Understanding Camera Sensor Sizes & Crop Factor [Photography Guide]

I’ll be the first to admit that DSLR cameras can seem pretty complicated before you get one (even after that). So many numbers, different equipment, brands… To make this even more complicated, every company also offers different sizes of sensors that ultimately affect your image quality! In this article, I’m going to explain as simply as possible how your DSLR’s sensor size and its crop factor are related to your photographs.

Sensor Size & Crop Factor

When photographers used SLRs, there was only one major film size: 24 x 36mm, also known as the 35mm format. Because digital camera technology was quite expensive in its early days, companies decided to use smaller sensors to save on some money. One thing they all had in common was the crop factor; similar to zooming in an image.

• Full Frame – No Crop/Entire Image (Canon FF, Nikon FX)
• APS-H – 1.3x crop factor – Blue Border (Canon APS-H cameras)
• APS-C – 1.5x crop factor – Red Border (Nikon DX cameras)
• APS-C – 1.6x crop factor – Green Border (Canon APS-C cameras)
• Foveon Sensor – 1.7x crop factor – Not on the image (Sigma)
• Four Thirds Sensor – 2x crop factor – Not on the image (Olympus, Panasonic, Leica)

Let’s use a Nikon D3300 for this example. It’s a DX model, so its crop factor is 1.5x which is the same as saying it gets you 1.5x closer to your subject than a full frame camera.

When I say crop factor, I don’t really mean that it captures a full image and then for some reason decides to crop it. It’s just an expression we use to compare it to same focal length being used on a FF camera.

Crop Factor x Focal Length = Field of View (FOV) on a Full Frame camera

With our Nikon D3300 and a 50mm lens, we would get something like this:

1.5 x 50mm = 75mm

This means that if you had a full frame camera and used a 75mm lens, it would give you the same field of view as a 50mm lens on DX models. The same applies to all other crop sensors; higher numbers such as 1.6 and 2x crop even more! Don’t even get me started on P&S and phone cameras, their sensors can be up to 40x smaller than DSLRs!

Full Frame Sensors – Pros

• No Crop Factor – Every lens gives you its “original” field of view
• Image Quality & Noise – Bigger sensors can have bigger pixels and therefore better image quality!
• Viewfinders – These cameras have bigger and brighter viewfinders due to bigger mirrors and better materials used
• Depth of Field – Larger sensors have shallower depth of field (same aperture)

Crop Sensors – Pros

• Crop Factor – Bad for some, good for many! You can also save some money because a 300mm lens on APS-C is the same as 480mm on FF.
• Lens Issues – Because lenses perform the worst at corners, and crop sensors “remove” corners, images have less lens flaws visible
• Save Money – Small sensors go into small cameras, making prices much more affordable! You can get APS-C for as low as $400, whereas FF models just entered the $2000 level.

Does it mean you can’t shoot sports if you have a full frame camera, or that landscape is not an option if you have an APS-C model? Of course not, some things are just easier to do with one than the other. Don’t let the equipment limit your potential and creativity, simply learn to use what you have for now!