Full Frame vs Crop Sensor

Canon 5d mk ii

The Canon 5D MK II has a full frame sensor and a recently reduced price tag

The discussion of a full frame DSLR versus a crop sensor (APS-C) camera just got more interesting when B&H Photo decided to offer an eye-popping discount on the Canon 5D MK II, offering the body-only with a 16 GB CF card for under $2,000 around Christmas (now back up to $2500).

While I can live without a full frame sensor, the concepts of “need” and “want” become jumbled at times, like when B&H offers a big discount on a full frame camera that I wanted anyway. So, it’s good to go back over the differences and remember why you select one over the other.

First, it might be good to understand where the term “full frame” comes from in the first place. Full frame means the camera’s image sensor is roughly the same size as 35mm film, or 24mm x 36mm. That, my friends, is a big sensor. And, when it comes to sensors, size matters.

Interestingly, one of the reasons you frequently find a Canon 7D being used on a movie set like Black Swan, instead of a full frame Canon 5D MK II, is because the APS-C chip also approximates a film stock used widely in motion picture production called academy 4-perf. PL movie lenses cover 16mm x 22mm and take a wild guess how big an APS-C sensor is? If you guessed 13.8mm x 20.7mm, you were cheating.

The bottom line is a Canon 7D with a PL mount can accommodate all those marvelous movie lenses. There’s even a place that will permanently alter your 7D to be a PL mount movie camera!

It’s More Than Physical

The physical difference between the sensors is significant, with the full frame sensor being closer to twice as large. That is both good and bad depending on the circumstances. Since big chips are harder to manufacture and have a higher defect rate, they are vastly more expensive. So, if your wallet has anything to say about your camera selection, you’ll likely end up with an APS-C camera.

sensor size

You can see the APS-C chip is slightly less than half the size of a full frame 35mm sensor

The payoff for the extra cost of a full frame sensor is in the detail you get and the low light performance. At ISOs above 1600 a Canon 5D will simply blow the doors off my 7D. Even though I don’t do that much low light shooting, that’s my excuse for wanting a 5D MK II.

Also, if you’re shooting a lot of landscapes or other fine detail, a full frame camera will provide better resolution at distance.

Notice the qualifier “at distance”. Up close, like in a studio setting, the difference will be extremely difficult to notice with the biggest differences introduced by the quality of the lenses.

What Strange Magic Is This?

It’s not magic, just that at studio and portrait distances a full frame camera is shooting largely on the center of the sensor and you’ll likely be cropping out the edges anyway. That’s why I can shoot studio shots side-by-side with my friends owning 5D MK II’s and they’re surprised to see very little difference in our final shots. However, were we to walk across the street to the beach and shoot some landscapes, they would remember why the extra money was worth it.

That’s why it’s important for people to have an idea of what kind of photography they want to do before selecting their gear. Buying the camera before figuring out your photographic specialty is the tail wagging the dog.

My decision to go with a 7D is because most of my work is as a PJ. Lots of run and gun, a lot of being bumped, dumped and jostled, and occasionally working in the elements. An armor-plated crop sensor camera is well suited to that type of work, plus I shoot a lot of video.

I was perfectly happy with my APS-C crop sensor…until B&H put the full frame 5D MK II on sale. Curse you, B&H, curse you. ;-)

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7 Responses to “Full Frame vs Crop Sensor”

  1. Tom January 18, 2012 at 2:27 pm #

    Your article is subjective and may mislead some of your audience.

    The 5D has been run of the mill for some te now and Nikon’s D7000 gives it ridiculous competition despite energy size of its sensor whether it be landscape or portrait. Its high ISO performance is also greater. And it’s cheaper.

  2. Michael Kipper January 18, 2012 at 2:33 pm #

    I’m barely even what you would call an amateur photographer, and I shoot with a Canon T1i. When I shoot pictures of my kids at the park with my 50mm f/1.8 the shots come out awesome and I love my sensor. But when we’re inside the house playing in the den, I wish I had the low light performance of a full-frame…

    • Hassan January 19, 2012 at 4:40 am #

      I have the same problem as well

  3. Brendon January 18, 2012 at 2:54 pm #

    I’m a professional photographer working in various countries throughout East Africa. I shoot with the 5D Mark II and cannot imagine going back to a crop sensor. This camera shines in low light. When the Mark III is released I plan to immediately upgrade.

    • lee November 29, 2012 at 9:39 am #

      Pro Photographer huh
      “Who cares”

  4. Ben January 18, 2012 at 3:30 pm #

    The gradation of color is also better on my 5d mk II. The skin tones are terrific.

  5. Max January 18, 2012 at 4:11 pm #

    While the bug has caught me only recently (last 18 months), I would call myself a borderline serious hobbyist. I love my 5D (granted, I was coming from a Rebel XTi) and love the indoor “no flash” performance (especially shooting at distance indoors with the 70-200 f2.8).

    As with most threads, the axiom holds true: “This thread is worthless without pictures!”. Seriously, it would be cool to see a studio/portrait photo shot with both sensors and then a landscape shot with both sensors. A simple 4 photos (and a sentence or two of exploiting the similarities/differences of said photos) would improve this article greatly!