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  1. #21

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    Quote Originally Posted by VPooler View Post
    Uuh, sounds cool! Take pictures of what you see on the ground glass! I am intrigued to try this when I get my Graphic. I already have a Box of Many Lenses aka a shoebox full of optical goodies I have scavenged over the years.
    Ok, here are some test shots, due to the dim light levels due to the time of day the camera taking the shots (Sony NEX-3 with a 35mm f1.7) was having a few issues with shutter speed (I always keep the ISO low).

    Here are a few shots anyway so you will get the idea, be aware that this is on the ground glass and looks clearer when looking at it:

    The 7 dioptre lens (3 element) (142mm)



    11 dioptre lens (2 element) (90mm)



    14 dioptre lens (2 element) (71mm lens)



    You can see that due to the fact I have to pull the bellows a long way back to focus for the 11 and 14 dioptre lens combos the rails are in view - pretty cool to see though lol but my DIY camera won't have anything sticking forward of the lens.

  2. #22
    Mustafa Umut Sarac's Avatar
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    Steve gave me the one of the best ideas I have ever found. At f295 was making teleobjectives for 35 mm camera with tube and collected diopters but no information on diopters and fl.

    I found it suprising , when lens designers spend years to make a lens design , your design is such simple and elegant.

    I am still looking for an answer , how cylinderical lens elemnents behave on image ?

    Umut

  3. #23

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    The first lenses were simple with just a single element which had different issues where the image wasn't flat and had distortions, modern lenses remove as many of these as possible with all sorts of coatings and setups to bend the light correctly. I will be using a paper negative for my DIY camera much like the pinhole shooters, the paper will have some imperfections which is fine, I also do cyanotypes which have their own imperfections with the way the fluid is put onto the paper.

    I am just looking for a simple lens setup that doesn't cost much, maximum of 3 elements and cheap to make, I am going to get various types of lenses from surplus shed, I am interested with ball lenses, those might be interesting, or indeed experiment with fluid lenses.

    My idea with fluid lenses is to suspend a small pocket of fluid in a spherical bag of some sort and put it under pressure slightly, I can then add or remove the fluid to focus the 'lens' instead of moving the lens I just change the focal length of it lol.

    I am thinking about mounting of the lens as well, plan is to look at getting some 50mm lenses (the close up lenses are 50mm) and then put them inside a 50mm ID pipe. I can then use another small piece of 50mm OD pipe which would go inside the other pipe and keep the elements in place - this could also allow me to add some air gaps and space them out a bit.

  4. #24

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    I find the 14 dioptre lens rather pleasing! Good job!

  5. #25

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    Quote Originally Posted by VPooler View Post
    I find the 14 dioptre lens rather pleasing! Good job!
    Yeah its quite a lot of distortion but might be interesting to shoot with, its a very wide lens on a LF camera, probably as wide as I could still use to cover a 4x5, might look to see if anything wider will work but I don't think it would be usable. I will have a look though, I have seen the travelwide camera (like pinwide camera but with an optical lens) which is basically just a double dark slide attached to a lens lol thats shooting a 90mm lens, might see if I can get away with a 70mm lens or wider as the lens is so compact.

    http://www.kickstarter.com/projects/...wide-45-camera

  6. #26

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    Here's an idea - get two cemented achromats, lets say, 200mm focal length ('bout 4$ each). Identical ones. Arrange them symmetrically, waterhouse/washer stop halfway between the lenses. You just made an actual large format lens, 100mm focal lenght!
    http://camerapedia.wikia.com/wiki/Rapid_Rectilinear

  7. #27

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    Quote Originally Posted by VPooler View Post
    Here's an idea - get two cemented achromats, lets say, 200mm focal length ('bout 4$ each). Identical ones. Arrange them symmetrically, waterhouse/washer stop halfway between the lenses. You just made an actual large format lens, 100mm focal lenght!
    http://camerapedia.wikia.com/wiki/Rapid_Rectilinear
    Thanks for that, I will have a check though some different lenses, I have seen a 79mm positive meniscus lens with a focal length of 133 so I will probably grab one of those as well lol I will probably buy a small collection of different sorts as well as a few matched ones

  8. #28

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    Quote Originally Posted by m1tch View Post
    Thanks for that, I will have a check though some different lenses, I have seen a 79mm positive meniscus lens with a focal length of 133 so I will probably grab one of those as well lol I will probably buy a small collection of different sorts as well as a few matched ones
    That would be the wisest! I'll wait until I have some cash and do the same - a few matched achromats, few different achromats, some meniscuses and so on. I heard something about getting to use a 3D printer and maybe even a CNC machining center in the university if I behave good enough, so that solves the issue of barrels for me.

    I wish you good luck on your endeavors! Keep us posted with the results!

  9. #29

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    Quote Originally Posted by VPooler View Post
    That would be the wisest! I'll wait until I have some cash and do the same - a few matched achromats, few different achromats, some meniscuses and so on. I heard something about getting to use a 3D printer and maybe even a CNC machining center in the university if I behave good enough, so that solves the issue of barrels for me.

    I wish you good luck on your endeavors! Keep us posted with the results!
    We have a 3D printer at work, but I don't think I will need to use it, I will look at using some basic off the shelf parts that are cheap and keep it well within the low cost option, I am thinking about using some plumbing parts example being perhaps some plastic pipe or copper pipework. Also if I were to need to focus differently I could perhaps use a threaded pipe and pipe cap and use the screwthread as a focusing ring. The plan is to make a simple sliding box camera initially as it would be easy to make and setup.

  10. #30

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    Just added a simple card aperture to the front of the lens, this is the 6 dioptre (166mm) lens with a 20mm hole (or there abouts) so this is at around f8.



    Here is the 14 dioptre (71mm) lens stopped down:

    Last edited by m1tch; 08-03-2013 at 04:14 AM. Click to view previous post history.

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