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Photo Engineer
05-25-2013, 09:06 PM
How slow did you go??

PE

Andrew O'Neill
05-28-2013, 06:02 PM
Is it possible to get a film density range which will allow carbon transfer printing?

Photo Engineer
05-28-2013, 06:08 PM
I believe that Chris is doing that right now.

PE

Hexavalent
05-28-2013, 07:59 PM
I made some carbon-transfer prints from my last batch of emulsion, but it was tricky - the density range was too high!

rwhb12
05-29-2013, 02:51 PM
I guess the question about how slow is really saying what's the ultimate quality? The best tonal range and the best grain = ? ASA? Ron maybe you can comment, but my guess is that the magic is in the formula, and therefore is not related to speed?

I too have great admiration for those bromide images of the forties and fifties. They have sometimes that does not exist anywhere else.


Russ


Almost ready to start emulsion making!

Photo Engineer
05-29-2013, 05:50 PM
Addition times from 1' to 15' are possible for this emulsion, but difficult o do by hand. The contrast will be quite low at 15' if everything behaves as normal, and the speed will probably move about 1 stop, but it may appear to slow down due to the loss in contrast. Here is a typical curve of the usual senitometric change with addition times from 8 - 14 minutes with a given emulsion. You can see what happens to speed and density as well as contrast.

PE

kb3lms
05-29-2013, 07:11 PM
Ron,

A longer addition time would produce a lower contrast, I understand that, but why would it increase speed? Is it because the grains formed first would have more opportunity to grow larger at the expense of the smaller grains than in a more monodisperse emulsion?

-- Jason

Photo Engineer
05-29-2013, 07:18 PM
You get more speed for the same reason that you get lower contrast. You get a broader size / frequency distribution. There are more fine grains and more coarse grains. With a very fast addition, you get grains that are more nearly alike and they are smaller.

PE

jnanian
05-30-2013, 08:34 AM
Can I ask a silly question, I've never considered making my own emulsion to coat plates, film, paper, etc., but why does it seem that the workshops I have seen that create materials create types that are not often avail (eg a bromide only paper, which I believe is only made in matte by Slavich, AZO which only one company sells, or a slow ISO film 25 or so - which is not even made anymore, I think)? See my point? It's like these workshops teach how to make materials that are limited or impossible to get!

Disclosure - I'm a fan of slooooowwwww film and bromide paper! Why's it seem the few places making this kind of great goods is at these kind of workshops?! I think you all are drawing me in :)

Would love to make a tips to Rochester to see where it all began ( in the states at least)

andy

if you go to thelightfarm.com
look under formulas
there is a very simple sea water emulsion
that the maker uses to coat plates
and it only has a few ingredients ..
no crazy chemicals, just silver nitrate
seawater/ salt+water and gelatin ( from what i remember )
salt prints were just saltwater and silver nitrate too, so this is just
a little different ... if a 20year old college student with NO EXPERIENCE
and a booklet from 1904 could do something like his at 2-3am ( in the 1980s )
i think it would be a piece of cake for you ;)

have fun with your experiments!

zsas
05-30-2013, 09:34 AM
andy

if you go to thelightfarm.com
look under formulas
there is a very simple sea water emulsion
that the maker uses to coat plates
and it only has a few ingredients ..
no crazy chemicals, just silver nitrate
seawater/ salt+water and gelatin ( from what i remember )
salt prints were just saltwater and silver nitrate too, so this is just
a little different ... if a 20year old college student with NO EXPERIENCE
and a booklet from 1904 could do something like his at 2-3am ( in the 1980s )
i think it would be a piece of cake for you ;)

have fun with your experiments!
Thanks J! Though my interest in photography is deep, but not at this point in the realm of coating due to other commitments, I'm just wondering why we've folks like me crying for the loss of APX 25 and Efke 25, but no one is making an artistian home brew for folks like me who'd buy a roll or two of 35mm/120 to play around with to 1) support home made goods, 2) a gap in our market? But maybe my query is self answered, Efke 25/APX 25 went under bc no one bought enough....

jnanian
05-30-2013, 10:51 AM
Thanks J! Though my interest in photography is deep, but not at this point in the realm of coating due to other commitments, I'm just wondering why we've folks like me crying for the loss of APX 25 and Efke 25, but no one is making an artistian home brew for folks like me who'd buy a roll or two of 35mm/120 to play around with to 1) support home made goods, 2) a gap in our market? But maybe my query is self answered, Efke 25/APX 25 went under bc no one bought enough....

hey andy

i have lack of time too ... so i get my emulsions bottled. it is what happened with me in college .. It was fun to know i could make it in a pinch, but in the end grabbing a bottle ended up being easier .. i would rather eat plain vanila ice cream instead of fancy-stuff too ... coating is just a matter of melting and usunf a brush to paint it on and letting it drt (.paper at least glass is a bit more involved ) ... its not as hardcore as one might think.

have fun!
john

Photo Engineer
05-30-2013, 11:10 AM
Andy;

The market is too small to make some of these items commercially and some of the items you want are at the edge of what people can or will make at home.

So, you can make an Azo type paper in 3 grades and a Kodabromide paper in 2 grades. You can make an ISO 1 - 40 emulsion that is blue or ortho sensitized. Beyond that, things start to get difficult and expensive. They can also get to be very time consuming.

So, we, the teachers and writers of this stuff try to formulate things that are very useful but take a minimum of effort and expense. Of course, it sometimes takes thousands of dollars of R&D to make these work. Most writers freely admit that they have not make the emulsions that they publish. They just copied it from somewhere. And, almost all of those in books are wrong due to omission or comission. Grant Haist published a formula in V2 of his book set and told me that it was heavily edited by the Kodak editors.

PE

jnanian
05-30-2013, 11:49 AM
Andy;

Most writers freely admit that they have not make the emulsions that they publish. They just copied it from somewhere. And, almost all of those in books are wrong due to omission or comission. Grant Haist published a formula in V2 of his book set and told me that it was heavily edited by the Kodak editors.

PE

andy

while much of what PE said is true, if you go to thelightfarm you will see emulsions that people (WROTE AND ) MADE and USED ( including the OP ).
the emulsion i made 25 + years ago was made from a photographic book published for people who wanted to make and use
emulsions ... i dont' remember which one it was, but it was easy ( just a few ingredients ) the publishers didn't make up-stuff and it worked fine ... i haven't made the ones that are in the back of silver gelatin ( the liquid emulsion book )
and i haven't made the ones at the light farm, but the aj-12 emulsion published in the (apug's ) articles section is one that a lot of people have made and used.
its not all smoke an mirrors as some would suggest ...

i must admit it would be very nice to take a workshop with today's master-chefs ... it would be easy to see what it is supposed to be like instead
of a blind guess ..

have fun!
john

Photo Engineer
05-30-2013, 12:24 PM
John, I have read formulas by Baker, Wall, Eder and others as well as copies of formulas from the FIAT and BIOS reports posted here. They all have omissions or errors. True, you can make a functional emulsion from them, but this emulsion is not what they made.

One simple reason is that we cannot buy the gelatin that they did. Another is that they don't usually publish addition times. And if you think that is unimportant, see the graph I posted earlier.

A simple published formula such as AJ-12, published here on APUG cannot be tinkered with unless you know a lot about what you are doing or have some expect backup. This is a Kodak formula, but one that can only be made exactly as written.

PE

zsas
05-30-2013, 12:28 PM
Hi PE, isn't ADOX's below product a game changer?
http://www.adox.de/english/ADOX_Papers/ADOX_Papers/Fotogelatin.html

Bob Carnie
05-30-2013, 12:54 PM
I plan to take a workshop on emulsion making in the near future at GEH.

We are lucky to have this wonderful group in Rochester and I for one plan to take groups there to our benifit.

Photo Engineer
05-30-2013, 01:23 PM
Hi PE, isn't ADOX's below product a game changer?
http://www.adox.de/english/ADOX_Papers/ADOX_Papers/Fotogelatin.html

I'm sure it is a wonderful product Andy, but how is it a game changer?

The Photographers Formulary has been selling photograde gelatin for years. Their current products are both from Kodak's former plant in Peabody MA.

PE

dwross
05-30-2013, 01:41 PM
John, I have read formulas by Baker, Wall, Eder and others as well as copies of formulas from the FIAT and BIOS reports posted here. They all have omissions or errors. True, you can make a functional emulsion from them, but this emulsion is not what they made.

One simple reason is that we cannot buy the gelatin that they did. Another is that they don't usually publish addition times. And if you think that is unimportant, see the graph I posted earlier.

A simple published formula such as AJ-12, published here on APUG cannot be tinkered with unless you know a lot about what you are doing or have some expect backup. This is a Kodak formula, but one that can only be made exactly as written.

PE

Oy! Ron,

Yuh just gotta stop saying stuff like this. People take you seriously and at your word, but they shouldn't. I just can't figure out why you want to make things seem so hard. But, words are only words. For more than words, please go to www.thelightfarm.com . The current homepage image (the big one) is AJ-12, coated as film. I made the recipe in a couple of hours, and I wouldn't have even needed electricity if I'd so chosen. Also, less than $5 for the whole batch of emulsion. The modifications I made were only arithmetic and a little trial and error. If you want to call that experience and expert backup, I guess it would be rude to object. In any case, there is a lot of info on TLF and I'm always only an email away. editor@thelightfarm.com.

For even more info, please start here: http://www.thelightfarm.com/cgi-bin/htmltutgen.py?content=05Mar2013.

I am pulling together the next set of web workshops, so stay tuned. Plans are to get through to ASA 100 (summer speed) ortho ("X2Ag") by the end of summer. If anyone doesn't want to wait for more tutorials, there are a lot of proven recipes on The Light Farm.

John: thanks for the support! Much appreciated.
d

Hexavalent
05-30-2013, 01:58 PM
$5 for a batch?

I'd like to buy from your chemistry source. :D

dwross
05-30-2013, 02:15 PM
Ian,

Artcraft has silver nitrate for $379 a pound right now. (I advocate buying bulk, once you know you're addicted to emulsion making!) That comes to a little over $4 for the 5 g used in AJ-12, and the KBr, KI, and gelatin are about a buck total, if that.