1st pinhole experience - advice please?

Discussion in 'Pinhole Photography' started by IloveTLRs, Mar 31, 2009.

  1. IloveTLRs

    IloveTLRs Member

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    Last edited by a moderator: Aug 15, 2009
  2. keithwms

    keithwms Member

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    There is an optimal effective focal length for each different diameter of pinhole. The optimal focal length will give best sharpness at the wavelength that you feed into the formula.

    This site seems to have some info that may be of use...

    http://www.mrpinhole.com/calcpinh.php
     
  3. Christopher Walrath

    Christopher Walrath Member

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    Wirelessly posted (BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

    Wider would be to shorten the focal length by moving either the pinhole or the film towards the other. However this will increase your f number thus slightly reducing sharpness a wee bit. Perhaps imperceptibly.
     
  4. DWThomas

    DWThomas Subscriber

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    Sharp is not really a pinhole characteristic, although I suspect you might be able to do a little better. The width, as Chris says, requires reducing the distance from pinhole to film. In your case, it looks as though the pinhole isn't quite centered left to right. There is hard vignetting on the left side, implying the pinhole is too far to the right. I have no idea what the construction of your camera is, maybe you can make some minor adjustments.

    The Worlwide Pinhole Photography Day folks have a resource page with a lot of links that might yield something useful.

    A few years back I had some problems with vignetting in a homemade body cap pinhole assembly. It turned out there was just too thick a stack of stuff clamped together for the diameter of some of the clearance holes. A careful scale diagram to sort it out, followed by a major rework, fixed the problem. Rev. 2

    DaveT
     
  5. Galah

    Galah Member

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    I understand that a soft image is a pinhole characteristic, but that some aficionados sharpen their images digitally in PP.:smile:
     
  6. FM2N

    FM2N Member

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    Hello,
    Can you tell me what the focal length of the camera is? The distance from the pinhole to the film? I may have a pinhole that I can send you and it will help with the sharpness of the image. Also check
    www.f295.org
    There you will see the different possibilties of pinhole cameras. There is no reason, unless it is what you want , for the image to be foggy or soft. With the right pinhole and no photoshop the images can be great and very sharp. The problem you are having is that you are being asked to make a pinhole with a needle in the foil given. You can not be expected to make the correct size pinhole for the focal length of the camera. Therefore the image will never be as sharp as it can be.
    Arthur
     
  7. 2F/2F

    2F/2F Member

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    PP? That must mean Piss Poor, because that's what it looks like most of the time when you take a soft image and try to make it sharp with a computer.

    I think the problem is that the camera probably has cheap foil and probably not the best instructions for how to make the hole. (Whaddayawant for 15 bucks? Heh heh.) It could be improved by installing a nicely-drilled pinhole closer to the "optimum" diameter, and by making sure that the camera is absolutely steady during exposure.
     
    Last edited by a moderator: Apr 1, 2009
  8. David William White

    David William White Member

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    I agree with 2F/2F. Revel in it, your photographs are wonderfully dreamy.

    However, for tongue-in-cheek completeness, I should mention there is one surefire way to improve the sharpness of your toy camera, and that is to put a focusing lens in front of it.
     
  9. Pete H

    Pete H Member

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    You can get sharper shots with a better hole (perfectly circular, without burrs etc) placed at the correct distance from the film plane, as 2F/2F said, but pinhole shots will never be perfectly sharp.

    I agree with David William White - enjoy the dreaminess. Maybe make some lith prints to exploit it, or cyanotypes. Use the vignetting pictorially in your composition. Sepia toned prints with the vignetting would have a very old-fashioned look, so make people think by taking modern subjects (as you have done) and giving them that kind of treatment.

    You can have all kinds of fun with it. :smile:

    cheers
    Pete
     
  10. IloveTLRs

    IloveTLRs Member

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    I made another pinhole today and will try the camera out again.
     
  11. Greg_E

    Greg_E Member

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    What is the correct distance? There are so many different "ideal" distances and hole sizes that trying to get things exact seems to be pointless. What color light do you want to be "in focus"? What correction factor? What is the distance of the object from the "lens"? All these things go into determining the "perfect" pinhole size. Use Pinhole Designer to work out some variations.

    My suggestion is get a bunch of different size holes, figure out what the approximate exposure will be, and shoot them all and see what you like best with the film and subjects that you are shooting. And before someone says, well just put an XYZ color filter over the hole so that you are dealing with "monochromatic" light, remember that a pinhole has almost infinite depth of field, so any bit of dust will show up in your image.
     
  12. keithwms

    keithwms Member

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    One general thing you can do to improve sharpness is restirct the rameg of sensitivity of your film (or paper). Recall that a pinhole focuses different wavelengths to very different distances... the very antithesis of an apochromatic glass lens. So what you can do is use ortho film or paper, which have mostly blue sensitivity. Once you work out the optimum effective focal length, you will indeed see more sharpness. Some of that sharpness is 'real' sharpness... and some of it is implied by the overall tonality and comes from the contrastier tone separation that you get from the ortho film/paper if you look for the right light. On this point, the very simplest thing you can do to make your pinhole images appear sharper is simply to look out for contrasty light and contrasty edges (e.g. stark shadows etc.). If you do that then you can indeed get results that people won't believe are pinhole images.
     
  13. keithwms

    keithwms Member

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    Yeah, many of the simple formulas are based on center green, around 532 nm or so.... because most people don't realize how horribly non-apo a pinhole is. If you want the best results, then, you'd have a film that has sensitivity only right around that point. For this reason, as I just mentioned, I'd dig into the formulas, insert a wavelength in the mid blue, and shoot to ortho film or paper. Done. [N.b. I do realize that some cool effects can be had by shooting to pan film or colour... but I think we're talking about maximum sharpness here.]

    Of course, you can also put on a colour filter to restrict the wavelength. That works too. Costs you light though.

    Whether restricting the wavelength is as important as looking for contrastier light, well, you be the judge!
     
  14. Joe VanCleave

    Joe VanCleave Member

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    The formulae for optimal pinhole size also favor longer focal lengths, and longer focal lengths imply that, for the same angle of view as your 35mm format pinhole camera, it would require a larger film format, which prints or scans with more detail, due to a lower magnification ratio.

    Thus, the simplest way to achieve sharper pinhole pictures is to up-size to a bigger film format.

    ~Joe
     
  15. Greg_E

    Greg_E Member

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    Can someone list the current ortho films? I spent a little time looking for ortho B/W film in 120 a while ago and didn't turn up much in the way of results. This is about the only way to effectively filter the light without risk of dust getting into the image. Even better if it can be processed with DR5 for positive images. Also must be a slow emulsion for finer/smaller grain.
     
  16. keithwms

    keithwms Member

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    Ilford ortho plus, arista aphs, and arista-II. I haven't used any ortho films in 120 format though.

    Paper is plenty good for LF pinhole though.
     
  17. Greg_E

    Greg_E Member

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    I am moving towards a lens cap hole holder, and macro extension tubes to get the desired angle of view on my regular lens camera, so paper is out for me. I'll have to see what DR5 says about processing those films, I scan everything and positives scan better than negatives.
     
  18. Rich Ullsmith

    Rich Ullsmith Subscriber

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    Sharper: 1) Bigger film (build yer own camera!) 2) Sharp pinhole (check it under a microscope, if practical) 3) Flame the hole with soot and recapitulate 4) Restrict a wavelength with a filter 5) Optimize hole to film plane distance, which requires knowing the size of your pinhole.

    Wider angle: 1) Move the film plane closer to the hole.

    For reference, my f250 cameras have a hole to film distance of about 10 to 11 cm, and that gives about 70 degrees of coverage.