How I Got the Colourful Marble

Have you ever tried to get a marble to float on water?  Well, if you haven't then you've definitely got to try this out!  I can't begin to explain how interesting the theory is, and how excited you will be once you've done the trick and got the marble to float.  It's all to do with the relative densities of water and marble and how you can use them to your advantage.  

If you're still reading on,  then I gotchya!  :oD  I've never been a good student of physics, so what do I know about relative density?  Ok.. so I never really got the marble to float on water!  I got it to sit on a sheet of aluminum foil (and I still feel strange saying aluminum which is American, as opposed to aluminium which is British and that's the way I had learned it growing up). 

Anyway, so back to the floating marble!  This was a very interesting project for me, because I had been visualizing something like this for a while and then on a hunch I went into iTunes and looked for apps for light effects  This led me to download this app call "Lights" by Gabriel Vicenti.  You'll find it under Utilities.  This app is pretty cool in that it has four options for coloured light - white, red, yellow and blue.  I'm hoping there will be an update with a few other colours.  So, if you have an iPod or iPhone, I suggest you to download this and use it for funky stuff.  

The image below will pretty much explain my set up.  I used my 90 mm macro lens for this happy exercise and I have to tell you that you will need to get a really shallow depth of field (a smaller f/number, if you want to create a more seamless kind of background.  With more in focus, the background will also be thrown into focus and you'll get the line where the foil meets the light source and that doesn't look half as cool.

The set up shot was handheld and was done in a hurry, almost as a second thought, so please excuse the quality of the image.  But the way I 've set it up is pretty well illustrated.  And you can only get the desired results if you did this shoot after dark, or in a dark room (the bathroom with lights turned off is an idea).

What to do:

1. Prop up your iPod against something a little heavy so it holds it up and doesn't slip out of place.
2. Place the marble on a sheet of cooking foil, shiny side up, of course, to catch the reflections.  Try to smooth down the foil at the edge so you get a smoother horizon line.  You could try to scrunch it up and see what the effect is as well (I plan to try this out myself).
3. Turn off all overhead lights and only use the light from the iPod.  
4. Set your camera on a tripod or some stable surface in front of the subject; I placed the camera on the table in front of the marble.
5. Keep your ISO down to avoid digital noise; I kept mine at 100 as that's the lowest it would go.
6. Set the WB to auto as the predominance of the different colours will throw off any WB you set anyway.
7. Set your camera to aperture priority mode.  
8. Set your aperture to wide open (the smaller the f/number the better; try a few different f/numbers till you like what you're getting).
9. Set the iPod to the desired light option and shoot.
10. While processing the images, you will need to crop out the side bands reflecting the nav bar of the iPod.
11. Sharpen the image, add some saturation and definition  as desired.
12. Show it off to the world!

You can add the saturation and definition if you choose, but again, this is absolutely the artist's vision.  You could keep it really soft as well and this could also add an interesting effect. 

If you play around with this idea, do post some images and let me know what you did with them.  I'd love to know!