A Scenic World

I’ve written before that if I could take only two lenses with me on an outing where I had no idea what the shooting subjects would be (people? flowers? landscapes?), I’d take my beloved D-FA 100/2.8 Macro and the FA 31/1.8. So when I can only take one lens on an outing, the DA 35/2.8 macro seems like an obvious choice. But is it? How does the macro capabilities of the 35mm compare to the 100mm? Yesterday, I decided to find out.

Truth be told, I don’t normally take “true” macros. A true macro is defined by wikipedia as “meaning the image on the film is the same size as the object being photographed.” This is mainly due to compositional choices; I feel like photos of flowers are often made special by adding something besides just the flower, whether that’s specular highlights (see here) or other elements of composition (see here). In fact, the number of “true” macros I have is astoundingly small, but it’s nice to know that if I have a macro lens with me, the capabilities are there if I need them.

These lenses both focus to true macro. For the 100mm macro, that means that its closest focusing distance is 12″ (30cm). For the 35mm macro, the closest focusing distance is 5.5″ (13.9cm). Their differences can be expressed in a few other ways as well.

I use these lenses on my Pentax K200D which has a cropped sensor, meaning that the sensor is smaller than 35mm standard film (although the crop factor of the K200D is actually 1.53, for purposes of computation, we’ll be using the simplified 1.5). This affects what the field of view of a given lens is. If you spin around once, you’ve taken in a 360° view. If you put a 35mm lens on a film camera,  then when you look through the viewfinder, you’ll see an angle of view of 63°. If you put that same lens on a camera with a 1.5 cropped sensor, your view of the scene changes drastically: you’ll only see about 45° of that same scene.

Likewise, changing lenses will affect your view of the scene. When I put my 35mm on my cropped sensor, I’m seeing a horizontal angle of view (from the left side of the frame to the right side of the frame) of 37.8°. When I switch to the 100mm on my cropped sensor, that horizontal angle of view changes to 13.7°. When we’re pretty far away from our subject, the difference is pretty tremendous. For instance, if I’m standing 10 meters away from a scene with the 100mm lens, the sensor is going to record about 2.5 meters across. By switching to the 35mm, I’m going to be able to take in almost 7 meters!

So how does this translate to the relatively tiny distances when we’re shooting macro?  The 35mm is definitely a wider-angle-lens, but as you’ll see in the examples, the difference isn’t as big as you might think.

The subject would be a red flower found in my friend’s garden. These flowers are particularly small but have nice stamina with visible pollen. I’ve added a little contrast and curved, and I desaturated each image a bit because the pink was really obnoxious, but otherwise these photos all have exactly the same edits with no other fixings (save one photo that was brighter than the others due to camera settings – I lowered the exposure afterwards to match the others). Ideally, a test like this would be done with precise measurements made of distances from the sensor to the subject and with flowers in a controlled studio setting and definitely with a tripod, but I did exactly none of that, so take that as you will. I did manually focus all the macro shots so that the lenses were focused as close as they would possibly go. In other words, this is very much a “real world” test.

First, an example of a semi-macro photo I would usually take with the D-FA 100mm Macro. I was standing approximately 50cm (about 20″) away when I snapped this:

From roughly the same position, I took a photo with the DA 35:

Next I moved closer (30cm away) to get a true macro of the flower with the D-FA 100mm Macro:

Then I switched lenses to the DA 35 and got MUCH closer (13.9cm) to take a true macro with that lens:

As you can see, there’s really not much difference at all!

Next I walked around the bush and looked for another likely subject to be taken from a difference angle. After all, what I was most interested in was how that wider-angle-of-view affected how the background and out-of-focus areas looked.

I found the next subject and took a snap from approximately 30cm (12 inches) away with the 35mm lens:

That same flower, from roughly the same distance, but this time with the 100mm lens:

But as you can see, when I step in closer with the 35mm (to that minimum focusing distance of 13.9cm), I got much the same shot:

So, in the real world, which lens would I prefer to use on a regular basis? Quite apart from how the lenses perform (they’re both pretty sharp even wide-open, but the 35mm generally seems to have the 100mm beat, although the bokeh on the 100mm seems easier to control), they both haves pros and cons.

• Controlling light: You have to get so close to the subject with the 35mm that it’s very easy to block out your light source with the camera. Clear winner: 100mm.
• Focusing distance: Sometimes it can be physically impossible to get as close as you need to with the 35mm (like if a flower is on a branch above your head, for instance). Also, getting close to things like butterflies and bugs tends to scare them away. In this sense, the 100mm is far more useful. Sometimes, though, you’re too close for the 100mm to focus at all – just yesterday I was in the car with the puppy, and he was sitting on my lap and looking out the car window. Luckily I had the 35mm on my camera, or there’s no way I would have gotten that shot. Winner: Tie.
• Ease of shifting view to get most interesting angle: With the 100mm, you often have to physically move yourself to get a more interesting perspective. With the 35mm, even a small shift can make a big difference. Winner: 35mm, but only if you already have good hand control (or a tripod).
• Taking semi-macros: it’s always easier to blur out the background with a longer lens, and semi-macros are no exception. Winner: 100mm.
• Versatility: Some people prefer tight portraits with lots of blurry background. The 100mm is a clear winner in this case. But almost no one’s ever going to take a portrait indoors in close quarters with a focal length like that, so the 35mm would be far more useful in that situation. For landscapes, some prefer capturing details of a scene, so a longer lens like the 100mm would be useful – although something longer would be even better. Other scenes are at their most dramatic taken with a wide-angle lens like the 35mm – although once again, something wider would be even better. Winner: Tie.

So in conclusion, they both do the jobs they were designed to do and do them well. Truth be told, I’m just glad I own them both :)

This entry was posted on Thursday, October 29th, 2009 at 8:29 am and is filed under Photography Tutorial. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.