In my last post I waxed a little poetic and dealt with the more esoteric considerations of choosing a camera. This time around we need to tackle some of the actual nuts and bolts of a camera purchase. Some of the jargon can seem overwhelming at first, but don’t worry! Once you start to browse around and deal with actual cameras, read reviews, and talk to other camera enthusiasts, much of what this post deals with will become, if not second nature, at least much less intimidating.

Removable lenses and you: the choice is yours

First and foremost, you need to decide if you want a removable lens camera. The easiest way to break this down (Steph will love this) is a pro and con list, so let’s hop to!

Pros of removable lenses:

  • Image quality will almost always be higher
  • Autofocus will be faster and more accurate
  • More lens options means better photos in a wider array of situations
  • Low-light capability is normally much better
  • More direct access to controls for the enthusiast and above level shooters
  • Video quality is usually higher
  • Good bokeh (see the “lenses” section!)
  • Can use more powerful detachable flashes

Cons of removable lenses:

  • Expensive
  • Much bulkier
  • More of a target for theft
  • Sometimes do not have flash built-in

 

Pros of a fixed lens camera:

  • Small, easy to always carry
  • Easy to use
  • Inexpensive
  • Inconspicuous
  • Nearly always have built-in flash

Cons of a fixed lens camera:

  • Lower image and video quality
  • Generally poor low-light performance
  • Some limitations will arise from lack of lens options
  • Cheaper cameras will have durability issues
  • Flash tends to be weak

Once you’ve made your decision based on my super extensive pros and cons lists we can move on the finer points of picking a camera.

Sensor size

By and large, this is going to be the biggest determination of your image quality. Very roughly, the bigger the sensor, the better the image. Very less roughly, it’s a little more complicated than that. When you look at the resolution for a camera, it’s always listed in millions of pixels, or megapixels (MP) in short. This means that a 24MP camera has 24,000,000 pixels on its sensor. That’s all well and good, but beyond that you need to consider the size of the sensor as well. If you have chosen either detachable lens or fixed lens, then, to some extent, the choice has been made for you.

Micro Four Thirds and larger are generally seen as “large” sensor cameras and are almost all detachable lens cameras, while anything smaller (such as any size that involves a fractional notation) is considered small and is usually fixed lens. See my helpful chart!

Various sensors compared to a 35mm “full frame” sensor. It’s not the biggest sensor out there, but for our use it’s not practical to consider anything larger.

Based on the chart above, a 24MP camera with a 1/2.5” sensor (this is considered small, and is typical of your point and shoot cameras) is going to produce a very different image than a “full frame” sensor with 24MP. Essentially, on a small sensor all these pixels do just what you think they would: they get crowded and interfere with each other. You get noise (think film grain, but uglier), false colors, and generally less resolving power than a larger sensor with an equivalent number of pixels.

If you’ve decided to get a fixed lens camera, there are ways to to get the most out of the smaller sensor. Namely, look for a camera with less resolution. That’s right. Something in the 10-12MP range is what you want. Certain manufacturers have gotten wise to the fact that “winning” the megapixel race will ultimately make then losers, and this is to your benefit. Until camera technology changes drastically, you DON’T WANT lots of megapixels on a small sensor. Just don’t do it, regardless of what any salesman tells you.

Another way to improve your images is to look for a camera with a fast (or “bright,” or “wide maximum aperture”) lens. This will let you use a lower ISO (sensitivity to light, to be covered in more detail in the next post) at all times, which will vastly improve your image quality. Which brings us to…

The Lenses

Once you figure out the whole sensor situation, you need to consider what you’ll be putting in front of it. Good glass is key to getting the most out of your sensor, and it can make or break your photos. You want to look for a balance between a fast maximum aperture (the maximum amount of light the lens will let in, confusingly, the smaller the number the better. More later…) and a good range of zoom.

When you look at a lens, the first thing you look at is focal length. Simply put, this is the zoom factor, and it is described in millimeters, or “mm.” When people talk about lens focal length, and they say it’s a 24mm lens or it’s a 90mm lens or whatever, what they are referring to is the magnification power of the lens. A larger number (200mm) means more magnification, and a smaller number (24mm) means a wider field of view. A 40-50mm lens is usually considered the midpoint of the zoom range, or essentially a “neutral” field of view, because it is close to our natural field of view with our eyes. A wide-angle lens is generally anything 28mm or less (slightly more falls into semi-wide angle category). Anything less than 14mm is considered super wide. A standard lens (this is your normal field of view just using your eyes) is 40-50mm. Medium telephoto lenses are 70-90mm and telephoto is anything over 100mm.

Often compact/fixed lens cameras will have a limited zoom range, so choose carefully, as you can’t change lenses. Generally, the wider the zoom range (say 24-250mm) the less light the lens will let in, especially when it is zoomed in, so pay close attention to the minimum aperture listed on the lens. Still more confusingly, this is often notated as 1:2.8, rather than using the f designation. Often, the lens will have a range of apertures (1:2.8 – 3.5), meaning that at the widest focal length the lens is an f2.8 and at the most zoomed in it’s an f3.5. More on aperture in a moment.

I tend to veer towards the wide-angle end of things, so a zoom lens with a range of 24-70mm suits me fine, as I rarely stray into the telephoto focal lengths. This also tends to result in faster lenses, as telephoto zooms tend to be slower than wide angles. I like to shoot street scenes, landscapes and interiors, so anything more than a medium telephoto isn’t too useful for me, and I think it’s a good formula for travel photography.

For a good way to see the difference between focal lengths, go here. This is in no way an endorsement for Tamron, it’s simply a nice tool if you want a good idea of what focal length really means.

For you removable lens shooters, there are two basic types of lenses: primes and zooms. They both have their advantages and disadvantages. Prime lenses do not zoom, they are one focal length. They also tend to be faster (let in more light), smaller, and sharper than zoom lenses, and most importantly cheaper. Zoom lenses do just what they say in the name, but they tend to do worse in low light and since they have so many moving parts, they tend to be a little less sharp, but you only need I lens to do the job of three or four primes. Now, if you want a really great zoom lens that is fast and sharp and all of that, you’re going to pay a lot of money. Which is why I shoot almost all primes, because I like to save money almost as much as Steph likes to save money.

Finally, aperture. This refers to the amount of light a lens can let in when you make an exposure (take a picture). Lenses will list their maximum aperture on the front around the glass, usually something like 1:2.8 or whatever the maximum opening is. This number simply refers to the largest amount of light the lens will let in. The smaller the aperture number is, the more light the lens can let in, which is good. Lenses that can let in a lot of light are referred to as “fast” because they allow you to use faster shutter speeds that freeze action and make for sharper pictures. This also affects your depth of field. You know those shots with the lovely out of focus background and the sharp subject? That blurred background is called bokeh (a japanese word, pronounced bo-ka), and the faster your lens is (and the bigger your sensor is and the more telephoto your lens is) the more of it you get.

A depiction of aperture sizes, to give some idea of scale.

A lens with a maximum aperture of f2.8 or less is generally considered fast. Again, the smaller the number, the bigger the opening. I know. Some people would say that fast is really only f2 or less, but f2.8 is pretty good, and you won’t find lots of lenses that are faster. Not cheap lenses anyway, and not zooms, pretty much at all. A maximum aperture of f3.5 is average, but not great and anything above f5.6 is fairly of slow and should only be used in good light or with a tripod in low light. Take note that these numbers refer to the widest opening a lens will allow. Since the aperture in a lens is a set of overlapping blades that can step to any diameter within the lens, it’s most practical and useful to refer to their maximum opening rather than their minimum, which is almost always f22.

In summary…

Your first considerations for a camera should always be the sensor and the lens. Everything else is secondary, as these two things are what directly affect your image quality. Pretty much any other option exists to modulate these two things.

In part 3 of this series I’ll deal with actually using your camera, give a helpful example of the parts of an exposure (picture) and how they all work together, and talk about some of the less critical (but still important) features to look for on your camera. Finally, I’ll make some recommendations of cameras to look at that will favor various tastes and purposes.

Written by: Tony


As a designer by trade and a former professional photographer, there isn't much in the world of visual communication that I haven't worked on. From web projects, to museum interiors, to weddings and portraits, my career to this point has run the gamut of visual media. Born and raised in a sleepy town in southeast Minnesota, I moved to Nashville to pursue my education. I ended up meeting the love of my life and adopting the two best dogs this side of the Mason-Dixon line. I love two-wheeled transport, trying new food and am a bit of a gadget freak. I love a good book, and have music playing almost constantly. After over a decade in the same city, I'm quickly getting used to the idea of having no fixed address, and hope all of you enjoy my ramblings about our ramblings.

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Read comments (2)

  1. September 15, 2012 at 1:03 am
    Sep. 15, '12

    Based on picture quality, is better quality DSLR camera or compact cameras with the same pixel? Sorry, my english is very bad..
    Idea Addict recently posted..Cameras Based On Your Character

  2. September 17, 2012 at 10:43 am
    Sep. 17, '12

    waiting for part 3! 🙂

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