Thursday, January 13, 2011

Fun with lights...

No cruise recap post tonight as instead of typing it up and getting all the pictures ready I went to Knit and Wine at Crazy Girl Yarn Shop (tons of fun).

I do have 3 pictures for you, from our St. Thomas day, but when we were back in port. They are all taken using a cool technique Kevin learned about that deals with covering the lense with a black circle with a tiny picture cut out of the center, then the picture is slightly out of focus (or something) and all the lights in the background (and sometimes glares off your teeth!) show up as that shape.

Me sitting in the porthole window. The lights of St. Thomas's coast in the background.
Can you tell all the lights are hearts? Click for a larger picture.

We moved up to the Lobby Deck hoping for a better view of the lights. We got one!

And the lights of the Carnival Dream are longhorn fans.
Maybe Kevin will chime in and tell you what lense he used and such. It's a fun technique for sure!


Kevin said...

So the technique is all about physics of light diffraction. When out of focus points of light go through the aperture on a camera lens, the points of light take on the shape of the aperture. This is known as "bokeh." If you have seen a picture where a streetlight in the far distance appears hexagonal or pentagonal, that's because the lens has a six bladed aperture or five bladed aperture and takes that shape when it closes.

In this case, I cut out a small shape (heart or Longhorn) that is smaller than the aperture of the lens. This only works on a lens with a wide aperture (such as my Canon EF 50mm f/1.8) because the cut out shape has to be smaller than the aperture, thus making it effectively become the aperture.

Autofocus becomes sketchy if not impossible because of the limited aperture (lenses like the autofocus as their largest aperture) so you have to switch to manual focus, which is tough in low light, hence the typically soft images. If you get the focus right, though, all single point light sources in the background look like the shape you cut out and all single point light sources between you and your focus distance are inverted, so you want to limit points of light close to you.

SuzyQ01 said...

Super cool...I love Kevin's pictures!

The Asker said...

This is an awesome technique. I'm going to share this post with my brother. He has an ameatur photographer.