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Thread: 8x10 Meniscus Lens Box Camera

  1. #21

    8x10 Meniscus Lens Box Camera

    Dear Joe,

    That`s an exceptionally nice camera! I like all the fine build details like the shutter.

    Congretulations!
    Phil

  2. #22

    8x10 Meniscus Lens Box Camera

    A recent trip to a local camera shop for some flash equipment (I had the opportunity to shoot a musician's recording studio) also led me to the used lens showcase, where I found this Fujinon Xerox 240mm F/4.5 lens. I gave it a quick test against a sheet of paper, and its corner-to-corner sharpness, and relatively short focal length, gave me hopes that it might work in my box camera. A week and much tinkering later, I have results.


    The lens in hand.


    The lens mounted in the camera. The wooden bracket holds the lens very snug, so the rubber band on top is redundant.


    A digital capture of the camera's fresnel viewscreen, of a view of my workbench. I was astounded by the 3-dimensional look of the projected image.

    More testing with this lens unfortunately shows that, being of a symmetrical design, I can't use external aperture stops without severely vignetting the corners. Thus, this lens will have to be relegated to lighting conditions where I can use the lens at it wide open F/4.5 aperture, for instance in still-lifes. Also, my recently built mechanical shutter won't go fast enough for bright sunny exposures at F/4.5 (heck, my Gossen light meter maxes out, too). Additionally, my nested box only draws out far enough for about a 30" lens-to-subject close focus, so I can't get real tight onto small scenes. But still, I'm amazed at the quality of the images I've gotten. See the Unconventional B/W gallery for some examples here and here. And a portrait here.

    ~Joe

  3. #23

    8x10 Meniscus Lens Box Camera

    Joe,

    It is a real shame that the lens does not have an aperture you can vary easily. I have found that over the last few years, by experimenting with what I can do with lenses (especially tilts and swings etc.), I have come to realise what makes pinhole pictures unique and how to choose the best compositions for them. I must confess I still love to see the projection on the ground glass too. I have recently added fresnels to some of my cameras and I also get the '3D' effect - just a shame it does not render onto the negative.

    Have you considered removing the elements and making another holder for them, but with a slot for Waterhouse stops?

    The pictures you have taken with the lens are really great.

    Best regards,

    Evan

  4. #24

    8x10 Meniscus Lens Box Camera

    Here's what the resulting image looks like when stopped down to a 3mm (F/90-ish) hole (link). I've thought periodically that I like the round image of the early Kodak Brownie box camera; the vignetting with this small aperture begins to approach a round aperture. Perhaps I need to pursue this further.

    ~Joe

  5. #25

    8x10 Meniscus Lens Box Camera

    Quote Originally Posted by 1351
    Thus, this lens will have to be relegated to lighting conditions where I can use the lens at it wide open F/4.5 aperture, for instance in still-lifes. Also, my recently built mechanical shutter won't go fast enough for bright sunny exposures at F/4.5 (heck, my Gossen light meter maxes out, too).
    ~Joe
    Don't forget about neutral density filters. They are available in several densities and can be stacked to make them even more dense. It'd be a pity to relegate that lens to only lower-light scenes.

  6. #26

    8x10 Meniscus Lens Box Camera

    I've taken Moot's recommendation of using a neutral density filter to heart; I'd really like to begin using this lens at wider apertures in daylight scenes. So I went outside this morning, into the cool autumn sun, and did some light meter tests, to determine how many stops I'd need to attentuate the daylight in order to get about a 1 second exposure time, using paper rated at an exposure index of 12, with a lens at f/4.5. It turns out that my trusty light meter (Gossen Luna Pro F) has suddenly went on the fritz, so I had to resort to a more experimental approach.

    I decided that I'd need more attentuation than what an ND filter would provide, so I ended up taping a Yellow #2 filter to the front of the Fujinon Xerox f/4.5 lens. The filter was a bit smaller than the lens barrel, but it doesn't vignette the image. I did a one second exposure using the hand-operated shutter on the 8x10 box. Bright sun, the subject is a garden trellis with dead vine branches. The highlights look a bit over-exposed, but I'm in the ballpark. Preflashed grade 2 paper.

    Attached files

  7. #27

    8x10 Meniscus Lens Box Camera

    Next, I decided a bit more attentuation was needed, on top of using the Yellow #2 filter, so I added an old ND2 filter, which I gaffer taped to the rear of the lens cell. As with the yellow filter, it doesn't cover the entire lens, but is large enough to cover the field of view without vignetting. It provides an additional 1 full f-stop of attenuation. Same scene, preflashed grade 2 paper, 1 second exposure hand-timed. Just to clarify, this is with a Yellow#2 on front and a ND2 filter on the rear of the lens. I think I might have something here.

    ~Joe

    PS: Both of these trellis shots were unmanipulated tonally in Photoshop after scanning the paper negatives; just rotation, flipping and invert the tones to a positive image was performed. If I had applied a subtle S-curve to the image, it would really sing.

    I'm hoping to get out this week and make a few scenic exposures, but this does look hopeful. Attached files

  8. #28

    8x10 Meniscus Lens Box Camera

    Yeah. I like it. Good idea to use the yellow. You really can get a lot of attenuation with ND filters, but why not get some tonal correction too?

    I think you might indeed have something there.

  9. #29

    8x10 Meniscus Lens Box Camera

    Very cool camera.

    I know this is wandering off topic and I can probably find the information elsewhere, but can you give me an idea of (ballpark) how to preflash paper for this kind of thing? Do you set your enlarger to a particular height, put on a lens, and flash for some interval at a particular aperture?

  10. #30

    8x10 Meniscus Lens Box Camera

    Walter, my initial attempt at preflashing was using my enlarger, where I found that in order to get exposure times long enough to time accurately with my old Gralab timer (longer than 1 second) required stopping the lens aperture all the way down to f/32, with the enlarger head raised all the way up, and still the exposure times were only about 1 second. So, I had to find a dimmer light source.

    I ended up using a type S-11 light bulb, built into a metal can with a ~1/4" wide aperture hole, suspended about 30" above the table, for a typical preflash time (with grade 2 RC paper) of around 8-10 seconds. The type S-11 bulb is available in hardware stores, and is frosted white, has a round globe about the size of a golf ball, is 120vac, 7.5 watts standard base size. The lamp housing I made from a metal soup can, some spare lamp cord wire, black paper and gaffer's tape.

    I suspect any white frosted bulb of about 7-10 watts would work well, just stop down the light to a smaller aperture via some sort of housing until you get the intensity into the range that you want.

    I did my preflash tests with this light source by making a series of test exposures in 2 second increments. I cut a round circle mask in a piece of black opaque craft paper, then made the test exposures through this mask onto a strip of photo paper, starting with 2 seconds, then moving the circle down the strip (keeping the rest of the photo paper covered up) and doing 4 seconds, etc. Then develop the paper strip with your standard development method (time, temperature, dilution the same as with your paper negatives). The first exposure that shows a faint, light-gray tone is the optimal preflash time for my purposes.

    ~Joe

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