Friday, January 18, 2013

Lens vs Lens

Because my life is perfect, I was gifted a Olympus 45mm F1.8 lens for xmas. Meg rocks.

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).




--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


--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 :)


David Hilgendorf said...

I can only speak from my experience. I have a 50mm 1.8 and a 100mm 2.8. With a 1.65x for the sensor, so about 80mm and 160mm equivalent. I absolutely love the 100mm and leave it on my camera all the time. It lets me get nice close shots without being nice and close. I rarely touch the 50mm now. Like you said, it also isolates the background much better and I hardly notice the light difference between the 1.8 and 2.8.

Alex Atterbury said...

Word, Dave. And while we're chatting, I am very very very fond of the photos you've been making over the last year or so. Some fabulous, and really varied images.

Will you soon join me as a man with offspring whose every moment you must document with your camera?

David Hilgendorf said...

Thanks Alex. I will indeed be joining you soon. Going to be working the stay-at-home-dad gig, at least for a while, and we're even moving back to Madison shortly. So all very exciting and sure I'll be documenting every moment of little baby's life.

Elvicious said...

Speaking from my experience, I also have a 50mm, though mine's the 1.4 which I leave on my camera constantly. I have been wavering between the 100mm and the 85mm as my next purchase.

Dave, I agree with Alex, and your work inspires me to get work harder to improve. Seriously, being a stay at home dad can be challenging, and if you ever want to talk about it, let me know.

Alex, post more. I really like what I've seen, and want to see more!