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  1. #1
    matti's Avatar
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    Folder lenses on 4x5? Rapid Rectilinear?

    It seems quite easy to find old folders for different formats with for example a Rapid Rectiliniear / aplanat with a focal length of 105 mm or 125 mm. Would it be out of the question for these to cover 4x5? I am of course not after corner sharpness. Far from it! I would like them to fuzzy up a lot. But I don't want total vignetting and a circular image.

    I tried to calculate different image circles based on an angle of 50 degrees and ended up with one meter of coverage. Obviously I don't understand this math very well...

    Dialytes seems to be quite common in these folders too.

    I could of course just buy one and try it out and crop the picture if I don't get what I want. But I suppose one or two here have tried this, no?

    /matti

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    Sure, this will work fine. The larger folders have lenses that will easily cover 4x5 and some of them are quite good. See this list of Kodak film numbers to get an idea of the coverage http://www.bvipirate.com/Kodak/FilmHist.html

    Nathan

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    Thank you for the list. Makes me think it would be interesting with a 4x5 roll film back to my Tachihara. And film to go with it...

    My 16,5 cm dialyte covers 4x5 without much to spare. I think I have seen somewhere that Rapid Rectilinears have a wider coverage. But I am not sure.

    /matti

  4. #4
    Ole
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    matti, I have tried. Even with some success...

    Aplanats tend to illuminate much more than they cover, which is exactly what you're after.

    This one was shot with a 3 1/4" WA Rectilinear at f:11ish - it really isn't supposed to be used above f:16, but I forgot to stop down. A "normal" Rapid Rectilinear would be much softer in the corners.



    "Normal" Aplanats/RR's have less coverage than this though - usable to an image diagonal around the focal length at small stops, soft corners at larger openings. Sharp coverage is considerably less than a dialyte!
    Last edited by Ole; 10-25-2007 at 09:46 AM. Click to view previous post history. Reason: Addendum and spellling.
    -- Ole Tjugen, Luddite Elitist
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  5. #5
    matti's Avatar
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    Was that on 4x5? That is wide!

    So "illumination" is about the focal length in Aplanats? That should mean I need a 165 mm lens? Or did you mean that after that I will just get a bit of vignetting and unsharpness?

    Hm, I understand these things are really relative and just up to what I am looking for. But I was thinking about 105 or 125.

    /matti

  6. #6
    Ole
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    No matti, the coverage is about the focal length. Illumination is quite a bit more. Something around 120mm should give plenty of scope for fuzzy corners, or almost sharp at very small apertures.

    That picture was on 4x5", but it's cropped to about 9x12cm since I didn't hold the camera straight (hand held Speed Graphic). Looking at the full slide made me dizzy, like I was about to fall over...
    -- Ole Tjugen, Luddite Elitist
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  7. #7
    matti's Avatar
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    That was what I hoped for. Now it is shopping time!

    /matti

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    Matti -
    The 3A cameras which used 122 film had lenses around 170mm and came in a variety of qualities, from meniscus to anastigmat. They would make a very nice lenses for 4x5. You can also use the camera as a panoramic by adapting it to use 120 film. I bought one a while back with a 170mm Tessar, but haven't done anything with it yet. I've been thinking of picking up one of those with the meniscus achromats just for the lens.
    Nathan

    Quote Originally Posted by matti View Post
    That was what I hoped for. Now it is shopping time!

    /matti

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    Quote Originally Posted by Nathan Smith View Post
    Matti -
    The 3A cameras which used 122 film had lenses around 170mm and came in a variety of qualities, from meniscus to anastigmat. They would make a very nice lenses for 4x5. You can also use the camera as a panoramic by adapting it to use 120 film. I bought one a while back with a 170mm Tessar, but haven't done anything with it yet. I've been thinking of picking up one of those with the meniscus achromats just for the lens.
    Nathan
    i've shot on an Ansco 3A, using paper negatives cut down to the 3x5 (roughly format). i also mounted the lens from one (i have two) on a lens board and did a test shot with my now-sold Calumet 4x5. covered 4x5 fine...as it should, since the original neg size was 3x5. i'll be putting one of the lenses on my toyo-view C when i can find the time to make a lens board.

    so yes, pick up a 3A of some sort, hopefully with a working shutter.

  10. #10

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    I tried to calculate different image circles based on an angle of 50 degrees and ended up with one meter of coverage. Obviously I don't understand this math very well...
    Basic trig:

    tan(1/2 * angle) = (1/2 * coverage ) / focal_length

    ie:

    coverage = tan(0.5 * angle) * focal_length * 2

    So: 2* 105mm * tan (25) = coverage

    Coverage would be about 97mm for a 105mm lens with a 50 degree coverage angle.
    The universe is a haunted house. -Coil
    .

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