Comparisons of ready made liquid emulsions for teaching students

[seanjmc]

Hi, I'm a future emulsion-maker (in a few months) and present long time user of Rockland's Tin Type system. Have also done some 20x24 prints on glass with great success in the past with Rollei BM. I've done some technical demos/artist talks at some colleges and have given demos of Rockland's Tin Type kit. It's relative ease of use and the fact that you can usually modify the older riteway sheet film holders makes it very accessible for students in an alternative photo class at a college and a great thing to demo.

Wanted to also now demo glass plate negs, so now have been coating on glass trying to make negs with unpredictable results. Have been using AG Plus. Rating at ISO 3 usually works, and have developed in Dektol but prefer to do it in film developer to demonstrate good enlargement capability. Did a little in HC-110 and it enlarged nicely although the founder told me and it says in the printed material to not use film developer. So not sure what that's all about...

Was wanting to get some feedback on which of the ready-made ones would be best suited to serve to develop in film developer and be at least an ISO 3. I am aware of Rollei Black Magic, Foma and Rockland and Fotospeed, (but seems like that one isn't sold in the US).

Or any feedback as to if I'm killing myself too much trying to focus on using the film developers versus paper developers, but it seems like the grain on the film developed ones were noticeably smoother. (I did those on thin plexi and they all peeled off when they dried so can't do comparisons at the moment, was judging from a naked eye inspection)

From what I can tell choices available to humans in the US are:

1. Rockland Liquid Light (thought it was always VC, but website specs seems to indicate Graded)
2. Rockland AG Plus (again, thought it was always VC, but website specs seems to indicate Graded)
3. Rollei (VC)
4. Rollei (Graded)
5. Fomaspeed - seems like it's Graded

I know the graded and VC are different kinds of emulsion but I can't seem to get enough info to figure out pros or cons for my proposed application.

Thanks for in advance for all of the brainwaves!

Please no comments about Llama dung or coffee developers, I believe there is another thread on that topic going...

 

[paul_c5x4]

The active ingredients are the same in most developers, be they for film or paper. You will find a few universal developers that are marketed as being able to do both (one example is Ilford PQ Universal). If anyone tells you that you "can't use a film developer for paper", just smile sweetly and carry on.

 

[Simon Howers]

Sean,
I make and use WP glass plates on 2mm glass (which I get free from a picture framer).
Currently I am using both Rollei RBM2 (Grade 3) and FOMA photographic (Normal) emulsions.
I clean the plates with "rottenstone" and wetting agent, then wash off and dry. I have not found subbing necessary.
Melt emulsion, add a little iso-propyl alcohol to thin and a few drops of wetting agent.
Pour plate, drain and place on a glass surface to cool/set.
Allow plates to harden for 36 hours before loading into plate holders.

Plates are processed in Dassonville D2 developer: (Darkroom Cookbook (3rd edition) page 263)
Water 750ml
Sodium Sulphite 32gm
Amidol 5.3gm
Potassium bromide 0.5gm
Water to make 1 litre.

I develop the plates for 2 minutes at 20 Deg C; then stop in Ilfostop 30 sec and fix for 4 mins in Kodak Hardening Fixer.

I am currently exposing plates at ISO 6 for salt printing. The amidol developer gives good blacks and a denser plate than Xtol so suits this type of printing. The plates work well with cyanotype and platinum/palladium. I don't use silver bromide printing so I can't help on the grade issue

The Kodak fixer gives a robust finish to the processed plate, so I don't have to especially careful with them and I guess they would be student proof!

Physically these two emulsions handle very similarly and pour easily. I found the SE1 emulsion was thinner, less robust when set and fogged more easily.

Good luck!

Simon

 

[seanjmc]

OK, thanks for sharing experiences...2 further questions:

1. Am I correct in assuming that Graded Emulsions are better here for use as 'film?'

2. The D2 Developer seems pretty easy to make, but any opinion on a what the best ready-made one would be?

 

[Photo Engineer]

Film developers are generally higher in solvents such as sulfite and thus can cause loss of speed or image in highlights when used with paper emulsions. Using paper developers for film is harmless but often grainy.

Graded emulsions used for "film" often cause distortion of colors as one emulsion is sensitive to green and the other to blue and they have different speeds and contrasts. I would not recommend this practice, but it can be done.

PE

 

[cliveh]

If you order from the UK I would suggest Liquid Light – SE1 Emulsion.

 

[seanjmc]

Thanks PE for the info, will stick with Graded for this liquid emulsion. For development, would a compromise be a staining developer? I just sent an email to Nick Brandereth at Eastman House, maybe he can give a suggestion as well...

 

[Photo Engineer]

IDK how a staining developer would work. Never tried one.

PE

 

[seanjmc]

PE has never tried a staining developer EVER? Or just with hand made emulsions....?

 

[Photo Engineer]

Tried once, didn't like the results, and also the chemicals are quite toxic.

PE

 

[seanjmc]

ok, fair enough!

 

[seanjmc]

OK, have some results, used the AG Plus as that's what I had around...Rated ISO 3. Two good results:

1. HC-110, dilution B, 15 mins at 68 degrees.
2. Dektol 1:2, 3 minutes, around 70 degrees...

Pyrocat HD seemed to be too weak at 1:1:100 for 20 mins at 68 degrees...next time may try 2:2:200 at 75 degrees, hopefully 15 mins should work, but if this Dektol and HC-100 work, I'm good for now with the students.

I will get some of the RBM Graded emulsion in the near future and give that a whirl, but for teaching purposes if I can use the AG Plus for the 'tintype' and glass negs I think I'm good....