In this case, the film with which I show the photo is Foma200 but of an unknown winder, without perforation marking, Microfen developer in 1/3 dilution. But of course, during life, to a greater extent, the film was Svema, and the developer was D-76
The magic of the number 3.14 & the magic of film development.
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In this case, the film with which I show the photo is Foma200 but of an unknown winder, without perforation marking, Microfen developer in 1/3 dilution. But of course, during life, to a greater extent, the film was Svema, and the developer was D-76
Who will collect the sample?
Pi is a ratio that rounds to 3.14. This is a rough multiplying of a roughly determined time to get a ballpark result. This could just as easily be 3 or 3.2. Probably easier to remember as 3.14, though.
You might mix up a developer. For example, 4 g metol, 18 g sodium sulfite, 3 g hydroquinone, 6 g sodium carbonate, 0.2 g potassium bromide in 500 ml water. That will develop film. I have no idea of any time for any film for it, though - but I do know it will develop film.
There's the usual one: put a piece of the film in the developer (in the light) and see how long it takes for it to get completely dark. Double that time as a guess for actual development.
OK! I see that there is some doubt, this is very good and correct, I am glad that the topic is of interest at all. Now I can move on. The second example requires a little introduction. In December, my daughter came to visit me, she lives, studies and works in the Czech Republic. It was a joyful and disturbing meeting at the same time. We haven't seen each other for the last year and she hadn't been to Ukraine before during the war. I was worried about her safety. My daughter brought me a Lomography film, which I cannot buy in Ukraine, and finished shooting the film in Kyiv. I invited her to show it together. For my daughter it was a valuable film and at first she also had doubts, but also interest. As a result, she trusted me and my experience. I said this in order to understand the degree of my responsibility. So, I had: Ilford Delta400 film, FOMADON LQN developer in 1/8 dilution. Can anyone tell me the development time of the film? I can add that the temperature was also unknown to me, but it did not matter to me, in any case I could not raise it in the absence of electricity)) so I gave a dilution of 1/8 instead of the traditional 1/10. Method "3.14" told me "Don't be afraid, boldly manifest 7.5 minutes!" I listened to him and the result is in the photo. The daughter posted some photos from this film here: https://www.lomography.com/homes/theridiida/albums/2421563-kyiv2022
I'm going to give it a try with Double X and MCM 100, should a rather long development times, maybe 18 to 22 m.
Thanks KitosLAB for your reply to my question. Well evidence is now building that it works with Microphen and Foma film at 1+3 plus D76 with Svema. petrk confirms success with HP5 and Excel
The video presenter from the U.S. had success with Rodinal
I am not a chemist but I see no reason why the ratio of developer be that stock, 1+1 or 1+3 or in fact any ratio stipulated by the developer's manufacturer with minimum required stock should not work
Can anyone else see a good chemical reason why other dilutions should not?
That leaves the question of: If it works with a developer and one film, does it work for that developer and all films?
Again I cannot think of any chemical reason why not as we know that for any known developer, be that Excel, Microphen etc they work with a whole range of films
pentaxuser
The video presenter from the U.S. had success with Rodinal
I am not a chemist but I see no reason why the ratio of developer be that stock, 1+1 or 1+3 or in fact any ratio stipulated by the developer's manufacturer with minimum required stock should not work
Can anyone else see a good chemical reason why other dilutions should not?
That leaves the question of: If it works with a developer and one film, does it work for that developer and all films?
Again I cannot think of any chemical reason why not as we know that for any known developer, be that Excel, Microphen etc they work with a whole range of films
pentaxuser
This method sounds like it's premised around the idea that there exists a target or ideal development time for film+dev combos, which aside from taking the fun out of push/pull, doesn't take into account what the photographer end goal is with the negative. It also doesn't take into account agitation, if I agitate like crazy it'll developer faster.
You would probably need to standardize it for a single image say at zone V, follow your method with different developers/dilutions, and test it with a densitometer to ensure its all consistent.
You would probably need to standardize it for a single image say at zone V, follow your method with different developers/dilutions, and test it with a densitometer to ensure its all consistent.
Regarding the different levels of strength for the developer, I would argue it would abide by Poisson variation. At too high or too low of concentration the time would effectively be random and no longer follow an expected pattern. I work with autoradiography film at work and have seen this happen. That and base fog might become issue, especially at higher concentration.
I don't think this method is a one size fits all, might be useful when paring a film with obscure developer, in my case MCM 100, to get a starting point. Might also be useful when developing long expired films. I willing to experiment to see where in it might fit in my tool tool box.
Can anyone with an understanding of emulsions explain to me what one is actually seeing in the un-cleared emulsion? Why does the immersed part go lighter and then darker, and what might be the significance of it reaching the same shade as the dry part?
Thank you! Thanks to my daughter, I was in Prague three years ago and I really liked it. I do not want to say that the method is ideal, perhaps it gives errors, but I am not sure that it will not spoil the film when there are any unknown
It may not be ideal, but it may be a quick way to determine a starting point for a given film+dev combo then you can proceed to fine tune the development from then on.
I presume when immersing the clip of film into the developer there is no agitation taking place. I wonder if this would skew the results with slower developers. Like, if the time measured is 62 seconds, would that time have been shorter with agitation? And if so, would that result be more accurate?
So I tried this with hc-110 H and K400 and I timed it at 15 seconds, which would give a developing time of under 5 min, which is too short. But maybe I'm not judging the time correctly. It's kind of subjective to evaluate whether the colour of the developing film is the same as the dry film. The colour doesn't exactly match. I ended up trying to evaluate whether the darkness was the same. Then, another wrinkle is that the film appears lighter when immersed in the developer, and darker when taken out. Lots of factors seem to be in play here.
It would be interesting to see whether a reliable test could be formulated. The factors which would need to be determined are agitation (yes or no), appearance of film in or out of developer, and whether your evaluating the emulsion or acetate side of the film.
So I tried this with hc-110 H and K400 and I timed it at 15 seconds, which would give a developing time of under 5 min, which is too short. But maybe I'm not judging the time correctly. It's kind of subjective to evaluate whether the colour of the developing film is the same as the dry film. The colour doesn't exactly match. I ended up trying to evaluate whether the darkness was the same. Then, another wrinkle is that the film appears lighter when immersed in the developer, and darker when taken out. Lots of factors seem to be in play here.
It would be interesting to see whether a reliable test could be formulated. The factors which would need to be determined are agitation (yes or no), appearance of film in or out of developer, and whether your evaluating the emulsion or acetate side of the film.
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Well both videos show the presenter evaluating the emulsion side and without any agitation and it is from stock solution. From this it is implied you get to a time for development using normal agitation Given how quickly the key number of seconds is reached then as far as I can see no meaningful agitation could be applied in the sense of this "test" agitation replicating normal agitation
What does worry me a little like you is deciding accurately at which point the emulsion colour and the colour from the drop of developer in the John Finch video or the immersion in the U.S. video becomes the same
However a video picture of when the presenters decided when that point was reached may not have given us the same picture. I thought that John Finch had waited a few seconds too long but frankly even if he had stopped his clock when I first judged the colour to be the same the 3.14 formula would still have given wrong times by quite a margin for what he said was the right development time for the developers he was using except for one for which it seemed close ro being right
pentaxuser
MattKing
Moderator
That was what my thoughts were about all sorts of weird numerical relationships until, way back when, my math professor started talking about Fibonacci sequences, residues and poles!
It was actually a fairly serious question. π shows up unexpectedly in a whole bunch of mathematical relationships, and mathematics probably has a role to play in explaining this phenomena.
Although it does show up only when the units are mixed. As Richard pointed out, when the units are constant it's a factor of 18.8. Since pi is a geometric quality I don't think it would enter into chemical reaction rates. If it was e (natural logarithm), then I would believe a correlation.
MattKing
Moderator
Well, π also describes the way rivers wind, how light ripples 
I make up/down movements and by the way it helps to determine the color. In the video, I did not like the application of the developer with a dot. Such a small amount of solution can oxidize very quickly. Yes, "catching" the color is a problem, this is achieved with experience. In some short term, I will try to shoot a video, at the same time see how it looks not in real life but on the screen. In winter, this was not possible, there was almost no electricity and short daylight hours. But now I know for sure that the lack of the benefits of civilization, such as communication, the Internet and even electricity, is not a reason to refuse photography)))
Oh! I found that I had a photo taken by my daughter when we developed her film, yes it was Ilford. I have already pointed out that the "3.14" method told me to exercise 7.5 minutes. The photo shows that the wet part has not yet reached the density of the dry part in 20 seconds, and the part that is in the developer looks lighter than in reality. Now everyone can see how I do it)))
Attachments
I have just tried it with HP5+ and Rodinal at 1 +25 dilution. I repeated it 4 times as per the U.S. video's method and twice as per John Finch's drop on the emulsion method
3 times with the U.S. method I stopped the clock on 18 secs and once on 19 seconds. With the "drop" method I stopped the clock on 18 and 17 secs
In all cases this was done under an incandescent 100 watt clear bulb. I found John Finch's "one drop method easier to judge as you can concentrate on the change in colour of the one spot in the centre compared to the rest of the emulsion. The U.S. dip method required movement of the strip up and down and I found it more difficult to judge the exact instant when colours matched
I think both methods may be easier in daylight
If we use the easier "divide by 3 " instead of the 3.14 the accuracy with HP5+ and Rodinal was remarkably good as the actual Ilford time and the Massive Development Chart time was 6 mins which I got. The least accurate time was the 17 secs which was 5 mins 40 secs which still isn't bad and as the clock cannot measure in tenths of a second it may be that 17 was very close to 18 anyway
So while 6 repeats in total does not constitute enough for statistical accuracy I'd conclude that it worked for HP5+ and Rodinal at 1+25
As I said if it works for Rodinal at 1+25 I see no reason why it would not work for this combination at 1+50
I am definitely going to try with Xtol and Microphen at a later date
pentaxuser
3 times with the U.S. method I stopped the clock on 18 secs and once on 19 seconds. With the "drop" method I stopped the clock on 18 and 17 secs
In all cases this was done under an incandescent 100 watt clear bulb. I found John Finch's "one drop method easier to judge as you can concentrate on the change in colour of the one spot in the centre compared to the rest of the emulsion. The U.S. dip method required movement of the strip up and down and I found it more difficult to judge the exact instant when colours matched
I think both methods may be easier in daylight
If we use the easier "divide by 3 " instead of the 3.14 the accuracy with HP5+ and Rodinal was remarkably good as the actual Ilford time and the Massive Development Chart time was 6 mins which I got. The least accurate time was the 17 secs which was 5 mins 40 secs which still isn't bad and as the clock cannot measure in tenths of a second it may be that 17 was very close to 18 anyway
So while 6 repeats in total does not constitute enough for statistical accuracy I'd conclude that it worked for HP5+ and Rodinal at 1+25
As I said if it works for Rodinal at 1+25 I see no reason why it would not work for this combination at 1+50
I am definitely going to try with Xtol and Microphen at a later date
pentaxuser
Nice test report. Given that + or - 10% is usually considered "close enough" by anyone but the obsessive/compulsive among us, this, as the Mythbusters used to say, sounds like "a result!"
If your #48 was a reply to me Donald then thanks I think if all of us interested in this subject were to try it on different developers and different films we can at least build up a database on which anyone faced with an unknown film can at least decide for himself if the method has any merits before he decides by being referred to the thread started by KitosLAB
I think that approach is a better one that each member saying either "do it, it works great or don't even consider it - it's crap " That way the person considers the evidence and if questions then follow we can try to answer
pentaxuser
I think that approach is a better one that each member saying either "do it, it works great or don't even consider it - it's crap " That way the person considers the evidence and if questions then follow we can try to answer
pentaxuser
I'll try to remember to try it next time I have some film ready to go into my D-23.
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