It’s been a while since I posted my last tutorial / how to, but it’s nice to answer your questions 🙂
This is not a scientific approach of some kind; rather my personal opinion on how you can choose the best lens(es) for you. Remember that different lenses suit different types of photography.
First of all – as I may have mentioned before – once you learn anything about cameras, you can be sure that the lens can be far more important than the camera body. Choosing a lens beyond the kit lens will broaden your photography perspective in an amazing way. Whereas changing the camera body without realising what the lens does may be ineffective.
You need to understand Focal Length
The focal length is the distance that lens zooms in on the subject. The higher the number, the larger the zoom. Easy, right?
The typical professional zoom lens is the 70-200mm (less angled perspective but higher focus on one point only), and a wide angle lens is generally between 10-24mm, giving a full perspective of the surroundings.
A detail: a full-frame camera (i.e. Canon 5D Mark III) has a different sensor than a cropped sensor camera (i.e. a Canon 70D or 600D). These last automatically take in less of the field of view in front of it, zooming the perspective of the shot by almost 50%. For example, a shot taken on a 50mm lens with a cropped sensor camera will look more zoomed in than when taken with the same lens on a full-frame one. The first shot has the image cropped by 1.6, meaning that a 50mm shot would be the similar to a 80mm shot on a full-frame: the sensor is cropped by 1.6, so if you multiply the 50mm x 1.6, you get 80mm (the actual result on the photo).
Check these pictures for a visual example:
Now, understand how much light you get – Aperture and f-numbers!
Apart from the focal length, you need to know what aperture is. When getting a lens, there’s a number after and “f/” or “1:” (for example 50mm f/1.8 or 50mm 1:1.8). The following number(s) is(are) the aperture of your lens.
What you need to know: the lower the number, the more light comes into the camera, because the aperture of the diaphragm is higher.
Smaller number = Bigger hole =Mmore light and less focus room.
Aperture seems like a scary word, but it isn’t.
As I’ve mentioned, lenses have an aperture number, like the Canon 50mm f/1.8. This amount indicates how wide the lens can open to add in light. The catch is that the wider the lens is open to take in light, the less of the photo it will focus on.
For example, if you are taking portraits and you want a nice, blurred out background, you’ll want to use a lens with the ability to take photos in low light or low aperture like f1.4 to f/2.8.
The 50mm 1.8 (photo on the right) or 1.4 (photo on the left) is a great portrait lens for this reason. It can take in a lot of light and blur out the background in tight spaces, whereas a lens that is f/3.5 or higher will not give you the same blurred background unless you have a lot of distance between yourself, the subject and the background.
On the other hand, if you’re taking pictures of landscapes with many layers of interest (mountains, for instance), you’ll want to go with anywhere from f/15 on, to focus on all the full depth of scenery instead of just part of it.
Which angle to pick?
Here’s a list of how it works:
Wide Angle: A landscape or scenery lens that gives a full view perspective, like 10mm.
Standard: A lens with a view similar to the human eye; a kit lens.
Zoom: A lens with a cropped in view, like 70-200.
Macro: A lens with the ability to focus on objects very close to the lens and in detail, like the Canon 100mm.
Since most cameras come with a lens in the standard range (often a 18-55mm), I’ll leve you three options to consider.
50mm f/1.8 STM – This is perfect for portraits and still life or nature photography; it’s a bit over expensive but really great value. If you’re looking for something a bit sturdier, the 1.4 version is a bit better. But “to go”, the 1.8 does the job.
28-135mm or 24-105mm – These are great for gatherings where everything is fast paced and you can’t move around a lot of have room to do it, because it shoots fast and allows to focus near and far quickly.
70-300mm f/4 – This it is larger and heavier that the previous lenses but it’s a fantastic lens for events that you may apply a zoom lens to. It’s great to shoot on a distance. If you can afford the 70-200mm, even better. It’s sharper than the 70-300mm
So what now?
Buying a lens is always an investment, so it’s important for you to decide what and when you’re going to use your lens. Choose wisely, check and test lenses if you’re divided and make your choice 🙂