Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,849   Posts: 1,582,839   Online: 737
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 30

Thread: Pinhole swirls

  1. #11
    edp
    edp is offline

    Join Date
    Oct 2009
    Shooter
    Multi Format
    Posts
    197
    Some people suggest dunking your pinhole in selenium toner, to blacken the brass.

    E.g. http://pinhole.stanford.edu/mt.html

  2. #12
    Perry Way's Avatar
    Join Date
    Sep 2008
    Location
    San Luis Obispo, CA
    Shooter
    Multi Format
    Posts
    825
    Blog Entries
    13
    Images
    118
    Quote Originally Posted by edp View Post
    Some people suggest dunking your pinhole in selenium toner, to blacken the brass.

    E.g. http://pinhole.stanford.edu/mt.html

    This is a good idea and I will keep this in mind in case I find thinner brass somewhere, but I've already removed the thick brass plate and in it's place I've put a single sheet of 120 film backing from Bergger (black on both sides). I'm going to purposefully compose a shot today sometime where the sun is directly aimed at and we will see if I can duplicate the swirl. If not, then I'm leaving the film backing. I've used that before in a homemade pinhole camera and it worked great.
    I love the wilderness and I love my trail cameras, all Fuji's! :) GA645, GW690 III, and the X100 which I think is the best trail camera ever invented (to date).

  3. #13

    Join Date
    Jan 2006
    Location
    Oklahoma
    Shooter
    Multi Format
    Posts
    588
    My thoughts are that this is caused by the gaps in the leaves in the canopy of the trees. Each gap is a pinhole of sorts, each at a random distance and angle from the camera's aperture. The leaves may be moving and reflecting, and the sun is certainly moving during the duration of the exposure. I wouldn't be surprised to see results like this under those conditions. Unless by chance dew or condensation formed in the pinhole during the exposure. That could be another explanation.
    "Lo único de lo que el mundo no se cansará nunca es de exageración." Salvador Dalí

  4. #14
    Perry Way's Avatar
    Join Date
    Sep 2008
    Location
    San Luis Obispo, CA
    Shooter
    Multi Format
    Posts
    825
    Blog Entries
    13
    Images
    118
    Quote Originally Posted by DannL View Post
    My thoughts are that this is caused by the gaps in the leaves in the canopy of the trees. Each gap is a pinhole of sorts, each at a random distance and angle from the camera's aperture. The leaves may be moving and reflecting, and the sun is certainly moving during the duration of the exposure. I wouldn't be surprised to see results like this under those conditions. Unless by chance dew or condensation formed in the pinhole during the exposure. That could be another explanation.
    Actually this same effect is noted on other negatives where there is a lot of sky and no canopy or leaves... like at the marina. I'm going with reflection in the pinhole due to the thickness of the plate. The brass plate has a thickness of .5mm. I measured it this morning when I disassembled it. With a hole of .5mm and a depth of .5mm that makes it kind of squarish. I'm thinking the 120 film backing will give me a perfect result. And of course I'll come back and share my findings when I develop it later tonight.
    I love the wilderness and I love my trail cameras, all Fuji's! :) GA645, GW690 III, and the X100 which I think is the best trail camera ever invented (to date).

  5. #15

    Join Date
    Jan 2006
    Location
    Oklahoma
    Shooter
    Multi Format
    Posts
    588
    Quote Originally Posted by 1SharpMonkey View Post
    Actually this same effect is noted on other negatives where there is a lot of sky and no canopy or leaves... like at the marina. I'm going with reflection in the pinhole due to the thickness of the plate. The brass plate has a thickness of .5mm. I measured it this morning when I disassembled it. With a hole of .5mm and a depth of .5mm that makes it kind of squarish. I'm thinking the 120 film backing will give me a perfect result. And of course I'll come back and share my findings when I develop it later tonight.
    That being the case, I would be interested in seeing a close-up of this pinhole. I can only imagine.
    "Lo único de lo que el mundo no se cansará nunca es de exageración." Salvador Dalí

  6. #16
    Perry Way's Avatar
    Join Date
    Sep 2008
    Location
    San Luis Obispo, CA
    Shooter
    Multi Format
    Posts
    825
    Blog Entries
    13
    Images
    118
    The 112 film backing has a wee little problem. To be brief, uneven pinhole. I took two shots roughly the same. One with TMax 400 the other with Tri-X 320. Both of them have rays, not swirls, but there is an elongation of the rays on one side of the frame that has a wee bit of undulation of fading in and out to it but still it is not swirls like the other one I uploaded earlier. And upon further examination, knowing what the negative looks like I can see where there is a little lip on the pinhole I made with the needle. Anyway the negs are still drying, even 2+ hours after photo-flo and hanging up. So I'm going to forego the printing. That was just an exercise. I did prove that the swirl effect was the brass plate that was on the camera.

    Now onto the next subject.. lack of sharp focus. Still there is not a strong focus on anything. I'm starting to think I really need to buy a "real" professional pinhole camera. This one I bought is nice, it is handmade from birch, the craftsmanship is actually quite nice. But at this point I'm seeing the merits of buying a Zero Image 75B Deluxe 4x5 camera. It's expensive, but I am thinking this is the best way to go. There are additional benefits with that camera. There is a remote shutter release, there's an actual shutter, its got interchangeable pinholes, and it's got body extensions so you can shoot in 25mm, 50mm or 75mm. Only one problem.. I just bought another camera that was on my watchlist on eBay the whole last week and now I'm holding myself back from spending any more money on hardware until next month.
    I love the wilderness and I love my trail cameras, all Fuji's! :) GA645, GW690 III, and the X100 which I think is the best trail camera ever invented (to date).

  7. #17
    edp
    edp is offline

    Join Date
    Oct 2009
    Shooter
    Multi Format
    Posts
    197
    1/2 mm thick brass is more like armour plating than foil ;-)

    As for lack of sharp focus, how long is the focal length in the camera you're using? Depending on which formula you choose and what value you pick for the constant, a 1/2mm pinhole is appropriate for something like 14 or 15 cm. Up to a point, if you use a smaller hole, you'll find it a bit sharper. If you make it too small, it'll get softer again due to diffraction.

    http://home.online.no/~gjon/pinhole.htm#formulas

    I've used pinholes between 0.15mm and 0.25mm for focal lengths from 20 to 50mm and got acceptably sharp images on 6x9cm film. Not that pinhole photographs are about sharpness, of course.

  8. #18
    Marco B's Avatar
    Join Date
    Jan 2005
    Location
    The Netherlands
    Shooter
    Multi Format
    Posts
    2,983
    Images
    169
    Quote Originally Posted by 1SharpMonkey View Post
    Now onto the next subject.. lack of sharp focus. Still there is not a strong focus on anything. I'm starting to think I really need to buy a "real" professional pinhole camera. This one I bought is nice, it is handmade from birch, the craftsmanship is actually quite nice. But at this point I'm seeing the merits of buying a Zero Image 75B Deluxe 4x5 camera.
    Yes, the Zero Image 4x5 is a fine camera, and the pinhole quality is high. But don't expect true "sharp focus" from any pinhole. I can't judge your photos against mine, but even my Zero Image won't give perfectly sharp focus. It's a pinhole! You just can't expect "sharp focus" from a lensless camera like a pinhole, although the results can be very satisfactory with my Zero Image...

    The "soft focus" effect of a pinhole is just one of it's charms.
    My website

    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  9. #19
    tony lockerbie's Avatar
    Join Date
    Feb 2006
    Location
    Bega N.S.W. Australia
    Shooter
    Multi Format
    Posts
    2,308
    Images
    382
    I like that swirly effect, with a bit of Jimi Hendicks....some weed....now I'm feeling it.

  10. #20

    Join Date
    Aug 2007
    Location
    Oslo, Norway
    Shooter
    Large Format
    Posts
    30
    Quote Originally Posted by Marco B View Post
    But don't expect true "sharp focus" from any pinhole.
    No problem: downsize the print: use enlarger or scanner/printer to make a copy smaller than the negative, I believe a 8x10" negative will be supersharp on a normal pc screen
    Řyvind

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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