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  1. #11

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    Quote Originally Posted by DWThomas View Post
    Here's a 4x5 negative scan:

    Attachment 60521

    A 0.305 mm pinhole @ 63 mm from the film plane, a relatively wide angle of view.
    Arista ULTRA 100 exposed 8 sec with the f/210 pinhole.

    The camera was a relatively fancy project using plywood.
    Thanks for posting that up, that's a nice image made from a nice looking camera, it almost looks like a large format field camera in its collapsed form, how did you make your pinhole?

  2. #12
    DWThomas's Avatar
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    Quote Originally Posted by m1tch View Post
    Thanks for posting that up, that's a nice image made from a nice looking camera, it almost looks like a large format field camera in its collapsed form, how did you make your pinhole?
    The pinhole was made by the traditional dimple-and-sand method, using 0.001 inch brass shim stock and #400 wet-or-dry sandpaper wet. You create a dimple with the tip of the needle, flip the sheet over and sand gently with a circular motion. It is not necessary to actually pierce with the needle, nor does the needle have to be as small as the desired hole diameter. I use a scrap of mat board as backup when "operating." In the ideal case, the hole is left with a knife edge and perfectly round. It's an iterative process, slowly working up to the desired diameter (in my case, checked with a direct reading microscope in my possession for about 45 years!)

    The finished pinhole plate was blackened with BlackenIt, a mysterious liquid found in model railroad oriented hobby shops.

    1 mil shim stock is pretty flimsy to handle -- I might suggest 2 or 3 mil for a first try. There are assortments of several thicknesses found in some hobby shops, auto parts stores and hardware stores. Often a K&S brand found with other brass strips and shapes for model making.
    Last edited by DWThomas; 11-30-2012 at 09:32 AM. Click to view previous post history.

  3. #13

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    Ah I see, so you dimple it rather than pierce it and then when you sand the back of it the dimple gets sanded through before the rest of the material? I think some of the acid etched pinholes are dimpled around the actual pinhole rather than just a 90 degree hole as is with the laser etched ones which apparently gives a clearer image.

  4. #14
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    Quote Originally Posted by m1tch View Post
    Ah I see, so you dimple it rather than pierce it and then when you sand the back of it the dimple gets sanded through before the rest of the material? I think some of the acid etched pinholes are dimpled around the actual pinhole rather than just a 90 degree hole as is with the laser etched ones which apparently gives a clearer image.
    Yes, think of running a razor over a zit -- uh -- on second thought, maybe we'd rather not!

    From my ancient days in etched parts, circuit boards, etc. it's almost inevitable that there is a slope to the etched edge, so that could produce a bit of a knife edge, even in a flat sheet.

  5. #15
    DWThomas's Avatar
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    Note: there is a page full of links to assorted and sundry pinhole information on the Worldwide Pinhole Photography Day website. Click on the 'Resources' link at the top. There are galleries there showing pinhole shots from all over the world on pinhole days back to 2001 or so.

    By the way, WPPD is something to line up for in 2013, it's usually the last Sunday in April. I've been going out for that each year now since 2005. usually I try to record some sort of unique/historic spot in my area.

  6. #16
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    When I get some time I will post some shots from the pinhole made from a PBR can, sand paper, needle, and a black sharpie. I come from the school of KISS.
    K.S. Klain

  7. #17

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    4x5 pinhole image:

    Click image for larger version. 

Name:	img272_trapedindoors.jpg 
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ID:	60538

  8. #18
    RalphLambrecht's Avatar
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    very good!almost too sharp.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  9. #19

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    Jon, that shot does look really good, especially considering that there isn't actually an optical lens on the camera it would be cool to KISS but then again its probably not as easy with a DDS.

    Here is a video on a beercan pinhole which is simple, but I can't really fit a 5x4 DDS in a beercan!

    http://www.youtube.com/watch?v=Hp-JMGQUAMA

  10. #20
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    How sharp can you get a pinhole image?

    Actually using a double dark is the best way, your not fiddling around it dark bags changing film. All the information your getting her is good you could also head over to f295.org a dictated pinhole forum.

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