Developer Speed And ISO Question For 4x5

[IanBarber]

I am trying to understand how different developers can affect film speed.

From reading, my understanding is that a developer can quite easily make an ISO 400 film act more like ISO 600 or on the opposite side act more like ISO 200.

I don't have the facility to do and serious testing and was wondering if anyone has done any tests on the following developers, and what their findings were.


Kodak HC110
Kodak XTOL Replenished
PyroCat HD

[ic-racer]

I'd not worry about it. Plus or minus a third of a stop or so should not keep you awake at night.

[docw]

If you have the facility to develop film then you have the facility to test. Don't be daunted - you don't need extensive testing to establish film speed and development times. Also, if you want a film to act like a 400 ASA film, then use a 400 ASA film! It might be helpful if you explained a little more what it is you are trying to do.

[IanBarber]

If you have the facility to develop film then you have the facility to test. Don't be daunted - you don't need extensive testing to establish film speed and development times. Also, if you want a film to act like a 400 ASA film, then use a 400 ASA film! It might be helpful if you explained a little more what it is you are trying to do.

I was actually reading a webpage which mentioned that certain developers and I think HC110 was mentioned that actually slows the film down during development. To be honest I am not 100% what they mean.

It got me thinking though, if developers can affect film speed, do we need to be concerned about this at the exposure time

[Leigh]

if developers can affect film speed, do we need to be concerned about this at the exposure time
No they can't, and no we don't.

There are numerous recommendations regarding film speed, exposure, and development.
Each is tailored to the particular tastes and shooting habits of its author.

When you get deep enough into the technology and technique that you can produce 100% consistent prints from a variety of subjects, then you're ready to explore variations that might make your shots more pleasing to you.

But not before.

I've been shooting and developing B&W since about 1950, using box speed and manufacturers' recommended development times. I'm quite pleased with the results... and nobody else cares.

- Leigh

[IanBarber]

No they can't, and no we don't. - Leigh

From someone with over 50 years experience, thats good enough for me :)

[Rich14]

I am trying to understand how different developers can affect film speed.

From reading, my understanding is that a developer can quite easily make an ISO 400 film act more like ISO 600 or on the opposite side act more like ISO 200.

I don't have the facility to do and serious testing and was wondering if anyone has done any tests on the following developers, and what their findings were.


Kodak HC110
Kodak XTOL Replenished
PyroCat HD


Ian,

You've got just about all the advice you need. The developers you listed will give you "box speed" for any film commercially available. Go shoot film. Expose it as recommended by the manufacturer. Develop it in any of the soups for the recommended time. The results will be fine.

The only thing you can really do "wrong" with B&W or color negative film is to under-expose. You can over-expose by an enormous degree (by as much as 5 stops) and you will still get excellent results. In fact, rating film at 1/2 or 1/4 box speed (1 or 2 stops more exposure than box speed) often results in increased quality and improves color rendering.

Go shoot. Don't worry about any of those developer formulas.

Rich

[esearing]

Thought excercise: Any one correct me if I have this backwards.

If HC110 dev time is 8 minutes for a given 400 speed film per manufacture. And lets assume that you get a meter reading of f16 @ 1/30 sec . That will give specific densities over base + fog for each of the different zones . A step wedge exposure helps to see this more clearly.

So if you expose your Film at EI200 you are over exposing because your meter will tell you to use 1 stop more f11 @ 1/30 or f16@1/15 - Thus your densities at 8 minutes of development will be more dense for your image zones and will show more shadow details but less details in highlights (maybe).

If you expose your film at EI800 you under expose by one stop and thus if you process for 8 minutes your negative densities will be lower than your normal 400 with less shadow detail but more control over highlights.

If you Decide EI200 is really what you want to expose 400 speed film at, you still have the flexibility to adjust development time to control negative density and contrast. Different developers will yield different results. Agitation method also comes into play to a lesser degree unless you are using rotary/aggressive agitation or on the other end of spectrum minimal agitation. With minimal agitation you would increase dev time, with rotary decrease it.

Most photographers pick an EI and time that gives them the range of tones they like to print with on a given paper. If you only use grade 2 paper you try to tailor the zones on the negative to reflect accurately on that paper.
As long as your negative densities are in the ball park with the density and contrast you want, then modern Variable Contrast papers allow you some additional flexibility.

[Corran]

Drop the term "ISO" and instead consider "EI" - exposure index.

Yes the ISO is determined by the manufacturer, as tested with the developer and methodology they employ. This generally has little bearing on the end user's process, and specifically when you talk about more exotic developers like Pyrocat there is a definite difference in your EI because the manufacturer did not test the film with that developer. There's also the issue with what exactly "ISO" is - see the historical change in film speed standards, etc.

I know that for most of the films I use, Pyrocat as well as Rodinal tends to cut my film speed by 2/3 to 1 stop. If I exposed at "box speed" I will lose shadow detail. Of course this is determined by your meter, your metering technique, your development time, temp, and agitation scheme, etc. etc. XTOL tends to give me a higher EI than box. Your EI more specifically gives you a speed at which the shadow detail falls appropriately on your negative/print.

If you don't want to do formal testing (as I don't, generally), the common recommendation is to shoot everything at half box speed. Alternatively, just bracket one scene at box as well as +/- 1 stop and see what you get. Adjust to taste. When trying out a new film/developer I do that and then adjust for the next time. I can usually hone in on a good EI and dev time after a few sheets.

[Michael R]

I am trying to understand how different developers can affect film speed.

From reading, my understanding is that a developer can quite easily make an ISO 400 film act more like ISO 600 or on the opposite side act more like ISO 200.

I don't have the facility to do and serious testing and was wondering if anyone has done any tests on the following developers, and what their findings were.


Kodak HC110
Kodak XTOL Replenished
PyroCat HD


The three developers you listed (and most general purpose developers) will give you essentially the film's ISO speed within a small fraction of a stop. XTOL will yield very slightly higher speed than the other two. All other things being equal, the same differences would be found when running an EI test, except that the target EI is 2/3 stop below the ISO speed.

[Alan9940]

Ian,

Lots of good advice here. In all my years of testing various films and developers, using a densitometer, I have only witnessed one combination that lost any significant speed vs the box speed; and that was Ilford HP5+ (8x10) tray developed in ABC Pyro. All other combinations, as others have already said, came in very close to box speed; typically, about 1/3 stop less for me and my working methods. Therefore, I wouldn't be concerned with any of it.

[IanBarber]

Ian,

Lots of good advice here. In all my years of testing various films and developers, using a densitometer, I have only witnessed one combination that lost any significant speed vs the box speed; and that was Ilford HP5+ (8x10) tray developed in ABC Pyro. All other combinations, as others have already said, came in very close to box speed; typically, about 1/3 stop less for me and my working methods. Therefore, I wouldn't be concerned with any of it.

Thanks Alan. I have read all comments and found them interesting and I can no longer lose any sleep over this one :)

[Bernard_L]

esearing if you expose your Film at EI200 (...) but less details in highlights (maybe)
(...)
If you expose your film at EI800 (...) but more control over highlights
"maybe" indeed! When you make such statements, is it based on personal experience? Would you support the statements with examples? Sorry if I sound harsh, but forums, that should be an information resource, are degraded by such pseudo-information.


Rich14 You can over-expose by an enormous degree (by as much as 5 stops) and you will still get excellent results. In fact, rating film at 1/2 or 1/4 box speed (1 or 2 stops more exposure than box speed) often results in increased quality
+1 and even more than 5 stops! see examples given by David Vestal in The Craft of Photography.

[tonyowen]

A related question - at least in my mind. A given film has 'printed box speed and a recommended development time at a certain temperature and a developer 'strength'[ ie 1: something].
NO PROBLEM, but what is the mechanism that makes 'Stand Development' work when the film is left in the developer for many times the duration specify by the manufacturer for a particular developer
just curiosity
regards
Tony

[Alan9940]

A related question - at least in my mind. A given film has 'printed box speed and a recommended development time at a certain temperature and a developer 'strength'[ ie 1: something].
NO PROBLEM, but what is the mechanism that makes 'Stand Development' work when the film is left in the developer for many times the duration specify by the manufacturer for a particular developer
just curiosity
regards
Tony

I'm no expert on stand development because I don't use that technique, but I do employ EMA (extreme minimal agitation) for certain film stocks. Basically, what happens is that the developer quickly exhausts itself in the dense negative areas (high values) while continuing to work in the thinner areas (shadows.) At some point, all developer activity stops. Then, an agitation cycle will start the process over again. Generally, one single agitation cycle is completed even with 'stand development.' All these development techniques can produce a different looking negative, but overall CI can reach what any normal development technique provides.

[Vaughn]

Reciprocity failure will give you more challenges than developers affecting 'box speed'. I rarely use anything except B or T for work under the redwoods. I have forgotten what 'normal' lighting conditions are!

[IanBarber]

Reciprocity failure will give you more challenges than developers affecting 'box speed'. I rarely use anything except B or T for work under the redwoods. I have forgotten what 'normal' lighting conditions are!

Vaughn, what challenges do you find with reciprocity. When in the redwoods, what film do you use, what times do you incur and how do you process the negatives

[Vaughn]

My expose times range from a few seconds to many minutes. Generally, I meter to place the darkest shadow areas I want detail in on Zone III -- that is, I use my spot meter, read just the shadow, then add two stops of exposure to that reading. With conventional films, I will add one to two stops of exposure to correct for the film's poor response to the low level of light in the shadows. With TMax and Acros, I might just add one stop. I then read the brightest area in the scene and determine the development time based on that (and on experience).

I use the reciprocity "failure" to help increase contrast by increasing development (more exposure to get the shadows right, then let the highlights take off). I am using alt processes for print-making that have a need for high contrast negatives -- quite a bit beyond what the average user would want for contrast. So my method does not translate well for others.

Best bet would be to look up the reciprocity corrections for the film you are using - they will usually include development corrections as well. A lot will depend on the scene brightness range and your printing method. Test by going out, shooting, developing and printing!

When I first began using LF (1979), I did not know about reciprocity failure. I began by exposing at what I thought the exposure should be (using a Luna Pro), and I would take a second image with one more stop exposure. I found that the second exposure was easier to print. I ended up cutting the ASA in half as a general rule -- which got me overly dense negatives when I ventured out into the sun!

[tgtaylor]

... but what is the mechanism that makes 'Stand Development' work when the film is left in the developer for many times the duration specify by the manufacturer for a particular developer...

While I don't have the requisite chemistry or physics background to answer Tony's question, I suspect that slowing down a chemical reaction in a particular spot enables better results than if it had proceeded there at full speed. I have noticed that printing a number of alternative processes slowly by using the open shade for the bulk of the exposure (slowing it down) took longer but also produced better results than if I had exposed it completely to the direct sun. Similarly, allowing the molecules of a diluted developer work on an area until exhausted before agitation to bring fresh developer to that point slows down overall development and may also bring about better results. (The UV present in the shade remains the same.)

Fuji's directions for developing its films offers an interesting analogy: It recommends an initial agitation of 60 seconds for the first minute and 5 seconds for each minute thereafter. Kodak, on the other hand, recommends 30 seconds for the first minute and 5 seconds each 30 seconds thereafter. The overall time of agitation remains the same but the developer is allowed to sit longer with the Fuji method.

Thomas

[IanBarber]

With conventional films, I will add one to two stops of exposure to correct for the film's poor response to the low level of light in the shadows. With TMax and Acros, I might just add one stop.

I found this interesting as I never think about adding more exposure above what I have determined for Zone III. I am right in thinking that although you have worked out your exposure for Zone 3, in effect, you are actually putting them on Zones 4 / 5 depending on what film you use

[Bernard_L]

Vaughn Generally, I meter to place the darkest shadow areas I want detail in on Zone III -- that is, I use my spot meter, read just the shadow, then add two stops of exposure to that reading.
To me this means those "darkest shadows" will be promoted to zone VII... That is before one starts to address reciprocity (which you do in the next sentence). Maybe you meant: "then remove two stops of exposure...", typical case of slippage of the keyboard.

[Bruce Watson]

From reading, my understanding is that a developer can quite easily make an ISO 400 film act more like ISO 600 or on the opposite side act more like ISO 200.

I don't have the facility to do and serious testing and was wondering if anyone has done any tests on the following developers, and what their findings were.


Kodak HC110
Kodak XTOL Replenished
PyroCat HD


The film's ISO is the result of specific laboratory tests. It's not a variable, it's a rating. When that film gets out in the field with us photographers, we don't use the same laboratory tests, so we get different results. That is to say, we get a personal exposure index (PEI, or just EI) that is different from the film's ISO rating. This isn't good or bad, it just is. And it's one of the reasons that Adams and Archer developed the Zone System, the first test of which is to find your PEI.

As to developers, there are several broad categories of developers. There are solvent developers which tend to give EIs that are lower than the film's ISO rating. HC110 is a solvent developer. It's been so long since I quit using HC110 I don't really remember, but I think my EI for TXP was 250 with HC110. This in high dilutions (which lessens the solvent effect) and continuous agitation (rotary, Jobo 3010 tank). More "standard" workflows will likely result in lower EIs.

Then there are so called acutance developers which tend to give EIs that match or are higher than the film's ISO rating. I'm not sure that XTOL would be rated an acutance developer, but for me it's always given a slightly higher (1/3 stop) EI over ISO rating. It did this for me with TMY, but with my exposure workflow it was always easier to just rate TMY at 400 and use that extra 1/3 stop as a slight cushion. That way I could work in even stops all the time. I'm lazy that way, what can I say?

Staining developers like PyroCat HD I can't discuss, having zero experience with them.

[xkaes]

The film's ISO is the result of specific laboratory tests. It's not a variable, it's a rating.

I must live on a different planet than you do:

https://en.wikipedia.org/wiki/Film_speed

The ASA standard underwent a major revision in 1960 with ASA PH2.5-1960, when the method to determine film speed was refined and previously applied safety factors against under-exposure were abandoned, effectively doubling the nominal speed of many black-and-white negative films. For example, an Ilford HP3 that had been rated at 200 ASA before 1960 was labeled 400 ASA afterwards without any change to the emulsion. Similar changes were applied to the DIN system with DIN 4512:1961-10 and the BS system with BS 1380:1963 in the following years.

"FILM SPEED" has changed MANY TIMES over the years. Write this 50 times on the blackboard. Then read Richard Henry's 10 page explanation about the history of film speed.

[tgtaylor]

The developer selectively reduces silver halide crystals in the emulsion to metallic silver, but only those having latent image centres created by action of light.[4] The light sensitive layer or emulsion consists of silver halide crystals in a gelatin base. Two photons of light must be absorbed by one silver halide crystal to form a stable two atom silver metal crystal. The developer used generally will only reduce silver halide crystals that have an existing silver crystal. Faster exposure or lower light level films usually have larger grains because those images capture less light. Fine grain films, like Kodachrome, require more light to increase the chance that the halide crystal will absorb at least two quanta of light as they have a smaller cross sectional size. Therefore, silver halide crystal size is proportional to film speed. The metallic silver image has dark (black) appearance. Once the desired level of reduction is achieved the development process is halted by washing in a dilute acid and then the undeveloped silver halide is removed by dissolving it in a thiosulfate solution, a process called fixing. https://en.wikipedia.org/wiki/Photographic_developer

Thomas

[Bill Burk]

IanBarber,

Getting back to the original question, when people talk of speed losing developers, I think sometimes they are thinking about the change in the standard which allows manufacturer to pick the developer. The corollary being, if manufacturer picked a particular developer to get the highest possible speed because they couldn't get the speed they wanted with the old standard ISO developer... and I don't use that particular developer... how much speed am I going to lose?

How much speed did the manufacturer gain by changing away from the old standard ISO developer?

I don't think it's that much. Probably 1/3 stop.

[Bill Burk]

I also think people lose speed when they do not develop to the specified contrast which is approximately 0.62 gradient.

Because for pictorial negatives, a gradient of approximately 0.5 is more commonly what photographers aim for.

It could be argued (by using Delta-X) that there is no speed loss considering how much of the toe you can use.

But most people measure their speed at the point of 0.10 above base+fog. And by that measure you will lose 1/3 to 2/3 stop.

The crazy thing is, yes you lost 2/3 stop the way speed is measured. But no you didn't lose speed practically. You can still use the 400 speed film at 400.