Sensor Size - Crop/Full Frame

Written by Andy. Posted in Sensor Size

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Full Frame or Crop, what does this all mean. Well to put it easily and quickly they are terms that refer to the size of your sensor. Full Frame being a bigger sensor, and crop being smaller....but is bigger better? What does this all mean? Well before you keep reading make sure you have read the MEGAPIXEL article first!

full frame

ROLL OVER THE IMAGE TO SEE THE FULL FRAME AND CROP SENSOR DIFFERENCE, I KNOW THE IMAGE LOOKS SMALLER BUT IT ISN'T THIS IS JUST THE EFFECT OF THE CROP SENSOR!

We've all heard the terminology whether at our local camera store or the internet - FULL FRAME SENSOR or CROP SENSOR! In this article I'm going to try to explain the pros and cons of each. There is no absolute winner, so when you are choosing your camera it's best that you know what is what and what you really need so the decision you make is the best one!

But before we begin and for me to be able to explain this well, we're going to have to go over a little bit of history....don't worry, I'll try to make it as short and sweet as possible.

Like almost everything in this world, the terminology was invented by a marketing department. The words FULL FRAME SENSOR and CROP FRAME SENSOR where actually invented by Canon's marketing department back in 2002 - 2003 (I don't know the exact date) to differentiate from the different Digital Camera Sensors Available. A Full Frame Sensor and still is very expensive to make, so the camera companies came up with smaller, less expensive sensors. These smaller sensors are called CROP and the sensor that is the same size as a 35mm camera is called a FULL FRAME.

Why did this marketing department come up with this terminology.

Well the story goes all the way back to the film days (no they really weren't that long ago). During the film days the most popular type of camera was called a 35mm camera. We've all heard it I'm sure. The 35mm term is actually referring to the size of film the camera used.

filmsize

As you can see in my attempt to reproduce film, the width of the film is why they called it 35mm! The actual size of the frame captured is 24mm x 36mm. This is where Canon's marketing department came up with FULL FRAME. The 24mm x 36mm sensor size is what we all now consider FULL FRAME! The FULL FRAME simply means that the camera has a sensor equal to the size of 35mm film.

Ok, so now you know where FULL FRAME came from, but what about CROP FRAME?

Well again, we're going to have to go back in time a little bit.

The first digital camera produced for the consumer market was surprisingly a company that is not in the camera industry anymore, The Apple Quicktake 100. It was brought to market in 1994 and had a whopping resolution of 640 pixels by 480 pixels, or in today's world .3 megapixels. That's right point three and the camera could only store 8 images! With a price of around $800US those .3 megapixels did not come cheap. It was followed by Kodak with the Kodak DC40 with slightly higher resolution, 756 pixels x 504 pixels or .38 megapixels in today's terms. The significance of this camera in my opinion is the price wars began. The Kodak was higher resolution and could hold a whopping 48 images and it was only $700.00US!

The price wars and competition had begun. You might be asking yourself, what does this have to do with CROP or FULL FRAME!

Well, camera companies knew that developing a FULL FRAME sensor is extremely expensive. And they wanted to make sure that digital cameras where placed in the hands of everyone on the planet. So to combat the price, they developed a Crop Sensor.

full frame

The Crop Sensor simply means that it is a smaller size than FULL FRAME! The term crop is used because the image is not being increased or decreased in size, it's simply being cropped or cut out. Look at the example above! When you roll your mouse over you can see the difference between an image taken with a full frame sensor and a crop. Notice that the image size does not change, it's simply being cropped. This is the effect of the smaller sensor. This image was taken at 28mm and you can see that it's a much wider shot on the Full Frame than what it is on the crop. Hopefully you're head didn't explode.

I know the image looks smaller, but it's not. This is just me trying to show you the difference in sensor size. In the digital world a smaller sensor does not mean a smaller image like it did in the film days. Yes, I'm going back in time just a little more. Back in the film days the size of film would define the size of your image. The larger the film, the larger the actual image size was and along with the larger image came greater resolution, greater amplification power and over all image higher quality.

But, in the digital age (read the megapixel article if you haven't) the size of the image is not dependant on the sensor size at all like in the film days, it's dependant on the megapixels. I know it sounds a little confusing, but just bare with me. When it comes to digital whether you have a FULL FRAME or a CROP FRAME camera if they are both 12megapixels, they both produce the exact same image size. The difference is the CROP Frame multiplication.

The CROP Frame multiplication means that on a full frame camera if you put a 28mm lens on, the lens acts like a 28mm lens. It's a wide shot like the one above. If you where to put that same lens on a CROP camera and take the exact same picture from the same location, the 28mm lens is amplified because of the smaller sensor and acts like a 42mm lens. So with wide angle lenses on crop cameras we lose the wideness of the lens, but with telephoto cameras, the crop cameras actually increase the range because of this CROP Frame multiplication.

The CROP Frame multiplication will be dependant on the size of the sensor. The smaller the sensor the tighter the crop in the image hence more amplification. Nowadays the different camera manufacturers all make different sized crop sensors. Nikon makes what is known as a APS-C sensor that has a 1.5x Crop (the 1.5 is how much you multiply the lens mm by to get their true performance). For example, if you where to put a 50mm lens on a APS-C Nikon DSLR, the true reach of the lens is 75mm, because 50mm multiplied by 1.5 is 75mm.

Canon makes a few crop sensors, they have a APS-H which is a 1.3x crop which is found on some of their professional bodies like the 1Ds-MarkIV and an APS-C with a 1.6x crop which they put in their prosumer models like the Canon 7D or Rebel line!

So now you know what the Full Frame and Crop terminology mean, but what are the pro's and cons of each:

Let's start with Crop:

Pro's:

Price, crop sensor camera's are much less expensive

Weight and size

Lens Multiplication Factor, if you are into bird photography for example a 300mm lens will act like a 400mm saving you a lot of money on lenses.

Cons:

Lens Multiplication Factor, if you are into wide angle shots.

Noise, smaller sensor usually means more noise in your image

Full frame Pro's and Cons:

Pro's

Noise, full frame sensor has larger pixels which usually result in lower noise in your image.