What are you buying? Why choosing the right equipment isn't always a matter of performance specs.

This is something I’ve been meaning to post about for a while and I’ve written down thoughts at various times in the past but never put it all together in to a single article. Finally, here it is!

One of the things I’ve seen time and time again is the constant comparing of various lenses, camera bodies and other bits of photographic equipment. To some extent these things are good, for one they can provide useful information to someone who may be finding a certain lens isn’t performing as well as they would have hoped. They also help to explain and expand the understanding of what defines the performance of a piece of equipment. The downside of the constant fretting over specs and performance figures like distortion and MTF, something called measurebating in the community, is that it often overshadows the most important factor in making new equipment buying decisions.

When you’re buying a new lens or camera, the biggest question that I think needs to be asked is “why?”   With cameras you may find that you need a better AF system for tracking action, or a larger and higher resolution sensor for making the detailed prints you want. Part of figuring out why you want to buy a certain item involves understanding what you’re missing and what that new piece of gear will do to solve that problem. For example, my own personal experience has led me to the 5D Mark II as the ideal upgrade for me at this point. I don’t need fancy AF systems, my main concern is that the camera is a light tight box with great imaging performance. The 5D Mark II accomplishes that and offers the right improvements in the right areas for my uses. That doesn’t mean I don’t understand the complaints about AF and that I’m not sympathetic to those issues, I think the AF system in the Mark II is a mistake as well and understand why many people look at the Nikon D700 as the better camera. There are people approaching these decisions from all angles and for me the D700 would not offer the improvement in resolution over my current equipment that I’m looking for.

In the lens world there are many examples of these sorts of trade-offs, even within a single brand. I’ll use one example I’m very familiar with because I own one of the lenses in question. This notorious debate involves the 24-70 2.8L and the 24-105 4L IS. These lenses are both in the same rough ballpark in terms of price and both perform quite well, although according to the measurebaters the 24-70 2.8L is supposedly the better lens of the two. The problem arises when people ask which they should buy because both of these lenses have distinct strengths that allow each to satisfy certain needs that the other cannot.

It seems that multiple times a week on any of the bigger photography discussion sites you’ll see questions asked about which of these lenses is the better lens. Inevitably you get a whole lot of people showing up supporting the 24-70 2.8L and another big group supporting the 24-105 4L IS. The person who asked the question dutifully reads and absorbs all these opinions and eventually makes a decision, often guided arbitrarily by either how many people show up in support of each lens or by one wordsmith who weaves a tale of wonder about how one particular lens is better than the other.

The problem with this situation is why haven’t they talked about what the photographer shoots or his or her shooting technique?  If the person is asking which lens is better have they thought about that in advance?  I’ve always believed that the weaknesses in your available equipment will become more apparent as you shoot more. If you’re entertaining the thought of spending more than $1000 on either of these lenses you should hopefully have an idea of what you tend to shoot and how you will probably use the lens.

If you shoot moving objects, like people, the faster lens makes a pretty strong case for itself. IS can’t freeze the action but the stop faster 24-70 just might be enough to do it. If you’re not shooting moving objects then you can look at other factors, like do you want shallower DOF or do you need a lens that reaches as far as the 24-105?  The most significant difference between these two lenses with an impact on use is that one is a 2.8 and one is a 4 with IS. That IS is good for around three stops, meaning that you have a theoretical advantage of two stops better handholding ability over the 24-70 2.8. If you shoot things that don’t move and if you tend to shoot in lower lighting conditions like I do, the 24-105 4L IS sells itself pretty easily. When I consider the fact that I will be shooting in the f/5.6 to f/11 range if I can help it, there’s no advantage to the 24-70 2.8. In fact the 24-70 2.8L would mean missed opportunities for me even if the shots I would be able to take with it might exhibit a little less distortion at the extremes of the zoom range.

Two words in the last sentence are really the point of this entire post. You will be best served looking at a potential purchase by thinking about what is best “for me.” If you must ask on a forum, give some information about your shooting style, techniques and the types of subject matter you intend to shoot with it. Post a few of your photos and talk about what could be better with your equipment. Hopefully someone will have the insight to explain the strengths or weaknesses of each lens, camera, flash or whatever given those particular conditions.

If you don’t know what to buy and why you’re buying it, you probably shouldn’t buy it.