Printout

holorefugee · Post by **holorefugee** » Wed Feb 08, 2012 5:31 pm

I got an email from a new holographer about printout and in looking through my papers it really surprised me how much of what I know about printout came from the forum. I am hoping we can summarize in this thread some strategies form eliminating printout.

Rinsing thoroughly with distilled water or at least with no Cl-- was the first thing that comes to mind.

A citric acid bath with a 50w halogen light is another method I have used. I know others have used SHSG methods. What else should we include?

Dinesh · Post by **Dinesh** » Wed Feb 08, 2012 7:45 pm

A final, post bleach, bath in KI solution. I can't remember the exact quantity, but I think it was 20 g/l.

Tommy · Post by **Tommy** » Sun Feb 12, 2012 10:40 am

I've also read about a final acetic acid bath, in "Practical Holography" I think. It didn't seem to work for me.

I've used a 20% ammonium dichromate path on PFG-3c processed in JD-4 developer and ferric EDTA bleach. It definitely works, the plate darkens dramatics and within days without it. But I've always had the vague feeling that it was bleaching the hologram too.

Ed Wesly · Post by **Ed Wesly** » Tue Feb 14, 2012 3:54 pm

Here is all we knew about printout in 1988:

http://nlutie.com/ewesly/printout.pdf

Not much has changed, although the earlier incarnation of holographic productis from Mobberley, England, I mean Ilford, the latest incarnation being dubbed Harman, used a hydrobromic acid bath as a stabilizer, which Nick Phillips could not believe they were using, but other than those bon mots I know nothing more about it.

Martin · Post by **Martin** » Wed Feb 15, 2012 1:44 am

Ed Wesly wrote:Here is all we knew about printout in 1988:

http://nlutie.com/ewesly/printout.pdf

Interesting, thanks for posting.
One thing I've never seen mentioned in all the printout tests described in numerous SPIE papers, was the influence of relative humidity. Whoever puts a "rehalo"-bleached plate/film under a strong white light will easily notice that a wet emulsion is darkening a whole lot more quickly than a dry one. By the way, the darkening of the wet layer takes place no matter what bleach has been used.

holomaker · Post by **holomaker** » Wed Feb 15, 2012 11:15 am

Using the Pyro chrome bleach i do two baths and it seems to work pretty well on Fuji transmissions. After processing and bleaching i place it in DI water and bathe it in sun until it prints out again then re bleach till it clears......