For when you’re doing groups and street, but want it fast.

This focal length is pretty common, maybe second only to 50mm. Easily the most useful prime for most people’s street photography and group photos. Honestly, if you already have a reasonably fast zoom, this doesn’t give you much benefit.

If you don’t know why you need f/1.4, don’t buy this. It’s not a small or light lens by any means. Even if you can articulate why you need it, ask yourself if Sony’s E 35mm f/1.8 OSS version, which costs half as much, is less than half the size and weight, and comes with image stabilization will do the job. Unless you’re just reading specs, it likely will.

If you do need the extra quality and speed, well then, enjoy it.

For when you must have macro, but also want portrait.

This lens is big, heavy, and slow compared to the same sized portrait lens, but it still takes insanely crisp shots. It is of course the (mostly) only way to make macros, so if you want macro and zoomed in narrow depth of field portrait shots, and can only afford one lens, this is the one.

Landscapes & Interior Architecture

Nuff said. You really need to go ultra wide-angle for certain things. If landscapes and architecture shots are your thing, this would be my third lens, after the 50mm and 28-200. I would get this before a portrait lens because the 28-200 can do portraits, unless you really need that narrow depth of field.

For when you just can’t get enough resolution.

At 61 megapixel, this is quite impressive, especially if you wish to have really large prints, or aggressively crop. As this is the R(esolution) model, don’t expect top of the line 4k60 10bit video. While it can do 4k30 8bit, this is strictly aimed at high resolution.

There are a million reviews out there, so I won’t go into it, other than to say this is a great camera to get, especially since the a7R V was just announced yesterday.