Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,924   Posts: 1,556,684   Online: 1172
      
Page 3 of 7 FirstFirst 1234567 LastLast
Results 21 to 30 of 61
  1. #21
    Ambar's Avatar
    Join Date
    May 2011
    Location
    Rio de Janeiro, Brazil
    Shooter
    35mm
    Posts
    104
    Interesting you should post this!
    I've been considering such a test for the past month and I'm now trying to attain all the necessary tools for such..
    The idea behind this has been to test the statement, Exposure controls density, but development controls density and contrast. I'm not try to test the veracity of this, but the quality and extent of manipulation possible.
    Yes I am very well aware about the variations in emulsion and developer combos but in reality I'm not interested in discovering a universal theory of everything photographic. Just the developer/film combo I'm interested in.
    Films I like PanF+ and HP5/Tri-X (decided eventually to stick with HP5). Developer available to me that works nicely with both? Rodinal (Adonal to be more specific).

    Let the games Begin..
    The general parameters behind this is set, I will construct a standard and controlled scene (which will include a target). The target area's lighting will be metered as zero at full box speed, then extensive bracketing will take place.
    The idea is.. Photograph a control scene at several different exposure indexes. Say for example, -4,-3,-2,-1,0,+1,+2.
    Repeat this several times and develop each strip for different a different amount of time. Say for example. -60%,-30%,-15%,0 (manufacturers suggestion), +15%,+30%,+60%.

    I am quite aware that there is some waste involved with this. As a scene that is seriously under exposed and under develop will produce little to no results. But the idea is to produce a scientific test, or as scientific as possible. So temperature, agitation, general processing routine, scanning (of course), and all other variables be standardized.

    Hopefully once I'm done, I'll have a menu of options indicating the exact look I want for a given developer/film combo.
    What I do need help with is, how much of each.
    I decided quite easily that I should vary the exposure in one stop increments, for simple ease of application afterwards. I wanted to maintain waste to a minimal and my idea would be to have 6 exposures per development strip. HP5 rated at 3200 (-3), 1600 (-2), 800 (-1), 400 (0), 200 (+1), 100 (+2), for example. PanF+ rated at 400 (-3), 200 (-2), 100 (-1), 50 (0), 25 (+1), 12 (+2). (even though PanF+ rated at 400 sounds really silly)
    But, how much should I vary ("bracket") development time?? Standard for 0 (iso 400 and 50) and how much plus or less? I've heard figures like 15% for each stop but sometimes that doesn't look right.. Maybe it's not a linear function? I would rather it be a constant between both films but I'm open for whatever works!

    Any help will be VERY welcome! Thoughts, comments or criticisms as well!

  2. #22
    dpurdy's Avatar
    Join Date
    Jun 2006
    Location
    Portland OR USA
    Shooter
    8x10 Format
    Posts
    2,057
    Images
    38
    Quote Originally Posted by Michael R 1974 View Post
    How did you come to the conclusion you needed a Beutler developer before choosing the film?
    I have a lot of experience with developers and films because I am old and have spent my whole life working with photography and darkrooms. I became a big fan of beutlers back in the day when you could still get Agfa 25 in 4x5. I still find it hard to beat beutlers with fine grain film. Not just for sharpness but for the mid tone density. I switched to Pryocat HD a couple of years ago to see if I could work the same negs in silver or platinum. I have a hard time putting my finger on what the "feel" of pyro is. I am still not sure I like it. I know that I get really clean unmottled film but the quality of the prints is inconsistent for me in that sometimes it is great and sometimes it seems flat and I don't know why. I am thinking of doing this old side by side testing with pyro and beutlers with my sheet films (fp4 and tmax 400) and my 120 acros. Just to see if I can get a better grip on the pyro. The other thing is that I have done these tests a lot of times and it is always surprising, once printed, just how little difference there usually is.
    Dennis

  3. #23
    mfohl's Avatar
    Join Date
    Jan 2007
    Location
    Westerville, Ohio
    Shooter
    Multi Format
    Posts
    386
    Images
    54
    So Mr. Purdy, where can I find Beutler developer? The only sources I find are Photographers' Formulary and maybe Freestyle. Is that right?

    Thanks in advance.

    -- Mark

  4. #24
    dpurdy's Avatar
    Join Date
    Jun 2006
    Location
    Portland OR USA
    Shooter
    8x10 Format
    Posts
    2,057
    Images
    38
    Quote Originally Posted by mfohl View Post
    So Mr. Purdy, where can I find Beutler developer? The only sources I find are Photographers' Formulary and maybe Freestyle. Is that right?

    Thanks in advance.

    -- Mark
    You only need Sodium Carbonate, Metol, Sodium Sulfite and Potassium iodide. (and a scale) The chemicals are available lots of places but Photo Formulary has them.
    I have used Sodium Carbonate from the grocery store as Arm and Hammer laundry additive or from the art store as soda ash dye fixative.

    You mix stock of part A and part B and use them 1-1-8 (or 10)
    You can find the formula with google.

    Dennis

  5. #25
    destroya's Avatar
    Join Date
    Jul 2012
    Location
    san jose
    Shooter
    Multi Format
    Posts
    270
    i did a very NON- scientific experiment kinda like what you asked. I used DXO Fimpack and just switched to every film and looked at the difference. It really told me nothing but it was fun.

  6. #26

    Join Date
    Nov 2012
    Shooter
    Multi Format
    Posts
    277
    Quote Originally Posted by Michael R 1974 View Post
    I'm referring to technical/scientific fields and literature.
    Well then you aren't talking about photography. I find politics tamer and more factual than a lot of discussions that go on in photography. A recent thread on lomography is a prime example.

    Quote Originally Posted by dpurdy View Post
    The problem most people are pointing out here is that there are too many variables with several films and several developers. I agree with that.
    If you only pick the popular emulsions at each speed and the popular and recommended developers it is not that big of a project, particularly for a photography periodical. You don't have to test every emulsion with every developer. As has been stated there is no point in testing Adox CMS 20 with anything other than Adotech II. ISO 100 would probably be the toughest area because so many people make decent ISO 100 B&W film. But most of those emulsions are commonly developed in Rodinal.

    And besides if it was a periodical they could do a head to head Rodinal extravaganza and do everything from ISO 25 to ISO 3200 in Rodinal. Then a few issues later do XTOL. Then a few issues later do D76. I mean what are these magazines doing if they aren't doing tests like that?! Who in their right mind wouldn't buy those issues? To me every time a new emulsion comes out if I was running a magazine I would wait a few months to get some feedback on what people are developing it in and how. Then I would do a test on multiple rolls with multiple developers and publish the results. Talk about useful information.

  7. #27

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,861
    Quote Originally Posted by Noble View Post
    Well then you aren't talking about photography. I find politics tamer and more factual than a lot of discussions that go on in photography. A recent thread on lomography is a prime example.
    Yes I am talking about photography, the craft of which is based on some very complex science. So, people who might be fine photographers but are not experts in the science, should not write about the craft from a scientific perspective if they do not have data and details on the testing methodology to present. That is what most books and articles are filled with.

    Quote Originally Posted by Noble View Post
    And besides if it was a periodical they could do a head to head Rodinal extravaganza and do everything from ISO 25 to ISO 3200 in Rodinal. Then a few issues later do XTOL. Then a few issues later do D76. I mean what are these magazines doing if they aren't doing tests like that?! Who in their right mind wouldn't buy those issues? To me every time a new emulsion comes out if I was running a magazine I would wait a few months to get some feedback on what people are developing it in and how. Then I would do a test on multiple rolls with multiple developers and publish the results. Talk about useful information.
    Well, knowing what I know now, I wouldn't buy it. I mean, I'd purchase it, but I wouldn't buy it. Why do you think the magazines would do a good job with this? What are you basing that on - Photo/Darkroom Techniques magazine? That magazine was all about technical articles which were usually based on nothing more than anectodal ramblings by noted photographers. You can do tests and publish all you like. Is the information useful? For example, how will you test for film speeds and contrast? To ISO standards, or will you do a Zone System test filled with flare, falloff and other errors? Etc Etc concerning every aspect. At the very least, you would have to be very clear and detailed about the testing methodologies so that people would be able to properly interpret the results. This is almost never done.

    The tests you propose are also an enormous amount of work.

    I'll back away from this now I think...
    Last edited by Michael R 1974; 01-25-2013 at 11:50 AM. Click to view previous post history.

  8. #28

    Join Date
    Nov 2012
    Shooter
    Multi Format
    Posts
    277
    Quote Originally Posted by Michael R 1974 View Post
    Well, knowing what I know now, I wouldn't buy it. I mean, I'd purchase it, but I wouldn't buy it. Why do you think the magazines would do a good job with this? What are you basing that on - Photo/Darkroom Techniques magazine? That magazine was all about technical articles which were usually based on nothing more than anectodal ramblings by noted photographers.
    There is nothing in my posts about merely taking someones word for it. I see you have an axe to grind with a particular periodical. I didn't have a particular periodical in mind. Frankly what I was thinking was a periodical funding and paying someone such as a university professor or someone who runs a large photo lab to carry out the tests. I read scientific journals all the time and have been a part of multiple scientific research projects. Developing film is pretty simple in comparison. As with all scientific journal articles you will write your materials and methods section. As long as you lay out your protocol and stick to it you will have some useful data at the end. Now the exact number and manner of inversions will be debated and someone can do a separate test to see if number and manner of inversions does in fact make a difference. The thing with scientific studies is you don't try and cure HIV in one study. You do a general landmark study that answers some questions but actually raises even more. Then you do some more studies to fine tune your understanding.

    Quote Originally Posted by Michael R 1974 View Post
    You can do tests and publish all you like. Is the information useful? For example, how will you test for film speeds and contrast? To ISO standards, or will you do a Zone System test filled with flare, falloff and other errors? Etc Etc concerning every aspect.
    I see you suffer from analysis paralysis. I would first breath and calm down. As I said start with the most popular emulsions at each speed. And yes I would shoot them at box speed. I would also develop them according to manufactures specifications as well as with popular alternatives. Basically make it as simple and cost effective as possible. If there are gross trends you will find them. If there aren't then even that is a result. Frankly as others have stated I bet the differences are so subtle that for the majority of the emulsions, developers, and developing techniques you are going to have to do all sorts of extreme things to see an appreciable difference in the prints. Some emulsions regardless of what you do will have finer grain than their ISO equivalents from other manufactures. So it isn't really going to matter which developer you use or what your technique is. That relationship will not change between the two films. That's the type of thing that will jump out from such an initial experiment.

    So the main point is avoid analysis paralysis. Start simple and look for trends... or debunk false tales of trends. After you get your results back as with any scientific endeavor it will open up new vistas for further exploration and actually close off other vistas. For example in the ISO 100 test which will be the most extensive you may discover that grain or resolution wise there is nothing to be gained outside of the top three emulsions. Maybe you will decide no further testing is really needed beyond the Fuji, Kodak, and Ilford offerings. Or maybe you will decide grain and resolution are close and other things like dynamic range and contrast are more of a differentiating factor.

    There are some highly specific things that you will not be able to get an answer to. That does not mean you shouldn't do the simple experiment to at least answer some questions. Anyone that has developed a few rolls of film knows it is not complicated. It really is a scientific experiment worthy of junior high school students.
    Last edited by Noble; 01-25-2013 at 12:21 PM. Click to view previous post history.

  9. #29
    markbarendt's Avatar
    Join Date
    May 2008
    Location
    Beaverton, OR, USA
    Shooter
    Multi Format
    Posts
    5,770
    Blog Entries
    3
    Images
    19
    Quote Originally Posted by Arctic amateur View Post
    What I'm interested in is the character, or "feeling", of films. I don't have any specific scene in mind and I'm not searching for a suitable film for a purpose, I want to see what this elusive "character" is simply out of curiosity. If different films have different character, there must be a difference, if subtle, in the final image. Is it the spectral sensitivity? Contrast? Latitude? I can read about differences and kind of understand descriptions of a film's properties, but it's so much easier to understand with two pictures side by side.

    Of course many other things can change the final result, which is why I was trying to say "don't change anything except the film". Difficult, certainly. Perhaps sending the films to a pro lab would make it easier to ensure consistent development?
    I'm actually going to say that taking the developer out of the equation and matching CI may be a mistake.

    For example TXP and HC 110 are complimentary, the film and the developer naturally lean toward the same type of curve, a long beautiful toe and great separation of tones middle to high. It is a classic combo. TX/HC110 similarly.

    Delta or TMax in DD-X or TMax developer will have a shorter toe, better separation in the shadows, but the straight line may actually be slightly flatter, so the mid to high tones might look flatter, if developed to the same CI. These are "classic combos" too.

    Adjusting the CI to match the "snap" in the mid to high tones of TXP/HC110 or some personal best CI would provide a more practical result, a better demonstration of character.
    Mark Barendt, Beaverton, OR

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  10. #30
    markbarendt's Avatar
    Join Date
    May 2008
    Location
    Beaverton, OR, USA
    Shooter
    Multi Format
    Posts
    5,770
    Blog Entries
    3
    Images
    19
    Shaping the curve http://www.apug.org/forums/forum216/...-negative.html

    Post 10 has a really good graphic.
    Last edited by markbarendt; 01-25-2013 at 12:44 PM. Click to view previous post history.
    Mark Barendt, Beaverton, OR

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

Page 3 of 7 FirstFirst 1234567 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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