Silver content of BW film in g/cm2

[Simon R Galley]

We do indeed call it "Core Shell" technology..internally CCG Controlled crystal growth...adds nothing to the debate though.

I also thought just for a second I could put PE into the shade by explaining that our CCG's were also hexagonal and not truly triangular..but if you look at EM pictures they are actually 'very' triangular but with the apex on each corner flattened in two angles...ho hum, and why are they like that? I have absolutely no idea whatsover, but our chief emulsion chemist and PE most certainly do...

Simon ILFORD Photo / HARMAN technology Limited :

 

[Photo Engineer]

Simon, I looked solely at the pictures! I just called them "triangular" kind of like a Greek Delta. I wonder where that came from?

Thanks for the elaboration. I've worked on both core shell and graded iodide emulsions. They differ only in the method and placement of the iodide, but as for your crystal shapes, I am not expert enough in this area to explain the nuances of the differences in shapes.

PE

 

[FotoGys]

I had fairly accurate figures for silver content of films at one time they are archived on an old hard drive somewhere, the figure's usually given in grams per square metre.

For B&W films you are looking at 3-5 g/m2 so it looks like you're figure is out by a factor of 10. If a film contained $1.7 of silver a roll (your figure) then that would add more than $6.8 to the cost of each roll after distributor & retailer mark-ups, transport costs etc.

Ian

1 m2 = 10000 cm2 so the factor is 10000

Guus