Let’s take a break from our photography and my media projects to have a TECH TALK! I’ve been wondering whether a full-frame sensor camera would really make that big of a difference in our photography. So I rented a 5d mark II to compare to our 7D and other crop-sensor cameras. Hopefully this will help someone else trying to figure out how a full-frame would actually affect their photography.
First, a brief lesson on crop-sensors:
All Canon dSLRs with a model number higher than 5 (ie- 7D, 60D, all Rebels, etc) have crop-sensors. A crop-sensor crops the image of a full-frame sensor by a factor of 1.6. This means a 35mm lens on a crop-sensor camera actually looks more like a 50mm lens on a full-frame camera (35mm * 1.6 = 56mm). The 5D mkII and the 5D mkIII are both full frame cameras.
This is the exact same lens on the 7D, then on the 5D:
Yeah yeah, I knew that. HERE’S WHAT I WAS WONDERING: “Could I achieve the look of a full-frame camera by simply using wider lenses on my 7D crop-sensor camera? What would be the difference?”
Below, I tried to match the look of a 35mm 1.4L lens on a Canon 5d by using a 17-55mm 2.8 lens on a Canon 7D and zooming in to about 22mm (22mm * 1.6 = 35mm). Then I tried to match the depth of field by leaving the 17-55mm at f/2.8 and stopping the 35mm down to f/4.0. It seemed pretty close. Here’s the result:
To some, the difference may be indistinguishable. To me, it was eye-opening… literally, like my eye was never open all the way. Those who have upgraded to a full-frame sensor know what I’m talking about. I was wandering around our condo with the 5D pressed against my face feeling like, “All these years I’ve never seen the world through a camera the way it’s supposed to be seen!” It was as though I had been wearing horse blinders every time I had put a camera to my face… like someone had cropped off my peripheral!
Do you see how in the second image, everything appears to be very square, and in the first one, it all seems to be a little warped? See how the background is “smaller” in the first one? This is what happens when you use a wider lens. An extremely wide lens is called a fisheye and does this warping a lot. Using a 1.6 crop-sensor on a 22mm focal length lens does not turn it into a 35mm lens. It just crops a 22mm! You still have the same warping effect of using that wider lens, which is not very attractive on humans. It is impossible to exactly match the focal length look of a full frame camera by using a wider lens on a crop-sensor camera like the 7D.
That said, you don’t always need to match the focal length look of a full frame camera. In our own business, we’ve used mostly longer lenses, and have never used a full frame camera! The wider angle lenses on a full-frame body is just a look that, as we are growing in our style, we personally find beautiful, and we are excited about incorporating it into our future work. Explaining what that “look” is, requires an entire post of its own. This one was simply to answer my own question: No, you cannot achieve the look of a full-frame camera simply by placing a wider lens on a crop-sensor camera.
Do you photo enthusiasts agree?