How does amount of silver content affect the look of film or paper?

Photo Engineer said:

Lenny;

Look again. I disagree in large part with the post by Nicholas. See my comments above along with some examples that do not agree with the satements that he made. You can have a film made of all one grain size and still have a low contrast image!

Click to expand...

I wasn't so much concerned with contrast. Would you agree that the different size grains could have a sensitizing effect - making the film more sensitive to subtle shifts in the light, separating the three steps in the 2100 step tablet? Or do you disagree about the effect of different size grains?

Photo Engineer said:

I also stated that these two characteristices (toe and shoulder) were coupled with an upward bow in the negative curve. This, I will add here, caused a corresponding downward bow in the charateristic curve of the print distorting the final image in the mid tones.
PE

Click to expand...

I guess both of these could cause what one of my buddies calls "mushy midtones" are you saying its only the latter?

More importantly - is there any way to fix this. Perhaps I should print with a higher dot gain? Do you have a recommendation to get what those of us that want this are looking for?

Can you make this film?

Lenny

PE,

It seems reasonable to assume that competitors will have done assays but they appear never to have disputed the high silver claim.
http://www.freestylephoto.biz/sc_prod.php?cat_id=&pid=1000003038

lenny said:

I wasn't so much concerned with contrast. Would you agree that the different size grains could have a sensitizing effect - making the film more sensitive to subtle shifts in the light, separating the three steps in the 2100 step tablet? Or do you disagree about the effect of different size grains?



I guess both of these could cause what one of my buddies calls "mushy midtones" are you saying its only the latter?

More importantly - is there any way to fix this. Perhaps I should print with a higher dot gain? Do you have a recommendation to get what those of us that want this are looking for?

Can you make this film?

Lenny

Click to expand...

Lenny, sensitivity depends on many things such as grain size, Iodide content, degree and type of chemical sensitizers (sulfur + gold) and the type of pan or ortho sensitizing dye added. So, there is no one answer. I can make a high contrast single size grain and a low contrast one, depending on the above ingredients so the comment I made stands.

As for soft toe and shoulder and mid scale bow, they all can contribute, but the toe and shoulder only play a major role in under or over exposures. Any of them can lead to a form of mushy tones anywhere in the print depending on camera and print exposure and scene.

PE

Alan Johnson said:

PE,

It seems reasonable to assume that competitors will have done assays but they appear never to have disputed the high silver claim.
http://www.freestylephoto.biz/sc_prod.php?cat_id=&pid=1000003038

Click to expand...

The time it takes for development depends on the halide type not on the amount of silver coated. I have coated a pure chloride emulsion at 1000, 500 and 250 mg / foot sqare and have found development time in Dektol to be almost identical. It is the chloride that goes fast. A bromo iodide of the same general type may take 3 minutes in the same developer that took 1 minute with the chloride, all things being equal.

A modern paper can achieve a dmax with anywhere from 50 mg/ft square on upwards but the curve shape depends on the way the emulsion is made and the ingredients added to it.

The trough method they describe was abandoned in about 1940 by most companies due to the slow speeds and the high defect rate in the coatings. The same papers can be coated at 10x the speed with exactly the same photo characteristics as the slow speed, but with higher quality including uniformity and defects per unit area.

I'm sure that the product is good, but it could be better with more modern methods. It would probably be less expensive, but that is another story.

PE

2F/2F said:

If I understand PE, the high silver content comes from the fact that thick emulsions (due to multiple coatings) are required with the older formulations in order to get enough density and contrast. So the fact that they are high in silver is not really of design, but of necessity.

Click to expand...

And perhaps also because of the manufacturing technology limitations of that time?

lenny said:

Ian,
It certainly appears to me from your web site that you are getting some very good results. It's the web, hard to tell, of course. I'm sorry you don't live around the corner, I'd like to look at one of those negs... and discuss how you got there.

Perhaps you can answer this (if you have a densitometer) - what is your target top end density? Are you shooting for a #2 paper?

TIA
Lenny

Click to expand...

Lenny, unfortunately I don't have a densitometer, so can't make any measurements. Very few photographers in the UK ever use a densitometer, I've never met one that does and I know a lot of photographers. Instead most use or pay lip service to the zone system, and when I did my own tests back somewhere around the mid 80's my target was Tmax negatives taht would print on Grade 2 Agfa Record Rapid.

Ian