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Thread: LF Pinhole - design and building

  1. #11

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    Brookfield, Vic., Aust.
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    Re: LF Pinhole - design and building

    Hi all, I don't try and make these cameras out of a sense of elegance, but because I like woodwork and also stability and ruggedness. A great justification for the latter was the other day when I'd just made the second test photo... I was coming down from the rocky area when I slipped and fell on my left side, on top of the camera I'd just used. Fortunately it was not damaged!

    Dave, there is a book by Renner referenced in this excellent article by Brian Young here: http://www.alternativephotography.co...h-really-said/ I haven't read it, but it, but it might be helpful. I find the web a great place for finding pinhole info.

    Hendrik, you may find this article helpful also. In general for close up work you need a small pinhole because each diameter of pinhole has a limit for close focus at a given film-pinhole distance. There are no hard and fast rules, so you might like to start experimenting with a pinhole of 0.2mm at a lens-pinhole distance depending on your camera. This should provide very close focus. For pinhole supplies there is Lennox Laser, https://lenoxlaser.com/ Also a man named Earl who used to be on f295, but I don't have contact details for him at present. He sold laser drilled electron microscope apertures which are just perfect for pinhole. James at http://www.aupremierplan.fr/ sells Earl's apertures already mounted.
    Last edited by Barry Kirsten; 9-Feb-2017 at 00:35. Reason: corrected surname

  2. #12

    Join Date
    Jul 2015
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    Sonoma County, California
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    71

    Re: LF Pinhole - design and building

    If you are interested in the math behind macro pinholes you can find the Prober-Wellman formula here. The "optimum" does not fall off all that fast as you get closer to the camera, for example if you make one to be optimum at 2 inches, it will work pretty well at 1 inch. Strong diffraction effects will be obvious in more more distant subjects, but can be interesting. The image looks different depending on whether the aperture is too big ( geometric blurriness ) or too small ( diffraction ).

  3. #13
    JoeV's Avatar
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    Re: LF Pinhole - design and building

    Quote Originally Posted by DHodson View Post
    Just wondering if someone could point me to a good starter book on pinholes.

    Thanks
    Dave
    Dave,

    Eric Renner's book is considered a modern classic on the subject. He's recently updated the book, here's an Amazon link:

    https://www.amazon.com/Pinhole-Photo...dp_ob_title_bk

    ~Joe

    PS: I see that Barry has linked the same book above.
    The photograph and the thing being photographed are not the same thing.

  4. #14

    Join Date
    Nov 2015
    Location
    Alberta, Canada
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    Re: LF Pinhole - design and building

    Thanks for the link to Eric Renner's book. I checked Amazon here in Canada and they want $62 (Canadian) for it so hopefully I can find a used copy somewhere.

    Dave

  5. #15

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    Re: LF Pinhole - design and building


  6. #16

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    Nov 2015
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    Alberta, Canada
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    Re: LF Pinhole - design and building

    Thanks Dan - that's a new link for me

  7. #17

    Join Date
    Jan 2014
    Location
    SW missouri
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    75

    Re: LF Pinhole - design and building

    Well Barry,"GOOD ON YOU"! Think this is a great idea and hope it takes off.
    Your camera is beautiful, a piece to be proud of for sure and looks like a good picture maker.You'll work out the vignetting issue,just a small bump in the road for ya.
    Guess you can access"Amazon" down under,I've found many parts for my builds there(and often free shipping)which helps a lot.
    Keep up the good work and please share as you go.
    Don

  8. #18

    Join Date
    Oct 2010
    Location
    Brookfield, Vic., Aust.
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    Re: LF Pinhole - design and building

    Thanks for the kind words Don. Actually I've just identified the cause of the vignetting, it's the filter ring, as Shane Booth suggested. Thinking the vignetting was caused by a ridge behind the pinhole, I ground away part of the mounting plate (with the pinhole removed) but it didn't work. Sighting along my alignment dots on the top of the camera, with the pinhole directly below the centre dot on the top, shows the edge of the filter ring directly in line. The solution is a larger filter ring. I found I can just sneak a 58mm ring in there and still be able to adjust the rise and fall. I hope it doesn't vignette with a filter mounted. Wait and see for next installment. Thanks for the tip about Amazon, I'll look into it. There is talk that Amazon may open in Australia, but we'll have to wait and see. Best wishes Don.

  9. #19

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    Oct 2010
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    Brookfield, Vic., Aust.
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    Re: LF Pinhole - design and building

    At last the modification. I made a new front panel out of 1mm aluminium and increased the filter ring to 67mm, which makes sense since I have standardised on 49 and 67mm filters and don't have any 58s. No sign of vignetting. This is a very wide camera (about 110 degrees). At the right end you can see blurring, which is actually my head. About 10 sec. into the exposure I realised I might be too close and moved away - sure enough that was the case. I also reduced the pinhole to 0.4mm and that slows the speed to f/340 but improves sharpness, I think. This morning's test shot, done at sunrise was on Kodak dental panorama x-ray film (double sided, green sensitive). Film was rated at ISO 100, exposure was 30sec. and development was in PMK 1+2+100 for 8min. I'm now developing on glass in the bottom of the trays, but am still getting scratches due to handling during loading and unloading, so I'm learning just how careful I have to be with this film. Film photographed on light box with digital P&S, no modification to image other than inverting.

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  10. #20
    Jim Jones's Avatar
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    Re: LF Pinhole - design and building

    Consider that Joe's link is for the 2009 edition while Dan's is for the 1999 edition which should contain most of the same information. My 1995 edition has more information than I'll ever absorb.

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