Residual Hypo or Residual Silver Test using Selenium toner

Hello all,

I’m currently trying to test for residual hypo using 1:9 selenium toners as well as undiluted selenium toner on an under fixed print; as well as fixed print and I’m not getting no staining.

I’m using this on Ilford MGFB Glossy, I can confirm that the selenium toner is fine, as it’s changing prints tone after 3.5min in it at 1:9 dilution!

Anyone got a idea of why it’s not showing any residual fix?

Thanks!

Why do you expect selenium toner to show the presence of thiosulfate? It's an ingredient of the toner in the first place.

Did you mean by any chance test for residual “silver” and not “hypo” or “fix?” Selenium toner would be used for the former but not the latter. For residual fixer, you would want to use AgNO3 based solution.

:Niranjan

Thread title tweaked

You can get the residual hypo test solution from Photographer's Formulary.

jaestorer said:

I’m currently trying to test for residual hypo using 1:9 selenium toners as well as undiluted selenium toner on an under fixed print; as well as fixed print and I’m not getting no staining.

Click to expand...

I assume for now, that you meant "residual silver" detection anyway, since this is what you would want to detect in an under fixed print.

First of all: how to you know the print is under fixed? Would the print still gain density if you turn on room light and put it back in developer? Did you just fix for shorter time than the data sheet said? Have you tried putting a droplet of selenium toner onto an unexposed and unprocessed patch of photographic paper? Did you leave that droplet on the paper for a few minutes, then washed it off and let the paper dry? Compared area "with droplet" to neighbour area "without droplet" ?

jaestorer said:

Hello all,

I’m currently trying to test for residual hypo using 1:9 selenium toners as well as undiluted selenium toner on an under fixed print; as well as fixed print and I’m not getting no staining.

I’m using this on Ilford MGFB Glossy, I can confirm that the selenium toner is fine, as it’s changing prints tone after 3.5min in it at 1:9 dilution!

Anyone got a idea of why it’s not showing any residual fix?

Thanks!

Click to expand...

Selenium is used to check for improper fixing. I use a quick rinse after fixing and straight into Selenium toner 1+3 for fiber prints with no staining, then use archival wash sequence.

Great video from Greg Davis on washing film and testing.

You need two tests to ensure print permanence: One for adequate fixing, which is a residual silver test, and one for residual fixer byproducts, the "residual hypo" test.

For testing residual silver you can use the Kodak ST-1 test (formula available by searching online or buying the pre-mixed product from Photographer's Formulary). Alternatively, you can use selenium toner in a rather strong concentration; it's results have shown to be just as good and the selenium toner solution lasts much longer. Note that this test does not test for adequate washing, just whether you're prints have been fixed properly.

To test for adequate washing, you need the HT-2 test (formula online or pre-mixed from PF). Originally, the test from Kodak came with a Hypo Estimator strip, which had different levels of stain for comparison. You can find a digital version of this for download on Ed Buffaloe's Unblinkinge Eye website on the page about archival processing. It's not really needed, however; what you want is no stain.

Best,

Doremus