Now that you've got a good background, let's talk cameras, brands and technology.
Images by me. Left: Nikon D610, AF-S 24-120 f/4 Bottom: Nikon D7500, AF-P 70-300 f/4.5-6.3 VR, Model: Billy
Now it’s time to get more technical. First, another disclaimer. My target audience for this article is beginners, not professionals or others that really dig into the science and technical details. As such, I am intentionally keeping this simple. If you want to dig in further with the technology, physics, and other science there are whole libraries of information out there that are beyond the scope of this.
One good thing about cameras (or bad thing, depending on how you look at it) is there are a lot of different options out there. This gives a lot of room for personal preferences. When it comes to the technology, there are three main options to consider. They are, in no specific order: Brand, Sensor type (Full-frame and APS-C, among others), and DSLR or mirrorless. You should consider all three of these when deciding what's best for you.
Image by me. Nikon Z50 Nikkor Z 16-50 f/3.5-6.3
The big 3 brands today are Canon, Nikon and Sony. When it comes to the consumer cameras, I don’t feel like any one of these has a clear advantage. When I chose Nikon it was because I shot it back in the 35mm days and most of my family that still shoots uses Nikon. The other reason was one I mentioned before. Ergonomics. Nikon cameras just feel right in my hands. The buttons are in the right places. I like their interface. I like their color science. Bottom line, I like my results.
The one objective differentiator with brands is lens availability. Canon and Nikon have been in this business for years longer than Sony. This makes for an abundance of used lenses out there for both. Canon and Sony have used different mounts over time and I’m not very familiar with them. If you choose Canon or Sony be aware there are differences that affect compatibility. Nikon has used the same physical lens mount for over 50 years, the F-mount. You might have to use a vintage Nikon lens in 100% manual mode, but with the right body you could use an F-mount lens from the 1970’s on a modern Nikon digital body. My favorite 50mm lens is the AF 50mm f/1.8D that’s been around since 2002. It's an older design, but it's smaller, lighter, and cheaper, and I like the results.
When it comes to the images themselves, that’s very subjective. You will see differences from one brand to another, especially with the "as-shot" or "in-body" JPEGs. Each brand has it's own software that controls this. Which is better is up to the viewer. On paper, all three brands are fairly evenly matched, class-to-class and generation-to-generation. (i.e. consumer vs. consumer level bodies.) A while back I saw a screaming deal on a Sony a6000. It’s a camera I’ve read a lot of good press on. If you’ve been looking into cameras lately, I’m sure you’ve seen that too. So I decided to give it a try and see if I was missing out on something. At the end of the day, the only thing that really impressed me was that it fit in my coat pocket. I’m not saying it’s a bad camera. It’s decent and definitely takes better pictures than a phone. And for many, that’s enough. Again, it’s subjective. Objectively, there were two things that pushed me to sell it. First, it wasn't in the budget to support two lens systems. I might have gotten to like the a6000 more with better lenses, but I wouldn't be able to use those on my Nikons. The other thing I disliked is that there seems to be about a 20% surcharge just because it’s Sony compatible.
The two sensor types that the big 3 use in their mirrorless and DSLR lines are Full-Frame (FF) and APS-C, also commonly called crop sensor. The third common sensor type is the Micro Four Thirds (m43) used by Fuji, Olympus and others. There are still other sensor types out there (bigger and smaller) and people who love them, but I don’t have any experience with them. With Nikon, the two sensors are branded FX for full-frame and DX for APS-C. The primary difference between these is the physical size of the sensor. Full-frame is physically larger than APS-C, which is physically larger than m43. (Full-frame is 36mm x 24mm. APS-C is ~24mm x ~16mm. m43 is 18mm x 13.5mm.) There are other differences from one generation of sensors to another such as resolution, ISO sensitivity, dynamic range, and more. Sensors are a place where newer is generally better, at least on paper. However, in practice if you are upgrading camera bodies, unless you jump multiple generations of sensors you would likely have to be shooting in specific situations, or printing on larger formats to see much difference.
The battle among photographers between full frame and crop-sensor cameras is akin to your favorite sports rivalry. It’s an emotionally charged battle and your answer is the right one for you. Taking the emotions out of it, both types of sensors are very capable. Just like the discussion with having a fancier camera, the real question you should ask yourself here is, what will best meet my needs? Each format has strengths. In my opinion as far as image quality goes, the current generation of sensors used in "enthusiast" level or higher bodies are all on-par with one another. There is a noticeable difference in image quality between an entry-level sensor and other higher end sensors. An entry-level sensor is still better than any phone. Here are a few differences and trade-offs between APS-C and FF.
This is the first time I've mentioned crop factor, so allow me to expand. Crop factor is often misunderstood and looked down on. It doesn't break anything or change the focal length of the lens. It doesn't change or hurt or improve the image quality. It doesn't make you less professional or less cool than the other guy (or gal). These are all things I've heard people say about crop factor, and it's all nonsense. In the simplest of terms, crop factor is like getting extra zoom. Using photo math (I bet you didn't know that was a thing), here's an example of crop factor. If you are using a FF body with a 50mm lens, shooting a subject that's 15 feet away, your field of view (or what you see in the frame) is approximately 11 feet by 7 feet. That would be pretty common if you were taking a photo of a small group of people. Standing in the same place, using the same lens, your field of view with a Nikon APS-C sensor is approximately 7 feet by 4.5 feet. Now you've cut off their feet and have room for a couple of less people on the ends. This is a 1.5x crop factor. It's like you zoomed in. In this scenario to get the same field of view with an APS-C body you have two options. First, use a shorter lens like a 35mm instead of the 50mm. Second, move back so you are 25 feet away rather than 15. Either option will give you a very similar field of view. The difference is as simple as that. For reference, Sony's crop factor is also 1.5x, Canon's is 1.6x, and m43 is 2x.
I used the 50mm and 35mm lenses as examples on purpose. A term you'll commonly hear when talking about crop factor is "equivalent focal length". The above scenario is an example of how equivalent focal length is used in practical terms. Using a 35mm lens on a camera with a 1.5x crop factor has an equivalent focal length of 52.5mm, which is very close to a "nifty fifty" on a full frame camera.
When it comes right down to it, the biggest difference between APS-C and full frame is cost. Full frame costs more. At the end of the day in the hands of a photographer that knows how to use them, a high quality lens paired with a high quality camera will get high quality results.
The SLR (single-lens reflex) design dates back to the 1930’s. The earliest digital SLR (DSLR) cameras date back to the mid-1980’s. Consumer type DSLR’s have been around since the late 1990’s. Bottom line, it is a tried and true design. A DSLR camera bounces the light coming through the lens off of a mirror, into a prism, and that is what the photographer sees in the optical viewfinder (OVF). This is also where a DSLR’s autofocus system lives. When the image is taken, the mirror flips up out of the way, the shutter does its job, and the mirror moves back down into place. It is the same basic design that goes back all those years. The only difference now is that the media is an electronic sensor instead of film. The movement of the mirror is why the photographer’s view is interrupted for a moment when the picture is taken.
Mirrorless (MILC, Mirrorless Interchangable Lens Camera) is a relatively new technology that uses the same optical designs, except the image is focused on the sensor full-time. The autofocus system on a mirrorless camera is part of the sensor. This is why mirrorless is generally better at video. (When using a DSLR for video, the mirror is flipped up, so the normal AF system is not available.) The image coming through the lens is processed by the camera and shown on either an electronic viewfinder (EVF) or the screen on the back of the camera.
There are a number of advantages to mirrorless. The main one is that you can see how changes to the exposure and other settings are affecting the image in real-time. But, this also leads to the main disadvantage, battery life. Because the camera is constantly processing the image, it uses up the battery much more quickly. Mirrorless cameras are generally lighter weight, physically smaller and are better at video. They can also add convenient features like eye autofocus. The other downside to mirrorless is that the selection of native lenses is smaller. Mirrorless just hasn't been around as long. There are adapters that address this, and they aren't as bad to use as many people preach. DSLR’s still shine in the autofocus and low-light arenas, but mirrorless is closing the gap here very quickly.
The battle between DSLR and mirrorless is very much like the battle between FF and crop sensors. They both work extremely well and take great pictures. I have 3 Nikons. One DSLR and two mirrorless. I switch between them depending on the situation. There are times I like having the optical viewfinder much better and the feel of the larger camera in my hand. Other times I don't want to pack the heavier gear around. Like so many answers in the photography arena, the right answer starts with "it depends".
One last note on this topic. There are people who like to warn (preach) that DSLR is dead or at least dying and that you need to go mirrorless to be "future-proof". A year ago I would have told you that they were wrong. Unfortunately I have to change this as both Canon and Nikon have announced that they will no longer be developing new DSLR cameras. But I don't think thats means you need to buy mirrorless. As I said before, I still have a DSLR that I prefer to use for certain things (birding). There's TONS of used gear out there and just because mirrorless is new and shiny doesn't mean that DSLR should be avoided.
The main motivation behind why we buy real cameras. (And the reason I was able to get the shot to the left being several miles away.)
Image by me. Nikon D7500, AF-P 70-300 f/4.5-6.3 VR
Lenses are the last piece of the puzzle, but also arguably the most important piece of gear you'll own. That's why this is the longest single section of this article. Some of this is brand specific, but bear with me. I’m going to do my best to keep this section brief. Even without talking specific lenses, this could easily turn into an entirely separate article. But I also think that having some basic information is absolutely necessary. The two terms you need to understand when buying lenses are: focal length (usually in mm) and aperture (usually noted as F-stop or f/x.x).
Here is an example of how you would see a Nikon lens’s specifications listed. “AF-P DX NIKKOR 70-300mm f/4.5-6.3G ED VR”. Every letter and number here means something to Nikon. The focal length is the 70-300mm part. The f/4.5-6.3 is the maximum aperture (how wide the aperture can open). The rest of it relates to the series/version and features of the lens and is Nikon specific. An example of a Canon lens name would be: "Canon RF 24-70mm F2.8 L IS USM". Again, everything here means something to Canon, but the focal length and maximum aperture are easily identified. 24-70mm is the focal length and it has a constant aperture of F2.8.
Focal length determines your field of view or how much you can see. Focal lengths can be fixed (a prime lens) or variable (a zoom lens). The shorter the focal length, the wider the view. The longer the length, the narrower the view. What you should understand right now is the bigger the number is, the further away you can be and still fill the entire frame with your subject. For example, if you want to take a picture of a tree that happens to have a bird in it, you want a shorter lens, such as a 16-50mm. On the other hand, if you want to take a picture of a bird that happens to be in a tree, you need a longer lens, such as a 50-250mm. (Because the bird isn't going to hold still while you get close.) The longer the lens, the further away you can be.
A lens’s aperture serves the same purpose and functions very similarly to the pupil of your eye. It controls how much light is let into the lens by opening and closing. It also controls another VERY important part of the photograph, the depth of field. Depth of field is how much of the depth of the photo is in focus. The best examples I can think of to describe depth of field is what you commonly see in portraiture. The person is in focus, but the background isn’t. That is the function of depth of field. This is another topic that could be an entire article, or series, or book(s)… So to keep it short, the smaller the “f/x.x” number is, the more light gets through the lens and the shorter the depth-of-field can get. Like the focal length, apertures can be either constant (f/2.8) or variable (f/4.5-6.3).
One other really important feature in many lenses is an optical image stablization system. Every brand calls it something different, but it's purpose is to correct some amount of camera shake. With Nikon it's called VR (vibration reduction). Sony is OSS (optical steady shot). Canon calls it IS (image stabilisation). Tamron and Sigma have their own names as well. Basically this feature allows the lens to correct some amount of vibration which allows for a slower shutter speed without showing blur in the image. It's most common and most useful on telephoto lenses.
Brands: There’s really no clear winner here. Nikon and Canon both have FF and APS-C models as well as mirrorless and DSLR. Sony has been all mirrorless for years and offers both FF and APS-C models. With brand choice, I think it’s primarily personal preference. Do you like how it feels in your hand? Do you like the menus? Do you like the in-body JPEGs? Is it in your budget?
I think mirrorless vs. DSLR is also mostly personal preference, with the exception of video. Because of how a mirrorless focuses vs. a DSLR, mirrrorless has a clear advantage. If video will be a regular use for your camera, that could be a deciding factor for you. If small size and lower weight is important, that could be another deciding factor.
Full-frame vs APS-C: Each type has its strengths and weaknesses. I think the primary driver here is cost, not image quality. The cost of the bodies varies greatly. FF is generally more expensive, but used FF bodies can be similarly priced to APS-C. On the other hand, APS-C lenses are generally going to be half or less the cost of an equivalent FF lens new or used. Some other reasons to lean towards APS-C. If you shoot lots of telephoto shots (long lens), the APS-C crop factor is free zoom. APS-C is also going to be smaller and lighter. I think APS-C does better with action shots like sports and street photography. I’d lean towards full-frame if you do a lot of low-light shooting, or if you have background with 35mm film. I’d also consider jumping to full-frame if I was doing paid work, with the possible exception of wildlife where the crop factor is so helpful. I shoot 70% or more of my shots with an APS-C camera. I am not one that will argue full-frame’s superiority for all things. Full frame will take great pictures, but it isn’t the best choice for every photographer.
Lenses: Every brand has a full lineup of lenses for their systems. Nikon and Canon have the most but many require an adapter for use with their mirrorless bodies. Sony is catching up. Canon is the most prolific as far as quantity of lenses on the market (new and used). Nikon is close behind and has the advantage of using the same physical mount for a lot of years. Sony is the new kid on the block and has embraced third-party manufacturers to help close the gap. All of them offer high quality optics.
I hope this has been a helpful read for you. I’ve enjoyed writing it. Photography is an adventure. It’s a fantastic hobby because there’s always more to learn. It can also become a very expensive hobby because there’s always something more to buy. Remember, the difference between a decent snapshot and a great photograph is the person behind the lens, not the gear.
Now get out there, get shooting and above all