Hello all,

I've just moved up to LF from MF and have got to get used to the joys of non-TTL metering again. I have some idea on the workings and aims of the zone system but as I generally take architectural shots inside dark / dingy churches, I have to compensate for reciprocity failure. I'm using B&W negative film, usually Delta 100. My problem is understanding whether the reciprocity correction makes any difference to the negative contrast and, if so, how to get around it. For example, I might have a 5 stop contrast range in a picture, I can meter for the highlight and put it on zone viii or meter for the shadows and put it on zone ii and get an equivalent zone v reading. (I suppose I should use the shadow reading to get to zone v reading rather than the highlight reading with respect to the "expose for shadows, develop for highlights?") Do I then just add on the reciprocity compensation for this zone v reading or do I have to do something else?

Any help appreciated if you can understand the above. Thanks.

-- Andrew Pell (adp88@btinternet.com), April 07, 2001

Answers

A good starting point for you might be Using The View Camera by Steve Simmons. In it he has a table of reciprocity corrections and recommended development time adjustments. The way I've been doing it is to meter the shadows and place them in zone 3 then adjust dev. time according to the contrast range after adjusting for reciprocity. In other words I might reduce dev time by 5% for reciprocity then 15% for n-1. But as I am still a LF rookie my times are still being experimented with. Rob

-- Rob Haury (rdhaury@home.com), April 07, 2001.

Thanks Rob, it looks like I'll have to carry on with cutting the development time. I've used approx 10% less to date but that was with my Bronica and I knew the lenses were contrasty as well as the light via my previous metering technique (meter and expose for shadows and try to get the highlight detail back via development and split grade printing) which, overall, is trying to rescue high contrast negs. I need to get enough shots done to do a proper LF test instead of giving myself printing headaches.

-- Andrew Pell (adp88@btinternet.com), April 07, 2001.

Reciprocity will influence negative contrast. The reason is that the highlights are less affected by reciprocity failure than the shadows. Exposure, though is typically based on shadows to ensure adequate density in the shadows. However, what you place on Zone VII may not need any reeciprocity correction (or less than required in the shadows). The nett result is that what you place on Zone VII is actually higher on the scale. Typical advise given is to increase exposure by about a stop beyond 1 second exposures, by 2 stops beyond 10 seconds and by 3 stops beyond 100 seconds (these are just rules of thumb - its worth checking your film's data sheets). Corresponding changees to deevelopmeent are 10% less, 20% less and 30% less. Again, worth testing. Good luck. DJ

-- N Dhananjay (ndhanu@umich.edu), April 07, 2001.

I have a reciprocity table on a label on my lightmeter. It is for HP5+ to be developed in PMK and beginning at 8 seconds (which adjusts to 19" seconds) I deduct 5% of development time. That is, I deduct 5% after deciding which time (i.e., which zone) in which to place the highlights. The far end of the table is 4 minutes adjusted to 3 hours, 10 minute and minus 30% of development time.

Don't know what I'd do if I wanted to do N-3 (about 5 minutes I think) and also needed to deduct 30% of that time!? But I cannot think how an extremly high contrast scene would need such a long exposure anyway.

The bottom line is you do need to take both elements into account in turn. It is analogous to bellows factor plus a filter factor.

-- John Hennessy (northbay@directcon.net), April 08, 2001.

Gentlemen;

Reciprocity failure is the breakdown in the linear relationship between aperture settings/film in regard to it's ability to record detail. Corrections for long exposures must be done IN THE CAMERA, by increasing exposures. Adjusting development will do nothing for a negative that is underexposed due to lack of correction in exposure.

-- Matt O. (mojo@moscow.com), April 08, 2001.

Matt, reciprocity also have an effect on the negative contrast. Because the shadows on the negative are hit by light of less intensity than the highlights, they are more affected by reciprocity failure. Thats why the contrast of the neg increase, and we need to shorten dev time to compensate

-- Lars Hagglund (laha@ljusdal.se), April 08, 2001.

I have several generic reciprocity tables for all films other than T Max (T Max films have their own reciprocity tables since they are less affected by reciprocity failure than other films). These tables were taken from several sources (a workshop, a magazine article). I've been using them for several years with HP5+ film and they seem to work well. FWIW, these tables show the following effect of development on reciprocity failure: no change in developing time until the metered exposure is 15 seconds (resulting in a 27 second exposure to take reciprocity failure into account). If developed normally, the resulting negative will be the equivalent of N + 1/2 so you reduce development accordingly (unless, of course, you want N + 1/2 contrast in the negative). When the metered exposure is 30 seconds, the actual expsoure time is one minute and the resulting development will be the equivalent of N + 1 so again you reduce development time accordingly (unless you want N +1 contrast). If the metered time is 2 minutes, the actual time is 6 minutes and the resulting development will be N + 1 1/2. If the metered time is 4 minutes, the actual time will be 15 minutes znd the resulting develoment will produce the equivalent of N +2. If the metered time is 8 minutes the actual time will be 35 minutes and the resulting development will be the equivalent of N + 3. That's as high as my tables go. You exrapolate for times in between these times.

-- Brian Ellis (bellis60@earthlink.net), April 08, 2001.

Andrew:

Just because the increase in exposure necessary to compensate for reciprocity law failure in the shadow areas will cause an increase in the overall contrast of the negative does not necessarily mean that it will be necessary to reduce development times. As a matter of fact, I have found a number of situations where an increase in development time was called for because the increase in contrast was inadequate to provide adequate overall desity range in the negative. It is not unusal to find a dimly-lit scene that does not have an adequate brightness range to provide the wanted density range in the negative even after the increased negative contrast resulting from the compensation for reciprocity law failure.

Let me give you an example. Say you have found a dimly lit scene that has shadows that are placed on Zone III of the exposure scale. Let us also say that the highlight areas of the scene fall only on Zone V (this is not unusual since a lot of dimly lit scenes are also rather softly lit). Let us say (for purpose of example) that this Zone III placement indicates an exposure time of 1 second at whatever f/stop we have elected to use (we MUST expose correctly for the shadows since, if we don't get the detail there through exposure, we won't be able to get it there at all). If we are using a conventional type of B&W film, we would probably find it necessary to give 2 seconds of exposure in order to compensate for reciprocity law failure in the areas of the projected image that fall in Zone III or lower.

Now, let's take a look at what is going to happen in the areas of the projected image that will fall in Zone IV and higher because of our Zone III placement of a particular shadow area. Since these brighter areas of the scene are at least one stop brighter than the Zone III area, these areas would have indicated an exposure of 1/2 second or less if they had been placed in Zone III. Therefore, these higher- falling Zones will not suffer from as much reciprocity law failure. As a matter of fact, in this particular example, they will, for all practical purposes, suffer from no reciprocity law failure at all. When we give a 2-second exposure to our negative, the areas falling in Zone IV and higher will actually get a full 2 seconds worth of exposure while the areas in Zone III and lower will get only 1 second worth of exposure.

The result of this will be that the areas falling in Zone IV and higher will get 1 additional stop worth of exposure. This will cause these areas of the negative to gain about 1 stop worth of additional exposure and resultant density. In other words, the highlight areas of our scene that fell in Zone V will get moved up to Zone VI. We must now determine if this resulting Zone VI density is appropriate. If we feel that it is correct, then no compensation in developing time is necessary. If we feel that the highlights should fall higher than Zone VI, then we must increase our development time. If we feel that the highlights should be darker than Zone VI (possible, but unlikely), we would then (and only then) reduce our development.

This is only an example of a single situation where reduction in development times could be disasterous! There are, however, some situations that will absolutely require a reduction in development times. In those situations, failure to do so can also be disasterous! And there are situations that will require no compensation in development time at all. What all of this means is that each situation encountered must be analyzed individually and handled individually. There are no rules-of-thumb that apply to all situations.

-- Ken Burns (kenburns@twave.net), April 08, 2001.

Thanks for everybody's answers so far.

Brian: From the reciprocity corrections and contrast increase, I'd assume that if a 30sec metered exposure plus reciprocity gave an N+1 contrast level, developing at N-1 would bring the contrast back to normal? I have an Ilford data sheet and have calculated the reciprocity curve but never really used the contrast / time curves apart froma a blanket "knock a minute off to stop developing the highlights." (Also, is N+1 the same as producing a contrast equivalent to 1 grade higher on multigrade / varicontrast paper?)

Ken: I understand your reasoning about wanting to increase development times if you have a flat subject to create contrast, i.e. forcing tones to lie on more separated zones. The problems I normally encounter are trying to flatten the contrast in a scene. My scenarios usually involve the dimly lit church having a dark oak altar below a stained glass window (hopefully I'm taking pictures on an overcast day but it doesn't always work out like that and I have to try to stop the window burning out and still get the shadow detail on film as you say - if it isn't there, you can't print it in.

At the moment I'm using a roll film back on the camera. It looks like I'll have to go to sheet film for some trials as I can't afford some more backs to label each one for different development / contrast settings. I'll have to dig out the old grafmatic backs.

Andrew

-- Andrew Pell (adp88@btinternet.com), April 08, 2001.

Andrew:

Yes, the situation you described is most definitely going to have an excessive range of overall brightness. In this type of situation, exposure will be extremely critical since any underexposure at all will result in total loss of shadow details. I would definitely advise basing the exposure on Zone III areas or lower. Such exposure will defintely dictate compensations for reciprocity failure. With some careful analysis of the particular situation you are dealing with, you should be able to accurately predict the ultimate Zone placement of the highlights.

Whether you shoot on a cloudy day or a sunlit day could turn out to be quite critical in determining you success. If you work on a sunlit day it is quite possible that N-1 or even N-2 development could still be quite excessive. Have you worked with any manipulations in your development techniques? Agitation, dilutions, etc?

-- Ken Burns (kenburns@twave.net), April 08, 2001.

Ken,

I've always used ID-11 at 1:1 dilution and developed for 9 mins (10 mins standard time) to try to reduce the highlights. Other than that I tend to stick to the indicated agitation periods / durations and temperatures.

I'd seen a report or two about the Barry Thornton DiXactol single / two bath developer but haven't tried it. On his instructions he mentions that N+1, N-1 isn't easy to control via time due to chemical exhaustion and to use dilution instead. This could be another option for me to investigate at some point.

As for the sunlight level, I sometimes can't win. The best time is when it's either very foggy or throwing it down with rain. The problem then is that in the larger cathedrals, people come in for shelter and long exposures are a pain as there's too many people around. As I have to work for a living (not in photography) I can't get to places during the week when it would be quieter.

Andrew

-- Andrew Pell (adp88@btinternet.com), April 08, 2001.

I was thinking about your subject matter. Have you considered trying some double exposures? Take the first picture in daylight and metre for the hihglights (the windows) then wait for night fall and do the second of the interior (lit by interior lighting) You would probably still have some reciprocity failure to deal with but you should get a much more normal contrast range. Rob

-- Rob Haury (rdhaury@home.com), April 08, 2001.

Try some pre-exposure and place the shadows on Z4 because the shadows will lose density when you contract your development. Use a low contrast developer or dilute developer. You can also use an old emulsion film such as fp4 or TriX and use stand development to try and build your shadows to their fullest extent while keeping your highlight densities under control. On top of that try making a contrast mask for those pesky windows and then print at a higher contrast to help bring out the detail in the shadowed alter. You can also use some selenium toner on the shadows to help build density so the contrast range between the highlights and shadows is lessened. Or try PMK Pyro which will develope with a stain which will self mask some of the shadows. You can also bleach some of the dense highlights on the neg. But I would go to sheet film and process accordingly. I use a lot of pre-exposure to help tame highlights when the contrast is +1 or less. But if you are going to use a development strategy that calls for decreased development or stand development, be sure to give the neg extra exposure to protect those important shadows. You've got 10 usable stops of curve so use it. james

-- james (James_mickelson@hotmail.com), April 08, 2001.

Rob, I'd never really considered double exposure due to the logistics of a) being able to stay in a cathedral until after dark (unless you go in November etc where closing time is after dark) b) having to leave the camera set up in position for so long without it either being moved (probably having the tripod kicked) or c) sombody trying to steal the camera. As I'm not a professional, I'm not able to pay to keep these places open to take a single exposure :-) but thanks for the idea. Another downside to this is the actual internal lighting of some of these places - it's worse than no lighting due to the harsh shadows and hotspots etc. At some places I've had to ask them to turn the lights off to give me a chance to even up the distribution. The people then think you are weird by wanting the lights off to take a picture.

James, One of the ways I've been trying to "rescue" negs is to use pre- flashing of the paper and split grade printing but it's not ideal. Were you meaning pre-exposing the film intead? You've given me a lot of ideas with the other things to try. My dad always sticks to FP4+ and I tend to think his negs are grainier and flatter compared to the Delta 100 but it looks like I'll have to swap films. Unfortunately he has the same problems with contrast as well but his negs look better to start with. His were also possibly flatter due to the old lenses he was using unlike my Bronica ones.

Andrew

-- Andrew Pell (adp88@btinternet.com), April 08, 2001.

Andrew:

These types of situations you are dealing with are some of the toughest ones to be found. The dark areas inside the church suffer from extreme problems with reciprocity law failure while the highlights in the windows do not suffer reciprocity problems at all. The areas of the negative that have recorded the darker areas of the church interior probably need all the exposure and development they can get while the highlights of the windows need as little exposure and development as possible.

The pre-exposure (or post-exposure) that has already been mentioned will help quite a bit with the additional exposure needed in the shadow areas. For development, you might want to consider using a highly compensating developer along with techniques that further the compensating effects. I like to work with highly diluted developers along with minimal agitation. One technique that I use is called the 1:4:1:4:1:4:1. You develop the film in a highly diluted compensating developer (such as Edwal FG7 diluted 1+31 with water only) for 1 minute with only 10 seconds of agitation. At the end of the minute in the developer, the film is gingerly transferred to water where it remains for 4 minutes without agitation. The film is then returned to the developer where the cycle begins again. In extremely contrasty situations, the last minute in the developer can be omitted. In situations that aren't quite contrasty enough, another 1:4 cycle can be added.

This method has worked quite nicely for me in situations similar to yours. I would recommend a little experimentation before using it seriously to get the details worked out right. This approach, though it works nicly with roll film, is easiest to work with if you use sheet films that can be developed individually.

-- Ken Burns (kenburns@twave.net), April 08, 2001.

Ken,

Thanks for your suggestions - it seems as though you have the same problems.

I don't know whether Edwal FG7 is available in this country (England) as it seems to be a US manufactured / sold item. I'll have to try and find an alternative unless you know of one. We don't have anything like the choice you have (assuming you're in the US.) Either that or I'll have to try tapping up a few of the chemical wizards I know and see if they can concoct an alternative.

I suppose whilst I'm experimenting, rollfilm might be a bit easier to handle as it would stay in the tank all the time to hopefully avoid damaging the emulsion I presume you mean rather than transferring the sheets between different baths etc.

From your 1:4 cycle, should the last bath be a developer one or water or doesn't it matter as the film is going to be put in stop-bath anyway? I guess it's a suck it and see thing found out with trials.

Andrew

-- Andrew Pell (adp88@btinternet.com), April 08, 2001.

Andrew:

Yeah, I'm over here on this side of the Atlantic. I'm not familiar with the chemicals and suppliers you have to pick from over on your side. I would think that Tetenal would have something that is fairly equivalent to FG7. Maybe Paterson would too. I've even heard of some people using Kodak's D76 for the process, but I've never tried it myself with D76.

Basically you need to use a developer that will become exhausted rather quickly in the hightlight areas of the negative but will still provide full development in the shadow areas. Of course, that is exactly what a compensating developer does. Many developers will do just that if they are highly diluted. Even HC110 will do it if it is diluted enough. However, you need to be careful that there is enough of the working developer for the quantity of film you are developing.

As far as the 1:4 cycle goes, it doesn't really matter which is the last step, developer or water. I have found that it takes at least three full 1:4 cycles, but in some cases you might need more cycles than that. You,ll need to do a little experimenting to fine tune it to your particular situation. As a matter of fact, with a little careful metering and note-taking you could probably come up with a system of matching different scene brightness ranges to the required number of 1:4 cycles.

Good Luck!

-- Ken Burns (kenburns@twave.net), April 08, 2001.

Andrew, Try pre-exposing the film. You will boost the shadows enough to lessen having to use such long exposures for reciprocity departure. Also by using the middle part of the curve(zone4 for the shadows) you won't have such a hard time in printing the negs. Using zone 3 and then trying to keep the shadow densities intact is hard. Using zone 4 or even zone 5 gives you some nice shadow densities to work with when you go to print. Now all you need is to keep the highlight densities from going to high which can be accomplished by using either a water bath with old emulsion type films or compensating developers with delta or Tmax films. There are myriad ways to do this. Divided d76 or rodinal at high dilutions will work fine. James

-- james (James_mickelson@hotmail.com), April 09, 2001.

James, I once tried pre-exposing the film with the Bronica. It made a slight difference to the shadows but only slight. I found I could get more useful results from pre-exposing / fogging the paper and it was a lot less hassle over having to rewind the roll film etc. I suppose it's better to do the film as it makes printing easier as opposed to having the same contrasty negs and trying to rescue them via the paper. I'll have to get hold of some sheet film and try that.

I've just developed my first roll out of the LF camera tonight using zone system metering (shadows placed on z3) and my usual developing sequence. Apart from the pictures not being sharp (as I said, I'm new to LF!), the density doesn't look as bad as some of the ones I've done previously although they aren't the most contrasty of subjects. There could be some hope :-)

Ken, I'll look around over here for some developer to try something different to ID-11 if I can't get any joy with weaker dilutions.

Andrew

-- Andrew Pell (adp88@btinternet.com), April 09, 2001.

Andrew, remember that the better the neg the easier to print. Dom what ever is neccasary to get a good neg because it easier than trying to salvage a bad neg. You end up wasting paper and chemistry and you never are able to calibrate your entire system properly. So when you come across an great scene or come up with a great idea, you struggle to bring forth all that it could be. James

-- james (James_mickelson@hotmail.com), April 09, 2001.

Get Phil Davis' Beyond the Zone System. There is a chapter near the end on miscellaneous topics such as reciprocity failure. If I recall correctly, he says that sometimes, with some film and developer combinations, contrast can actually reduce.

Like for your non-reciprocity-failure exposures, you ultimately want to characterize your exposure and developing process through testing.

Of course, if you don't mind resorting to using variable contrast printing, and a little lack of predictibility, you can use the guidelines for developing reduction for your film and developer combination and get into the ball park.

-- John H. Henderson (jhende03@harris.com), April 10, 2001.

Thanks to everybody for the all the replies, suggetions, hints and tips. It looks like I've got a fair amount of reading and testing to do and hopefully I'll be able to sort out some of my "difficulties."

Andrew

-- Andrew Pell (adp88@btinternet.com), April 11, 2001.

The previous answers indicate the connection between reciprocity and development. What I use is the following: If the indicated meter reading is 1-4 s, and I then figure out the time I should use, I regard that as N-1/2 If the indicated meter reading is 8-60s, and tthen I figure out the time, the development is N-1; indicated meter reading=1-4 minutes, Dev. is n-1 1/2; Indicated meter reading is 8m-60m, development time is N-2. Neat thing is that if the dynamic range of the scene is low--ie you would need a + dev. time to start with, you can use the excessive contrast reciprocity causes to your favor and adjust the dev. times appropriatey. Hope this helps. Bob

-- bob moulton (bobmargaretm@home.com), April 11, 2001.

Hi Andrew - In response to the question you asked me, yes, if the extended exposure necessary to take reciprocity failure into account will produce the equivalent of N + 1 contrast in the negative with normal development, you would develop for N - 1 to end up with a normal negative. I'm not sure of the answer to your question about variable contrast paper. Brian

-- Brian Ellis (bellis60@earthlink.net), April 15, 2001.