Using iPad as light source for backlit macro

Discussion in 'Nature' started by Glenn McCreery, Jul 8, 2013.

  1. A recent issue of Popular Photography describes a setup for back lighting natural subjects with a pure white background. The method looked rather complicated for field use so I have been searching for an easily portable alternative. I have been experimenting with using my iPad (version 1) with the free app. FreeLight. It provides a quite uniform white, or other color, light field. There are two problems with using the iPad directly; the screen is reflective, and the screen pixels are discernible in close macro photos. My initial solution is to use a semi-transparent sheet of white paper. This works fine for reducing reflections and renders the pixels invisible, but reduces the intensity of the light by one or two stops. Attached is an initial photo attempt, a bug on a willow leaf. (Canon 5D II with 100mm Canon macro, f:6.3, ISO 800, 1/60 s. Backlit plus side-lighting from an open window). I am interested in comments on my method and suggestions of other alternatives.
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  2. There is no reason why your i-Pad should not work, but as you say the pixels are visible and also (I presume - I don't have an i-Pad) the brightness level has been designed for viewing rather than photography. Other possibilities are a light box of the kind used to view negatives and transparencies or even just a piece of white plexiglass (advantage - could be quite big and still portable and cheap) which you fix up so that it is backlit by the sun.
     
  3. Thanks for the ideas David. I still have an old light box which I have used for this purpose. It's disadvantages are that it
    requires A.C. Power and produces a rather uneven light field. A piece of white plexiglass will work, but requires
    illumination from the bottom if specimines are to be placed on top of a horizontal surface. Perhaps a sheet of plexiglass
    placed on top of my I-Pad will work better than paper; I will give it a try. As for brightness, the FreeLight app. has
    adjustable brightness, and at it's brightest provides reasonable exposure durations for static subject, especially if side
    lighting is also used. If you own an I-Pad give it a try, it is easy to set up and the app is free.
     
  4. I see no reason it shouldn't work. I've used the screen of a succession of laptops for the purpose with good results. No special app, just open notepad and make it full screen, which leaves only a small colored border that doesn't bother anything with a 17 inch screen. If the level needs adjusting, use the screen brightness. It has been a small annoyance that none of the notebooks would open flat, they all stopped a little short but were still quite workable. The I-pad would be much more convenient, the only down side I see is the small screen size.
     
  5. The pixels would be visible at high magnification because they're composed of R-G-B components. Have you tried something like wrapping the iPad in tracing paper?
     
  6. Andy, you are correct, the pixels are visible at high magnification. A diffusion screen such as tracing paper solves this
    problem as well as eliminating unwanted specular reflections from the screen.
     

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