liked Tri X's mid tone separation to begin with so I switched to HP5+ about 7 years ago. This film has good separation in the mids. I've developed it in almost everything including HC110 at high dilutions and it's beautiful. My favourite developers are Xtol and Pyrocat-HD, at various dilutions, in trays or tubes, constant agitation, a little agitation and stand. Xtol gives better midtone separation than Pyrocat. HP5+ has much better reciprocity characteristics than TriX and contrast is constant regardless of how much exposure given. I used HP5+ in old dark coal mining buildings in Japan for years, with exposures ranging up to 4 hours and got great results. I usually print on Forte Polygrade V or Ilford MG IV fibre base. If you've never tried Polygrade V you should....it's grrrrreat! If you're ever in Coquitlam area I'd be happy to assist you as much as I can!

Cheers!

Andrew

paulr
16-Aug-2004, 15:56
my first suggestion would be to try t-max 100. At long exposures, because of its better reciprocity characteristics, it will actually be a faster film (and a more predictable one) than tri x.

rodinal might be the easiest thing to experiment with. it's not at all a fine grain developer, but the grain looks nice on tmx, and the sharpness and speed are both excellent.

what i've worked with most is the formula called GPQ, which you can find here: http://www.nationalacademyofphotography.org/os-dev.html this was formulated specifically for t-max, and gets really nice shadow and midtone separation without blocked highlights. i find the speed to be average with this formula at its normal strength (around asa 50).

there's also a mix-it-yourself formula for rodinal on that page.

i'd experimient with both at the weakest dilutions (assuming you have highlight that need to be controlled .. otherwise stronger dilutions will give you better separation).

it might be worth it to borrow a watch (or an egg timer, or hourglass .. ) to keep the shooting and developing consistent, just so you don't lose your mind while experimenting.

that's the best i can do for now with what i know. let me know if you have any questions!

Ralph Barker
16-Aug-2004, 15:59
Without knowing the details of the scene lighting ratios, along with the specifics of your procedures, Annie, it's difficult to make anything but generalized suggestions.

While you might benefit from "going back to basics" and taking a more traditional or disciplined approach, it sounds like what you're doing is (almost) working for you. Thus, you might be better served by trying some variations on what you're now doing. You might, for example, experiment with augmenting your stand development with measured increments of mild aggitation, and see what that does for you. Or, you might try mixed-filter VC printing. Or, maybe a little rubbing of the mid-tone areas of the print during development.

For really sublime seaside cave images, though, you might need to add babies hanging in cheesecloth hammocks attached to the cave ceiling. (lol)

paulr
16-Aug-2004, 16:05
there's more detailed info here: http://www.jackspcs.com/gpq.htm

Robert Musgjerd
16-Aug-2004, 16:45
I too photograph in very low light most of my exposures are in the 15sec to 3min range I shoot 11x15 and print in platinum I try to keep things simple I shoot Bergger and develop in rollo pyro I also follow the reciprocity corrections from the mfg as well as compinsation for bellows draw I have found this combination to give me great highlights woderfull midtone seperation as well as good shadow detail No magic bullet just what works for me Good luck

Chris Gittins
16-Aug-2004, 17:21
It sounds like it would be worth your time and effort at this point to do some materials testing. It is a lot of work and not much fun, but from how you describe the problem it sounds to me like a little testing could pay big dividends. If you're not inclined to do full-blown sensitometry, I've found that you can draw most 'big picture' conclusions - for example, what works and does not with respect to improving mid-tone separation - by eye just looking at test sheets.

Chris

PS I'll second John Cook's recommendation of HP5 + ID11/Dektol with Ilford paper - very flexible combination.

Annie M.
16-Aug-2004, 19:44
I have low enough tides for 5 days (20 hours of early morning light bouncing in from the surface of the sea) at the end of the month so I'm going to shoot a few boxes of the films with more favourable reciprocity characteristics as well as a few boxes of what I am familiar with and do a lot of double bracketing. That should give me lots of fodder for tweaking a few developers, then I can hopefully link up to one of the papers I favour.... plus I have Don's masking technique in my pocket just in case.

I hope I can nail it because this winter is when the real reciprocity fun begins..... The low tides come in the middle of the night and the light that bounces into the caves is from the moon..... It is very lovely tiptoeing along a midnight beach with a wee krypton sunbeam strapped to your head.

Cheers..... you are all great!

Chris Gittins
16-Aug-2004, 20:10
> PS I'll second John Cook's recommendation of HP5 + ID11/Dektol with Ilford paper - very flexible combination.

Sorry, I meant D-76 not Dektol with HP5. Multigrade and Galerie work well with Dektol.

Jim Galli
16-Aug-2004, 22:17
Couple more ideas. 1) Unsharp masks can do phenomenal things. 2) I was flabbergasted (yes, flabber-d-gasted) the other day after I'd done a days work on interiors guessing that Fuji Acros was probably just like boring old Kodak film. I hadn't read the spec sheet so was doing my usual reciprocity thing. 1:1 2:3 4:7 8:19secs etc. So after the fact I finally read Fuji's sheet. Up to 120 seconds with no reciprocity. IMPOSSIBLE i said. So I set up a shot in my shop and did five sheets. 1 sec thru 120 sec of the same scene, just stopping down. D76 for whatever Fuji said and SHAZAAM. They're all the same. Nice film. Damn expensive, but the US taxpayers are paying for it.

Diane Maher
17-Aug-2004, 10:23
This is an interesting thread, as I don't really understand the whole reciprocity thing. I use mostly FP4+, but like to do some IR too. Times with the IR film usually are at least a half second to one second with an 87 filter.

What is adjacency?

Annie M.
17-Aug-2004, 12:35
OK ....I had a few boxes of 4x5 Tmax pouting next to the Klondike bars in the deep freezer... I had never bothered with this film because of all the snivelling about grain structure, pink dyes and blown out highlights. I have only pulled a few proofs (Agfa Classic).

Tmax loves water and the early light..... It absolutely glides along the meniscus of the sea and laps up every nuance of light from the wet beach rocks. I used Xtol 1:1 (looking forward to trying Paul's formula also) and Agfa FX-universal, no pink, no pin holes, no blow-out, no strange grain at the size I am printing.

Ralph Barker
17-Aug-2004, 18:38
Diane - reciprocity, or more accurately, reciprocity failure, is a film characteristic that could be said to require long exposures to be longer than long to be long enough. Unlike short exposures, where one increment of exposure time is equal to a reciprocal change in f-stop, with long exposures, this reciprocal relationship fails, hence the term. It (reciprocity failure) varies with each film, and requires some adjustment in exposure to compensate.

The underlying cause of reciprocity failure might be described as being a function of the "energy" of the flow of photons hitting the film. With long exposures - those with just a trickle of photons, you might say - the energy level is less, so it takes more to effect a change in the emulsion. In contrast, a short exposure would be more like a firehose of photons - lots of energy where the reciprocal of f-stop and time hold true. Some films start to show reciprocity failure with exposures longer than 1/10th of a second, others around the 5 or 10 second mark, and a few with exposures as long as 120 seconds. With FP4+, exposures longer than 1/2 second will require some adjustment, for example. Check the individual film's spec sheet for its characteristics.

Adjacency, sometimes called "edge effects" or accutance, is essentially the abruptness of change in negative density that corresponds to different tonal values in the scene. (At least that's how I've always understood the term.) Thus, negatives with "good" adjacency appear "sharper", while low-adjacency negatives appear "softer". In scenes where the variations in tonal value are subtle, such as Annie's cave pictures, adjacency is probably more important than with higher-contrast scenes.