Brownie Hawkeye pinhole conversion question

Discussion in 'Pinhole Photography' started by 02Pilot, Mar 25, 2013.

  1. 02Pilot

    02Pilot Subscriber

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    In an effort to participate in the upcoming Worldwide Pinhole Photography Day, I'm in the process of converting a Kodak Brownie Hawkeye Flash to a pinhole camera. It's essentially a very simple matter to replace the lens with a pinhole, but there are two potential locations for the pinhole - which one to choose is my question.

    For those unfamiliar with the Brownie Hawkeye, there is a flat glass plate located at the front of the camera to protect the shutter. Behind the shutter is the actual lens. The distance between the two is roughly half an inch, with the ~5mm aperture hole that is integral to the shutter in between. My plan was to place the pinhole where the lens was, but this means it will be behind the aperture in the shutter and about half an inch behind the front of the camera body. Would there be any reason to instead replace the glass plate on the the front of the camera body with the pinhole, and simply remove the lens? My concern was that doing the latter would result in serious vignetting, but I'm not sure if the former arrangement won't have problems of its own.

    According to information I've gotten from around the internet, the ideal pinhole size for this application is 0.015 inches. My plan was to use a drilled brass plate with a #79 (0.0145 inch) drill in a pin vice.

    I'm quite new to the whole pinhole photography thing, so any advice or suggestions you might have are very much appreciated. Thanks.
     
  2. DWThomas

    DWThomas Subscriber

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    Hmmm - it's possible locating the pinhole much of a distance from the aperture could result in vignetting -- maybe someone out here in cyber-photo land has actually done one and can chime in. Substituting a pinhole plate for the lens will result in a field of view similar to the lens version so that could mean everything will be happy. I know in some other pinhole stuff I've done where there was a relatively wide angle of view, it's amazing how easily vignetting reared its ugly head.
     
  3. 02Pilot

    02Pilot Subscriber

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    I've looked around the web for any examples of similar conversions without success. I'm hoping that the distances between the aperture and the pinhole plate will not interfere, but I can't find any specifics that would allow me to determine this prior to loading film and finding out for myself.
     
  4. whowantstoast

    whowantstoast Member

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    I used an Agfa B2 to make a pinhole, and had the same set-up. I put the pinhole where the lens was and got a complete circular vignette. I haven't tried changing it to the front yet, but I think it's going to vignette in either spot. (How's that for an unhelpful answer?) I'd be very interested in how yours works out, just to satisfy my curiosity. I'm sure someone is going to come along and throw some serious math at this question and give you a real answer.
     
  5. SMBooth

    SMBooth Member

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    I think you need to mount it on the 5mm hole, otherwise it will interfere with light path.
     
  6. summicron1

    summicron1 Subscriber

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    a pinhole will vignette a bit because it doesn't spread light as well as a glass lens. I would think putting the pinhole where the lens is would give it the same angle of view as the lens, and then you can use the camera's viewfinder!
     
  7. 02Pilot

    02Pilot Subscriber

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    I don't mind some vignetting, but I want to avoid the "looking through a drinking straw" look.

    Mounting at the 5mm aperture might be better from a light transmission standpoint, but it is the least convenient option. Checking the current setup with a flashlight and ground glass suggests significant vignetting. I'm going to make up another plate to try in the forward mounting point and see what it looks like.
     
  8. DWThomas

    DWThomas Subscriber

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    In theory you could plot out a scale drawing using the film frame dimensions and distance from film to pinhole, aperture, etc. But in fact, it can be pretty challenging to get accurate measurements. The film/frame diagonal defines the minimum circle of coverage to avoid vignetting. Drawing a pair of lines from each end of the diagonal and crossing at the pinhole lays out the limits. Then the issue is plotting in any other "stuff" accurately to see if it encroaches on those lines. It's probably easier to load cut pieces of film and make test exposures.


    Apug_PinholeGeometry.png

    (Some day I may learn to use this CAD package ....)

    The numbers there are extremely loose guesses based on general 6x6 format and your comments.
     
  9. 02Pilot

    02Pilot Subscriber

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    That is an extremely helpful diagram - thanks. Since the camera is so easy to take apart, I'll take some measurements and see what I come up with. Stay tuned.
     
  10. 02Pilot

    02Pilot Subscriber

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    Well, a few measurements and a quick sketch tells me that my plan isn't going to work unless I can get the pinhole closer to the aperture in the shutter plate. For anyone who might want to do such a conversion, the easiest way to this it is going to be to insert the pinhole plate from the front of the camera, into the very bottom of the conical well; short of mounting it directly to the shutter plate, which would require removal of the shutter mechanism, that's as close as you can get and it should prevent vignetting. For the moment I think I'm just going to reassemble the camera in its original form and use it that way. I'll come up with another pinhole project for the short term.

    Thanks for all the help.
     
  11. 02Pilot

    02Pilot Subscriber

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    A brief semi-related follow-up for anyone who's interested. When I got the aforementioned Brownie Hawkeye, I also picked up a Brownie Flash Six-20; the latter camera is, it turns out, far easier to convert to pinhole. By simply prying the lens off the front (held on by three small tabs), one can afix a pinhole plate directly over the aperture/shutter. The shutter has a B setting, and the camera even has a tripod socket already. All I need to do is drill the top plate to accept a cable release and it will be ready to go.
     
  12. DWThomas

    DWThomas Subscriber

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    Sounds promising, hope it works out well. Pinhole cameras are basically a box with a hole in the end, but it is nice to be able to work with some sort film transport mechanism rather than have to run to a darkroom or changing bag if you want to do multiple shots.
     
  13. bobwysiwyg

    bobwysiwyg Subscriber

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    This is the very first camera I ever owned. Given to me on about my 10th birthday.. a long, long time ago. I still have it.
     
  14. 02Pilot

    02Pilot Subscriber

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    I don't do my own developing, so roll film will make it much easier to use. It's an even more basic design than the Hawkeye, and the simplicity means it is easy to eliminate the vignetting issues. The fact that it's 6x9 instead of 6x6 is a nice bonus.

    I bet it was the first camera for a lot of people, and they probably recorded countless moments in a fascinating period in American history. It may be a simple camera, and a relatively old one (produced from 1941-51, according to what I've read), but it seems perfect for what I intend to do with it.
     
  15. DWThomas

    DWThomas Subscriber

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    Yes, my first personally owned camera was a Brownie Target Six-20, but not a flash model. I believe I got it around 1950 +/- a year or two, when I was about 9 or 10 -- probably to keep me away from a folding Kodak my parents had! :blink:

    And hey, it still works! (So I have no plans to convert it to pinhole.)
     
  16. 02Pilot

    02Pilot Subscriber

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    This one still works as well, but it's important to me to make sure that any such conversion is reversible, so if I decide to bring it back to its original form it will only be a matter of removing the pinhole plate and reattaching the lens.
     
  17. 02Pilot

    02Pilot Subscriber

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    Got the Flash Six-20 converted over to pinhole. It's a completely reversible conversion - the pinhole plate is held on with contact cement, and the lens can simply be popped back in place. The only permanent mod is the hole I drilled for a cable release. Hopefully I'll get it out for testing this weekend.

    [​IMG]

    [​IMG]
     
  18. NedL

    NedL Subscriber

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    Looks good, have fun!
     
  19. 02Pilot

    02Pilot Subscriber

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  20. DWThomas

    DWThomas Subscriber

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    Lookin' good!

    And you've got over a week to WPPD! :D
     
  21. NedL

    NedL Subscriber

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    I agree, that looks great. Have fun!
     
  22. TheToadMen

    TheToadMen Subscriber

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    Excellent job! I can't wait to see what you're gonna make for Worldwide pinhole Day (April 28th. 2013).

    I have an old Gevabox converted (like you did) and it is wonderful to use it. Freedom and great images ...
     
  23. 02Pilot

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    Another practice shot (this time on Ektar) as I get ready for WPPD.

    [​IMG]

    A couple more are on the blog (link below).
     
  24. TheToadMen

    TheToadMen Subscriber

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    You're ready, all right!