Compounding

Who can tell me what this classic figure is demonstrating? This is a lead in to a much more involved post that I am working on for next week.

15 Comments

  1. Christopher Taylor October 7, 2011 6:42 pm

    Relative size of the eyes to overall body size of a pipunculid fly?

    But as that would be a trifle esoteric, I’m guessing it has something to do with the amount of sensory input from a compound eye compared to our own eyes.

    http://coo.fieldofscience.com

    • Michael Bok October 8, 2011 10:30 am

      Good guess, but that’s not it.

  2. Wilf October 9, 2011 4:05 am

    At a guess I would say the size required for a compound eye to achieve the same visual performance as a human eye.

    Total shot in the dark, though.

    • Michael Bok October 10, 2011 11:40 am

      Yep, that’s it. In order for a compound eye to have the same resolution as a human’s camera eye, it would need to be a meter in diameter. In hexagonal facet actually represents 1000 individual facets.

      This seems like a pretty damning trait of compound eyes, so why are they so successful?

      • Lucy Carty October 10, 2011 12:11 pm

        “They have at least eight different type of cell involved in colour vision (compared to the human three), including several sensitive to ultraviolet wavelengths (to which humans are blind). In addition, they are able to sense and use minute information about the direction of light – known as its ‘polarization’”
        http://www.bbc.co.uk/nature/blueplanet/factfiles/crustaceans/mantis_shrimp_bg.shtml
        I know I cheated…
        Sorry…
        But, it is fascinating…
        I’ll go get my coat…

        http://www.lucycarty.com

        • Lucy Carty October 10, 2011 12:16 pm

          That was mantis shrimp specific btw…

          http://www.lucycarty.com

          • Michael Bok October 10, 2011 12:26 pm

            Those characteristics have more to do with the structure and sensitivity of the photoreceptors. I am referring to the optical structure of the compound eye in a general sense.

          • Lucy Carty October 10, 2011 12:38 pm

            Am so out of my depth. Will check out your post next week though…

            http://www.lucycarty.com

      • Wilf October 10, 2011 1:45 pm

        Good question.

        Thinking about it compound eyes tend to be found on small animals, and if I remember my high school physics, the resolution of a single lens depends on its’ radius. I would guess that a small animal would be incapable of supporting a single lens capable of producing a useful image and the use of multiple smaller lenses gets around the problem.

        Also I suspect that it takes less energy to produce a workable compound eye than a camera eye, probably not worth the investment when many arthropods are so short lived.

        And, of course, when evolution makes a ‘decision’ it’s hard to go back!

        Wilf

  3. JR October 9, 2011 8:48 am

    smoke more pot?

  4. Daniel October 10, 2011 11:15 am

    He is a banker looking for people, so he can compound his assets? Hungry eyes?

    http://www.youtube.com/1156511

  5. Daniel October 10, 2011 11:18 am

    If the human’s eyes relative to the size of their body were the same ratio of an insect’s [compound] eyes to their body, the human’s eyes would be equal to 1 meter in proportion to his body?

    http://www.youtube.com/1156511

  6. Pentatomid May 17, 2012 2:50 pm

    Who is this figure by?

    http://pentatomid.blogspot.com

    • Michael Bok May 17, 2012 7:53 pm

      Not sure about the artist (E.F.), but I think this was in one of the “Animal Eyes” books. Not sure at the moment, I’m in the field and don’t have access to all my references.

    • Michael Bok January 23, 2013 12:30 pm

      Here is the original reference for that figure:

      Kirschfeld K (1976) The resolution of lens and compound eyes. Neural Principles of
      Vision, eds Zettler F, Weiler R (Springer, New York), pp 356–370.