Ilford - new reciprocity failure compensation factors

[LabRat]

FWIW, I do a lot of night work with different B/W films, and the films have different LIRF, but in practice, the supplied charts usually work fine (for me)... I meter so that the darkest part of the scene that I want start to render is 3 stops under zone V, to have some detail is 2 stops under V, and full detail 1 stop...

The long exposure time covers up most of the minor differences allowing some "fudge factor", so not a problem...

What's annoying to me now is the only sheet film I can afford these days is (Foma) EDU100, and not unusual for an 8 min (or much) longer exposure (a still life I was doing was properly exposed in an hour!!!), so sit back, and get comfortable...

Steve K

[Drew Wiley]

Actually there was a tremendous amt of technical info avail to night photographers if they needed. TMax astro glass plates were still avail maybe 25 yrs ago, and other plates well before. But like many others, I'd just test bracket some 35mm frames of a promising film before using sheets. And that low tech method still works extremely well.

[David Karp]

Reading this thread makes you wonder how on earth generations of photographers made extraordinary night images without voluminous pages of theorising, correction tables and the arcane practices of specialist astronomical photographers...

Apologies for the sarcasm above, but there are some people who could do with a lot less huffing and puffing about zones and reciprocity and the essentiality of one particular (discontinued) film & instead just get on with making images...

Good idea. Who needs good technical information? And why stop there? Why not stop using light meters too? A good photographer should be able to guess at the proper exposure. (I have heard that one more than once over the years.) Why would we use test data derived by the film manufacturer? Even better, why would we even try to make sure we understand that data and its implications?

Now that I got that out of my system, please accept my apology for my sarcasm above. I have made plenty of long exposures in low light situations. Most of them are fine. Some did not work out. This new data may or may not impact my success rate. I think in zones when I photograph. I am trying to understand how the new information can be put to use effectively and put it in the context of my photography. You may not need the information or input from others. Great. I find much of the information in this thread to be interesting and helpful to me precisely because of the fact that there are others who are more technically oriented than I am. I appreciate others taking the time to contribute something. Maybe I will make a better photograph as a result of their contributions.

[Tin Can]

Yes, David, however I for one need definition of terms somewhere.

It wasn't until miles into this thread that LIRF was defined.

Now I know it's not the acronym for LIRF - Rome Fiumicino Leonardo da Vinci, an Italian airport!

[David Karp]

I know Randy. Sometimes we get lost in our own jargon. LIRF, however, was mentioned in the very first post.

Like you, I prefer a simple explanation of what to do and how to do it. I also like the detailed technical explanation, which sometimes I can understand and sometimes not. I am far from the most technically oriented. I don't have a densitometer to measure my negs. I eyeball things. I always use a two bath developer even when I am going to print in the darkroom even though I have been assured my results will be better if I developed in a single bath developer by time and temperature. Ridiculing the more technically oriented among us and denigrating their contributions, which you never do, doesn't move anyone forward. I have found so much help on this forum and the home page on so many topics. The range of expertise of the contributors is amazing. I am a better photographer because of what I have learned here.

[Tin Can]

I know Randy. Sometimes we get lost in our own jargon. LIRF, however, was mentioned in the very first post.

Like you, I prefer a simple explanation of what to do and how to do it. I also like the explanation, which sometimes I can understand and sometimes not. I am far from the most technically oriented. I don't have a densitometer to measure my negs. I eyeball things. I always use a two bath developer even when I am going to print in the darkroom even though I have been assured my results will be better if I developed in a single bath developer by time and temperature. Ridiculing the more technically oriented among us and denigrating their contributions, which you never do, doesn't move anyone forward. I have found so much help on this forum and the home page on so many topics. The range of expertise of the contributors is amazing. I am a better photographer because of what I have learned here.

Sorry I missed LIRF in the first post. I read all day long and tend to skim very fast. I learned nearly everything I know about photography on this site. I have written several times here about how this forum saved my life, by enabling my goals. I was sick and down. Now I wake up each day happy for the challenge. I needed and still need this forum. So many acronyms, so little time.

[David Karp]

So, I will do some testing to find out, but after puzzling over whether or not to worry about zone placement, as I posted above, I think I am back where I was right after Michael posted.

I am leaning toward thinking that the answer is not to worry any more than normal. Zone placement is unavoidable no matter how we think about our photography. The zones will fall around whatever point we decide upon to expose our photograph. We set the meter and what we decide to read will play on through the reciprocity corrections. The dark zones will be dark, because that is what happens. We might lose detail in the lowest values, but if we place things higher, we are probably intentionally saving something else we need in the photo. We know from the Ilford data what the values are going to be 3 1/3 stops below our chosen light measurement and that below that things are going to disappear into the blackness. Is that what Michael was driving at?

[David Karp]

Excuse my personal preferences, but a Smartphone or calculator is just one more battery-dependent item I don't want in a pack, esp on a long trek where pack space is at a premium and there's no cell reception anyway, in case of emergency. That kind of thing is best done in a trial run and then either jotted down or memorized per representative times. Working with large format in a snowstorm or downpour already has enough steps and gadgets to keep track of without adding yet another.

Drew, one alternative, which I have used, is to print the information on an Avery 5388 index cards. They come in an 8.5 x 11 sheet and are easy to punch out. There are three 3" x 5" cards per sheet. You can put the information into an Excel table and then drop them into Word. Avery has templates that you can download and use to print out the tables. You can carry the tables with you in your backpack. I have cards for filter corrections, measured shutter speeds for my lenses, selecting the f/stop for near/far focus, and reciprocity. I will have one with the new Ilford reciprocity information on it. Avery also makes some adhesive backed laminating sheets that I use to stiffen up the cards and protect them. Works great for me anyway.

[Pere Casals]

Reading this thread makes you wonder how on earth generations of photographers made extraordinary night images without voluminous pages of theorising, correction tables and the arcane practices of specialist astronomical photographers...

Apologies for the sarcasm above, but there are some people who could do with a lot less huffing and puffing about zones and reciprocity and the essentiality of one particular (discontinued) film & instead just get on with making images...

Of course, a highly compensating development does the trick. And with Acros it was even simpler...

[Michael R]

Doremus,

It's just place and fall. I think we're saying the same thing but my wording was probably unclear. If you meter something and place it on Zone V, something else in the scene falls on Zone I ²/₃ and should register as a density of 0.1 in the negative. All I meant was that if you instead give an extra stop of exposure, everything moves up the curve - what previously fell on Zone 0 ²/₃ now falls on Zone I ²/₃ and should register as 0.1 in the negative.

On the subject of contrast under LIRF conditions, yes contrast increases so development adjustments may be required (or print at lower contrast). I think the reason Bond found the contrast increase to be inconsequential in his tests is that he targeted a constant density for Zone III (ie higher on the curve).

David and everyone else,

Again, I would say don't overcomplicate this by mixing the Zone System in with LIRF adjustments. I probably shouldn't have even brought up Zones in my initial response to Pere. What matters is that the Ilford factors are designed to preserve shadow values. Figure out your exposure first, using the Zone System or whatever other method you use, then adjust using the Ilford factors. The longer the exposure, the more of a contrast increase one would expect.

LIRF in the field is not an exact science (actually, even regular exposures in the field are an inexact science).