DX vs. FX

On a recent trip to Central Oregon, we visited an incredible landscape. The lighting was so perfect, the composition just magically appeared, and I was quick to get the tripod out, click goes the shutter. What did I miss? The night before, I was doing some astrophotography of the moon, and was in Nikon’s DX format. Not (always) good if you’re trying to capture a vast panoramic view of a landscape…

But lets step back… DX mode is where the full-frame sensor, in Nikon terminology, FX, is cropped. This impacts a couple important aspects. First, it narrows the focal length by 1.5x. Thus, for example, a 100mm framed shot becomes 150mm, allowing for more “zoom” to occur, lens and body equal. Next, it also changes the minimum aperture by 1.5x as well (f/2.8 is now f/4.5 rounded). It also reduces the mega-pixels captured in the frame, making post-production cropping a bit less capable.

DX is by no means “bad,” in fact, the ability on a Nikon to interchange between DX and FX allows for a lot of capability, all with the same kit. For example, FX is great for capturing a full-framed landscape with many mega-pixels of detail. But, it doesn’t do a great job of really allowing close up shots at a distance. Such as with bird or other wildlife photography. That is why, switching to DX, you can suddenly allow you telephoto lens, already at 200mm for example, now reach 300mm.

The main point… know the camera’s abilities, the pros and cons, and always remember to ensure you have the right settings in-play before getting too eager to get a shot.

For more on DX vs. FX on Nikon cameras, here’s a great summary from Nikon: https://www.nikonusa.com/en/learn-and-explore/a/products-and-innovation/the-dx-and-fx-formats.html