{"id":4500,"date":"2014-01-23T15:02:57","date_gmt":"2014-01-23T20:02:57","guid":{"rendered":"http:\/\/www.starkeith.net\/coredump\/?p=4500"},"modified":"2014-01-23T15:02:57","modified_gmt":"2014-01-23T20:02:57","slug":"aperture-focal-length-sensor-size","status":"publish","type":"post","link":"https:\/\/www.starkeith.net\/coredump\/2014\/01\/23\/aperture-focal-length-sensor-size\/","title":{"rendered":"Photography Experiments: Aperture, Focal Length, and Sensor Size"},"content":{"rendered":"

It snowed here recently, so I took a photo of a branch with some snow on it, which came out decently enough, but it prompted me to think: what would this look like at different apertures – or even different sensor sizes? So I decided to perform a little photography experiment to find out, and these were the results.<\/p>\n

\"snow<\/a>First is the original photo – taken at f\/5.6, at max zoom (200mm, equivalent to 400mm on a full-frame camera) using my Lumix G2 camera. Even on my smaller micro four-thirds sensor, you can see that the background is completely blurred out – even more so than I could’ve gotten with my f\/1.7 lens!<\/p>\n

The depth of field in this photo is very shallow – if you look closely at the bottom right of the photo, you can see the bottom part of the branch is slightly out of focus (because it was angled slightly towards me). This gives you an idea of how thin a “slice” of the scene was in focus.<\/p>\n

\"snow<\/a>Next, I changed the aperture to f\/22, but kept everything else the same. As you can see above, the background is still blurred out, but not as much. It is still blurred somewhat because I was focusing on a branch just a few feet in front of me, while the background is easily another hundred feet beyond that.<\/p>\n

Compared to the first photo, you can see that the bottom bit of the branch is in focus – meaning the depth of field was greater, and a thicker “slice” of the scene was in focus.<\/p>\n

\"snow<\/a>Finally, for this last picture I switched to a different camera – a compact Canon PowerShot ELPH 320. The aperture here is f\/5.9, nearly the same as my very first shot, but as you can see the background is hardly blurred at all! The depth of field here is very<\/strong> deep – a very large portion of the scene is in focus.<\/p>\n

Unfortunately, the little compact camera I was using couldn’t zoom to the same focal length – so this photo is at the equivalent of 255mm, instead of 400mm, and that contributes to the greater depth of field as well.<\/p>\n

However, the smaller sensor size also has a significant impact – because the sensor is so small, there’s less room for the light to be “smeared out” (as it were), and so less of the background can be blurred.<\/p>\n

So, what did we learn from all this? All else being equal:<\/p>\n