Development defects that may appear on the films.

[georgegrosu]

Lately, I have seen several posts where various malfunctions (star, darker spots) are discussed for various films.
I am going to present same information about the faults I know when processing of films and which may be useful for some.
For the word "zoneje" I did not find a translation.

Agitation of the developer solution.
Kinetics of the development process depends largely on the speed of diffusion of substances is made (ie ions) from solution of developer to the emulsion of film and the products of reactions from emulsion go to out.
Besides of diffusion direction : developer - emulsion – developer, It takes place an internal diffusion inside of the emulsion, causing an interaction between neighboring areas of the image that received different exposures and between layers of color films.
The rate of diffusion of substances depend on the solution temperature and the distance they have to go.
Exchange of substances between emulsion and outdoor hindered by an adherent layer of developer on the surface of emulsion film, that has a different chemical composition than the rest of the developer. Adherent layer of developer is poorer in active substances of developer and richer in the development products (oxidised). If the diffusion process is slowed down or accelerated from this adherent layer, or other causes, there are some defects in development which is manifested by unevenness of density in areas that have received the same exposure.
The main defects of development are as follows:
- the effect of developer directed;
- zonajele (no english translate) ?;
- marginal effects (adjacency).
Effect of developer directed occurs - as shown in Figure 2 - by under developing areas (lower density) behind some image detail that received huge exposure. Because transporting film (agitation), the products of developer (bromine ions, oxidizing substances, etc.) results in an area with high exposure to developing intense and go down through the adherent layer and slows diffusion and film development in the surrounding area. Zonajele (see Fig. 3) are some unevenness of density in the vertical direction, visible only on the screen (displacement of images), which light travels to the side. Is due to the fact the developer adheres more easily and dripping down mainly on certain portions of the surface of the emulsion, which over developer. These defects, which is seen better on lower densities occupying large areas in the image (ie the sky), are all the more powerful as the development airline (sometimes without developer) is longest.
The effects of the adjacency, which are presented in Figure 4 the effect of the border, the effect EberJiard represents unevenness of density that forms the boundary of separation of areas with different exposure, due to anomalies in the conduct diffusion of substances that occur within the emulsion in during development. To liquidate or reduce defects above, it is necessary to intensify the diffusion process, which is done by reducing the thickness of developer adhering to the surface of the emulsion. By strong agitation of the developer can eliminate the routing development and severe reduction of zonajelor and marginal effects. When developed industrial agitation of developer, is done in two ways: general agitation and local agitation.
• The physical state of the developer. During the development process, the developer solution is gradually contaminate due to the following main reasons:
- the formation of insoluble organic compounds;
- accumulation of metallic silver;
- impurification of developer by the film.
Insoluble organic compounds are formed by polymerization of oxidation products of developer substances (eg quinone) resulting from the reaction developed or oxidation. These organic compounds forming a precipitate in suspension, reddish-brown, it accumulates with time particularly in developer with low sodium sulfite concentration, such as chromogenic developer.
Metallic silver resulting from the reduction of silver ions (Ag +) in solution of existing developer substances. Silver ions that come from partial dissolution, in a small proportion, the photosensitive silver halide crystals by sodium sulfite existing in developer. Therefore, developer containing high sulfite concentration (eg for developer black and white for negative film) impurification with metallic silver an extent most significant developer than the others developer.
The film transport and introduce permanent in developer powder of support and emulsion remained from cutting and perforation operations at the factory. To this we add small amounts of gelatin that are separating from the emulsion due to friction conveyor rollers of the processing machine of film. Gelatin particles remain in suspension is lighter and other impurities formed by embedding so-called ,, slime” that adhere easily on film surfaces, especially emulsion.
Impurities that accumulate are deposited on pipe walls, which reduces solution circulation and thus the degree of agitation of the developer. In addition, some substances can stain or dirty emulsion film.
Because the process of development to take place in good conditions, it is necessary that the developer solution be cleaned by removing impurities.
Cleaning the developer, and other solutions, surgery is typically performed by filtration.

George

 

[AgX]

The sketches you present refer to roller-transport processing. Where the film is moved in longitudinal direction through the bath.
A manner of processing typically not used by amateurs.

 

[AgX]

"Directed Developing" = Bromide Drag in tank processing without agitation

 

[georgegrosu]

AgX, the chemical processes that are produced during processing in a developing machine are similar to those you follow and in an amateur dose.
So, the malfunctions that may appear on the film are similar in both a developing machine and an amateur dose.
Imagine that the developed dose does not stay on the bottom, it s stay like Jobo.
In Jobo, the film rotates in a circle while the processing machine moves to form a spiral.
When I came to the cinematography, a colleague told me, the processing machine is like a meat grinder.
The sketches I have been presented to understand the phenomenon and where to expect the defect to occur.
“Zonajele” are seen only in cinematic projection as lines of other density that walk on the screen.
If you can help me with the translation for “Zonajele”.
If you find writing / speaking mistakes that can make the text easier to understand, I'm waiting for suggestions.

George

 

[georgegrosu]

Completion
In the image of Effect of directed development and "zonaje" of development = Fig. 2 and Fig. 3 .
Fig. 2 is the effect of developer directed, or Bromide Drag .
The black circle is a high density image, and below it is a lighter area than the rest of the background.
More or less rare hatched represent a higher or lower density on the film.
Fig. 3 shows “zonaje” of development, some lines which serpent on the image, having a lighter density than the rest of the background.
More or less rare hatched represent a higher or lower density on the film.
Fig. 4 marginal effects is the effect of EberJiard and the border effect.
Below the photo, you can see the density coordinates D1, D2, D3, D4.
More or less rare hatched represent a higher or lower density on the film.

George

 

[Craig75]

Is "zonaje" those lines you get in skies when the development time is too short eg under 5 mins? I dont know what those are called in english. I like the name zonaje for them.

Ah just reread. Zonaje isnt just that. Its the whole spectrum of different development problems.

 

[georgegrosu]

“Zonajele” are seen as traces that have a density other than the image.
“Zonajele” are due to the fact that the film is same area where the solution tends to drainage preferentially.
In the processing machine and Jobo, the film is not always sinking into the solution.
The film stays in the air when it passes from one cuvette to another, to the developer machine.
When the film comes out of the solution and starts climbing, solution transported by film tends to come down.
When the film reaches the top roll, it begins to descend to get into the solution.
The solution that accumulates on the top roll will pass on the film and will again tend to fall down on those preferential directions.
Careful! Lines = cross hatch in the image represent different film densities.
More Lines = Higher Film Density.
“Zonajele” occurs due to over-development during aerial development.

George

 

[georgegrosu]

I rebuilt drawings.
I hope to understand better.

George

 

[georgegrosu]

To better understand the issue of 'Zonaje”, you can watch the movie
"Asta seara dansam in familie" from the minute - 1:04:53 to the minute - 1:05:50.
It is a plan with sky.


George

 

[georgegrosu]

To see the "Zones" malfunction correctly, you must watch the movie fluent.
You do not have stop and start the film while watching the movie.
I also had computer problems and that's why I did not put the example of the movie from the beginning.
Finding a movie with "Zones" was not an easy one.
Many movies on the internet do not have the proper quality to see this malfunction.
The "Zone" malfunction is due to the aerial development of the film and to the place where film revelator droplets best adhere.
This air development occurs both in the development of film on processing machines, on Jobo or at the dose.
In a modern development machine, besides the revelator's general circulator pump is submersible jets that send the revealer to the emulsion of the film (locally).
http://www.kodak.com/KodakGCG/uploa...t_en_motion_support_processing_h242_h2402.pdf pag 2-14.
In Fig. 2-9 shows that the top rollers are not in solution (developer).
That is why air development occurs.
At a development in dose, when the developer is removed and the next solution is introduced, we have air development.
I hope these additions information have made you clear of misunderstandings.

George