Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,565   Posts: 1,573,467   Online: 761
      
Page 7 of 23 FirstFirst 1234567891011121317 ... LastLast
Results 61 to 70 of 229
  1. #61

    Join Date
    Aug 2005
    Location
    Westcliff-on-Sea, Essex, UK
    Shooter
    Large Format
    Posts
    100
    Robert, with big events/big workflow I guess that's just the way things were back then, but how much was a penny worth to a struggling, often itinerant photographer? 20 people = 20 pennies?!

    The main exception, to my mind, would be a plate that would be ruined by varnishing it, as explained earlier. The term "in the bright" after all has entered into the vernacular - if it wasn't a commonplace thing, I'm not sure that it would have become so widely an accepted practice and one that would warrant it's own by-line.

    Chloroform is indeed a small amount in the original sandarac formula, but there may have been a good reason for it. Sometimes the alcohol content of the varnish attacks the collodion. I believe this is partly the reason why some people warmed the plate - the excess alcohol in the varnish was driven off by the heat before it had any deleterious effects. George Berkhofer cautions against warming the plate to just bloodheat for this reason - others say "uncomfortably hot to hold." Perhaps that is why Kendrick uses a blowlamp? (I did try that, but cracked many plates, burnt my hand and singed all the hairs on my forearm off!) Maybe the chloroform content counteracted this - I don't know. I do know that the amber formula relies on the solvent effect of chloroform and ether to firstly dissolve the amber and secondly to evaporate quickly leaving a thin, hard amber film behind - one that could have been cased immediately. It may be just my bad luck, or bad chemicals (bearing in mind that, at worst, we are talking about people who used water from puddles and chemicals whose purity doesn't even come close to those we use today - the water content of collodion being a prime example when the ether/alcohol mix used to dissolve guncotton was highly questionable), but the sandarac formulas I have used do not fully harden with heat - they take time as well. I've had stacked plates stick to each other, and I know others have, to.

    If you want to try a sandarac varnish with chloroform, Towler's 1864 masterpiece has this formula (note that it is a cold varnish):

    "The following varnish is used on the cold plate, is very hard when dry, and is not softened at a high temperature when printing.

    Gum sandarac, 4 ounces.
    Oil of lavender, 3 ounces.
    Alcohol, 28 ounces.
    Chloroform, 6 drachms.

    Digest, dissolve, and decant as usual."


    Note that he doesn't say that it becomes hard immediately, which would have probably precluded it from events when people wanted to take the image away with them - probably!

    Regards,
    Neil.

  2. #62
    RobertP's Avatar
    Join Date
    May 2006
    Shooter
    ULarge Format
    Posts
    1,130
    Images
    8
    Thanks Neil, The formula I was referring to is the one Wayne Pierce uses. He got it from the " Silver Sunbeam" and it is also listed as a cold varnish but Wayne heats his plates before and after. His varnish, Szabo says, is like glass. I'm sure his formula is very similar to the one you list here if not the same one. Since it is from Towler's book.
    Last edited by RobertP; 10-15-2007 at 10:29 AM. Click to view previous post history.

  3. #63
    RobertP's Avatar
    Join Date
    May 2006
    Shooter
    ULarge Format
    Posts
    1,130
    Images
    8
    Here is the formula Wayne uses: 220 ml ethyl alcohol 32 gm powdered gum sandarac 28 ml oil of lavender 3 ml chloroform

  4. #64
    Ty G
    Hello Austin, TX. About approx. ISO's etc. There is no use to figure it. If you figured it with todays light, collodion mix, lens. Then tomorrow it would be different because as collodion ages, the sensitivity changes as well. My exposures just depend on what the light looks like. I do lots of Civil War reenactments, and exposure ranges from 1.5 seconds to 5 seconds.

    Ty Guillory
    www.tystintypes.com
    Mineola, TX

  5. #65

    Join Date
    Nov 2003
    Posts
    5,243
    Images
    9
    So, how do you figure exposure?
    Technological society has succeeded in multiplying the opportunities for pleasure, but it has great difficulty in generating joy. Pope Paul VI

    So, I think the "greats" were true to their visions, once their visions no longer sucked. Ralph Barker 12/2004

  6. #66
    schrochem's Avatar
    Join Date
    Nov 2004
    Location
    Austin,Tx
    Shooter
    Multi Format
    Posts
    324
    Images
    182
    Hi Ty. Nice to see someone closeby doing tintypes. Thanks for the answer on the speed, I figured as much
    There is another question about time that I'd like to ask to you or the community itself. What are the time constraints involved. I haven't really found much in terms of that. It sounds like you need to wait a 'little' before putting the plate in the silver, then after that I don't know how long you have to make the exposure and get it developed. Are we talking within 10, 20, 30...mins?? What kind of anomalies do start sprouting up as the plate starts to dry?
    Thanks

    Scott

    PS: well I'm now revested in an 8X10 and two lenses....so I'm that much closer....just don't tell my wife BUT I have an excuse. I can make a beautiful portrait of her beloved son. Yep, that's it!
    I also sent off for Coffer's manual and DVD set.

  7. #67
    Ty G
    Mark,
    Honestly it just becomes an very well-educated guess. You learn your lens and collodion mixture. I sometimes do a test plate before I start with customer tintypes, then go from there. Of course, exposures change somewhat throughout the day. Also, keep in mind that I hand-develop, so that gives more control with exposures.

    Scott,
    The question about time; collodion gels before putting into silver (@20 seconds). From the time pouring collodion to fix should be less than 10 minutes for entire process. Then of course is washing, drying, and varnishing.
    J. Coffer's manual will make everything make more sense.

    Ty Guillory
    www.tystintypes.com
    Mineola, TX

  8. #68
    schrochem's Avatar
    Join Date
    Nov 2004
    Location
    Austin,Tx
    Shooter
    Multi Format
    Posts
    324
    Images
    182
    Thanks Ty, that's pretty fast.....
    Okay, I should stop with the questions until I have more hand's on experience, but I'm a curious creature
    Do people 'adjust' the process in some way to affect different parts of the color spectrum? I guess what I'm saying is do be make different 'films' like modern day TMAX vs. TRI-X, etc, etc. and so on and so forth?
    Scott

  9. #69
    Ty G
    Collodion is monocromatic. There really is no "spectrum." It is blue-light sensitive.

    Ty Guillory
    www.tystintypes.com
    Mineola, TX

  10. #70
    RobertP's Avatar
    Join Date
    May 2006
    Shooter
    ULarge Format
    Posts
    1,130
    Images
    8
    http://www.apug.org/forums/attachmen...2467671....But you can hand color your tintypes. This was my first attempt at hand coloring.( Of course I was assisted by John Coffer.) The man is holding a spectrum chart this will give you an idea of how blue sensitive this process is.
    Attached Thumbnails Attached Thumbnails Untitled-444.jpg  



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin