Welcome to a new series called, What Camera Should I Get?, where we look at what goes into a purchasing decision and help steer you in the right direction. This will be a truthful and honest critique of the available options for you to make a decision, what will be different than other camera comparisons is that I'm not going to compare two cameras against one another, I'm going to compare types of cameras. Also, as a way of opening this series, I'm going to state that I have no endorsements by camera companies or their affiliates. I'm not part of an affiliate program and none of the links here will benefit me. If you'd like to support my blog, please think about visiting my photo store.
Since I'm going to be looking at types of cameras, let's start with the two types of cameras that you can get; full frame vs., a cropped sensor.
What is a full frame sensor and what is a cropped sensor?
This is camera lingo for the size of the digital sensor inside the camera. I have owned both and I can say that having two full frame cameras have been beneficial for my photography but only because the lenses that I was using. Please keep in mind, getting a full frame camera will not automatically make you a better photographer. Owning a cropped sensor camera does not inherently make you a hobbyist either. Let's just dispel those myths right now.
The meaning of cropped sensor means anything that is less than full frame. Full frame is considered the same size as a 35mm camera, that has been the standard ever since 1909. There are a couple of main sizes of cropped sensors to be aware of; 4/3rds and APS-C. Those are the two that I'm going to be looking at today. What does cropped sensor actually mean though? Look at the graphic below for more information.
From what I've illustrated above, you can see the difference of taking a photo with a full frame camera versus taking a photo with a cropped sensor. The outlines are how much of the photo you would have seen with those types of cameras. I've labeled what Nikon / Sony use for their cropped sensor cameras, a crop factor of 1.5x and what Canon uses for their cropped sensor cameras, a crop factor of 1.6x.
You'll notice the micro 4/3rds cropped sensor there too, these type of cameras are traditionally much smaller than full frame or APS-C type cameras because their sensors are so small. Cameras like these are much smaller but offer big advantages with regard to size and also, image quality. Olympus OMD EM10 is a wildly popular micro 4/3rds camera that has been a big hit with travel and lifestyle photographers for the last several years. You can read one photographer's article about the Olympus OMD EM10 here, and my take on this article is that he is generally right. The days of "bigger is better" are gone and "less is more" is in. You'll notice in the illustration above that the 4/3rds crop factor is 2x, what does that mean?
Suppose you're using a 100mm lens on a full frame camera, a full frame camera has a crop factor of 1 so the effective focal length is 100mm. That is not the case with a cropped sensor camera. Using that 100mm lens on an APS-C camera on a Nikon would have an effective focal length of 150mm and on a Canon, the effective focal length would be 160mm! That's what you're seeing with the illustration above, the effective focal length. Further yet, a 100mm lens on a micro 4/3rds camera would have an effective focal length of 200mm. There are advantages and disadvantages for using a cropped sensor camera which I will below.
Advantages of a Cropped Sensor
If you're a wildlife or nature photographer who frequently uses a telephoto lens, there can be an advantage to using a cropped sensor camera because of that effective focal length. Suppose you're using a 400mm lens on a Canon APS-C camera, your effective focal length would be a staggering 640mm! This is not to say that you're any "closer" to the action but the image taken would appear to get closer because it's a crop of what a 400mm lens on a full frame camera would capture. But again, the benefit here is that you could mimic having a 600mm lens for a fraction of the cost! That is a big advantage and most of the advantages of a cropped sensor camera are going to come back to pricing. A high-end full-frame DSLR is going to run $2,000+ and often times above $3,500.
Whereas most APS-C cameras are going to be under $2,000 and some are going to be under $800 while still maintaining good image quality. Pentax and Nikon are currently (as of 3/2018) dominating this space, Pentax with its wildly popular K3II and KP cameras while Nikon is offering the D7500 and the D7200. All of those cameras have plenty of megapixels to make large prints (if need be) and have some really great features too like weather-sealing, GPS, and built-in WIFI. So should you go ditch your ambitions to get a full frame camera and get a cropped sensor?
Advantages of a Full Frame Sensor
Traditionally, cameras that have a full frame sensor are top of the line cameras and those always come with top of the line features like; full weather-sealing, ridiculously high megapixels, burst modes, etc. But aside from those features, the biggest advantage that I have found using a full frame camera comes with wide-angle photography. Remember that crop factor that I mentioned above? Suppose you wanted to take a wide-angle landscape, some of my favorite types of scenes, and you needed to get an image at 16mm. On a full frame camera, what you see is what you get. You're going to get all of the effective focal length at 16mm, you're going to have a very wide shot. If you're using a cropped sensor, your effective focal length is going to be about 25mm and you're going to lose what you had between 16mm and 24mm. That is the biggest difference right there. So for me, it made the most sense to get a full frame camera because I really like landscape photography and especially wide-angle shots. While there are specialty lenses designed for APS-C cameras to make the effective focal length match the actual focal length of the lens, they are not numerous and there isn't a lot of support for them.
When thinking about purchasing a camera, there are several factors that will play into that decision and this ought to be one of them. I believe that there are instances where having a full frame camera are more advantageous than not as well as vice versa. For me, since I decided to pursue professional landscape photography I felt that it would be better for me to have a full frame camera and I have owned both the Canon 5D Mk. II and the Canon 5D Mk. III.
My advice would be to look at price first and foremost, it will be easier if you have a budget range to work backward from there. Consider what area of photography you might want to develop into a specialty, what is going to best future-proof your camera for years to come? That doesn't always mean a top of the line camera.