Now you guys know I don’t like to get overly “techie” when it comes to gear, but this month I wanted to talk about something that is for the most part ignored. Our lenses.

What about a lens can control the look of an image? Obvious answers come to mind regarding perspective, viewing angle, and even the use of tilt shift lenses can make a dramatic effect There are however some hidden aspects of a lens that get lost in the fog when people make lens selections for a project or make a new lens purchase. Often times lens selection can be a bit more tricky when using strobes rather than using through the lens (TTL) metering. This is why understanding the effects our lenses can have on an image is important. Lets think about some of the reasons why lens choice really makes a difference when using strobes.

PROBLEM: One thing by far is the use of non-professional zoom lenses. What I mean by “non-professional” is that the aperture of the lens actually changes when the lens is zoomed in and out. A lot of people do not realize the impacts this can have when shooting with strobes and how much images processing tweaks are needed to adjust under exposed images. 

Lets look at one of Nikons most popular lenses, the 18-200mm f/3.5-5.6 G ED-IF AF-S VR DX Lens. A great lens that has a nice coverage however the devil is in the details. The features that make the lens compact and lightweight  also are what make it difficult to use for flash photography. The fact that the lens changes sizes as it is zoomed in and out is what also causes the variable aperture. When we talk about a fixed lens we talk about a lens that is affixed size and therefore also has a fixed maximum aperture. So having a smaller lens that is easy to store away and covers a wide zoom range also comes with the downside that the aperture does not remain constant when the lens is zoomed or widened.