FX-1 and the RECIPROCITY EFFECT

[Omar.Morales]

Hello to Everybody,

I would like to receive some advice:
* I am developing with PAN F+ and I am coping with the RECIPROCITY EFFECT (more than 1 second),
* I am using a MAMIYA 67 RB,
* Normally, I am developing with the FX-1 (which is an "automatic” developer): the process is about 18 minutes,
* Due to the RECIPROCITY EFFECT (more than 1 second) I would like to give longer exposures.

There is a way to cope with the RECIPROCITY EFFECT using the FX-1?

Thank you,
Omar Morales.-

[sanchell]

For FX questions the person to ask is Bill Troop, one of our forum moderators. In fact, I think I'll create an FX forum for that purpose.

For Reciprocity, I can weigh in on that. Reciprocity is primarily a function of exposure and has to do with the reciprocal relationship between f/stop and shutter speed with which anyone reading this is probably already familiar. That is, if your exposure is f/11 @ 1/60 and you decide to open one stop to f/8 you must RECIPROCATE by using a faster shutter speed, 1/125. That is the "reciprocal relationship" between f/stop and shutter speed.

However, there is a limit to the relationship, and when it doesn't work it's called Reciprocity Failure. This limit is engineered into each film at the time of manufacture. Many forum members are familiar with long-exposure films, such as Vericolor Type L, or Super Panchro Press Type B, and tungsten transparency films. These films were engineered to have the reciprocal relationship extended into long shutter speeds for photo bulbs, low light and night photography.

Normal reciprocity for most films is between about 1 second to 1/1000 second. The reciprocal relationship fails for exposures longer than 1 second or shorter than 1/1000, ergo reciprocity failure. The result is underexposed shadows on the slow shutter speed side, and underexposed highlights on the fast shutter speed side.

To compensate for long exposures you'll need to increase the exposure time and decrease development to prevent overexposed highlights.

To compensate for fast shutter speeds you should use a larger f/stop. So, if you have an exposure of f/5.6 at 1/2000, you'll need to open by about 1/2 stop to f/4.5, leaving the shutter speed at 1/2000. You may also need to overdevelop by about 10% to increase the highlight density.

A good place to start is a reciprocity chart such as this one by Ilford, http://tinyurl.com/yd4mf485, or the one I hand out to students on my large format workshops, see attached. Bear in mind that for precision work you need to test your specific film and developer combination under actual working conditions as EVERY film has slightly different reciprocity characteristics.

BTW, Bill Troop informs me that reciprocity is not as great an issue with tabular grain as with conventional grain. Hopefully Bill will weigh in on this.

[Omar.Morales]

Hello Mr.Anchell,

"To compensate for long exposures you'll need to increase the exposure time and decrease development to prevent overexposed highlights."

Could you illustrate with a practical example?

Maybe the constrains could be:
* developer FX-1,
* exposure 5 seconds
* focal f/32,
* Ilford PAN F+.

Thank you,
Omar Morales.-

[sanchell]

Could you illustrate with a practical example?

Maybe the constrains could be:
* developer FX-1,
* exposure 5 seconds
* focal f/32,
* Ilford PAN F+.

Increase exposure by opening the lens to f/22 OR leave the f/stop at f/32 and increase the exposure to 10 - 12 seconds (but not both).
Decrease development by 10% - 15%

"Test, test, test." -Ansel Adams

[Omar.Morales]

Thank you Mr.Anchell for the suggestions.

One more thing: normally, in my process with the FX-1, which is "œautomatic"€ for film until 200 ASA, consist of

- 30 secs of agitation
- then 18min of process with:
--- 2 minutes without agitation,
--- then shake it for 3 seconds,
--- and repeat

Maybe I could decrease the development by 10% - 15% by cutting the process to 16min (more or less)?

Thank you,
Omar Morales.-

[sanchell]

Omar, you have mentioned "automatic" development previously. To be honest, I don't know what you mean by that. Your method of agitation is also one that is new to me. That doesn't mean it's not good, it's just not familiar. With that said, if it's working for you then I would assume that you are realizing the highest acutance possible with FX 1, a developer known for its high acutance. That's a good thing.

As far as decreasing the development, I believe the basis of your question is how to manage reciprocity resulting from long exposures using Pan F+. As noted, the first step is to increase exposure to increase density in the shadow regions. The reason for decreasing development time is to prevent the highlights from being blown out due to the increased exposure.

So, the first thing you need to do is expose a test roll of film under conditions similar to those you wish to eventually record. Keep VERY careful notes of exposure for EACH frame, numbered 1 to 36. In total darkness, cut the film in four equal pieces. You can do this by folding it in half, cutting in the middle, then fold the two halves again and cut. Place three strips in a daylight film developing tank and seal it with tape so you don't accidentally open it (ask me how I know this).

Develop the remaining strip for your normal time and see what the highlights look like. If they are blown out then decrease development for a second roll for your best guess. If they're just slightly too hot then decrease by 10%. If they're really blown out then decrease by as much as 30-40% as a starting point.

[Omar.Morales]

One more question:
* Suppose that the "automatic" is absent; which is "your" developing time with FX-1 using Pan F+ in normal "conditions" (e.g. summer at mid-day, using a 135) with the developing procedure? Probably the word "automatic" lead to some confusion.

Normally I use the "digital truth massive dev chart" to guess the developing time, but the Ilford Pan F+ is not listed with the FX-1. Of course, developing procedure is absent.

With the experiment that you suggest me it is a good starting point.

Thank you,
Omar Morales.-

[sanchell]

Were I to develop a roll of Pan F+ in FX 1 I, too, would consult the digital truth massive dev chart. I find the times are not always correct for my methods, but they always get me within a few minutes - and I ONLY develop test rolls until I have determined the correct time, either through printing or measuring with a densitometer. Since digital truth doesn't list a time for Pan F and FX 1 you'll have to determine your own. A good starting point would be 12 min. at 68F.

That said, you have already indicated that you develop for 18 minutes with your own agitation method, a method I am not familiar with. While not faulting your method, the slight gain in acutance you realize with your agitation method, is probably not worth the extra time you need to develop your film. Below is my method for developing film.

Steve Anchell’s Film Development Method

There is a right way and a best way to develop film. The right way will always give you results—if it doesn’t it’s the wrong way. The best way will give you the best results. The following method for developing film is the BEST way for ALL films and ALL developers. If you use this method and find stains, spots, blemishes, aerial fog, or used chewing gum on your film then your developer has been poorly formulated OR you are not using enough developing solution per 8x10 sq. inches of film OR you dropped chewing gum into the tank. Use a MINIMUM of 350 ml of developer per 8x10 sq. inches (1-36 exp. 35mm film, 1-120 film, 4-4x5 sheets, etc.). Read that again: MINIMUM. More would be better.

Develop – Rinse – Fix – Wash – Wetting Agent - Dry

1. Develop
• Note: Agitate for 1 full minute, then either for 10 seconds or 4-5 immersions/rotations every minute thereafter.

2. Rinse In Running Water: 1 minute

3. Fix (Alkaline Fixer): 3 minutes
• Agitate for 30 seconds
• Let sit for 30 seconds
• Repeat

4. Wash in running water: 10 minutes

5. Wetting Agent: 1 minute (with slight agitation)

6. Hang to Air Dry

NOTES:

1. Do not use a sponge squeegee or ANY squeegee, including your wetted fingers (which also work), that squeezes the film on both sides. Wipe one side of the film at a time.

2. The fixing sequence is based on using alkaline fixer. If you use an acid fixer (Kodak Rapid Fix, Kodafix, Ilfofix, etc.) you will need to add hypo-clearing agent for 5 minutes between the fixer and the final wash.

3. In either case, whether you use alkaline or acid, you should eliminate acid stop bath altogether and substitute a running water rinse.

4. If a wetting agent is not available try using a highly dilute hand soap with a few drops of citric acid in it (lemon, lime, orange, etc.). Wetting agent can be reused during a single darkroom session. However, it should be discarded after each day’s development session – it can develop film-damaging sludge.

[Omar.Morales]

Thank you!

Omar Morales.-

[Omar.Morales]

Hello Mr.Anchell,

One more question about your method:

* no STOP in the method?

Omar Morales.-

PS: this is a process AGFA?

[sanchell]

Running water stop bath, one minute.

This is not an Agfa process.