Higher silver content.

Funky Face

A
Funky Face

  • 0
  • 0
  • 44
faded glory

A
faded glory

  • Tel
  • Oct 7, 2022
  • 0
  • 0
  • 42
Parkbench images

A
Parkbench images

  • 0
  • 0
  • 70

Recent Classifieds

Forum statistics

Threads
179,585
Messages
2,472,887
Members
94,843
Latest member
ocieb
Recent bookmarks
0

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
Evidently. But for what purpose? The argument I heard, and never verified in any way, was that the cadmium deliberately or by accident prolonged the product's life. Was this in fact the case? Out of all people in this thread, you're in the best position to say something about this.

You see, I wouldn't be surprised if it was there for a totally other reason, just like certain rare earths still play a role in sensitization in today's emulsions, because they apparently play a crucial role in how the silver-halide lattice creates developable sites.

It is all about competition for electrons. We know if certain rare earth metals are added when the grain is formed or grown we get a certain result. If reciprocity failure is less we assume an electron was captured and held in place. It is all theoretical based on experiments conducted to test a hypothesis. The proof is in the pudding; make the emulsion with and without the rare earth metal and study the result. Film builders run many, many designed experiments. Explanations provided after it was demonstrated in the laboratory. Combinations that are to be tested are determined by experimental investigation (educated guesses and Edisonian trial-and-error. "We don't know what works; but we know what doesn't work". Don't rule out "by accident". It doesn't matter how you found the material that works.
 

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
No worries, didn't take it that way :smile: I just meant to say: it's a good question and frankly, I don't see the practical use for capturing a 14-stop range.

Photographing atomic explosions requires a wide range. This was done by Dr. Harold Edgerton when EG&G had government contracts. Not much call for this.
 

koraks

Member
Joined
Nov 29, 2018
Messages
3,940
Location
Europe
Shooter
Multi Format
Don't rule out "by accident".

Oh no, certainly, I don't. But your case is very clear - the addition of rare earths and probably (?) cadmium back in the day is a matter of photon efficiency primarily. If it so happens to extend the useful lifetime of a material far beyond the manufacturer's reasonable interest (the Agfa paper example), it's truly an unanticipated accident. Not the kind of accident in terms of "we don't know why it works, but it does", but the kind of accident that makes people deep in their retirement say "I never thought it would pan out like this".
 

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
Hello everyone ...

A higher silver content in the films (such as those of the 50s / 60s), made them qualitatively better?
What peculiar characteristics were due to more silver, compared to thin modern ones?

Many thanks.

Back to the original question. More silver was needed because the imaging process was less efficient than modern technology. The desire for "old looking films" eludes me. However, whatever characteristic is desired can be fine-tuned in modern films. It is all about control. The 21th century emulsion maker has much better control over the process than his processors had. Just tell the emulsion maker what you want. High halation, weird curve shape, truncated spectral sensitivity, emulsions with a wide range of grain sizes, poor MTF. He/she can control the emulsion to get just what you want. The problem is that there ismay not be agreement for the desired characteristics nor enough people that want the same characteristics. Films like TX, T-MAX, Portra were based on feedback from photographers regarding what they wanted. T oday photographers have the benefit of being able to modify the characteristic using PhotoShop. Of course this eliminates optical printing unless you create digital negatives.
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
39,632
Location
Delta, BC, Canada
Shooter
Multi Format
the kind of accident that makes people deep in their retirement say "I never thought it would pan out like this".

Sounds like my (lifelong loyal to employer Kodak) Dad before he passed away, in regards to photography in general, and Kodak in particular.
 

AgX

Member
Joined
Apr 5, 2007
Messages
29,757
Location
Germany
Shooter
Multi Format
It is interesting to note that another Adox film which was promoted as being designed specifically for reversal processing - Adox Scala 160 - is also claimed to have "an increased silver content."

Adox Silvermax and Adox Scala 160 are the same film, just differently labelled, for marketing.
 

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
Oh no, certainly, I don't. But your case is very clear - the addition of rare earths and probably (?) cadmium back in the day is a matter of photon efficiency primarily. If it so happens to extend the useful lifetime of a material far beyond the manufacturer's reasonable interest (the Agfa paper example), it's truly an unanticipated accident. Not the kind of accident in terms of "we don't know why it works, but it does", but the kind of accident that makes people deep in their retirement say "I never thought it would pan out like this".

I agree with you. Most of the 100-200 discrete chemicals used in a modern films serve multiple purposes. We know what characteristics are provided because so many characteristics of films are carefully measured in order to control the results. Know one knows all the mechanisms, they just know what works. Statistical Design of Experiments and Analysis of Variance (ANOVA) are statistical tools that are used.
 

koraks

Member
Joined
Nov 29, 2018
Messages
3,940
Location
Europe
Shooter
Multi Format
Thanks Bob, that's a really interesting insight. It makes perfect sense as well, although I didn't expect that unexplained effects would play such a significant role. Then again, it's just not feasible or even technically possible to figure out why some things work and others don't. I hadn't really anticipated this because the industrial environment I spent my early career in revolved all around the absolute necessity to also figure out why unanticipated effects would pop up. Then again, one company I worked for actually has a veritable army of PhD's across all relevant sciences running around, not even counting what happens at their partners and suppliers. Different worlds.
 

flavio81

Member
Joined
Oct 24, 2014
Messages
4,947
Location
Lima, Peru
Shooter
Medium Format
The way you get 14 zones is you take the 10 zones and make them smaller.

The film cartridge gives you 36 exposures, so you can easily take a picture of 14 or more places, "zones", landscapes, etc.
 

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
9,063
Location
Humboldt Co.
Shooter
Large Format
No worries, didn't take it that way :smile: I just meant to say: it's a good question and frankly, I don't see the practical use for capturing a 14-stop range.
Hmmm...I sometimes use Zone -I and occasionally Zone -II...but that might just be my imagination...when I make carbon prints. Due to the raised relief of the process, I can get a zone or two of image-related pure-black texture at or below Zone 0 on the print. Kinda of fun. Expose for detailed deep shadows, give extra development to expand the mid-tones and high lights -- then print the shadows down.

Favorite image is a 13+ stop SBR inside a sea cave looking out into the sunlight. I actually kept the development close to normal for that one.
 

koraks

Member
Joined
Nov 29, 2018
Messages
3,940
Location
Europe
Shooter
Multi Format
@Vaughn, my apologies tor being pedantic, but that's not zone -I or -II. By definition, these don't exist. You get shadow differentiation that the process allows for and this enables you to create zones I and II, which happen to be at higher densities than they would be in a silver gel print etc. But that wouldn't expand the zone range. It's a matter of definitions.
 

braxus

Member
Joined
Oct 19, 2005
Messages
1,437
Location
Fraser Valley B.C. Canada
Shooter
Hybrid
(off topic) Laser- do you know what changes Kodak made to Panatomic X in the last years of its run? Did they remove the cadmium long before it was discontinued? What changes did the film get in its last years, or was it basically the same with minor tweaks all its life? Is it a film Kodak could technically make today, if they so chose to? And what made this perticular film so stable from aging, unlike most other films? You can use decades old Pan X at its rated speed with no issues.
 
Joined
Jul 28, 2016
Messages
2,452
Location
India
Shooter
Multi Format
Why would Henning Serger be a candidate for such a question?

That's because he appears to be very knowledgeable about Adox's products and way back in 2012 he was testing this film:

This film is one result of the cooperation between Adox and InovisCoat.

The film is currently in the test phase here in my lab. First results look good. The spectral sensivity of this film is identical to the Agfa APX 100.

And BTW the questions were answered by Mirko:

In our product description for Silvermax we claim that it has more silver than comparable films and that this leads to a higher DMAX and the possibility to get an extended copy range out of it if developed in Silvermax developer.

This is all true.

If you manufacture a film there are certain things you can do to get the desired characteristics. It starts with making the emulsion and it "ends" with the amount of emulsion you apply per sqm. The more you apply, the higher is the silver content and the higher will be the DMAX which the film can build up (same emulsions compared with each other).
So if you don´t object the costs, you can make a "better" film this way if there wouldn´t be an affect on the contrast as well.
Your contrast is also increasing and this limits you in using this as a means of achiving a superior quality.

The aim when manufacturing this film was to achieve a better DMAX on the clear base so the film would be good for reversal processing but not putting too much so it can also be used as a regular negative film.

As said before it is based on Agfa technology and very similar to APX but on a clear base and with a thicker coating (silver rhich).
The spectral sensitivity is the same as identical sensitizers were used (up).
So compared to APX you will get more DMAX and a slightly higher contrast apart ofcourse from the different base.
This is why we formulated the Silvermax developer with it. This developer is soft working similar to our ADOTECH developer and optimized for Silvermax.
If you use both you get instantly very good results and (hopefully) can see the difference to "normal" fims.
While "normal" in this context means a film designed as a negative film with just as much coating (silver cotent) as nevessary to achive good DMAX for regular printing work.

..

Mirko
 
Last edited:

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
(off topic) Laser- do you know what changes Kodak made to Panatomic X in the last years of its run? Did they remove the cadmium long before it was discontinued? What changes did the film get in its last years, or was it basically the same with minor tweaks all its life? Is it a film Kodak could technically make today, if they so chose to? And what made this perticular film so stable from aging, unlike most other films? You can use decades old Pan X at its rated speed with no issues.

Panatomic-X was made in small volume so that the changes in the late 1970's were only made when material availability changed. The small grain size/slow speed helped the stability. T-Max 100 had superior image structure at a much greater speed and was technically superior in other ways.
 

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
Hmmm...I sometimes use Zone -I and occasionally Zone -II...but that might just be my imagination...when I make carbon prints. Due to the raised relief of the process, I can get a zone or two of image-related pure-black texture at or below Zone 0 on the print. Kinda of fun. Expose for detailed deep shadows, give extra development to expand the mid-tones and high lights -- then print the shadows down.

Favorite image is a 13+ stop SBR inside a sea cave looking out into the sunlight. I actually kept the development close to normal for that one.

Off topic. Minor White liked his toast Zone VI. I would expect that Fred Picker did too.
 

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
9,063
Location
Humboldt Co.
Shooter
Large Format
@Vaughn, my apologies tor being pedantic, but that's not zone -I or -II. By definition, these don't exist. You get shadow differentiation that the process allows for and this enables you to create zones I and II, which happen to be at higher densities than they would be in a silver gel print etc. But that wouldn't expand the zone range. It's a matter of definitions.
Not really. Zone II is lighter and receives less exposure than Zone 0. So how can my "Zone -I " be Zone I or II if it gets more exposure than Zone 0? I get textural detail in the form of raised relief in areas of pure black (Zone O). I call it Zone -1, it gets more exposure than Zone 0 and is as black as the material can get.

I am a little off-topic since my prints contain carbon and no silver or other such metals.

I just invented the term Zone -I, so it now exists! 😎
 
Last edited:
Joined
Jul 31, 2012
Messages
2,574
Shooter
35mm RF
Just because something is "technically" better doesn't make it better for every purpose. Frankly older films had more life and better tonality. You can see it. Look at Tri-X for example. It kept getting "improved" to the point where it doesn't look anywhere near the same as it used to. Some people think that is a good thing, but in today's world I'd argue it isn't really.

Seems to me by limiting silver and also thinning the emulsion films have become rather generic and digital looking. I wish someone would rewind the clock and make a film that was more malleable, like old films used to be. If I want grainless I can just use a digital camera, which at this point has eclipsed film for "grainless" purposes.
 

laser

Advertiser
Advertiser
Joined
Jun 16, 2005
Messages
821
Shooter
4x5 Format
That's because he appears to be very knowledgeable about Adox's products and way back in 2012 he was testing this film:



And BTW the questions were answered by Mirko:

Just because something is "technically" better doesn't make it better for every purpose. Frankly older films had more life and better tonality. You can see it. Look at Tri-X for example. It kept getting "improved" to the point where it doesn't look anywhere near the same as it used to. Some people think that is a good thing, but in today's world I'd argue it isn't really.

Seems to me by limiting silver and also thinning the emulsion films have become rather generic and digital looking. I wish someone would rewind the clock and make a film that was more malleable, like old films used to be. If I want grainless I can just use a digital camera, which at this point has eclipsed film for "grainless" purposes.

I am sympathetic to the desire for items from the past. However, very careful analysis doesn't support that modern materials can't yield the same tonality as older materials.
There is a difference in resulting grain structure. This is a combination of printer optical properties, film developer, density level, and the grain structure created in film manufacturing.

The use of less silver is a desired result of using the silver more efficiently. Adding silver only to have it ending up in the fixer doesn't accomplish much.

Technically better means the measurable characteristic are measured and the results are repeatable. Some unmeasurable characteristics may change but objective and even subjective evaluation doesn't support the argument. For the final evaluation of new film performance we depended on side-by-side evaluation in the hands of highly skilled practicing photographers doing many kinds of work in a wide variety of locations throughout the World.

In most cases the number of possible film products is limited. Having tens of different b&w 400 speed films might be desirable but not practical. In the case of T-Max we thought the differences were sufficient to justify a film in addition to Tri-X. We also demonstrated that a specific T-MAX 100 was justified because of the grain advantage. We had multiple variations of each and chose the ones that were preferred by customers. The same is true of Portra Films as described in "Making KODAK Film". We tried variations in saturation, spectral sensitivity, contrast, inter-image, MTF, grain, curve shape etc. Originally we had Natural Color and Vivid Color choices. With scanning on one survived.
 

Craig

Subscriber
Joined
Apr 8, 2004
Messages
1,518
Location
Calgary
Shooter
Multi Format
Seems to me by limiting silver and also thinning the emulsion films have become rather generic and digital looking.

Can you tell me how film can "look digital"? I have no idea what a digital image would look like, since there are so many different ways it can be changed and processed there isn't a single way that things can be digital. Or does it just mean you don't like the look of modern film?
 

AgX

Member
Joined
Apr 5, 2007
Messages
29,757
Location
Germany
Shooter
Multi Format
The use of less silver is a desired result of using the silver more efficiently. Adding silver only to have it ending up in the fixer doesn't accomplish much.

But, aside of having such silver-efficiency competence or not, by adding silver one can market such film and yield higher profit much better than saying that one uses the silver more efficiently and thus gained such result.
On the other side one has higher investment, that rests for quite some time as masterroll in the storage.
 

koraks

Member
Joined
Nov 29, 2018
Messages
3,940
Location
Europe
Shooter
Multi Format

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
9,063
Location
Humboldt Co.
Shooter
Large Format
No no, that's not what I meant :smile:
Zone 0 is dmax of your process. Zone -I or -II would mean a deeper black than dmax. See the problem?
Correct!! That is exactly what I mean!

Or almost...I am defining zones by information content also. A carbon print is built by varying the thickness of the pigmented gelatin layer -- not by the amount of dark silver compounds trapped in a thin layer of gelatin (emulsion). Blacks are a thicker layer of gelatin and pigment (carbon) than the light tones.

So I can expose down to create a thick enough layer of pigmented gelatin to achieve 100% black (Zone 0)...and then expose even deeper into the gelatin with image-forming UV light. With silver printing, one would just be exposing black into more black...no visual affect. But with carbon, I can get a visible image in relief (not in tonal difference) that is formed by adding more light after exposing with enough light to get to Zone 0.
 
Last edited:
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab
Top Bottom