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  1. #31
    Curt's Avatar
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    That's way too cool, Ive wanted to make a camera like that or like this one. I'm looking for the right WA lens to come around.

    http://web.mac.com/cjbroadbent/Site/fivebyseven.html
    Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand

  2. #32
    Steve Smith's Avatar
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    Quote Originally Posted by Curt View Post
    I'm looking for the right WA lens to come around.
    I have thought about doing this a few times in the past but have not had the right lens. I could have made it with a 135mm (or similar) lens but that would not give the angle of view I wanted and would make for quite a bulky camera.

    It was only the chance find in his loft that one of my father's friends found last week that enabled me to get the 65mm lens.

    Attached are a couple of shots to show that a dis-assembled Minolta lens and a couple of CNC cut nylon pieces can become a focusing mount for this lens.

    Judging by the lens to film distances for focusing at infinity and one metre, I think the original focusing scale on this lens is going to be fairly accurate. If not, I will print out a new one and stick it over the old scale.


    Steve
    Attached Thumbnails Attached Thumbnails 612-4.jpg   612-5.jpg  
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  3. #33
    Steve Smith's Avatar
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    And now for a viewfinder....

    Again, I could spend £100+ on a viewfinder or I could make my own from some spare lens elements.

    After some Googling to learn a bit about optical design, I started playing around with some lenses. If I understand correctly, using a simple negative lens at the eypiece and a positive lens at the other end, I can make a Galilean viewer (or a very simple telescope). The problem with this is that I can only get life size or bigger. i.e. positive magnification.

    After a bit of experimentation, I found that a positive, negative positive combination gave me the view I wanted with about an 85 degree view once masked to a rectangle.

    The pictures here show the elements mounted in some prototype mounts. I am going to make something better, this is just to see if it works.
    The second picture is what it looks like if you hold it up to one of those non-film cameras on macro mode. The actual view with your eye is much better than this and the rectangular mask is crisp and clear but it does show the wide angle of view.



    Steve.
    Attached Thumbnails Attached Thumbnails 612-6.jpg   612-7.jpg  
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  4. #34

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    Absolute great job, Steve, salute !!!

    I have been using the 58XL and I know you will love this new camera.
    Great for interior shots, that's what I use it for, and wide, wide landscapes.......

    Peter

  5. #35

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    Steve
    You must have had some good lens elements at your disposal. When I tried to make a viewfinder for my 47sa/6x9 combo (not far off your 65sa/6x12 as an angle) I found it a no-go unless I could settle for some nasty, weird distortions. A narrower 65/6x9 angle of view was no problem. Glad you did it!

  6. #36
    Steve Smith's Avatar
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    I'm am quite surprised that I managed it too since I know nothing about optical design. I had quite a few lens elements at my disposal from various lenses which have evaded repair over the years.

    I found that quite a large positive lens at the front and negative lens about 3/8" behind it coupled with another positive lens at the eye position spaced about an inch from the negative lens worked relly well.

    This is one of those things that needs three hands. Holding the lenses and working out the relationship between them.

    I found that the 3/8" between the front and middle elements was not very critical but the spacing of the rear element in relationship to the middle element was crucial to get the focus right.

    The lens does introduce a bit of distortion. In order to make the rectangular mask appear straight in the viewfinder, I had to cut it to a slight pincushion shape. I know that the finder may not accurately show exactly what is being projected to the film but I am confident that the angle of view is the same so as long as I line it up based on comparing the viewfinder image with an image on a temporarily fitted groundglass, I should have a good idea of what I am pointing it at.

    Anyway, it's such a wide view that I am going to have more of a problem keeping things out of the image than in.

    Changing the subject, I was also planning on fitting a spirit level to the top. A few days ago, I found, in my shed, an old Rabone wooden spirit level. These have a brass plate with the manufacturers name engraved on it fitted to the top with the glass tube fitted below. This one has rotted away a bit so is of no use any more so I am thinking about routing out the camera's top (which will be oak) to take this plate and fit the bubble tube below it.

    http://www.patented-antiques.com/ima...s/PB110762.JPG



    Steve.
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  7. #37

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    The level idea is good. Silverprint do a single bubble round level that drops into a round hole. Levels both ways with one bubble.

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