Rockland Colloid - Should I bother?

Discussion in 'Alternative Processes' started by bvy, Mar 23, 2014.

  1. Photo Engineer

    Photo Engineer Subscriber

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    Now, I know that the main thrust of this thread is coating on metal, but I thought I might stress again how simple this can be.

    Mark Osterman and Nick Brandreth teach their students that washing in plain water with Dawn detergent, then rinsing and drying in plain tap water will do the trick. No hardener is used in the coating and the negatives are just fine. It is not a complex problem requiring undercoats, special treatment and other aids. Just wash, dry and coat.

    Thanks to Mark for this photo. See more on his Facebook page.

    PE
     

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  2. OP
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    bvy

    bvy Subscriber

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    That said, maybe Don can reiterate for us what issues he was having in the beginning that led him down this path. He's getting good results in any case.
     
  3. jnanian

    jnanian Advertiser Advertiser

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    last i spoke with mr osterman
    he said they weren't doing silver gelatin tintypes ...
    just the same, it is great to hear other ways of cleaning plates !
     
  4. DonF

    DonF Member

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    The issues I had with the tintype plate surface began when I switched from the anodized plates supplied by Rockland Colloid to the shiny enameled plates as supplied by Main Trophy Supply. After the switch, I began to have significant issues with the edges of the emulsion loosening during processing. I also had increased reticulation and a very uneven surface to the emulsion after drying.

    The anodized plates have more of a matte finish that seemed to supply some "tooth" to which the emulsion could adhere. The glossy Main Trophy Supply plates have an almost mirror finish. These are likely great as is for making collodion plates.

    I found lightly dry sanding the plates with 1200 grit wet/dry sandpaper solved the adhesion problem without any additional subbing or surface prep being necessary, other than scrubbing the plates thoroughly with a finger and some powdered washing soda a few times after sanding, rinsing thoroughly, then drying. I omitted the Photoflo rinse after washing, as I seemed to get poorer results with the residual Photoflo on the plate. Dawn would probably work as well or better than the washing soda, as it is an excellent degreaser.

    I still have slight reticulation issues with the prepped plates, but a post-processing coat of crystal clear spray varnish (3 coats) fills in the minor irregularities and results in a nice smooth finish on most plates.

    I was sent a small packet of chrome alum by a kind forum member. I may experiment with adding it to the emulsion (or developer) to see if that helps the reticulation. I am satisfied with the adhesion of the emulsion with my current prep and am assuming the reticulation issue is somewhat an independent issues.

    Best,

    Don
     
  5. DonF

    DonF Member

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    Todays's shoot. First time taking camera out in the field. Good results with plate prep as described.

    [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG][​IMG] [​IMG] [​IMG]
     
    Last edited: Aug 6, 2016
  6. jnanian

    jnanian Advertiser Advertiser

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    these look great !
    the tonality is really pretty
    and i love how the image is sometimes not edge to edge, it has a dreamlike quality to it :smile:
    wonder when the process was a commercial process back in the day
    if the photographers trimmed to the edge. the one we have of my grandfather
    was a full image edge to edge as if it was trimmed. it is a gem photo so i am guessing
    when they stamped it out of the "master plate " they cleaned it up
     
  7. DonF

    DonF Member

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    Thanks! I needed to adjust the levels after scanning some, but I did try to keep the contrast and exposure (as seen on my monitor) representative of the actual plate.

    The non-edge-to-edge effect is intentional in that we leave the emulsion uncoated near the edges. It gives the plate an interesting appearance.

    On these exposures, I used my Iphone with the "Pocket Light Meter" app (and some blue acetate over the lens) to meter the shots. I assume 1.6 ISO on the plates in daylight, which seems pretty accurate. That app has a spot metering capability that seemed to work well, within limits. I used it on the two barn shots with a brightly lit background and shaded subject. However, on shots with a significant amount of sky in the frame, the limited dynamic range of the process seems to result in an overall overexposed plate, although the subject I spot metered is exposed OK. Best results were in a sunny location, sun over my shoulder, not too much sky (UV light) in the frame.

    My home brew "Rockland" developer was used for all these.

    Don
     
    Last edited: Aug 6, 2016
  8. DonF

    DonF Member

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    Here's a bad exposure where I attempted to spot-meter the subject's shaded face, but wound up with a grossly overexposed plate due to the bright white building and sky.

    Don

    [​IMG]
     
  9. OP
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    bvy

    bvy Subscriber

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    So this means lightly sanding the trophy plates and applying the emulsion directly? In other words, you're no longer using the gelatin subbing?
     
  10. DonF

    DonF Member

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    Yes, I am just sanding and cleaning, although the single coating of food grade gelatin on the unsanded plates worked pretty well too. It takes a lot more time to prep the plates with the gelatin though.
     
  11. DonF

    DonF Member

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    A bit off topic here, but we are seriously considering trying collodion wet plate in a few weeks. Unfortunately, we can't afford the time to take a proper workshop, but we have watched so many videos and Bostick and Sullivan make it so easy to obtain the needed materials, I may order some basic supplies or perhaps their kit and give it a go. Now that we have the camera and quite a few modded film holders, it would be fairly easy to try.

    Don
     
  12. jnanian

    jnanian Advertiser Advertiser

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    if you make wet plates ( alumitypes ) when the
    plate goes into the fixer, it is a mind blowing experience
    watching what looked like a negative instantly reverse into
    a positive ... truly magical.

    the "mistake plate" you posted looks almost like
    an old faded albumen print. the soft, subtleness and tonality
    of the church building has an almost glowing look to it. ...
     
  13. DonF

    DonF Member

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    Interesting shooting session yesterday. I used the "Pocket Light Meter" app to meter the exposures and most turned out very overexposed. I believe the averaging type light meter apps gave better results. I was just spot metering the main subject, without regard to the levels in the rest of the scene. Part of the issue may have been that the plates were poured 5 days before exposure and the emulsion ISO may have been greater. I believe I had better results with the averaging style of light meter app, although perhaps I just need how to use the zone system more effectively.

    There was zero reticulation on ANY of the plates! I believe this was due to the fact that the plates were prepped by sanding/washing and allowed to dry for a full 24 hours or more, rather than overnight, around 8 hours.

    I also noticed that fingerprints were a major issue in this batch, ruining a few otherwise good shots. This was not an issue before. It may be oil on the fingers affecting development or perhaps chemical contamination. I think gloves are a must when putting the dried plates into the film holder. Maybe the better-dried plates are more susceptible to fingerprints?

    Here's the best ones:

    [​IMG] [​IMG] [​IMG] [​IMG] [​IMG]

    ...and the not so good....Note fingerprints on last image....others as well...first two were grossly overexposed and fixed in Photoshop

    [​IMG] [​IMG] [​IMG]

    Best,

    Don
     
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  15. hoffy

    hoffy Subscriber

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    I don't check into this thread for a few months and look what happens! This is great work Don! You have given me some inspiration to get that kit out of the cupboard and give it a try.

    BTW, how long do you let the plates for? Also, how are you storing them while they are drying?

    Cheers
     
  16. DonF

    DonF Member

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    Thanks, Mate!

    I have an unused bathroom in the house I am using for a darkroom. It has a second inside room with bathtub and toilet. I pour the plates in the main area, then move to the darkened inner room inside the bathtub for drying. I place the poured plates flat on some cookie cooling racks, then place the racks inside the tub. Now in the summer (air conditioning), the room is probably 65 degrees F with very low humidity. I dry for a full 24 hours. This makes a huge difference in eliminating the emulsion lift and frilling problems. Drying times will certainly vary with temperature and humidity, but since I've allowed longer drying I have had no issues with emulsion irregularities. However, the slightest bit of contamination of the prepped and washed plates before pouring can create a weak point of emulsion adhesion at that point. A photoflo dip and rubber gloves help in that regard.

    After drying, I store in a paper light safe with sheets of wax paper between.

    I plan to build a light-tight drying box with some old PC fans installed so a separate dark drying room is not required.

    Cheers,

    Don
     
  17. hoffy

    hoffy Subscriber

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    Great! Thanks for the reply. Do you warm the plates before the pour?
     
  18. DonF

    DonF Member

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    Here's a brief summary describing how I pour the plates:

    1.) I use "Trophy" aluminum plates from Main Trophy Supply in Palatine, Illinois, USA (a few miles from my location!!!). These plates are coated on one side with a high-gloss enamel and protective peel-off covering. The plates supplied by Rockland Colloid are much thinner anodized aluminum plates. The next step is only needed for the glossy Trophy aluminum plates.

    2.) I thoroughly scuff the enameled surface of the trophy plates with 1200 grit wet/dry (black) sandpaper. Used wet, a more even texture is obtained. Change a 2 inch x 2 inch piece every 4 plates or so,

    3.) I scrub the plates with a toothbrush and "washing soda" (Sodium Carbonate) until water runs off a rinsed plate cleanly, with no spots remaining. Any water spots will create a point of weak adhesion for the AG Plus emulsion. which is likely to lift during washing.

    4.) I warm the thoroughly dried plates 6 at a time on a heating pad set to "High" in the darkroom.

    5.) I chill a "pizza stone" or pastry marble slab in the freezer and bring that to the darkroom as well. I cover the slab with a sheet of wax paper.

    6.) I heat the AG Plus bottle in a 110 degree F water bath (no hotter) for 10 minutes to partially liquify the emulsion, being careful not to shake or bump the bottle, which would cause bubbles in the emulsion.

    7.) Under a dark amber or red safelight, I add two drops of Kodak Photoflo surfactant to a small beaker. I carefully decant enough emulsion for 6 plates (about 20ml) into the beaker, pouring down the side of the beaker to avoid bubbles. I stir gently with a coffee stirrer stick to mix the Photoflo with the emulsion.

    8.) Wearing nitrile gloves, pour a puddle of the mixed emulsion about 1 1/2 inches in diameter onto the center of a warmed plate. I tilt the plate in a circular motion to cover as much of the central portion as possible without touching. I then use a gloved finger to touch the emulsion and guide it around to the uncoated edges of the plate in a rectangular motion, being careful not to lift my finger from the plate. A small bubble invariably forms when my finger lifts up from the plate. When the surface is wet with emulsion, I slide my finger off an edge, then tilt the plate to even the emulsion over the plate surface. I then tilt at about 30 degrees toward one corner and flow the excess back into the beaker. Do not allow too much to flow off the plate or the coating will be too thin and the dark plate will be partially visible through the "white" portions of the developed plate. The plate should have an even whitish-grey appearance over the emulsion coated area. About five seconds of drainage is about right. I then back-tilt the plate to redistribute the emulsion evenly over the plate. Placing the coated plate onto the heating pad a few seconds helps the reflow if the plate has cooled too much,

    9.) I examine the coated plate under the safelight for any bubbles in the coating. If any are present, I return the coated plate to the heating pad and use a toothpick to either pop the bubble, or guide it to the edge of the emulsion. The warmed plate will heal any irregularities caused by this process after a few seconds.

    10.) I transfer the finished plate to the cooled and level pizza stone, which sets up the gelatin emulsion in a few seconds.

    11.) I reheat the beaker of emulsion in the 110 degree F water bath for 1 minute between plates to keep the emulsion the correct consistency. Also, check the temperature of the water bath so it does not drop below 110 degrees F.

    12.) After three plates have been poured and cooled on the stone, I transfer the plates onto a cookie cooling rack and place into a dark, dry, cool room to dry for 24 hours. It is important to allow a full day for drying, in my experience. Insufficiently dried plates will frill and reticulate, causing a rough surface on the dried tintype. A spray oil-based varnish will help fill in any roughness after the plates have dried thoroughly, though.

    13.) Excess emulsion may be poured back into the AG Plus bottle.

    14.) After the plates have dried, I transfer them into a paper light safe with sheets of waxed paper in between to avoid sticking. I have 6 modified sheet film holders that accept the 4 x 5 plates (cut 1/16 inch short on each dimension, to match the dimensions of sheet film). I sometimes load directly into the holders. This allows shooting up to 6 plates in the field before returning to the darkroom. See an earlier post in this thread for particulars on the film holder modification.

    Regards.

    Don
     
  19. DonF

    DonF Member

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    During our shooting session this weekend, I took some time to calibrate the free "Pocket Light Meter" app using some blue tungsten color temperature correction gel I found in a local surplus store.

    The gel I placed in front of the Iphone lens was a tungsten > daylight 1/3 CTB filter with 2/3 transmission. With the filter in place, I used Rocklands exposure guide and outdoor lighting conditions for the shoot to calibrate the app by adjusting the ISO from the nominal 1.6 ISO value I was using. The uncalibrated meter app was producing consistently overexposed tintypes. BTW, it always better to underexpose rather than over expose a Rockland emulsion tintype!

    Rockland recommends the following exposures as a guide for their AG Plus emulsion:

    Bright Sun, EV9, f/11, 1/4 Second
    Bright Sun, EV9, f/16, 1/2 Second
    Bright Sun, EV9, f/22, 1 Second

    Cloudy-Bright (No shadows), EV7, f/11, 1 Second
    Cloudy-Bright (No shadows), EV7, f/16, 2 Seconds
    Cloudy-Bright (No shadows), EV7, f/22, 4 Seconds

    Open Shade (shaded subject, clear sunlight), EV6, f/11, 2 Seconds
    Open Shade (shaded subject, clear sunlight), EV6, f/16, 4 Seconds
    Open Shade (shaded subject, clear sunlight), EV6, f/22, 8 Seconds

    Since it was a Cloudy-Bright day, I set the Pocket Light Meter app (with gel in front of lens) to f/16 and adjusted the ISO in the app until the exposure read 2 seconds. This required setting the ISO from 1.6 to 8 to get results that matched Rockland's recommendation

    I followed the same process when conditions changed to Bright Sun, also ending up with an ISO setting of 8 for exposure times that matched Rockland's recommendations.

    I found that an ISO of 8 with the gel produced very consistent and good exposures throughout the day under variable lighting conditions and lens openings.

    Of course, the calibrated CTB gel isn't strictly necessary to follow this procedure. I was using a clear blue plastic file folder tab before. It does provide a sort of benchmark though.

    The same ISO calibration value of 8 also produced consistent exposure time recommendations for several other Iphone light meter apps I own.

    Best,

    Don
     
  20. DonF

    DonF Member

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    Brian had sent us some chrome alum crystals to use as a hardener with the AG Plus emulsion. We finally got around to using the hardener on the latest shoot. We mixed up a 5% solution in distilled water and pre-soaked the exposed plates for 5 minutes followed by a 5 minute wash before developing. We had excellent results. There was zero emulsion lifting. Thanks for the suggestion. We will order up a jar of the crystals for future use.

    We have been using washing soda (sodium carbonate) with a drop of photoflo 200 and Dawn to wash plates. This stuff MUST be washed off thoroughly, or the high ph will fog the plates severely. We also have been wiping the plates with 91% isopropyl alcohol after rinsing and drying with good results.

    We also suspected our dark amber safelight was getting too close to the emulsion/plates and causing fogging. We redirected the safelight to bounce of the white walls of the darkroom. Fogging seemed much reduced.

    Our Ilex Acme #4 shutter with a Schneider 210mm 1954-vintage single-coated lens was getting very balky. A new shutter was 4x the cost of a "new" used lens with a modern Copal shutter. We picked up a newer Schneider 210mm Symmar-S multicoated lens in a Copal #1 shutter (1983-vintage). Images are sharper with more contrast, but we do like the soft off-center effect of the older lens. The shutter is a dream to use compared to the 1954 Ilex.

    Lighting is critical to good results (no surprise!). Best results are under full noon sun with subject shaded facing North. Shooting within a couple of hours before sunset or after sunrise makes exposures much more critical and variable. The first three images below were under ideal conditions.

    We did a bit of research on how the Rockland "reversal" developer works. Apparently, the Ammonium Thiocyanate is the secret ingredient. It has a complex chemical effect on the developed silver such that very tiny "balls" of silver are formed in the exposed areas rather than tangled threads of metallic silver that form with conventional developer. The dimensions of the "balls" are on the order of the wavelengths of visible light, causing the exposed areas to render as light colored rather than dark. Ammonium Thiocyanate is commonly used in holographic developers so the interference pattern is preserved by the tiny sub-micron silver "balls".

    We also are changing the developer and fixer after every plate. Since doing so, we have not been plagued by the metallic "comets" that can occur due to contamination of precipitated silver in used developer. We also rinse and clean the developer tray thoroughly between plates. It is well worth the effort and doesn't reduce the yield of a liter of developer by much if a small tray and minimal quantity of developer (40-50ml) is used per plate.

    Some examples with the new lens (using a new scanner as well - more representative of actual tone and exposure):

    Regards,

    Don and Jenni

    [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG]
     
    Last edited: Aug 27, 2016
  21. OP
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    bvy

    bvy Subscriber

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    Don. I got your PM and I'm thrilled to hear that this worked for you. Glad I was able to help.

    Regarding depletion, the solution turns color when it's no good. It should be bluish-purple, deep and dark -- almost black in large volume. What color it turns to when it depletes, I don't know. Maybe PE can chime in.

    Also, just curious, but how did you decide upon the 5% dilution?
     
  22. DonF

    DonF Member

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    I spotted another post here on APUG from PE that recommended the "5% - 5 minute soak - 5 minute rinse" pre-development treatment. I was reluctant to add it directly to the AG Plus emulsion. so just stuck with his suggestion. There was no apparent staining of the emulsion.

    =================================

    Well, I would add that you should be using Chrome Alum as hardener in the emulsion at about 5 ml/100 ml of emulsion using a 10% solution. If that does not work, then soak your plates in 5% Chrome Alum just before development. Hold for 5 minutes, wash 5 minutes and then develop.

    Plain Alum (the white powder) is not a good hardener. Chrome Alum (the purple powder) is a good hardener.

    PE


    =================================

    Off topic, but I ordered supplies from Bostick & Sullivan for collodion wetplates. The one thing about the Rockland Colloid dry plate process is that the contrast and brightness of the image does not seem as good as actual tintypes I have seen in-person. I certainly like being able to pre-prepare the plates and take six loaded plate holders with me to the shooting location!

    Best,

    Don
     
    Last edited: Aug 29, 2016
  23. Photo Engineer

    Photo Engineer Subscriber

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    Exhausted chrome alum is greenish IIRC.

    Sorry for the typo above in my post. I use 5% for prehardening plates but 10% for adding to the emulsion. Different amounts and different percentages.

    PE
     
  24. analog65

    analog65 Member

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    Don, I just run across your post when researching for reversal developer for AG Plus on black aluminum plates. Were you able to get a full recipe to make your own developer with the Ammonium Thiocyanate, vs. buying the commercial developer. My intent is creative control and not trying to be a cheapskate and buy the pre-made developer. I try and mix all my solutions from raw materials so I can control their impact on my work.

    Thanks




     
  25. DonF

    DonF Member

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    This formula works identically to that in the bulk kit. I have used quite a few batches with no failures or performance variation. Here it is:

    To make 950ml of working developer (about 1 quart), divide the mixing directions from the Bulk Kit into fourths, as follows.

    1. Prepare 250 ml of 41% Ammonium Thiocyanate solution by dissolving 102.5 grams of Ammonium Thiocyanate powder in 110ml of distilled water. Add additional distilled water to make 250ml. Store in stoppered bottle. This is good for 4 batches of 950ml each.

    2. Mix dry contents of Dektol packet thoroughly. Dissolve 37 grams of Dektol powder in 750ml of lukewarm distilled water.

    3. To the Dektol solution (while warm) dissolve 75 grams of Sodium Sulfate. Cool solution to room temperature.

    4. To the cooled solution, add 62.5ml of the 41% Ammonium Thiocyanate solution prepared in step 1. There should be a significant ammonia smell.

    5. Add distilled water to make 950ml (1 quart) of working developer.

    6. Store finished developer in stoppered bottle at least overnight to ripen before use.


    Best regards,

    Don
     
  26. Photo Engineer

    Photo Engineer Subscriber

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    The only part I have problems with is the use of part of a solid kit (Dektol). It is hard to get a uniform portion from a solid kit and this can lead to variability from mix to mix.

    PE
     
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