Wednesday, April 29, 2009

Camera Update

I've been geeking out with my photos lately. I'll show some of the more interesting results.

First, I was curious as to how I actually use my zoom lens. A zoom lens is one that can change field of view, meaning that you can zoom in on stuff. Most of my lenses are the opposite, called prime lenses, and they give you one field of view and cannot change.

Back to the zooms. I searched for all images that used my Pentax DA* 50-135mm f2.8 lens, and then from those I computed the number of shots taken at each field of view. I knew that I hit the stops on the wide and narrow ends more than I used the middle, but this tells me more exactly what I actually do. Here's the chart:



62% of my shots were at 50mm or 135mm. That is a whole lot. Depending on your point of view, this either means that I should stick to primes or that 38% percent of the time I like the flexibility of the zoom. Or you could say that even if I used the zoom at one extent or the other, it is like having two primes mounted on my camera, giving me a great deal of flexibility. Or you could say that I'm a fool, because I use the most compromised positions on my lens (things in the middle are better optimized, see Feynman's story on plastic gearing).

Next, we take a peek at which lenses I'm shooting most. The gray/black pies are lenses which I've sold for one reason or another. The colored slices are in my current bag. This graph doesn't account for my preferences over time. I've only had the DA 35mm f2.8 for a year, and it is already catching up to the 50mm.



Last, I compiled some data on which apertures I use the most. This is a neat graph.



This one is neat for a few reasons.
First, you can see my favorite apertures right off the bat! f8.0 makes any lens look good. And most of my lenses are full-open at f2.8, so that one gets a lot of action. f1.4 is the max for the 50mm, and it gets used a lot too.
Second, this graph shows the difficulty in making meaningful graphs. Not all ranges in the graph are equivalent. The ranges could have been made equivalent. I could have made buckets the size of one stop, or made each bucket contain the same number of shots and had the range indicate preference. Maybe a scatter plot would make more sense. Maybe a hybrid scatter plot could indicate the number of occurrences at each point. And so on.
Third, the data shows a number of shots at f27-f38. Which is weird because I don't think anything I own goes beyond f22. So the whole thing could be fake anyway.

Lastly, I got a new camera yesterday. The Pentax K20D is here to replace my K10D. I put my K10D up for sale at my work's version of craigslist and got a buyer within minutes. Yay.

Keep your eye out for future shots at ISO 3200 and occasionally ISO 6400. Or maybe some 21fps sequences. It is gonna be awesome.

2 comments:

Thomas said...

In case you are wondering, I gathered the exif data using a tool called exiftool, which is free. Here's the command I used:

find . -name "*.PEF" -print0 | xargs -0 exiftool -focalLength -if '$lensType eq "smc PENTAX-DA* 50-135mm F2.8 ED [IF] SDM"' | grep -v "PEF" | sort -k4 -g | uniq -c

Tea Pot with Natasha said...

I have one thing to say to you: Con Law!