Now I have a dilemma - I have two fast prime lenses, as 20mm and 45mm, but which do I leave on the camera for all those household snapshots that won't wait for a lens change?
- These are multiplied by factor of 2.0 for a 4/3 sensor, equating to a 40mm and 90mm focal lengths. In other words, a classic slight wide-angle lens and a classic portrait lens. In short, both are perfectly functional for taking pictures of living things inside your home, but they have very different behaviors.
Today I just happen to find myself with an unscheduled few hours an home (the muchkin had to come home from daycare due to a fever and is currently zonked), so I decided to do a short series of test photos. I promise I'll finish my homework later.
Test Subject - Nola the Cat, aka The Plush Statue
Why she's perfect for studio tests:
--Doesn't move, except to relocate to whichever place in the house has the best photographic lighting
--Great detail and dynamic range
--Couldn't care less whether her picture is shared on the interwebs
--A suitable proxy for the relatively less-static things I photograph (the other cat, the kid, plants)
Note: These images were taken at F1.8, so the difference you see are mostly due to the difference in lenses. I did a bit of post-processing to get the exposures as close as possible, including recovering some highlights. My blog, my rules.
Test Series #1 - Closeup
This first shot is more of a classic portrait, and the 45mm is...a portrait lens. I think it wins out because of the huge difference in depth of field and subject isolation. With the 20 you inevitably get a more cluttered frame. Nola's face is nearly identical in each, and pleasantly sharp and undistorted (and furry).
Test Series #2 - Body Shot
The change here is subtle as I frame her whole body, and while the same things are true as before (DOF, cluttered frame), I think the 20mm facilitates a slightly more interesting photo. Here's why: the height of the camera relative to the subject. The first image is straight on, even with eye level. The second is just a bit below her eyes, which I prefer.
When you take a photo of a person, being above or below them has a huge impact on the feel of the image. How many lousy images have you seen of kids taken from a parent's eye level? By getting below a cat you see her the way you see another adult human, and it's a more pleasing picture. You can't take a from-below, full-body photo of a cat with a 90mm focal length without putting her on top of a bookshelf, but at a 40mm focal length you can lie on the floor and take the shot.
Beyond this, as I took photos with the 20mm I naturally made all sorts of different angles - above, below, on the side. Rotation is easy when the radius around your subject is short (a 1-2 feet vs 5-10 feet).
45mm--Generally impossible to get below the subject, especially for cats and kids
--Better subject isolation - short dept of field and more control over framing
--More accurate metering, as the frame can more easily be kept clear of bright light and dark shadows
--Not much flexibility in positioning, as often you have to stand in a different room or on top of furniture to get the distance right
20mm--Easier to frame above or below the subject, especially for cats and kids
--Facilitates rotation around a subject, almost inadvertently taking a wider variety of angles and frames
--Option to take a photo of the whole scene, not just the subject
So the best lens is both of them, depending. Still, this exercise helped me see what types of photos I can make with a lens and why a specific shot would be better done with one or another. And I got to play with my camera during a weekday afternoon :)