As with everything else in photography, lenses are simply tools used to create a specific look. So when you walk into a scene, or are preparing for a session, you’ll want to first think about what you want the final image to look like. This will help guide the decisions you make. For now, we’re just focusing on lenses.
When you have a SLR/DSLR/HDSLR, you have the option to choose different lenses. Point and shoot cameras require mini adapter lenses to get a similar option. But we’re going to stay with interchangeable lenses here.
There are obviously tons of lenses options out there varying in brand, zoom, speed, and price. So what’s the difference and what does it mean for you? Well, it depends on what you’re doing.
Lens glass: With lenses, glass is a very critical factor. Lower end lenses will work out just fine for the average person, but the professional often requires a much higher quality glass. The difference in glass could be the difference between a clean, clear, vibrantly colored pictured and one that is dingy and off-colored. Some brands are better known for their glass than others, such as Nikon. But even Nikon has both higher and lower end glass options. A brief reading on each glass type will let you know which is better. Of course so will the price.
Lens speed: If you have ever been confused when someone talks about how fast a lens is, done feel bad. I remember when I knew nothing and assumed it referred to how fast the lens focused on a subject. What it really refers to is the aperture rating of the lens. For example, a lens may be referred to as a 2.8 lens, or a 4-5.6 variable lens. The lower the aperture rating, the better the lens, and the more expensive it is. This is not something the average person will need to worry about unless you are a serious hobby shooter working in low light or needing shallow depth of field on a regular basis.
Prime verses zoom: Most people are immediately aware of what a zoom lens means. So the opposite would be a non-zoom lens that has only one focal length. This would be a prime lens. Where a zoom lens is convenient, and prime lens is sharper and cleaner. Most people assume buy one really big zoom lens (such as Nikon’s 18-200) than lug around a bunch of primes. But be aware that lenses with these larger ranges usually sacrifice on quality. Again, probably nothing the average person will notice, but will drive the professional crazy. My personal favorite zoom lens is Nikon’s 24-70 2.8 lens.
Perspective Control: Ok, this will be really different to most people. A perspective control lens (PC lens), also called a tilt-shift lens, is a really cool fun toy. It can be related to a lens-baby (for those familiar with it), but it’s not completely the same thing. These lenses are prime lenses that are manual focus only, and are very expensive. The user is able to rotate, pan, and shift the lens in order to achieve the desired perspective and depth of field.
Ok, so you know a few things about lenses now, now you need to know a little more about how to make the best use of them. So let me share a few things more for you.
Protection First! Have a UV or Haze filter on your lens at all times unless you’re replacing it temporarily with a different filer. Filters protect that expensive glass you just paid for and help give you a better image. Different filters do different things, so check out websites such as Tiffen and see what kind of fun things you can get to play with.
Be conscience of your shutter speed! The general rule is that your minimum shutter speed should be the same or greater than your focal length. So if you’re zoomed out to 200mm, then your shutter speed should also be 200 or faster in order to properly stop motion. Again, this is a general rule that everyone breaks, but know you can before you try. This is where faster lenses are handy.
Think about subject compression! I probably had you up to this point, so let me try to get a simple explanation and some example photos. Imagine you are photographing two people, and one is standing ten feet behind the other, but you’re only focusing on the individual closest to the camera. Compression how to do with how close or far apart they appear from each other in the final image. A wider angle lens (such as 24mm for example) and closer to subject position (say 5 feet) will make the two appear much farther apart. If you use a longer lens (such as 200mm) and are father away (maybe 20 feet), then the two will appear much closer together in the final image. This does not mean they will both be in focus, so don’t confuse compression with depth of field.
The image on top was with a 24mm at less than 5 feet from the tree. The bottom image was with a 200mm at just over 10 feet away. Same tree and same background, but different compression.
Now you know a bit more than you probably did before about lenses, and hopefully have a slightly better idea of how to choose a lens that will best suite the job you need it for. Remember the average person that is just taking vacation photos and capturing family moments is probably just fine with a basic low-end lens with a simple range zoom of between 24-80-ish. Just remember that it is a lower end lens with limitations, and put a filter on it for goodness sakes!