Is the difference between an f/2.8 and an f/4 lens really worth the price?

You’re buying a new lens and there are two versions available of the same focal length. Do you go for the f/4 aperture, or do you splash out an extra grand for two extra stops of light, buy the f/2.8 lens and walk away smug that you’ve bought the ‘best’ option?

It’s a common question and most photographers will tell you that you ‘get what you pay for’, especially when it comes to glass. However, it’s not that straight forward. Obviously it depends on what and how you shoot. In this video Nigel Danson takes a not very scientific approach to discovering the answer to this question. He is a landscape photographer so the video pertains mostly to that genre, although it’s an interesting experiment no matter what you shoot.

Nigel is testing out the Nikon 24-70mm lenses in both apertures. Now generally for landscape photography you don’t shoot wide open very often. So it makes sense then that there would be very little difference between the two lenses. He is largely shooting at f/11 and is also focus stacking in post. Surely then we shouldn’t see much of a difference, at least not a thousand dollar difference.

Size matters

Ignore what everyone tries to tell you, size really does matter! One major difference between the lenses is indeed the physical size. The f/4 lens, having less complicated innards (that’s my technical term!) is of course a smaller and lighter lens. This could be really useful if you’re a landscape or travel photographer. Just keeping weight and dimensions down could make the difference between taking just one lens or more out with you.

Sharpness

In order to really evaluate the difference between the lenses, Nigel has printed identical images out. He actually had to write on each print which one was taken with which lens. That should tell you something about the amount of visible differences.

The f/4 lens is just ever so slightly softer around the edges of the image than the f/2.8 lens. The middle of the image is pretty much identical. Nigel says that overall for his needs, the f/4 suits him well and he will generally pick that one over the larger f/2.8 lens unless he’s not walking far.

His parting thought is an important one for any of us that suffer from GAS (Gear Aquisition Syndrome). More expensive equipment will not make you a better photographer. If you really need the option of shooting wide open, for instance if you are a concert photographer, then by all means, go ahead and spend the money. But you should know if you really need that. If you’re generally shooting in the mid-range of apertures and a lighter weight lens would be beneficial to you, then perhaps you don’t always need to buy the most expensive option.