TJ-1 and exposure time

Simple answers are here! For Theory look in General Holography.
Tom B.

TJ-1 and exposure time

Post by Tom B. »

Colin Kaminski wrote:The simplest is to use a 5% TEA solution and rinse completely in DI water.
Excellent idea. I believe a factor of at least 2X sensitivity increase is possible with TEA. Or (for reflection holograms), if you are not planning to make an H2, don't rinse at all afterward to take advantage of the wavelength shift due to preswelling with TEA. Going from say 650 nm as the diode laser wavelength to 600 nm or less with TEA preswelling would result in a more orange-yellow hologram with a major increase in apparent brightness since our eyes aren't very sensitive to deep red. Be aware that TEA leaves a bit of oily scum on the non emulsion side that should be wiped off with a wet paper towel after squeegeeing (how could this possibly be a correct spelling??) and drying the emusion side. You can see the scum by reflection in a safelight.
Colin Kaminski

TJ-1 and exposure time

Post by Colin Kaminski »

Tom B. wrote:
Colin Kaminski wrote:In simple terms: Exposure to light activates the silver particles. Development grows them larger. Lots of active silver grown for a short time is smaller particles.
I had never made that connection! I can see how this could potentially improve results with coarse-grained films like PFG-01. As for loss of sensitivity with PFG-01 film as it ages, I have experienced this. I think there may be some things you can try to revive it - I think I saw some posts on this topic here a long time ago... I can't say I ever had any success with this, but I didn't try very hard since I found that I liked the fine-grained emulsions much better, though these have their own problems.
Small particles are also important to eliminate blue haze when working is short wavelengths.
Viking

TJ-1 and exposure time

Post by Viking »

Thanks a lot for your replies.
I am going to order some TEA right away! And also I'll try the fog killer I found on the Wiki (20g Ferric EDTA and 10 g KBr per litre). It is for PFG-03, but who knows, it just might work for PFG-01 also.
Does anyone know for how long the TJ1 A and B solutions can be stored?
A: 6g Metol, 40g. Ascorbic acid
B: 100g sodium carbonate anhydrous, 30g sodium hydroxide
I keep them in syringes. It makes it easy to squeeze out what you need without letting air in.
Colin Kaminski

TJ-1 and exposure time

Post by Colin Kaminski »

It is important to exclude air when storing them. If it starts to turn brown it is OK but if it goes black then it is time to discard. If you can exclude air you can store it for some time. There are collapsible containers or floating lid ideas for excluding air.
Tom B.

TJ-1 and exposure time

Post by Tom B. »

Only part A goes bad. I keep mine in the fridge to slow the process down. Excluding oxygen is also very helpful. Refrigerated, it's good for 6 months or more. Part B lasts forever with no special storage requirements. Once A+B are mixed, they are good for 1-2 hours, but I wouldn't be surprised if refrigerating a mix with air excluded kept it good for a day or more. After some awkward discussions with my spouse, I ended up purchasing a small bar fridge to keep my nasty toxic chemical brews chilled, and my superglue and plates and film and batteries .... Everyone is happy now.
Viking

TJ-1 and exposure time

Post by Viking »

Thanks Tom. Just wandering, when part A eventually goes bad, does it turn black or does this only happen to the AB mix?
Tom B.

TJ-1 and exposure time

Post by Tom B. »

Part A starts off turning light yellowish brown, then gets darker as it ages. It still seems to work OK even when fairly brown, but I always use it up before it gets really dark so I don't know what the limit is. I've had stuff in the fridge last for a year or two with only slight yellowing. Outside the fridge, it seems to take at least a couple of weeks to start turning moderately yellow (in a cool basement). Excluding air from the container would likely extend this time.
Viking

TJ-1 and exposure time

Post by Viking »

Thanks a lot. Thats great news.
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