full frame vs crop sensor

Full Frame vs Crop Sensor in Photography

Here is the thing that Full frame vs crop sensor is often the deciding factor for photographers and that is looking to buy new gear. But another thing that do you know why this sensor size debate is so heated?

We are here to set the record straight and let you guys know what crop and full-frame sensors are and again what they do differently. And also you will know how you can take better pictures with both of them.

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Do You Know what Is a Sensor?

It is a photosensitive surface. The sensor is called the soul of a digital camera because it records the scene you are photographing or capturing.

The sensor detects light waves and turns the recorded information into electric signals, and eventually an image.

A bigger sensor is going to have a higher resolution and lower noise levels in general (with lots of exceptions).

It’s size is a significant consideration when it comes to selecting your camera. The sensor that Larger-sensor cameras come with a cost – financially, but also in size and weight.

Full Frame

Full-frame sensors cameras can be very expensive. It depends on what you capture or photograph and do with your pictures, you may need one.

You can get away with an APS-C camera or a smaller sensor if you are photographing to share on social media.

You need a full-frame DSLR with a larger sensor if you are shooting large-scale commercial projects for large companies or even professional wedding photography.

The full-frame sensor, it is based on film photography. 35mm frame size in film photography is about 36 mm × 24 mm. This size, any digital sensor is regarded as a full frame.

The 35mm film format has been the standard since the beginning of the 20th century. It stood out as a balanced size among other (smaller and larger) formats. The thing combines good image/pictures quality with portable size.

In today’s era, full-frame digital cameras are presenting a higher-end standard. Types of widest-spread camera use smaller sensors.

 

Equivalency

One of the key traits of a lens is its focal length as you all know. Focal length is used by a photographer as a measurement of the angle of view. But an interesting thing is the focal length alone does not determine the angle of view. It will not show the same angle of view as on a smaller-sensor camera if you take a lens and put in on a full-frame camera.

The focal length defines the angle of view and the sensor size of the camera it’s currently used on. The unit of equivalent focal length emerged to solve this problem.

Even though it’s described in mm, the equivalent focal length is practically an angle. As a standard it takes the 35mm full-frame sensor, and the viewing angles, which various lenses produce on it.

Now you take a look at a 70mm lens. Its viewing angle is 29 degrees horizontally on a full-frame sensor and 19.5 degrees vertically. But diagonally it’s about 35 degrees.

Thus, It is called 70mm equivalent which means any lens on any sensor that has the same diagonal angle of view.

You need to multiply the crop factor and the real focal length of the lens to get the equivalent focal length.

But what about the crop factor?

Crop Sensors

A full-frame sensor is 36mm x 24mm.

Any sensor smaller than 36mm x 24mm is called a crop sensor. You’re effectively cropping the full-frame image that is why it’s called the crop sensor.

The crop factor is the ratio of their diagonal and the full-frame diagonal (which is ~43mm). Corners of the picture/image that you can see on a full-frame sensor, are entirely out of the coverage on a smaller sensor.

In Today, there are standard crop sensor sizes in use. The most popular and famous crop factors include:

  • Micro Four Thirds (MFT) system uses 2x. MFT’s aspect ratio of 4:3, and also compared to the standard 3:2. In Panasonic and Olympus cameras, you can find 2x crop sensors mostly.
  • Canon uses 1.6x Solely. Most of the consumer-level cameras utilities 1.6x crop sensors. The Canon APS-C that’s also called.
  • The standard APS-C, 1.5x. Now this is a wide-spread format. Except Canon, every brand manufactures their APS-C cameras with a 1.5x factor.
  • Slowly going extinct is 1.3x, but don’t worry you can still find cameras with it. Canon the brand used it in the original 1D series (not 1Ds or 1DX, full-frame).
  • 1.0x. 35mm is exactly full-frame sensors.

Of course, the world the brands don’t stop at full-frame. If you look for there are bigger and medium-format sensors which are found in even more expensive cameras. These are not called crop sensors, but you can still apply easily a crop factor to them. Their crop factors which are very smaller than 1x.

full frame vs crop sensor

What Does This Mean in Practice?

It is very easy. For example, you’ll see a 70mm * 1.5 = 105mm equivalent image (in terms of angle), if you place a 70mm lens on a 1.5x crop camera.

You’ll see a 70mm * 2 = 140mm equivalent image, if you place that same 70mm lens on a Micro Four Thirds (2x) camera.

Suppose that your lens easily can cover more than a full-frame sensor. You’ll get a 70mm * 0.8 = 56mm equivalent view if you put it on a 0.8x factor medium-format camera.

How You Can Calculate the Crop Factor?

An interesting thing you’ve all learnt in high school, the math to find out the crop factor is simple.

You’ll need to know the diagonal to get the factor. Using the Pythagorean Theorem (a² + b² = c²), the diagonal can be determined by the two sides of the sensor. Let’s say the sides are a and b, and the diagonal is c.

For example, 22.2mm * 14.8mm which is a Canon APS-C sensor. Now at first, calculate a² + b². In this case, it is 22.2² + 14.8², which exactly equals 711.9. Now you take the square root of c² (711.9), and you’ll get c, which is the diagonal. And the result is 26.68mm.

43.27mm as the full-frame diagonal using same math term.

Now anyone easily can simply divide the full-frame diagonal by the Canon APS-C diagonal. Now the very expected crop factor is 43.27 / 26.68 = 1.62x.

full frame vs crop sensor

Crop Sensor Disadvantages

Unfortunately in some ways a cheaper sensor is an inferior sensor. You will find there are disadvantages to using a crop sensor.

For one, your lenses work in a different way as the scene is cropped. Noticeable thing is the crop factor of your camera applies to every lens that you put on it.

But this might not be a problem with telephoto lenses (those get even longer), but it’s a big problem with wide angles for photography. Lenses are cropped to behave only like widish-standard-angle lenses that would project a wide-angle on full-frame.

Specifically designed for crop sensors, this problem is fairly easy to counteract by buying lenses. A Tokina DX 11-16mm on a full-frame camera and Tokina FX 16-28mm lens on a 1.5x crop sensor, they have equivalent in view, just for example.

Crop sensors require quite a sacrifice if you’re a fan of nicely blurred backgrounds (bokeh). If you’re using an equivalent lens with the same aperture you’ll get more bokeh on full-frame.

A 50mm lens on crop provides a similar view to an 85mm lens on full-frame, for example. The bokeh is smaller – a 50mm really can’t give you as much as an 85mm (both at f/1.8) can and it’s performances. When you stop the 85mm down to f/2.8 then they are comparable.

Crop sensors collect less light because of their smaller surface. Another thing is that the full-frame sensors have a roughly 2.5x larger photosensitive area than APS-C crop sensors.

It means that the absolute amount of light they gather is 2.5x less than full-frame. So, a crop sensor’s image has to be amplified 2.5x as much in order to get the same exposure. You will find the results in more noise.

Also, you will notice that the density of pixels on crop sensors is usually higher. They always require more and more resolving power from lenses. So, a lens might not produce the same sharpness on smaller sensors that is sharp on full-frame, if setting up both sensors have a similar resolution.

You have to be more careful when buying such lenses as manufacturing sharp lenses for crop sensors is thus actually harder.

Last of all, Crop sensors have a practical limit in resolution around 30MP. The brand Canon is little different in this case because It’s recent 90D has 32MP. Users sometimes complain about not enough sharpness who use that camera. And that is because the sensor is too demanding. A full-frame sensor would have a 72MP resolution at the same pixel density.

Crop Sensor Advantages

Though many disadvantages arises there are some important advantages for smaller sensors too.

Probably most important is their price. You can get the crop sensor one for half the price If you want comparable tech (autofocus, speed, resolution) in a crop and a full-frame camera. This is simply due to the generally cheaper sensor and smaller size.

It’s the second advantage of crop over full-frame in terms of size. Especially enthusiasts and those who travel a lot, value a smaller body over a bulky one, you won’t really find tiny full-frame cameras and Sure, also you can find big crop sensor bodies (Canon 7D MkII, Nikon D500).

The brand-new Sigma FP is the one expectation and that is a modular full-frame camera. As such, anything you think this is not really comparable to anything else.

Another good point for crop sensors is drum roll that they crop your image. So what’s the deal here for you to get?

You will value that 1.5-2x crop if you’re shooting sports, wildlife, action, or anything that requires a long reach. It significantly reduces the weight you carry and the price you need to pay of course.

A 600mm full-frame lens weighs over 5 pounds and costs a fortune. While providing the same view, a sharp 400mm lens on APS-C might just do the job perfectly for you. And also for you same with a 300mm lens on Micro Four Thirds.

Another thing is this also works for up-close subjects. You should know that the macro photography is a field of photography that a crop sensor can help with immensely.

By using a crop sensor and if you have a 100mm macro lens, you effectively have a 160mm lens. This kind of format gets you closer to the insects or flower you are photographing, all at no extra cost.

full frame vs crop sensor

Conclusion

It is a sad news that there is no easy way to decide whether a crop sensor or a full-frame camera is for you. It really depends on several things; mostly your intended use for it and your budget.

You can’t really avoid going full-frame if you need the best low-light performance, and/or very high resolution.

A crop sensor camera gets you closer to them without any extra cost if you are photographing objects far away.

We have both of them and use them for different purposes and duties. However, really think through your purpose with it if you have to choose one camera.

lenses for fashion photography
Lenses for Fashion Photography

That no matter having an array of lenses, what you are capturing, it is still possible with either system.

You just need to re-imagine the focal lengths if you want your kit to include a wide-angle lens, a standard lens, and a telephoto lens.

You can find 11mm-16mm, 35mm and 50mm-135mm lenses to cover the same focal length instead of 16mm-24mm, 50mm and 70mm-200mm lenses.

Your choices should be plenty for smaller systems, such as Micro Four Thirds, too.

In the end, for you, your camera is only a tool. With all the different sizes of sensors, world-famous works have been created. You should not set limited yourself by either crop or full-frame.

Fashion Photographer’s Toolkit
Photographer's Toolkit

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