Full-Frame and Crop Sensor Cameras - Understanding Lenses

Now that we've covered full-frame vs. crop sensor cameras, how do lenses collaborate with these types of cameras? Can we use any Nikon lens on any Nikon camera? Not exactly. I'll tell you why!

With a Canon camera, EFS is the term for a crop sensor lens and EF is the term for a full-frame sensor lens. With Canon, full-frame EF lenses can work on crop sensor cameras, but a crop sensor EFS lens doesn't work on full-frame cameras. 

Nikon's lenses for crop sensor cameras are called EF-S and the full-frame lenses are called FX. With Nikon, you can also use FX lenses on crop sensor camera bodies; however, if you mount an EF-S lens on a full-frame camera body, the edges of your image will be dark (vignetting). The image circle of the crop lens isn't big enough to record the image on the sensor and get the full photo; you'll get dark vignetting if you take a photo with a crop lens on a full-frame camera. The example below shows what the circle of view might look like through a full-frame lens. 

Canon's crop lenses won't even mount on to a full frame sensor camera. Nikon's crop lenses will mount on a full-frame camera body just fine, but the functionality is basically toast because of the dark vignetting that will show in your image. You can get an idea of what this looks like in my example below; the circle-of-view on a crop lens is smaller.  

Another thing to consider if you go with a crop sensor camera is the focal length of your lens. A crop sensor changes the focal length of your lens because it changes your field of view. To find your true focal length, you can use a focal length multiplier.

Nikon lenses have a crop factor of 1.5x. Canon's crop factor is 1.6x. To find the focal length, use the focal length of your lens and multiply it by your crop factor. 

Here are a few examples of how to calculate the actual focal length of your crop lens!

• A Nikon 50mm lens would really be 75mm (50 x 1.5 = 75). 

• A Canon 50mm lens would really be 80mm (50 x 1.6 = 80). 

So your 50mm lens would have a longer focal length, bringing you much closer to your subject because it acts like a 75mm lens. With crop sensors, you basically get free zoom :)

I will include my same example from the previous post to illustrate how focal length varies between a full-frame and crop-sensor camera. The image on the left was taken with a full frame camera; the image on the right was a crop sensor camera. The images were taken from the same spot with a 50mm lens.

When it comes to lens selection, remember that on a crop sensor camera, your lens will be longer than it seems.

Don't get too worried about the full-frame vs. crop sensor camera dilemma if you're just starting out and budget is an issue. I've used crop sensor cameras for years; they are still fantastic cameras, especially when paired with a good lens. 

It is smart though, to think about which lenses you'd prefer to invest in; if you can spend a little more for the full-frame lenses it will benefit you greatly if you decide to upgrade to a full-frame camera in the future!

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