Developer/Film Speed question

[Mark Herrick]

Just started getting back into shooting 35mm B&W and processing my own film. I picked up "The Film Developing Cookbook" and had a question about speed decreasing/maintaining/increasing developers.

If I plan on using a developer that decreases or increases the film speed, do I set my film speed accordingly on my camera/light meter prior to shooting? For a 100 speed film say 50 for a decreasing developer and 200 for an increasing developer? (The book didn't seem to be clear on this.)

I see many references to shooting 400 at 320; is the processing adjusted for the 320 speed or are they processing for 400 even though they are shooting at 320?

The book also mentions when using a diluted developer to be sure to increase the amount of developer. I take it that means when processing two rolls of film I should use a four reel tank rather than a two reel tank?

Sorry if these questions seem rudimentary; I haven't done this for a while and never really got that far into it...

 

[fotch]

Hi Mark and welcome to APUG.

 

[dehk]

Yes you would set the film speed prior to shooting and it should be set for the whole roll. If you want to expose a roll of ISO400 film at 200 or 800, you set it accordingly before hand.

Its not so much for a decreasing or increasing developer, it has something to do with the developing time using the same developer at a certain temperature. For exposing under the ISO rated, you're pulling it, for exposing over the ISO rated, you're pushing the film.

"I see many references to shooting 400 at 320; is the processing adjusted for the 320 speed or are they processing for 400 even though they are shooting at 320?" The developing time would be adjusted for ISO320. They used the pull development.

'The book also mentions when using a diluted developer to be sure to increase the amount of developer. I take it that means when processing two rolls of film I should use a four reel tank rather than a two reel tank?' Lets say you're using D-76 as a developer, doing it stock (straight), will develop faster and you can re use the developer (through out that time you will be developing, not talking about over night). If you use it as 1:1, it had a slower developing time, you save on chemical, but then you can't reuse it. A lot of other developer has different dilution for different strength/purposes. So it all depends on how you want to do it. Using a four reel tank also saves time, BUT, they had to be same kind of film and have the same development time.

 

[Saganich]

Yea it can be confusing. Best to start off with a film developer combo that gets you close to box speed. After about a year of that you will likely be ready to move-on.

 

[Bill Burk]

Hi Mark,

You're getting back into it, so you probably will get deeper in this time. Nice answer dehk. Chris, you might be right about it taking a year - for Mark, this might be that year!

Dilutions like 1:1 will have enough active agent that you can cover the film and go. For example a pint of stock plus a pint of water in a 4-reel stainless steel tank.

Liquid concentrate developers have several dilutions. When you get very weak dilutions and rotary processors (that can cover film with a few ounces of developer) then you have check the charts to find the square inch film coverage per amount of concentrate. You might have to add more developer than what it takes to cover the film to make sure you have enough active agent to completely develop.

Liquid concentrates have the advantage of giving consistent results, every mix is fresh. D-76 stock keeps for six months (I've used it after 2 years with no problem. Dump it if it's brown but dip a snip if it's light yellow. If film darkens it's probably ok), but D-76 activity goes up and down over the first few weeks as the buffering agents cancel out chemical reactions - in the long run it actually becomes more active.

For 35mm if you want the absolute finest grain and sharpest image, then carefully select your film and developer. Come back to these forums for refinement of the ideal and elimination of variables.

If you appreciate a little grain, then breathe a sigh of relief. Any developer will work, you can experiment until you find one that you like. Hit the film hard with light and you will have something to work with. Worst thing that can happen with a stop or two overexposure is increased graininess. Something worse happens if you underexpose, you have an image that can only be seen when you hold the negative to the light with a black background behind it.

 

[Ian Grant]

You need to understand why many of us shoot films below their box speeds, it's usually to help retain shadow details and at the same time we control development to retain the highlights.

Ideally you should choose a film.developer combination and then do your own effective film speed tests, this gives you the film speed and development times for normal contrast situations. There's plenty of articles on the internet on how to do this,

The biggest issue of developer volumes and dilution is with rotary processing because of the low volumes used, but it's also relevant when diluting 1+3 with ID-11/D76, Xtol etc because the developer exhausts faster.

Ian

 

[2F/2F]

First, you should determine how you are going to judge film speed. There are a few methods.

Many – probably most – people like to use the very lowest values as a way to judge film speed, and then tweak development to match a predetermined contrast of their (or usually of Ansel Adams') choosing. They usually do this if they routinely practice tonal placement, because to do this accurately, calibration to a low tone is needed. It is these people who definitely should rerate their films based on individualized testing in order to get the results they desire.

Others – like myself, most of the time – like to develop in a certain way, and then use the printed values of the mid tones to decide how to rate the film. In this method, shooters are generally using an incident meter, and use knowledge of where low and high tones will fall in relation to a placed mid tone (placed via incident metering) to decide how to alter exposure and development to change the way the scene is captured.

The first method forces any film and developer combination to roughly fit a set idea of what a negative should print like. The second method is a little more laid back, and you simply analyze the way different films behave when given different development, and choose a film/development combination that suits what you need for the shot. For instance, you shoot one emulsion, and develop it five different ways, and you have five tools from which to choose to capture a shot.

Because of the preference given to shadow detail and texture by many photographers, the method of testing the low tones a la Ansel Adams is usually what people use. This method is almost certain to produce results indicating that you should use an EI lower than box speed, though I do uprate one b/w film and developer combination. (With new T-Max 400 in D-23 1:3, I rate the film at 640). This is not because the film makers are lying. It is just that different criteria are being used to judge the film speed.

With the midtone method, the box speed is usually right on IME, or within one DIN number. I shoot most films at box speed with incident metering. (I shoot Kodak Portra 400NC at 500 in order to get the mid tones as dark as I think they should be, and I also often push this film 1/2 stop or one stop, even when I have plenty of light to expose it "properly.") Because of this, I would make the general statement that box speed will be acceptable to use without a lot of EI testing, if using an incident meter, though you can always benefit from testing. I would definitely recommend testing for the range of your film, however. If using incident meters, you have to have an eye for what luminance ranges your film will or will not be able to capture in order to get best results.

I think testing low tones for your EI is the way to go if you are using a reflected meter, especially a spot meter with tonal placement, and testing for midtones and learning the range of your film in a few different methods of development is the way to go if you use an incident meter.

 

[Rudeofus]

I frequently read postings indicating that this and that developer is "terrible" or "the only one worth using", usually followed by both supportive and contradicting replies. Likewise lots of folks seem to take pride in rating ISO400 film precisely at ISO393 or ISO405 to achieve exactly their vision, of course using some random light meter which hasn't been calibrated in decades but "should be right within a stop or two". Needless to say that the same forums which claim huge improvements from over- or underrating film generally cheer the gigantic latitude of negative film :confused:

Of course there are (semi-) pros who have shot thousands of rolls of the same film stock and who have reached their setup after years of experimenting with the same setup over and over again, but most amateurs, especially beginners will only be distracted by these details. For some cases rating an ISO 400 film at ISO320 could make the result better to some extent. Shooting the same scene at box speed would probably yield results that most amateurs would barely recognize as different (without explanations), not to mention people completely outside the field of photography. There may be an optimum, but it is extremely flat, mathematically speaking.

For these reasons I strongly concur with Saganich: shoot at box speed, use some dev that is easily available in the low quantities you need at first. Once you grow confident and see things in your prints you want to improve, start experimenting or ask for advice here in the forum. If you start out with a complete non standard setup (random film/developer/paper some users praised in some forum, film rated 2/3 stop below/above box speed, then pulled/pushed by 1 stop) and run into troubles, chances are slim that anyone else has such a setup, and advice will be mostly guess work.

 

[Steve Smith]

Needless to say that the same forums which claim huge improvements from over- or underrating film generally cheer the gigantic latitude of negative film.

Excellent. I wish I had thought of that line!


Steve.

 

[markbarendt]

I'm coming to the opinion that that the box speed is only right when the standard development is used.

Problem is the only standard development is probably the ISO standard and I don't know many people who actually do ISO standard developing.

Take a look at page 3 at this link for Delta 400's data sheet: http://ilfordphoto.com/Webfiles/2010628953322222.pdf

The times in bold all indicate the points where Ilford found normal contrast.

Go to the top of the chart and you'll see that they say "meter setting".

So, if we are willing to trust Ilford's word and we follow their directions in the data sheet and use PERCEPTOL stock and a camera meter setting of 250 we should get a "normal" negative.

If I plan to use DDX or Xtol and follow the directions, I probably need to set my camera close to 500 to get what I expect from the negative. These are safe bets.

Beyond these "standards" our personal preferences and metering techniques become bigger factors, that you just have to experiment with.

 

[markbarendt]

Needless to say that the same forums which claim huge improvements from over- or underrating film generally cheer the gigantic latitude of negative film :confused:

And rightfully!

It's not just the "forums", Kodak and Fuji make the same latitude claims about their C-41 films.

This latitude can be used creatively in many ways. This is simply a method of getting proper exposure placement to get a desired result, it is not truly over- or under-exposure.

The biggest advantage for me of re-rating is in this exposure placement, it's like using exposure compensation (the effect is absolutely identical), just a simple way to knowingly "trick" a meter into giving me a camera setting that works for getting a planned result.

The second biggest plus of that latitude is that it makes shooting more reliable with any camera and makes getting reasonable results with a Holga or Diana pretty easy.

Shooting high latitude films makes shooting more fun and reliable for me, I don't need to sweat the back end stuff while I'm shooting and that helps me focus on the moment and make/take better pictures; so much so that for 135 and MF I'll probably be fully switched over to XP2 and BW400CN for B&W by the end of the year.