50mm 1.8g or 35mm 1.8g for D5500

mayboo

Hi, very new photographer having just bought a Nikon D5500. I'd primarily like to take pictures of my children as they grow- a combination of portraits and candid action shots. My question is the 50mm lens better or the 35mm? I bought the 50mm 1.8g as I read great reviews about it, but when I tried using it I found the background blur a bit difficult to get adjusted to. If one of my children is sitting behind the other in a candid close up, they are blurred. Apologies for such a silly question, but can you adjust the lens to reduce background blur to make the picture more 'in-focus' overall, particularly if you want some background features to be included in the shot? Or should I have invested in a different lens altogether? Thank you.

bruto

Background blur is directly related to aperture, distance and focal length. If you want to increase depth of field (decrease blur) with the same lens at the same distance, decrease your aperture (go to a higher F number). With the DX format you may start to notice a little overall softening at apertures smaller than f/11, owing to diffraction, but chances are good that for most purposes, especially people, you can go to f/16 without much effect. You can experiment, and decide partly depending on how big you're going to make your prints, or how much you intend to crop later. For a small uncropped print there's very little to worry about, and most of the time you're probably going to find that you get good results at about f/8.

Aperture priority is probably your best bet for making sure you get the aperture you want. You can use manual mode too, and keep an eye on things, or shutter priority, and adjust shutter speed to force your aperture, or you can use P mode and use the rear wheel to choose which combination of aperture and shutter speed you want. But A is simplest.

The shorter the lens focal length, the less the blur. A very wide angle lens has enormous depth of field, and a telephoto very little.

The closer you are to your subject the less depth of field and more the blur. Macro shots have almost no depth of field. Scenic shots of mountains and skies have lots.

Since depth of field is the issue here, background blur will depend greatly on how far a subject is from the background. If you put a person up against a brick wall, the person and the wall will both be in focus. If you put the person a few feet in front of the wall, a large aperture will blur the wall. Remember this when you do want to eliminate distracting background from a portrait. Try to keep near objects out of the frame. Sometimes it helps to get down low, and shoot upward to keep low objects and the ground out of the frame.

Once you're used to the behavior of the 50mm I think you'll find it very nice for portraits, because you can pretty well dial in your depth of field, and make backgrounds disappear as you choose. The 35mm will give a slightly more inclusive view from the same distance, and will give a little more depth of field (less blur) for the same framing. But if you have the kit lens, you already have that focal length included anyway, so when you simply need the field of view, you can use that. The 35mm is a nice lens, with good contrast, sharpness, and so forth, but for general use the kit zoom will do quite well.