I'm often asked at markets, and recently on facebook, "What camera should I buy". This is nearly always from novices, presumably baffled by the options available.
I'd contend that almost certainly there aren't any bad cameras around but probably the biggest mistake you can make is buying a camera you simply don't get on with.
But, to try and simplify the options and boil it down to a few choices, here's the first idea - buy a DSLR.
The DSLR - Digital Single Lens Reflex camera - is the digital offspring of the classic film SLR design that has now been around for fifty years or so. It's the kind of camera you associate with "serious" photography, a "proper" camera. Not a point and shoot, definitely not a smartphone.
So what is a DSLR and why buy one?
The defining feature is the viewfinder. Top and centre of the camera is an optical viewfinder. Put the camera up to your face and look through the little hole and you see the scene. The view you see comes directly through the lens and is exactly (well, almost exactly) the same as the camera will see when you take the picture. For me this is the most important part of the camera because it's how you will see the world when you're taking pictures and looking for compositions. There's nothing worse than trying to find a composition by holding the camera at arms length in bright sunshine to look at the rear screen.
Apart from the viewfinder here are the reasons you buy a DSLR:
Interchangeable lenses - you can remove the lens and put a different one on. From ultra-wide to ultra-long, macro, zoom, every imaginable type of lens is available to you. Whatever style of photography you want to try you'll be able to get a suitable lens. If you don't like the lens you've got, buy a new one and try that.
Ultimate control - every aspect of the picture taking experience is directly controllable.
Responsiveness - most DSLRs are fast to use. Little delay when switching on and pressing the shutter button.
Reliability - they usually do the job well when you need them to
Accessories - filters, flash, remote controls, whatever you need is usually available
In short, DSLRs will do the job, whatever the job is. The design, which is now pretty much universal, is also nice to use.
As a beginner, a DSLR is a safe choice. They all nowadays have good image quality and almost certainly the camera will be more capable than you are. You'll get longevity - from the build quality but also from being able to buy new lenses and accessories.
So why wouldn't I buy one? Well, here are some general downsides:
Size and weight - they generally aren't the smallest and lightest. This is important. There's no point having a camera that you leave at home because it's too big to carry. Of course they vary, some are fairly compact by DSLR standards but none are pocketable.
Convenience features and bells and whistles - even the latest models are fairly conservative in the features they include. Compact point and shoots and smartphones are often far more advanced in their features. Things like sweep panoramas, automatic multiple exposure blending, are not often found in DSLRs.
Nowadays there aren't so many brands still selling DSLRs. If buying new you can choose between Pentax, Canon, and Nikon but these, especially the last two, still have so many models available that whatever you want you'll be able to find. Pentax is my own favourite but you can't argue with the huge range that is available from Canon and Nikon.
Not all DSLRs are the same. All three of these manufacturers have split their ranges in two, divided by sensor size. The two options are known as Full Frame and APS-C. Full frame cameras have a larger image sensor, 36x24 mm. APS-C sensors are 25.1x16.7 mm. The bigger sensor can deliver better image quality but both bodies and lenses will be significantly larger and heavier and more expensive. The image quality advantage isn't all one-sided though. The smaller sensor cameras have the advantage in being easier to get full depth of field and being easier to hand-hold. A full frame camera needs better shooting discipline to get the most out of it and in any case an APS-C camera can still make prints up to A2 in size, which is a big print indeed, more than most of us will ever need.
The different sensor size also requires different lenses so watch carefully which lenses you're buying. For example, Nikon lenses are branded either DX (APS-C) or FX (Full frame). The DX lenses only work properly on Nikon's smaller sensor cameras while the FX lenses work on both ranges but the effective focal length will be multiplied by 1.5 when used on a smaller sensor camera.
So if you buy a Nikon APS-C body and a set of Nikon DX lenses, you'll be able to upgrade to another Nikon APS-C body and still use all the lenses you've bought but if you upgrade to a Nikon full frame body you won't be able to use the lenses properly. The same goes for Canon and Pentax.
So you'll end up with the following choice. Should you buy the bottom of the range cheap and cheerful body and lens, or the all singing all dancing professional level full frame body with professional lens for five times the price? Mike Johnston, The Online Photographer ( theonlinephotographer.typepad.com ) once wrote a long post on this subject. He started by recommending the then best of the best full frame Nikon D700 (today it would be the D750). He then justified recommending a several-thousand-pound purchase for a beginner by describing what would happen over a period of a few years after buying a bottom of the range body to "dip your toe in the water". He suggested you'd then spend years trying different bodies and lenses because you'd always have the suspicion that your pictures would be better with a better camera. Eventually he said you'd end up with the D700 anyway, so why not buy one from the start?
There's a logic to his argument but you really need to think about your budget. A bottom of the range DSLR can be relatively affordable but today's D750 body is nearly £1200 and a pro-grade lens to match would be that much again.
Whatever you decide I'd strongly recommend trying a few in the hand before buying. Like I said at the top, you need to get on with a camera and a big part of that is the way it handles. You need to be sure the DSLR design is for you and then you need to be sure about the size of body and lens you'd be happy to tote around.
The final advantage of DSLRs, especially APS-C and especially from Canon and Nikon, is availability second hand. There are huge numbers of bodies, lenses and accessories available from reputable second-hand dealers. You could be up and running with a good camera for less than £300.
Next to be discussed - the "mirrorless" options.