HOME BREW 4X5 PLATES?
SO I GET A 3.9X4.9 " PIECE OF NON GLARE FRAMERS GLASS
now what? my purpose is to produce a neg that is loosely the same as those that were used to make the salt/alb/cyano/vandyke etc that i make now with film negs
i can make paper negs with rc projection paper in camera and they work quite well but now on to the real thing-i want an emulsion probably gelatine that will emulate a colloidon plate
i think i want silver chloride but wile i have experience coating 'paper' and even polyester i never tried glass
the textured surface of the framers glass should reduce the subing needed but what should i start with for the gelatine emulsion?
if there are links to earlier threads please supply
vaya con dios
You say you want to emulate a collodion plate. Why not just use collodion and do a "real" wet-plate?
Over at www.alternativephotography.org (get that URL right?) there are a few articles on mixing emulsions or using Liquid Light premade emulsion to make dry plates.
And right here we have Ron Mowrey (PhotoEngineer) and his merry band of emulsion makers.
I am a very poor plate maker. My friend Mark is teaching me how to do it, but like everything else it is an art. I usually end up with emulsion dripping from my elbow.
Almost any plate of glass can be used, but it should be clear glass if you want a good negative. Silver chloride will be very slow due to the fact that it is mainly UV sensitive.
The emulsion formula that I posted here (SRAD - with ammonia) will give a reasonable blue sensitive emulsion in the range of ISO 6 - 40 depending on how you treat it.
That is about all I can add.
EMULATION FOR THE NATION
thank you for the link
Originally Posted by rwyoung
i don't want to use colloidon and i don't want to use any of the many ready made liquid emulsions
i am looking for the input of those who may have done what i intend to do or are doing someyhing similar
the input of pe will of course be my most valuable resource-but i am sure that there are others who have much to say about this
this particular project is a side bar to my present 'green' efforts
a gelatine emulsion on glass is what i intend to do by home brewing
i am presently in contact with someone who is doing it but he is a very busy man and i am hoping that some one on this forum can add to my mix
vaya con dios
speed not an issue re silver chloride-what can you tell me about silver chloride only emulsions?
Originally Posted by Photo Engineer
i suspected that your srad would be good starting point-will dig in to posts -the prodigious out put you have provided here makes good reading but i get lost in the go-to cirlces of trying to follow them
reminds me of the spagheti-code of interpreted basic so common in the 80's
could you direct me to mark or his writnigs if any?
pe without you what would we do? we would be lost in the wilderness and expire from exhaustion i suspect
i know that the subing you must do for glass is an important issue-thats why i thought of the textured non glare glass-its used to cover art so its spectral character should be good-what do you think?
regular float glass is high iron so it blocks uv more than you might be aware and that is what leads to the long exposure times in contact frames and i suspect the old glass negs
pe-- rescue me!!! dispatch your merry band of jelo junkies to my aid!!! dont let the high sherif of not helping ham and his nefarious crew of blahblahblogers capture me again!!!
silver chloride is the treasure, i suspect ,and i will guard it with my every effort
if its foolsgold than i'll be fooled and a fool-so what else is new
but seriously now-what do you think and what do you like?
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Silver Chloride emulsions will have a visible light speed of a minute fraction of an ISO value. They will need very very long exposures, especially with a more modern lens which blocks some UV. A quartz lens or older lens will help.
Mark is an instructor of alternative photography and a conservator at the George Eastman House, and does not publish on the internet. He does give workshops.
Neither Mark nor I sub glass plates. It is not necessary as long as they are well cleaned and use the proper hardener which is Ghrome Alum. I made the error of using Glyoxal, and was corrected by several friends who told me that the Chrome Alum binds better to the glass.
I would only use AgCl emulsions for making lantern slides not for making any sort of camera original. Even then, you will find that you need rather long exposures, as so much of the sensitivity of the emulsion is in the UV.
Both Mark and I use an AgBrI emulsion for in-camera and lantern slide plates and film exposures. Depending on emulsion, we get speeds from ISO 3 - 80 on film support or glass.
I have posted a starting AgCl emulsion here, originally used by my friend Bruce Kahn in his course on photography at RIT. It is here already, but if you can't find it, then I'll look it up and repost it.
For gelatin, use 250 Bloom Photograde Deionized Gelatin. This is available from the Photographers Formulary. And, BTW, I understand that this is genuine Kodak Gelatin from Eastman Gelatin.
Originally Posted by Photo Engineer
thanx-just got back from a 3day hospital stay-was takeing a lightmeter reading off the back of the "gate house" a 1800's pump house now part of the ny city college campus at 135th and convent ave
was asaulted by a maintainence worker employed by city college when i refused to move from a public access public domain area -city of ny public streets etc
the cops got him off me but i was taken to the em room and admitted for possible heart muscle damage-will get reports tomorrow
could you please post siver chloride emulsion?
will take your advice but still am interested in plain silver emulsion
can't do to much research on the web right now-to exhausted-you think that pf prices are ok?
vaya con dios
Wow! Hope you are OK.
And while I don't generally approve of the tort system, I do hope you consider legal action against your attacker and maybe even the college. Not talking millions here, but enough to make it stick and get the college to better train (screen?) their employees.
But really, I do hope you are OK!
That is outrageous. No one should be attacked for photography from a public place. Get well soon...
I hope you sue the guy! That is outrageous. And, I hope you recover fully from the attack.
I'm sorry but I don't have Bruce's formula here, and would have to look it up. I will repost it ASAP, or post a URL for it. It is here on APUG. I should be able to find it.