I recently rented a Lumix 35-100mm f/2.8 G Vario lens from LensRentals.com so that I could show you the difference between a 70-200mm lens on a full-frame Nikon and a 35-100mm lens on a Micro Four Thirds Lumix, as well as the value of such comparisons. First of all, let’s define some things:
- Bokeh: The out of focuss-ness of the background in a photograph. Sometimes photographers use the word to describe the quality of the softness, and sometimes we use it to describe how deep the depth of field is. I’m sure this isn’t the precisely correct definition, but it’s the way the word is used around me.
- Depth of Field: This is how we talk about how much of the picture is in focus. There’s a certain slice of the world, a plane parallel to the camera’s sensor, that can be in focus. The slice has a thickness or depth, and anything within that thickness is in focus, and everything else is out of focus. Three things affect depth of field: aperture, focal length, and distance to subject. A shallow depth a field (a thin slice) comes from a wide aperture, a long lens (telephoto), and/or a close subject.
- Full-Frame: This means the sensor in the camera is the same size as negative of 35mm film. Often used to declare superiority, full-frame cameras cost more money, and so do the lenses; I guess feeling superior about my gear helps me justify the ridiculous costs (lenses cost more, too). Trouble is, buying expensive gear didn’t make my pictures any better.
- Cropped Sensor: Traditionally refers to sensors that are smaller than full frame, and usually specifically the APS-C sizes that are roughly two thirds the size of full frame. All major camera manufacturers offer many bodies in this class. They take full frame lenses, but also have product lines made specially for them.
- Mirrorless: An unfortunate name describing what a camera doesn’t have, rather than what it is. These cameras are smaller and lighter than their DSLR counterparts. They may or may not have a built in electronic viewfinder. These cameras are generally highly innovative, offering more features and new technology than most DSLRs.
- Micro Four Thirds, MFT, M4/3: A class of mirrorless camera that is advantageous because it’s an open format–any MFT lens fits and works on any MFT camera (DSLRs require proprietary lens mounts). The cropped sensor is about half the size of a full-frame sensor. The bodies and lenses are incredibly lightweight, and far less expensive for similar features than other professional cameras. Why’s it call micro four thirds? There are a bunch of complicated answers, but one simple thing is that the sensor dimensions have a 4 to 3 ratio (4/3). DSLR’s all have a 2 to 3 ratio (2/3). This means the MFT pictures are a little taller than the wide 2/3 pictures.
Since my Lumix sensor is MFT sized, it’s half the size of my full-frame sensor. That means that a lens that’s half as telephoto yields a similar view. That’s why I’m comparing the 70-200mm with the 35-100mm–they give similar views on the two different cameras. They both have big apertures, f/2.8, and they both have excellent stabilization, so they are very comparable lenses, and when you switch from a full frame DSLR to an MFT mirrorless camera, this is the big question: are my pictures the same?
Let’s take a look. For these images, I shot first with one camera, and then the other and tried to maintain similar framing. Keeping that framing is really tough, but I think we’ll get the point here. Since we’re examining bokeh, I zoomed to the maximum on both lenses for each photograph. (Sorry about some of the lighting changes; we were working with sunlight and clouds.)
Examining the background, you’ll see that the bricks behind the woman’s head are definitely less distinct in the top image, which is the full-frame shot. The top step is also a good comparison spot. The bricks in the far background are more distinct in the second MFT image, but I think the horizontal lines are equally visible in the full-frame image, but because of the light change they are less contrasty.
For these two, the light didn’t change, and since I stood in the same spot, they are a very good comparison. The top image’s bricks are softer, and the back of the bench is less distinct, as well. However, my model looks great in both, and one advantage to having less shallow depth of field is that more of my subject is in focus. If the camera focuses on the far eye, both eyes may still be in focus instead of the near one being soft (Hint: in portraits, focus on the eye nearest the camera).
Moving in closer, now. Obviously I ended up a little closer with the GH4…which is easy since it’ll focus as close as 2.8 feet, whereas the 70-200mm can’t get closer than 4 feet! Things look great in both images, though, of course, the full-frame image has a slightly softer bokeh.
These are the two lenses side by side. The 35-100mm is smaller than a can of Coke and weighs just 12.7 ounces. The 70-200mm is enormous and weighs 54.24 ounces, not to mention the difference in weights of the camera bodies, too. At the end of a shoot with the 35-100mm I feel fresh and ready to go shoot some more; with the 70-200mm I feel like I’ve been doing bicep curls for an hour.
Softer bokeh doesn’t make you a better photographer. Yes, the depth of field is shallower on the full-frame camera when you make a similarly framed picture. And yes, the full-frame camera and lens do cost $2000 more than the MFT setup. I hope you don’t have the same assumptions that I did when I bought a full frame camera–that full-frame would make my pictures better, ’cause it’s just not accurate.
I have two suggestions for everyone reading this blog.
- Rent an MFT camera, like the GH4, or GX7, or EM-1 and give MFT a try
- Take the $2000 you’ll save on gear (or get for selling it) and do something that really will improve your photography, like coming to Photoshop World.
If you’re really stuck on shallow depth of field, then while your at LensRentals snatch up the Leica Nocticron 42.5mm f/1.2 and watch all your wildest dreams come true.
Anybody wanna buy a bunch of Nikon gear…?