I read a lot of discussions on forums and Facebook that begin with someone asking, “what camera should I buy?” Or, “I’m upgrading, should I buy camera X or camera Y?” The comments tend to fall into categories. “You should buy X. That’s what I have and I love it.” “Forget about X or Y, you should buy a camera from another manufacturer. (Oh, and that’s what I have and I love it.)” “Here’s a site which compare X to Z created by folks who don’t know what they’re talking about.” (They usually don’t add that last part!) “Here are some random ‘facts’ that are, actually, incorrect.” And, usually swamped by the others, there might be one or two “What do you need? What kind of photos are you taking? Why do you think you need to upgrade?”
I will sometimes throw in my two cents in that last category, but it’s difficult in these forums to have the sort of conversation that’s really required. And, sometimes, I think the original poster already has made up his or her mind and is just looking for other folks to confirm the decision. We all like to feel we didn’t blow a ton of money for the wrong thing. That’s also behind all the comments from people arguing in favor of what they own.
The first question that should be asked is, what do you need? It’s a broad question with several sub-questions. What sort of photography do you do? What sort of photography do you want to do? If you have a camera now, what doesn’t it do or do well that you’re looking to improve? If you primarily shoot sports, that may lead you in a different direction than for shooting scenery on your vacation. Would your needs be better served by purchasing a different lens?
Where are you getting your information and recommendations? How well do you know the source? Is it someone you know personally and trust (and can even show you examples to back up the claims)? Or is it from some random website (ahem – like this one!)? I’ve seen several sites that purport to compare two cameras, comparing a list of features. Let me tell you, most of them are rubbish. There was one site that gave the nod to a mid-level pro camera over a top of the line camera and the biggest factor for the former was popularity. Seriously. Who would have thought a $2500 camera was more popular than a $6000 model? Ugh.
Let’s try to look at this somewhat sensibly. There are a ton of cameras from many manufacturers that will take boffo photographs. The quality from modern cameras is staggering. You can easily be led down a rabbit hole by people harping about quality. I saw a comment once, totally off-topic from the original question, pointing everyone to some site with diffraction curves for a lens. The commenter was basically just bragging about his knowledge and (as so often is the case) justifying his own purchase. In fact, the knowledge part was debatable.
I wrote once about focusing on the art and not the technical aspects of photography. But it is easier to learn facts and figures than learn how to see with real vision. Photography has always had that technical side that can too often dominate the conversation.
Does sensor size affect the image? Yes. Usually, a larger sensor is better in low light. A larger sensor will provide shallower (apparent) depth of field at a given aperture. If you want someone’s eye in focus but nothing else, a big sensor will help you achieve that look. The down side is, to get a particular field of view, you need bigger lenses. The field of view from a 200mm lens on an Olympus OM-D is equivalent to a 400mm lens on my 5DMkIII. Let me tell you, the size and weight difference between those lenses is huge. If you want to go to a full-frame sensor like mine, you should understand these pros and cons. You should need the pros and be ready to accept the cons.
Is size and weight a factor? Will you be carrying this camera around all day? Just using it on a tripod in a studio? There are now many small (but not necessarily inexpensive) cameras available. Sony has a line of very well-reviewed cameras with large sensors, even a full-frame one now. Olympus and Panasonic use the 4/3 sensor size and have built some nice cameras that can all share lenses. Fuji is in the mix as well as Samsung now. I’ve mentioned renting the Canon SL1 for a vacation which was great for me. Nikon has it’s “1″ series of mirrorless cameras.
Do all cameras provide the same image quality? No. Generally, though, those with the same sensor will have similar image quality (given the same lens, etc.). Newer gear may or may not have improved sensors, but maybe other features are important to you. Between two cameras, will the image quality differences be noticeable to you? In many cases, the answer might be no. Low light capability is one that may be a factor, but extra noise may not be noticeable on your Facebook post. Or, you may not shoot that much in low light conditions.
How does the camera feel in your hands? Is it comfortable? Are you able to reach the controls you use? When I used the SL1, I found it a bit awkward to change certain settings. Those adjustments are simple on my 5DMkIII. But I adapted and was more than happy to cope with this when I could carry it around all day without getting a sore shoulder. And, the SL1′s touch screen was great. I used it more than I expected. Sometimes, you won’t know what you like and don’t like until you’ve used the camera for a while. These are things you typically won’t see discussed in open forums.
Do you have a set of lenses that you hope not to replace, at least not all at once? If you shoot Canon and have any EF-S lenses, they won’t work – at all – on the full-frame cameras. If you shoot Nikon, you can move up to full frame and keep your lenses, but they won’t let you use the full frame. Obviously, if you shoot with one system (e.g. Canon), switching to another (e.g. Nikon) usually means all new lenses. There may be adapters, but they have their own issues. Factor this into your costs.
What other features are really important to you? Canon’s new 70D has an all-new sensor that provides much better focusing for video of live view (when you look at the scene on the LCD rather than through the viewfinder). If that’s how you shoot, this might be important. Many newer cameras include GPS to add location information to your shots. You might like that for travel and landscape photography. If you mostly shoot your kids at home, it’s probably less important. Newer models also are including Wifi. That could be nice for pushing photos to Instagram or Facebook. Both of these features use some battery power.
Speaking of batteries, some cameras will run on a battery for a thousand shots. Others are done with 200. Is that important? Do you need an articulating display? Those are helpful in letting you put the camera really low or above your head. Or for selfies!
So, where can you get good information to help you decide? I like dpreview.com which has many good reviews. They can be a bit technical, but they cover lots of info even including how the camera fits in your hand. I also highly recommend renting a camera before you buy it. I’ve rented from LensRentals, and I’ve heard good things about BorrowLenses.
Take user reviews and comments on discussions with a big grain of salt. Be especially wary of those who try to steer you in a completely different direction or push highly technical nuances. If you can use before you buy, that’s great. Maybe you rent or borrow from a friend. Find someone you trust to help. Eventually, if you keep at it, you may find yourself becoming that trusted friend for someone else.