New (?) two-bath developer: Bellini Duo-Step

[David Allen]

Just came across this reference to this new (at least to me) two-bath developer:

https://ntphotoworks.com/product/bellini-duo-step-tentative-diafine-bw-film-developer/

Has anyone tried it?

Bests,

David.

Note: temporary addresses for

• my website: http://dsallen.carpentier-galerie.de
• slideshow:
• interview: http://dsallen.carpentier-galerie.de/video.php

 

[jim appleyard]

Interesting, but I didn't know that you could get lower contrast by simply lowering your films EI???

 

[jim appleyard]

It's now available at Freestyle. I may try it when I run out of Diafine. I wonder if it pushes TX as far as Diafine? Note that it isn't any cheaper than Diafine. Due Step sells for $42.00 for 1 liter bottles, Diafine is $33.00/quart.

 

[mrtoml]

I got good results with it using FP4 at 250 and HP5 at 640.

FP4:

HP5:

 

[relistan]

I got good results with it using FP4 at 250 and HP5 at 640.

FP4:

HP5:

Excellent images

 

[pentaxuser]

David Allen's link is now over 4 years old and clicking on it gives me the usual 404 error. I had a look at Nik and Trícks website and can find no mention of this developer which appears to be diafine based

The 2 bath developer now stocked seems to be Thornton's. So what's this developer actually called that Freestyle now stocks and is it linked to what David Allen linked to which appeared to be Diafine based?

Thanks

pentaxuser

 

[foc]

David Allen's link is now over 4 years old and clicking on it gives me the usual 404 error. I had a look at Nik and Trícks website and can find no mention of this developer which appears to be diafine based

The 2 bath developer now stocked seems to be Thornton's. So what's this developer actually called that Freestyle now stocks and is it linked to what David Allen linked to which appeared to be Diafine based?

Thanks

pentaxuser

I found this on their website.
https://ntphotoworks.com/product/bellini-duo-step-diafine-film-developer/

 

[pentaxuser]

Thanks, foc I wonder what real connectíon it has the Diafine. The description of it on that level is somewhat vague and crucially what does it do that none of the current speed increasing developers such as microphen do?

pentaxuser

 

[mrtoml]

I ordered some from them this week. It is due to arrive today.

 

[mrtoml]

Excellent images

Thanks for the comment. I should say that looking at my notes the HP5 image is 35mm, the FP4 one is 645 format.

 

[Milpool]

There isn’t a lot of definitive/official information out there on the complete compositions of either Diafine or the Bellini Duo Step developer, however what is available suggests from a processing perspective the Bellini developer has more in common with so-called “divided” developers than Diafine which was always supposed to be a “true” two-bath, the main difference being that in the former case development takes place in both A and B while in the latter case virtually no development takes place in A.

In other words with Duo Step bath A is likely a fully functioning developer, but you truncate the development time in bath A and then “finish” development in bath B (development in bath B being limited by some amount of bath A carried over in/on the emulsion). This is analogous to all the old divided developers which were often based on a metol-sulfite bath A, and incidentally Thornton’s version is a more or less inconsequential variation on Adams’s “divided D-23”.

With the Diafine type development activity in bath A is suppressed by it having a mildly acidic pH, and whatever amount of bath A is absorbed into the film emulsion is then activated by immersion in the alkaline bath B. In this case the amount of bath A carried over into B limits the amount of development that can take place, which makes variable such as temperature somewhat less relevant.

An advantage of the first type is that you can control contrast by altering development time in bath A. You can’t do that with the Diafine type.

In both cases the shape of the film’s characteristic curve will tend to be somewhat “straightened” with a shortening of both toe and shoulder. With the Bellini type emulsion speed will tend to be fully realized even if overall contrast is reduced. With the Diafine type, emulsion speed may or may not be fully realized - it will depend on the formula and possibly the film.

Thanks, foc I wonder what real connectíon it has the Diafine. The description of it on that level is somewhat vague and crucially what does it do that none of the current speed increasing developers such as microphen do?

pentaxuser

 

[pentaxuser]

T hanks Milpool for your explanation in #11

pentaxuser

 

[jim appleyard]

Thanks, foc I wonder what real connectíon it has the Diafine. The description of it on that level is somewhat vague and crucially what does it do that none of the current speed increasing developers such as microphen do?

pentaxuser

I found this info on their website:

https://ntphotoworks.com/wp-content/uploads/2022/01/Duo-Step_Guide-Sheet.pdf

"Higher contrast situations can be mellowed by lowering the film speed if desired" I didn't know it was this simple!

The chart shown is merely the speeds recommended for Diafine, however, they imply this stuff works just like Diafine.

Every now and then, some Diafine pops up on ebay for a reasonable price, I'll stick to that!

 

[pentaxuser]

"Higher contrast situations can be mellowed by lowering the film speed if desired" I didn't know it was this simple!

Neither did I Can anybody else help here on what seems to be a statement that lowering film speed is all that is needed to "mellow" contrast

Is the word "mellow" as opposed to the word "lower" deliberately chosen because lowering film speed does not lower contrast per se in what is the usual understanding of lowering contrast?

In a high contrast scene lowering film speed works but it has to be combined with less development to lower contrast, doesn't it? Henry Horenstein in his book "Beyond Basic Photography" has a good example of this with 2 identical scenes

pentaxuser

 

[Milpool]

They’re simply repeating the conventional wisdom which is that you give a little extra exposure when you plan to develop the film to a lower-than-normal contrast. Same type of thing that’s in the Zone System etc. and it’s not anything particular to two-bath developers.

Neither did I Can anybody else help here on what seems to be a statement that lowering film speed is all that is needed to "mellow" contrast

Is the word "mellow" as opposed to the word "lower" deliberately chosen because lowering film speed does not lower contrast per se in what is the usual understanding of lowering contrast?

In a high contrast scene lowering film speed works but it has to be combined with less development to lower contrast, doesn't it? Henry Horenstein in his book "Beyond Basic Photography" has a good example of this with 2 identical scenes

pentaxuser

 

[pentaxuser]

They’re simply repeating the conventional wisdom which is that you give a little extra exposure when you plan to develop the film to a lower-than-normal contrast. Same type of thing that’s in the Zone System etc. and it’s not anything particular to two-bath developers.

So they are right in stating that doing nothing else other than lowering film speed will reduce contrast? Will this be to an extent that makes it meaningful in terms of print quality?


pentaxuser

 

[Milpool]

I think it’s their wording that’s confusing you (probably not the best translation). Lowering the exposure index in and of itself doesn’t affect contrast. All that amounts to is giving the film a little more exposure. Contrast is a function of development, so what they mean is simply that if you plan to reduce contrast at the development stage they suggest lowering the film speed (exposure index, really).

So they are right in stating that doing nothing else other than lowering film speed will reduce contrast? Will this be to an extent that makes it meaningful in terms of print quality?


pentaxuser

 

[MattKing]

As it is a two-bath developer, the contrast/development inter-relationship may be a bit unusual.
Increased exposure can reduce contrast, if the increase is sufficient to drive the image up into the top part of the curve.

 

[pentaxuser]

As it is a two-bath developer, the contrast/development inter-relationship may be a bit unusual.
Increased exposure can reduce contrast, if the increase is sufficient to drive the image up into the top part of the curve.

What kind of increase in exposure is required( 1/2 stop; 1 etc) and what is sacrificed in the resultant outcome, Matt?

Thanks

pentaxuser

 

[MattKing]

What kind of increase in exposure is required( 1/2 stop; 1 etc) and what is sacrificed in the resultant outcome, Matt?

Thanks

pentaxuser

I don't know, as I've not used this particular developer.
My post was in response to an observation about more typical developers and contrast.
My very small amount of experience with two-bath developers is that the normal rules have to be refined.
Plus, of course, I've over-exposed film, and suffered a loss of dynamic range/available contrast as a result.

 

[snusmumriken]

Thanks for the comment. I should say that looking at my notes the HP5 image is 35mm, the FP4 one is 645 format.

The FP4 one is beautiful.

Is the HP5 one a crop? If not, the graininess seems uncharacteristically coarse. Could it be reticulated?

 

[Philippe-Georges]

At BELLINI's website:

DF2 DUO STEP Film Developer - Bellini Foto

Two parts Developer Solution A + B to make 1 L to 2L each one

www.bellinifoto.it