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Thread: image help

  1. #1

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    image help

    Here an image I processed today. I am not sure why it fogged on the side. also some of the image appears to turn to a more of a light tan. In the image on here I know i missed a bit with my pouring. This was the only one I poured so poorly but it had the best exposure out of the images i made. I have my ideas as to why but I am not sure maybe someone can give me their advice or ideas.


    Thanks
    Attached Thumbnails Attached Thumbnails Untitled.jpg  

  2. #2
    dehk's Avatar
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    If you tell us what format and how did you develop it with the procedure, i am sure we can help.

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    browning box camera...
    med apeture at 18 seconds
    collodion , 5 minutes soak in silver exposed for 18 seconds poured developer on for approximately 15 seconds wash then fix for 5 minutes

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    smieglitz's Avatar
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    You are probably grossly overexposing the plates. Here is a test strip sequence I shot recently using a passport camera. The exposures are all at the same aperture (f/11 IIRC) for 2, 4, 8, & 16 seconds starting in the bottom left quadrant and going clockwise.



    Because there really is no true black anywhere on your plate including the islands the collodion pour didn't cover, I'd say you have too much developer activity as well. (Compare to the black corners in the plate above.) Usually that's from trying to "push" the development but since you state development was 15 seconds, then the developer is probably too strong. You actually say "approximately 15 seconds" and if you are getting out to 20 seconds, you are overdeveloping. Develop exactly 15 seconds every time and tune your exposure and chemistry to that exact time. (You could use a different time, say 30 seconds, but then you'd have to adjust your exposure and chemistry to that time. The point is to be consistent.) Try diluting a small batch of developer with 50% more distilled water and see if that gets rid of the fog on the unexposed parts of the plates. Sometimes chemical fog results from developing in a tray that is dirty and has silver deposited on it.

    If your silver bath is made correctly 3.5 minutes sensitizing is probably OK. Some of this may be from the plate soaking too long in the silver bath. Check the progress by noting when the fluid runs off the plate in an even sheet rather than in rivulets. At that point, the plate has sufficiently sensitized.

    The color shift may be a result of an insufficient wash. As with the silver nitrate, wash the plate until there are no visible rivulets draining the plate. Then, wash it further in clean water for about that same time.

    Sometimes the plate starts to dry out and the drier areas will not have the same color as the rest of the plate because the chemical action is different. But, I don't think that is the problem here. I think it is the brief wash time. Another possibility is exhausted fix which tends to give yellower plates. Which fixer are you using?

  5. #5

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    I guess I really do not understand this the way I thought. Will any of the impulsion turn black? I think in part I am trying to treat it like paper so I am looking for blacks when i develop. When i do paper i look for the true black or area i want to be black and watch of they to turn. what I am wonder as I look at his is maybe I am going to have to learn how to shoot for this format as well. for example what back drop color works best when doing a portrait.

    on the corners of your test images is the impulsion black or clear and I am seeing the black backing. I have never actually held a collodion print long enough to examine it. I am going to setup in a bit hear and run a set of tests shots. your correct though I am not timing my development exactly. I maybe pushing the developer to long. I do not see the same results as i see in the films i have watched. Most of my image still looks white like after the silver bath after I have developed it then it clears in the fix. I am waiting to see the image in the dev like BW paper. When i run my tests today i will set the dev time and be consistent. Most likely this a combination of mistakes. to wide an aperture I am using the middle of the brownie setting I have no idea what that is. Maybe over exposure and over developing. I need to some time and run a test fun until i get this right. Thank you for your help

  6. #6

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    Ok today i had the worst time. my first image was soft but it had an image at 2 seconds in full sun ... I had to stop after that because i have kids and they cannot wait a second of they will die. when your a 16 year old girl everything in your life is life and death or worse. Anyway when i get back i start up again and i can't get an image. just clear and some white. so I alter the times and I keep getting plain clear glass on the edges i get that kind of tan over exposed part. I am not sure how i could go so bad so quick. my pouring developer sucks i think but I am not sure. part of my problem is I cannot see under the red light. i guess I will have to break down and make a head lamp one so i can see when I pour. tonight i will mix up more developer and try this again. I just can't get how I can go so bad. It was so clear i ended up scraping a couple of the plates just to see if there was any collodion there. The only think I can think is maybe my silver bath is bad can that be ?

  7. #7
    smieglitz's Avatar
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    Fog isn't usually a silver bath problem unless the pH is not in the proper range. You might get "comets," clear pinholes, or have a speed/contrast issue, but the silver bath usually doesn't cause problems. You could "sun" the bath if you are not sure. Just put it in a clear glass or plastic open container and set it in the sun away from kids and pets for a few hours. The silver will react with anything organic in the bath and it may turn cloudy and have a black precipitate. Just filter the sunned bath and you should be OK. The ether and alcohol that may have accumulated in the bath will also evaporate during sunning and that will also improve the quality of the silver bath. After some use, you may need to add a little more silver nitrate to keep the strength up. That's all I've ever done and I've been using the same baths for 3-5 years. Others do more like boiling the volume down and neutralizing the bath, but I've never had the need to do so.

    But, while we are talking about the silver bath, did you pour a glass plate with salted collodion and let it sit overnight in the silver bath? (Don't use an aluminum plate for this.) You need to do that to obtain proper contrast initially. The silver bath must contain adequate silver iodide (the iodide comes from the collodionized plate) in order to be in equilibrium with the iodide on future plates that are sensitized. If the bath someday gets too much silver iodide in it, you will start to see pinholes on your plates. At that point a more severe maintenance step is required to return the silver bath to the proper state. But don't worry about that now. It may take years before you will have to do something that involved to rescue your silver bath. Directions can be found in some of the early collodion manuals available online if you ever need to remove the excess iodine that builds over time.

    Do you know the pH of your silver bath? It should be near neutral (pH 6-7) for negatives and more acidic (pH 4-5) for positives. If the bath is too neutral, you may get some fog. If so, lower the pH incrementally and slowly drop-by-drop with acid until your plates don't show the fogging when everything else (developer strength & time, exposure, etc.) has been adjusted. You only want to add enough acid to get rid of the fog. Too much will lower the sensitivity of the collodion. It is recommended that nitric acid is used for this rather than acetic acid. Acetic acid will react to form silver acetate which may cause later problems and which also takes some silver out of the system. Nitric acid will be in harmony with the silver nitrate but it is also a very hazardous chemical to use. In particular it represents an inhalation hazard that can cause severe corrosion of the lungs with subsequently lethal pulmonary edema. Don't breathe the stuff and keep it off your skin.

    Before you change anything else chemically, work on the exposure and development aspect. It sounds as if 2 seconds is too short and 16 seconds is too long. Once you have an image you will be able to adjust other variables one at a time if needed to improve the quality. Don't try to change everything at once.

    Based on some exposures done with a Brownie two weeks ago, I would think an exposure of around 4-6 seconds in midday northern skylight on a sunny day would be close to the proper exposure with the camera at its widest aperture. I was in that range with 3-week old collodion and a fresh silver bath. I also used a Brownie that had the aperture removed and a good exposure then was about 1.5 seconds IIRC.

    Are you using a book, manual, or some sort of guide as you begin your wetplate trials? The most often recommended are:

    - John Coffer's Do'ers Guide to Wetplate Collodion +/- his DVD set. See www.johncoffer.com
    - Quinn Jacobson's new manual might be available through http://studioq.com/
    - Scully and Osterman's manual or their chapter in John Barnier's Coming Into Focus book on alternative photographic processes. See www.collodion.org
    - John Towler's 1864 The Silver Sunbeam

    George Berkhofer and Wlll Dunniway also have brief manuals on the process. You can also find other 18th-century references by Desire Monkhoven or Mathew Carey Lea or Estabrooke's book online for free. Googling should turn all of these up.

    And I have to push my online article as well. See my signature below for the link.
    Last edited by smieglitz; 05-17-2012 at 11:24 PM. Click to view previous post history. Reason: added safety warning



 

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