Dinesh wrote:Martin wrote:Assuming you cannot increase FAO concentration much further
Well, I put in 6gms of FAO in 300 mls water, as per the original instructions. I can presumably load more FAO into it.
Good. Let's see if you'll get some significant absorption from your blue laser. You might simply verify that with a FAO solution without adding any gelatin...
In fact, I was going to try doubling the FAO concentration next. I assume that there will be a point when the FAO will saturate, but 6 gms dissolved very quickly.
Yes, I remember having heard photo people say, gelatin could take much more FAO than dichromate - maybe up to 3x the quantity of dichromates.
Also, I forgot to mention that I put in 3 drops of Kodak Photoflo;
Right - actually my surfactant was Triton-100.
Yes, 300 mJ is not very good, but it may get better with increased FAO. By the way, what if I mix the FAO with FAC?
Yes, that might be worth a try.
On the other hand, I now really wonder if FAC wouldn't be more appropriate to blue recordings. Photographic wisdom used to claim far better speed for FAO than FAC. But then, wasn't that essentially based on broadband UV exposures?
FAC has some benefits: it's much less toxic. Hence it's easier to purchase than FAO (by the way, you'd have to look for the green stuff, not the brown one).
Code: Select all
[quote="Martin"]How much light do your standard DCG plates absorb at 457nm?[/quote]
You know, I never measured this!
I see - thanks for reminding me of Shankoff. So how does your ammonium dichromate solution look like under your blue laser (and how does it compare with FAO or FAC solutions)?
[quote="Dinesh"][quote="Martin"]Assuming you cannot increase FAO concentration much further[/quote]
Well, I put in 6gms of FAO in 300 mls water, as per the original instructions. I can presumably load more FAO into it.[/quote]
Good. Let's see if you'll get some significant absorption from your blue laser. You might simply verify that with a FAO solution without adding any gelatin...
[quote]In fact, I was going to try doubling the FAO concentration next. I assume that there will be a point when the FAO will saturate, but 6 gms dissolved very quickly. [/quote]
Yes, I remember having heard photo people say, gelatin could take much more FAO than dichromate - maybe up to 3x the quantity of dichromates.
[quote]Also, I forgot to mention that I put in 3 drops of Kodak Photoflo; [/quote]
Right - actually my surfactant was Triton-100.
[quote]Yes, 300 mJ is not very good, but it may get better with increased FAO. By the way, what if I mix the FAO with FAC?[/quote]
Yes, that might be worth a try.
On the other hand, I now really wonder if FAC wouldn't be more appropriate to blue recordings. Photographic wisdom used to claim far better speed for FAO than FAC. But then, wasn't that essentially based on broadband UV exposures?
FAC has some benefits: it's much less toxic. Hence it's easier to purchase than FAO (by the way, you'd have to look for the green stuff, not the brown one).
[code][quote="Martin"]How much light do your standard DCG plates absorb at 457nm?[/quote]
You know, I never measured this![/code]
I see - thanks for reminding me of Shankoff. So how does your ammonium dichromate solution look like under your blue laser (and how does it compare with FAO or FAC solutions)?