Glenn McCreery Posted July 8, 2013 Share Posted July 8, 2013 <p>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.</p><div></div> Link to comment Share on other sites More sharing options...
dhbebb Posted July 8, 2013 Share Posted July 8, 2013 <p>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. </p> Link to comment Share on other sites More sharing options...
Glenn McCreery Posted July 9, 2013 Author Share Posted July 9, 2013 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. Link to comment Share on other sites More sharing options...
srspeck Posted July 11, 2013 Share Posted July 11, 2013 <p>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.</p> Link to comment Share on other sites More sharing options...
andylynn Posted July 11, 2013 Share Posted July 11, 2013 <p>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?</p> Link to comment Share on other sites More sharing options...
Glenn McCreery Posted July 12, 2013 Author Share Posted July 12, 2013 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. Link to comment Share on other sites More sharing options...
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