What is a compensating developer?

[Large Format Mike]

Is Kodak HC-110 a Compensating Developer or a Standard Developer???Is Kodak HC-110 a Compensating Developer or a Standard Developer???

[Dustin McAmera]

I think the answer is that it can be, if the solution is weak enough.

As I understand it, a compensating effect is where the developer in highly-exposed areas of the film becomes significantly depleted. That means the development there slows down, while less-exposed areas still have plenty of developer left, and they get to catch up. Whether this is a good or bad things is up to you and your situation. Compensation can bring out shadow detail without burning in the printing/photoshop stage; but another way of describing the effect is that it lowers the contrast.

Several developers can give a compensation effect. I have done it with Rodinal and less often with HC110. I copied from other people's accounts here and at Flickr. This is one of the effects of 'stand' development, where people include hardly enough developer in the solution, and then don't agitate at all, with development times of an hour or so. This will also give you edge effects, where the plentiful developer in a shadow area diffuses across the border and gives extra development to just the edge of the highlit area next to it. Some people give less time and 'not much' agitation and call that 'semi-stand'.

You will only see the effect with low concentration, or the developer won't become limiting in the exposed areas. With Rodinal, I was putting 3ml of concentrate in the solution for a 36-exposure roll of 35mm; and I worked out the volume for other film sizes from that in proportion to the area of film. Offhand, I forget what amount of HC110 I have used.

 

Edited December 20, 2022 by Dustin McAmera

[glen_h]

The one that commonly gets that name is Diafine.

But the above mentioned process is called stand development.

For stand, an unusually weak developer is used for a long time, sometimes up to an hour.

There is some agitation early, but most of that time has no agitation.

 

Diafine is different, but the goal is the same.

Diafine has two parts, A and B.

You soak film in A for 3 minutes, between 70 and 75F, agitating every minute.

Pour it out, then pour in B.  Again 3 minutes, agitating every minute.

 

The way it was first explained to me, by my grandfather over 50 years ago,

is that part A soaks into the emulsion, but mostly doesn't develop yet.

(A mostly has the developing agent, but not the alkaline agent.)

The part B activates the developer. It can only develop until the A is

used up, or has diffused out.  The result is that it can't overdevelop

highlights, while shadows can develop much longer.

 

A not so obvious result is that for most film, you get a higher effective speed.

The recommended EI for Tri-X are between 1200 and 1600.  (It changed

over time.)  When I was younger and didn't know so well, I pretty much

believed that.  I understand film speed better now, but it still gives

amazing results at those speeds.  But also, it is mostly independent of

temperature over 70 to 75F, and 3 minutes or somewhat more.

 

For many more modern films, the speed increase is much less.

PanF+ goes from 50 to 80.  TMax 100 goes to 160, and TMax 400

goes to 500. 

 

And also, it lasts close to forever, except for how much you lose

soaked into the film, or spilled. 

[Alan Marcus]

A compensation developer: A developer so formulated that it operates less aggressively in areas receiving high levels of exposure and more aggressively in areas that have received low levels of exposure. This formulation delivers detail even though the film displays lowered contrast. 

The mechanism is a highly diluted formula that quickly diffuses into the emulsion. In those areas of high exposure, it exhausts and thus stops working. In areas of low exposure, it continues to work. In this way it compensates for subjects that otherwise would challenge the ability of the film to handle expanded tonal range.  

[rodeo_joe1]

The edge effect from using a very dilute developer at stand times can be quite exaggerated with 35mm film, and in extreme just looks like uneven development - which it is.

OTOH using a 2 part developer, as described by Glen, has no such (often ugly) exaggerated edge effect. Although it does give a strong acutance effect. 

A 2 part developer consists of having the reducing agent(s) and preservative only in part A, and an alkali activator only in part B. 

In its simplest form, part A consists of a solution of Metol and sodium sulphite, while part B is a solution of sodium carbonate. 

This is the old 'Beutler' formula of:

Metol............................ 5 gm

Sodium Sulphite....... 25 gm

Sodium Carbonate.. 25 gm

Water to....................... 1 litre

Time @ 68F is given as 7 to 10 minutes. 

This is a 'soft working' - low contrast - developer to start with, but can be split into two 1 litre solutions with the Metol and sulphite in part A, and the carbonate in part B. Giving even greater control over contrast by varying the relative times in the two baths. 

This is an old formula and modern thin emulsion films don't hold much developing agent in them. So it might be found beneficial to increase the quantity of Metol to 8 gms or thereabouts or add a small amount, maybe 1gm, of hydroquinone to part A. 

Edited December 22, 2022 by rodeo_joe1

[Dustin McAmera]

Plainly, I didn't find the effect ugly or exaggerated, or I wouldn't have been doing it. I only did the full one-hour stand a few times. That's a long time to wait. If I was reducing the agitation, I mostly developed for about twenty minutes; just time to drink a beer; with an inversion at (say) one, two, four and eight minutes. As I said above, this wasn't devised by me: I think I copied it from someone either here or at flickr. On my most artful days I have consciously increased or decreased the amount of agitation to vary the effect.

The edge effects are modest; you have to look for them; and in some pictures it enhances the edge, say of a silhouetted feature. But the main effect is to give you some detail in deep shadows.

 

[rodeo_joe1]

2 hours ago, Dustin McAmera said:

Plainly, I didn't find the effect ugly or exaggerated, or I wouldn't have been doing it.

Like many things in life, moderation is often better than exaggeration. 

Naming no names, and especially not yours Dustin, but I've seen quite a few examples of stand development posted on PN that have obvious streaming and edge outline effects that do nothing to enhance the picture, quite the opposite.

Stand development was fine when nobody shot anything smaller than quarter-plate, but on a small format the outlining effect can be really obvious and intrusive.

So what's wrong with just using 'normal' development if nothing is added to the picture by doing otherwise?

[glen_h]

6 hours ago, rodeo_joe1 said:

 

(snip)

 

This is an old formula and modern thin emulsion films don't hold much developing agent in them. So it might be found beneficial to increase the quantity of Metol to 8 gms or thereabouts or add a small amount, maybe 1gm, of hydroquinone to part A. 

 

I have wondered about this.

The Diafine instructions, now and 50 years ago, say it develops all films to the optimum contrast.

But that was for 50 year old films.  There is no new Diafine for new films.

And I did have the thought about mixing A to a higher concentration, but didn't do it.

[glen_h]

6 hours ago, rodeo_joe1 said:

The edge effect from using a very dilute developer at stand times can be quite exaggerated with 35mm film, and in extreme just looks like uneven development - which it is.

OTOH using a 2 part developer, as described by Glen, has no such (often ugly) exaggerated edge effect. Although it does give a strong acutance effect. 

 

The other developer that, at least used to be, made by the same company is Acutane.

It seems to be named for the acutance that it, presumably, generates.

 

But yes, just like most things, you don't want too much acutance.