My first attempt... is in the fridge.

Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by Jadedoto, Aug 15, 2007.

  1. Jadedoto

    Jadedoto Member

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    ...I hope.

    I'm working at the local university to make an emulsion... And my brain hurts already. And it's not the strange chemical I knocked over in the fridge!


    ...All that said, I'm using the emulsion number two from Silver Gelatin: A User's Guide to Photographic Emulsions. The fomula, eh, I'll type it up. Why not.

    Solution A
    Water at 40C 140mL
    KBr 17.5g
    KI .1g
    Inert gelatin 7.5g

    Solution B
    Water at 40C 120mL
    AgNO3 20g

    Solution C
    Water at 50C 110mL
    Inert gelatin 16g
    KBr (.8% sol) 10mL


    The process is in a nutshell (for those of you interested), B->A over 30 secs. Hold the solution then at 45C for about ten minutes. Immerse into 2C water (cold water and ice) to gel the solution and stop the ripening.

    This is the stopping point for me today. I have the emulsion in the fridge and will add solution C tomorrow in the following manner:

    Shred and wash the B and A solution in water fro two hours, then in purified water for 20 minutes (I'll probably be using distilled; I used DI water for the chemicals). Melt the emulsion and ass Solution C. Raise the temperature to 50C

    The book also has the following: adding 7mL of a 1% KBr solution to minimize fog for the next 45-90 minute digestion at 50C. More time=more speed and contrast (and fog).

    Finally, 1g of KBr per 20g AgNO3 for stabilizing and optionally phenol at 1% for bactericide.






    I didn't have a bucket with ice to cool the gel in after mixing, so I stuck it in the freezer. My temperature control was a bit screwy (but I did get close with a refreshingly fast mercury thermo).

    I could probably do this easier in my home darkroom in all honesty... Light proofing a fume hood isn't the easiest thing in the world. I spent several hours trying that. I was miserable.

    Anyway, enjoy the formula, and PE, any hints would be most appreciated. I plan on having a coating and print and develop a print here within a week. I'll keep you all posted. :smile:

    Vince
     
    Last edited by a moderator: Aug 15, 2007
  2. ben-s

    ben-s Member

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    It's nice to see someone else experimenting!
    I'm all agog to hear how it goes - good luck!
     
  3. Photo Engineer

    Photo Engineer Subscriber

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    Don't freeze any emulsion. You can ruin it.

    Thymol is better than phenol, but you have to dissolve it in iso propyl or methyl alcohol. One drop of a 10% solution / 100 grams of emulsion is enough. Without either phenol or thymol, the emulsion will begin to spoil in a few weeks, otherwise it could keep for months in the fridge.

    Try to use distilled water throughout the wash, as the impurities in tap water can fog the emulsion. I keep a gallon of DW in my fridge just for washing.

    That is a lot of KBr to be adding at the end, but may be needed for stabilzation. IDK for sure. Mine require no such addition. I have not tried this emulsion. It will have most of the iodide trapped in the center of the crystal and have a low ISO value of probably about 3 in a camera. It will be about 3 - 5 stops slower than an enlarging paper.

    I'm not sure about contrast. Many formulas like this have good contrast but some have low contrast.

    Good luck.

    PE
     
  4. Ian Grant

    Ian Grant Subscriber

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    Vince, with some experience it's possible to get good speed and contrast with an emulsion like this. However it needs a lot of experimentation and testing varying the ripening and after-ripening times, also as Ron has posted elsewhere doping the gelatin helps to get greater sensitivity as well.

    It's definitely possible to make an enlarging speed emulsion this way, I did for about 10 years, and it was very close in speed / contrast to the Ilfospeed Grade 3 emulsion which I had to test from Ilford. [​IMG]

    While I can't find my notebooks, (they are packed away in storage as I'm moving continents) but I have found some of the Agfa emulsion formulae published by the allies after WWII.

    Ian
     
  5. Photo Engineer

    Photo Engineer Subscriber

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    Ian;

    Lets hope your formulas never get lost in the dustbin of history. I hope your move goes well.

    PE
     
  6. Ian Grant

    Ian Grant Subscriber

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    Thanks Ron

    Actually I began my emulsion/coating planning while in hospital for 12 weeks on traction with a broken leg. First I went down a commercial route, I remember I was the first UK customer of Rockland Colloids. But it wasn't good enough for what I wanted so my first experiments with emulsion making was from a little Kodak sheet on emulsion making and my first attempt gave reasonably good results.

    Doing a lot of research and reading, particularly "Photographic Emulsion" by B H, etc. Carroll, (Focal Press), looking at the published Agfa formulae, also quite a few Russian formulae, meant I was quickly able to evolve an appropriate emulsion that I could apply by spraying. I guess it could be coated in other ways as well, I just never tried.

    For anyone wanting to make their own emulsions I have to highly recommend the Hubbard, Caroll etc book, Photographic Emulsions, not for the formulae they used but rather the experiments they did because they provide an invaluable guide to how an emulsion changes as you vary a variety of parameters.

    Ian
     
  7. Neanderman

    Neanderman Member

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    Can you provide citations for these, by chance?

    Ed
     
  8. Ian Grant

    Ian Grant Subscriber

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    Yes they were printed in Glafkiddes, PE might correct the spelling, after the war, Kodak had a set, the books were extremely limited in distribution.

    I borrowed a copy from a member of the Lumiere family, (Autochrome process) actually he was English his mother was from the Lumiere family, and Tim was a technical advisor to Elinchrom and Alpha.

    Getting hold of the books is difficult, so when I did I copied every thing of relevance to me. I found the negatives a couple of hours ago, so can access them easily, when I've got time and in the right continent.

    Ian

     
  9. Photo Engineer

    Photo Engineer Subscriber

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    I remember Burt Carroll very well. He and his wife were close friends of ours up until his death. We used to vacation at the Glen Iris Inn at Letchworth park and Burt and I used to sit on the porch after dinner and talk about photography. That really brings back some old times.

    At that time, he was professor emeritus of photography at RIT and a fellow of the research staff at EK and member of the senior staff (retired).

    I think that Glafkides is the correct spelling, but not sure. I've met him once unless it was another person with the same name at EK. I never talked to him at length.

    There are some of the things you mention above, in abbreviated form, in the text "Photographic Theory" by James and Higgins. It is a mere chapter but very interesting.

    There was also a set of monographs issued publicly by the Kodak Research Labs over a period of about 10 years. They used to give them out to empolyees and were also sold. Some of them contain very valuable information if you put them together with some of the published texts and patents.

    PE
     
  10. Jadedoto

    Jadedoto Member

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    Ron, I have the luxury of distilled water on tap there. The problem is, however, the place wasn't build with blackout in mind. You should see my ... "lightproofing" I set up around the hood- some 50 feet of 3mil plastic in various layers and forms. It still leaks light, so until I get a definite way of closing all light out there, I don't think I'll be doing any serious attempts that require control outside of my homemade lightproof bag.

    I wish I could take the chemicals home to my darkroom... I'd have to drag water but that's easier than light proofing this place!


    Ian, I've been reading this forum here extensively as well as studying the bok I do have like the uber-Bible. I hope it goes well. The first choice emulsion (which I don't have and at the moment can't get the chemicals for) is faster and higher contrast- an SRAD as Ron would say. I'll try that if this formula is way off base (which I have a gut feeling it won't be).


    More to come!
     
  11. gr82bart

    gr82bart Subscriber

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    I really admire you guys making these emulsions. Truly fascinating. I'm looking forward to the results of the OP's emulsion.

    Regards, Art.
     
  12. steven_e007

    steven_e007 Member

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    Hello Jadedoto,

    I'm following your experience with interest. I too am in the middle of making my first emulsion.

    I posted a thread earlier (misspelled 'a femulsion formula I've found') which I've been working on. I think I rather rashly said something like 'I'll be mixing it up this week'. That was about six weeks ago :-o

    O.K. it is a learning experience, I've wised up a bit now, after running into several brick walls!
    Not least was working out how to manufacture my own 0.880 ammonia.

    Now, I am a complete novice with very little experience to share, I'm behind you by the sounds of it. But here's two suggestions, which might be of interest.

    Fisrt one is that I have lightproofed my emusion vessel, rather than the fume hood. (My fume hood is the open window of my garage ;-)

    I took a 500ml brown glass bottle. Brown may well be 'safe' anyway, but to be sure I painted it with Rustin's stove enamel. This is black heat resistant paint. I fitted a cork with a glass tube vent, bent over to act as a light trap. I painted the cork and tube black, too. This sits in my water bath which is stainless steel and opaque and I place a sheet of aluminium foil over the top with a hole for the tube, just as belt and braces. The only bit where I need some darkness is adding A > B, which I can do in a changing bag or in the darkroom. I then fit the cork and then take my light proof bottle to the garage where I can then cook my emulsion for as long as I like in daylight...

    Second suggestion was I decided to try stripping some old plates and coating them with a 'dummy' emulsion of gelatine and food colouring (with some chrome alum).

    What a complete nightmare!!!

    Obviously there is a lot of skill to hand coating a glass plate and I most certainly do not have any of it!

    I got emulsion everywhere, my coatings were uneven, the plates where not clean enough and didn't 'flow' well at all, I got coating twice as thick on one side than the other and plenty of emulsion on the back to glue the plates to my drying slab...

    First attempt was a total disaster. Second attempt was only slighly better, but I am slowly getting there. I need to spend a bit of time fully understanding the importance of temperature and the effect of the chrome alum. I will be making a post to plea for help from some of the experienced members later...

    Point is, I am very glad indeed that I was only playing with food colouring and gelatine, and not my valuable silver rich emulsion - most of which would have ended up on the bench, probably ;-)

    I will not be coating with real emulsion until I get my act together with the coating technique... I'm not sure if you are doing a glass plate or a paper emulsion, but I would certainly try your coating methods out on a dummy emulsion, first!

    Steve
     
  13. rknewcomb

    rknewcomb Member

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    Hello,
    Emulsion coated glass or paper shelflife?
    Reading with great interest, making notes and paying attention. But, a question.
    If one were to coat a glass plate with this emulsion, what could be expected in the way of shelf life? Does a glass plate need to be shot within a certain quick amount of time or will it last a few days?
    thank you!
    Robert Newcomb
     
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  15. Photo Engineer

    Photo Engineer Subscriber

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    My paper coatings seem to last at least a year, but film emulsion coatings are fogged after a few days or so. I have not been using the stabilzer, as it is too hard to get and too expensive. I'm waiting to solve some problems with the film emulsion that are not present in the paper emulsions.

    I agreed that it is best to practice coating in the light with gelatin containing a food dye. Just remember that the food dye changes the gelatin coating properties as food dyes are often sulfonates. Also, remember that the real emulsion is thinner at the same gelatin content due to the effects of the crystals suspended in gelatin. So, 10% gelatin emulsion behaves like about an 8% or 6% plain gelatin or gelatin with food dye.

    There are a number of types of black plastic bags and black plastic bottles on the market. I buy them from the Formulary. I bottle and ship emulsion that way in a bottle then a bag.

    PE
     
  16. rknewcomb

    rknewcomb Member

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    Stabilizer agent?

    "I have not been using the stabilzer, as it is too hard to get and too expensive".

    So may I ask, what is the stabilizer agent?

    Robert Newcomb
     
  17. Photo Engineer

    Photo Engineer Subscriber

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    Tetra aza indene, given in another post here and in Jim Browning's formula.

    PE
     
  18. Jadedoto

    Jadedoto Member

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    Whirring , whirring, whirring!

    This is so exciting. I decided that I was going about the thing all wrong like, so I revised it a bit. I tore down my fume hood... contraption today. My mentor was giving a tour or the lab to new students throughout the day (classes at UK started yesterday), so the spectacle (it was a sight to see!) was gone for all but the first ones :smile:


    I ended up taking my 1L steel inversion tank to mix the emulsion in. It hit me after reading my emulsion bible (they mention it). The only problem I had was draining whilst washing (I used a clean cheesecloth instead of a mesh- lesson learned! Next time, mesh or screen it is!).

    I used distilled water throughout the washing process, per PE's suggestion. I did a 10 minute fill/dump process for washing for 2 hours... I hope that was sufficient. It did wash clear by the end of the washing.

    Temperature control with the SS tank was MUCH easier than wonderfully non-covective(?) glassware...

    I also learned that gelatin is a PITA to dissolve completely, even in really hot water.



    ...In any event, the run I did last week I knew didn't turn out (first try, sorted out kinks in my process). I threw that out, and made the entire thing in one go today, carefully documenting everything.

    Tomorrow is Friday evening, so I'll coat and print one sheet tomorrow. My el-cheapo $15 red safelight burned out (after 45mins of use?), so I have to get a new one tomorrow as well as some Sodium fix...

    As per suggestion, I'm going to document everything online on a website (either a personal one or the UK site), so I'll post a link to that as soon as I build it!
     
  19. Photo Engineer

    Photo Engineer Subscriber

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    I use my wife's old panty hose to hold the emulsion during washing. Just cut a suitable piece from the toe and stretch it, then put the shredded emulsion into it and submerge into the wash water.

    The wash is usually complete, when the wash water does not become cloudy when a drop of residual hypo test solution is added. (This is just silver nitrate in acetic acid)

    I just pour some wash water into a beaker and add 1 drop of the test solution. If a cloudyness is observed, then salts are still present. Now remember, this is a VERY rough test and can cause fog if you go too far. At Kodak we used a precise measure of the conductivity of the wash water.

    PE
     
  20. Ian Grant

    Ian Grant Subscriber

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    A better suggestion and far stronger than "panty hose" are the bags available from home brewing shops designed to drain the juice from fruit while retaining the pulp.

    Ian
     
  21. Jadedoto

    Jadedoto Member

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    Okay! Here we go.

    I must say, that while I coated my first test sheets of real emulsion, I got a bit pretentious and put some developer on my glove... just to see if the scrap of emulsion would, in fact, turn black. It did, and I jumped around the house many times in euphoria that I didn't screw up... completely.

    Next, I dabbled on a piece of glass, developer in a puddle to see a black, and then a few drops of fix to see if it turned clear. It did, so I knew that I was on the right track!


    So I grabbed a 4x5 negative and printed it on a 135mm lens about 5 inches above the baseboard at f/4, on my enlarger, this is very bright. A test strip of 2 second exposures from 2 to maybe 8 or 10 (I don't remember, didn't write it down because normally I can see the difference in shades).

    This yielded a very fine... grey blob!
    [​IMG]

    Above was coated with a sponge brush. I found on this particular paper (Strathmore drawing paper), it gave a smoother finish than my other attempt: the BRUSH!



    On the brush, however, I did give the paper a second coat (the first one is one coat). This seemed to improve maximum density... I'll stick these all under my densitometer tomorrow for a more accurate reading (in comparison to my maximum black tests).

    In any event, I decided that my previous attempt was too short of a time, so I exposed for 32 seconds for the heck of it. Result? slightly more recognizable.
    [​IMG]

    I definitely did not like the brush strokes. I need to work on those though.


    My main concern is the fogging around the image. This paper is creamy colored, but I'm certain that something has fogged or is fogging. I suspect my safelight- I'm using an OC lamp because my red lamp burned out today on me.

    Is an OC lamp safe to use with it? Is OC OK for ortho?!

    I also altered my formula procedure in that I ripened for one 45mins on the last ripe, and I added the KBr "fog controller" 20 mins after I started that, because I forgot (I figured better late than never?). Also, I wasn't sure to start that ripen time from when I immersed the emulsion into the water bath, or when the emulsion melted. I went with immersion time.


    So next time I mix this up, I'll do it on a day I don't have school so I can do the 6 or 7 hour procedure without staying till 8 or 9, as well as: decrease the B>A time to 20secs, final ripe time for 90 minutes.

    Tomorrow I go shopping for a decent paper (i.e. one with more white tone), as well as a nice brush.

    The original image I'm printing, if you care to see it:
    [​IMG]
    Shot in 4x5 with an enlarging ektanon at f64


    I'm getting there, slowly but surely. This is more difficult than I imagined!
     
  22. Removed Account

    Removed Account Member

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    I'm just observing and I'm excited! Who knew reinventing the weel could be so interesting?

    - Justin
     
  23. Photo Engineer

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    Ok, based on the results I see in the pictures, the emulsion formula you have was designed for active gelatin and is therefore giving you low contrast and low speed.

    The safelight is ok. The fog level may be due to the amount of silver coated or to overwashing, IDK. It might also be the amount of iodide used.

    Try adding 100 mg of sodium thiosulfate pentahydrate to each mole of silver nitrate used in making the emulsion. (just work out the math, I'm too lazy this early in the AM) Do this to the final washed emulsion. Then heat the emulsion to 60 degrees C and hold for about 60 minutes. (you may want to sample it at 30 and 45 mins to check for fog. Stop the treatment if the fog seems to be going up too rapidly. This adds sulfur sensitization to the emulsion. See Jim Browning's formula here for similar treatment.

    This can add up to 5 stops in speed and up to 2 grades in contrast.

    PE
     
  24. Jadedoto

    Jadedoto Member

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    Cool! I should note that the formula does explicitly state inert gelatin.. But I'll try the sulfur sensitization anyway. I don't know what it'll do if I don't try.

    I also am going to do the rough wash tests you were talking about in a previous post.

    Thanks :smile:
     
  25. Ian Grant

    Ian Grant Subscriber

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    Maybe there's a language problem here. "Inert gelatin" is not necessarily de-activated or oxidised gelatin.

    The term "Inert Gelatin" here in the UK refers to a type of laboratory gelatin used for biological applications, and it means Biologically inert. The formula comes from a British author.

    Ian
     
  26. Jadedoto

    Jadedoto Member

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    Ah. I knew I should've brushed up on my British English first!:sad: