Photo Tips Podcast: Do You Need A Fast Lens? #86
Do You Need A Fast Lens? #86
I am often asked the question, “Is a 2.8 lens or faster really necessary?” My arrogant answer has always been yes, most definitely YES! But as time has gone on, I am finding that I am softening on this position. The bottom line is that fast lenses are great. They tend to be sharper and of course they also gather a lot more light. And we are almost always looking for more light. However buying a fast lens is not just about spending a lot of cash, you will also need to decide whether or not you are willing to actually carry that much weight. So it’s a cost not only to our wallet but also to our back. The faster the lens the more glass it seems to require to gather that light. This often makes them 30-100% heavier than their slower counterparts. If you are young, tall and fit? It’s much of a problem. But as you get older and are faced with knee or back problems, it’s an issue. So when you are considering a faster lens it shouldn’t just be a financial consideration but a physical one as well. If carrying the extra weight is going to cause more problems physically then it is going to reduce your enjoyment of photography. Which means you’ll be shooting a lot less. It will also mean the distance between you and the car is going to get shorter and shorter, which means fewer and fewer great photo ops. Right now, for me I’m still willing to put up with the pain and suffering. But I don’t know how long that’s going to last.
But what about the question of lenses that are even faster than 2.0? What I find is that those who are shooting lenses faster than 2.0 are having a difficult time landing their focus at those wide apertures, because the depth of field is just too shallow. So often they are closing the lens back down. Before you jump to the question, “What’s the point?” do consider that these lenses tend to be incredibly sharp. But again they are incredibly heavy and the fact is that you will have to carry multiple prime lenses to make up for what one zoom lens will do. I am aware that there are a couple of zoom lenses that are faster than 2.8 but generally they are very poorly rated at the faster f/stop and you’ll have to close down to eliminate that problem. Then there are those who will argue for the 50mm 1.8 lens which is a very compact, lightweight and inexpensive. I find that this lens is most often used for portraits, in an attempt to achieve that shallow depth of field. But the fact is I can achieve that with a 70-200mm lens without any problems. So if I can do that that why would I carry an additional 50mm lens? And to be clear a 50mm lens is not technically considered a portrait lens, especially on a full frame sensor. Which further begs the question of why carry a nifty fifty when I already have a 70-200mm in my bag, and I have a lot more flexibility with my zoom lens versus the 50mm?
When we’re talking about fast lenses, I think there are a lot of things to consider well beyond the financial one. But the choice is personal and you’ll have to weigh the pros and cons.