Palladium/Platinum contrasting with B&S FO - chlorate

[scootermm]

Palladium/Platinum NA2 explanation (formerly B&S Chlorate thread)

So Ive heard on many fronts that using NA2 for a contrasting agent is a much better method than the Chlorate added to Ferric Oxalate in their solution #2. I am working on a series of prints and have been using the Solution #2 for contrast control and it is actually doing a pretty good job. Its rare that I use alot of the #2 solution but this one I really found it helped the negative and resulting print.

Thought I would share the results with anyone whos in a similiar place as myself (still feeling their way through pt/pd printing)

I still plan on trying the NA2 as contrast control in the future but have been getting fairly good results with the basic setup that comes with the B&S kit. (of course Ive long since gone through a starter kit )

heres the test strips I came up with..

 

[Kerik]

You might want to try this test on an image that has a lot of smooth, even toned areas. I think you'll see grain and lose the creamy quality of pt/pd. An image like you've shown is all texture and graininess is much less apparent. These look pretty good, though.

 

[scootermm]

kerik, Im looking forward to hopefully getting the NA2 chemicals in january and testing it out and comparing on some "sky" type images... you and many others have mentioned the same thing, which is tantamount to scripture (especially when I test it out for myself). Guess for right now Im just lucky this series is very textural and the possible graininess gets hidden by it.

 

[clay]

Any particular reason you are using more total metal solution drops than ferric oxalate drops in your drop count? I always use the same volume of each with the thought being that if there is no ferric to convert the metal, it just ends up being washed down the drain.

 

[scootermm]

no excuse other than misinformed. The drop count tables Ive seen always had like one or two drops (depending on the print size) less total FO than metal. dually noted and thanks for the info clay, me showing my ignorance and newbieness

edit note: the JPG should read 9 drops of PD and 3 drops of PT I misslabelled the file.
still one drop more than needed so I think Ill start adjusting that to save some solution.

 

[Thomassauerwein]

NA2 is great! you don't need much and there is adjustment in exposure but it is very conveniant and less grain. I only use about on average 1/2 a drop.

 

[photomc]

OK, Matt...even more newbiee to the DOP process, what is NA2? I keep hearing about it, but have not seen anything on the B&S site. Guess I need to pick up Dick Arentz book, I have the Chris James book (which I find good for coverage of all the differetnt alt. process), and was considering the Sullivan & Weese book, in place of Arentz book. Plan to give DOP Pld a try after all of the POP (Zia's) to compare.

 

[Ray Bidegain]

Matt:

I have been using the Na2 for a while now and the level of contrast increase is much higher than the #2 FO. The one thing I do miss however is the ability to add in more platinum to the mix with out increasing the contrast. All the prints basically become palladium with very small amounts of platinum. Before with he #2 FO I was able to make changes to the look of the prints by changing the PT to PD ratio. Does anyone know if you can still add straight Platinum#3 into the mix when using Na2 for contrast control?


Ray Bidegain

 

[Peter Schrager]

Pall #3

Yes Ray-you can add one drop to the mixfor incresed black...
Best, Peter

 

[Joe Lipka]

Na2 is what we call Sodium Chloroplatinate. I use it because FO #2 is evil (Jorge says so and I don't argue with Jorge on this topic ) and was the cause of most of my failures in Pt/Pd printing. Even though it does contain platinum, I don't subtract that amount from the Pt contribution of my sensitizer.

Would any of the tech wizards (or alchemists) out there be able to do a comparision between the Na2 and the Potassium Chloroplatinite's contribution of Platinum metal to the sensitizer formula?

 

[colrehogan]

It's not so much the contribution of the Pt metal to the formula, but a matter of the Pt metal changing oxidation states in an oxidation/reduction reaction. The difference is the oxidation state of the Pt metal in each solution. In Na2PtCl6 (sodium chloroplatinate) the platinum has a 4+ oxidation state. vs. the K2PtCl4 (potassium chloroplatinite) in which the platinum has a 2+ oxidation state.

 

[Joe Lipka]

Can you translate that into English?

 

[Thomassauerwein]

Joe, the way I think of it is: NA2 tans darker values faster with a bit more contrast. Kind of like printing multiple contrast does in silver. At the exposure level rather than in the devloper. doing it at the developer level seems to push existing imformation within the emulsion further which seems to effect the grain. Kind of like push processing.
I don't know all the teck talk stuff so this is an observation only.

 

[clay]

In simple terms, the Na2 consumes twice as much ferrous oxalate (ferric oxalate is converted to ferrous by UV light) than the palladium salt during the final reaction where ferrous converts back to ferric and causes the metals in the paper to reduce to the tiny particles that end up embedded in the fibers of the paper to form the image. Because it consumes the sensitizer at twice the 'normal' rate, it has a preferential effect in restraining the development of highlights, which have very little 'activated' sensitizer anyway. This causes the increase in contrast in the final image.

By way of a simple example, say a highlight area has 4 molecules of 'activated' ferrous and a shadow has 128 molecules of the same. Two extra molecules of Na2 in each print area would totally consume the 4 molecules of ferrous in the highlights, leaving none to convert the remaining palladium. The same thing happens in the shadows, but the reduction is only taking 4 out of 128 molecules of ferrous out of commission, leaving the rest (128-4=124) to reduce the palladium to image forming particles. The net result is hardly any effect on the resulting print density in the shadow areas on a percentage basis, but a profound effect in the resultant print density of the highlight areas.

This is vastly simplified, but that is basically how the contrast agents all work. The differences between the contrast agents come about in the side effects they create. The chlorates tend to cause the image-making particles to clump together and cause graining, while Na2 does not have this annoying tendency.

That is probably way more than anyone cares to know about this stuff. The simple fact is that the Na2 is just a good contrast increasing agent without the bad side effects that come with using chlorate in the sensitizer.

It's not so much the contribution of the Pt metal to the formula, but a matter of the Pt metal changing oxidation states in an oxidation/reduction reaction. The difference is the oxidation state of the Pt metal in each solution. In Na2PtCl6 (sodium chloroplatinate) the platinum has a 4+ oxidation state. vs. the K2PtCl4 (potassium chloroplatinite) in which the platinum has a 2+ oxidation state.

 

[Kerik]

Awesome! That's the best explanation I've read on how Na2 works. (Below is an artist's rendition of Clay explaining this phenomenon.)

 

[clay]

You should see my new Christmas beanie. It plays Jingle Bells when the propeller turns.

Awesome! That's the best explanation I've read on how Na2 works. (Below is an artist's rendition of Clay explaining this phenomenon.)

 

[Michael Mutmansky]

Kerik,

I know a person who wears double-breasted shirts with TWO pocket protectors. He calls it 'full frontal nerdity'.

---Michael

 

[colrehogan]

I guess Clay and I don't speak English, we speak chemistry.

 

[scootermm]

so Ive edited this thread title so its more fitting to the topic. Hopefully thatlly make it searchable. good explanation clay.

 

[Thomassauerwein]

It still needs a bit of dumbing down. Is It light reactive or chemical reactive? I only have one pocket and no protecters.

 

[clay]

Chemical reactive. The light sensitive compound is the ferric oxalate.The contrast agent just consumes (oxidizes) more of it during the image formation process.

 

[clay]

You can imagine my embarrassment when after ten years of marriage I realized my wife was not saying " Talk nerdy to me".

Kerik,

I know a person who wears double-breasted shirts with TWO pocket protectors. He calls it 'full frontal nerdity'.

---Michael

 

[Michael Mutmansky]

Let me go on the record as saying that I have never seen Clay wearing a pocket protector of any kind, let alone a pair of them. There was no implication that Clay is nerdy in my funny, but true, OT contribution to this thread.

I do think he may have geeked out on us a little with that description, however.

***Please note that neither nerds nor geeks are protected under federal anti-descriminatory laws. I think that means it's open season.***

 

[sanking]

I hate to show my ignorance, but what is a pocket protector?

Sandy

Let me go on the record as saying that I have never seen Clay wearing a pocket protector of any kind, let alone a pair of them.

 

[scootermm]

Here you go sandy...
Dead Link Removed