At some point in your photographic career, you might have faced the dilemma of whether you should get a full-frame camera or an APSC camera. There is a vast demand for full-frame cameras in the market.
A full-frame camera is a really big investment for many. Besides, APSC and micro four-thirds cameras often produce the same result as a full-frame camera. So why do we need a full-frame camera? Is full-frame only a gimmick? If those questions ever bothered you, then this article is just for you as we are going to discuss if you really need to buy a full-frame camera.
Getting the Same Quality as a Full-frame Camera
In some situations, full-frame, APS-C, and Micro Four-thirds can produce almost the exact same results. It’s all about the simple math of crop factors. As we all know, full-frame cameras have a crop factor of 1, for APSC cameras, it’s 1.5. And if you are a Canon shooter, it’s 1.6. Lastly, micro four-thirds cameras come with a crop factor of 2.
Now suppose, you are using an 85mm 1.8 lens. If you take images with the same lens but different cameras, you will get different results based on the sensor size of those cameras. A full-frame camera will produce an image with a much wider view. But an APSC camera will give you a cropped image. With a micro four-thirds camera, the crop is even intense. But why is this happening? Well, it is because of the crop factor. When you are using a full-frame camera, you are getting the exact 85mm focal length view. But when you switch to an APSC camera, the lens focal length is multiplied by its crop factor. So you are getting 85 multiplied by 1.5, which is nearly equal to 128mm focal length. And this is why you are getting a cropped image compared to the full-frame. And for the exact same reason, you are getting even more cropped in view with the micro four-thirds camera, as if you were using an (85 x 2) 170mm lens with your micro four-thirds camera.
If you want to get the exact image, and not the cropped-in image, in all three cameras, you need to do a little calculation with the crop factor.
In terms of the APSC camera, you have to divide the focal length of the lens used in the full-frame camera by 1.5. So 85 divided by 1.5 is equal to about 57mm if we consider only the round figure. When you use a 57mm focal length, you will get almost the same amount of background and the same size of your subject as the full-frame camera.
For micro four-thirds, 85 divided by 2 is equal to about 43 mm. So you have to use a lens with a 43mm focal length.
Although everything looks about the same size with those calculated focal lengths, the three pictures you’ll capture by those three cameras may not be exactly the same. There is a difference in terms of depth of field in those images. And it is because we have only considered focal length, not the aperture.
To get the same depth of field out of those three cameras, we have to consider the crop factor again. Suppose the image was captured using the full-frame camera with an aperture of 4.
If you want the same depth of field in your APSC camera, divide the aperture used in the full-frame camera by 1.5. Thus 4 divided by 1.5 is equal to about 2.67. If you can’t dial 2.67, then 2.5 would give you almost the same depth of field as the full-frame camera. And for the micro four-thirds camera, you can set the aperture to 2, as 4 divided by 2 is equal to 2.
Now we are almost there. The images are almost the same, except the exposure level of those three images still doesn’t match. And again, our good old friend “the crop factor” is here to save us. However, this time, we have to use the square values of the crop factors.
Let’s say we captured those images with a full-frame camera at an ISO number of 400. To match the exposure for APSC, divide 400 with 1.5 square, which is about 178. If your camera doesn’t let you dial in ISO 178, then dial a nearby number. And you will get almost the same result. For micro four-thirds, it is 100, as 400 divided by 2 squares is 100.
However, there is a limitation to using this trick. For example: if you are using an aperture of 1.2 on a full-frame camera, you have to use an aperture of (1.2/1.5) 0.8 on your APSC camera. And if you are using a micro four-thirds camera, you need an aperture of (1.2/2) 0.6. However, unfortunately, lenses with those aperture values don’t exist. The same goes for the ISO value. While using ISO 100 on your full-frame camera, you have to dial in ISO 45 on the APSC camera and 25 on the micro four-thirds camera, which is not available in any APSC or micro four-thirds cameras.
Hence if you want to take images with a full-frame equivalent look, depth of field, and exposure with smaller sensor cameras like APSC and micro four-thirds cameras, you can do it to a certain limit. But as you push the quality higher with your full-frame camera, things start to get difficult to match up for APSC and micro four-thirds cameras.
So which one should you get? Well, it really depends on you and your shooting needs. If you want to achieve higher quality footage, full frame is the way to go. But if you don’t want to push the limits like a full-frame camera. You can choose an APSC or micro four-thirds camera. Besides, because of the crop factor, APSC and micro four-thirds cameras have their usefulness in sports photography as well as wildlife shooting.