First things first: this'll be a quick and dirty post for photographers who might be considering the purchase of a 35mm lens. I shoot Nikon (a D700), so I bought the Nikkor 35mm 1.4, which has a hefty price tag, so I really mulled over the purchase quite a bit. Of course, I rented it first, which was worth the $35 or so, because then I could really know if I liked it.
Also, I should just come right out and say it: this 35mm lens is my new favorite, and I don't see that changing any time soon.
Of course, that's not to say that it should be every photographer's favorite lens, or even that it's the best lens out there. I'm a big believer that a) the best lens is the one that's on your camera, and b) the best lens depends on what you're shooting and how you're shooting it. That "how you're shooting" part is super key.
So, if I love the 35mm so much, what does that say about how I shoot? Well, I shoot natural-light portraits, mainly, and I love creamy bokeh and sharp-sharp-sharp images. I shoot fast, and I don't style my shoots, so I want the most natural and true-to-life images I can get. Go ahead and call my style "lifestyle" portraits, or whatever you like. The gist: I'm not trying to create images that don't depict at least SOME aspect of what it's REALLY like to be in my subject's shoes. Some of my subjects dress up or style themselves, but some don't. I like kids who dress themselves. Heck. I like kids in their jammies with scruffy bedhead. That's just me.
The 35mm fits that shooting style because it's just wide enough (as opposed to the 50mm) to work well indoors, and it won't distort the subject's face, as it's not TOO WIDE. Also, it does work well outside, because you can get a lot of interesting things in the frame that, again, you can't get in the frame with the 50mm. When shooting families up close or children near buildings, or kids or pets indoors, that extra 15mm of "wideness" can mean the difference between a pleasing composition and a useless image.
Also, one thing I think it does better than the 50mm (and I'm comparing it to that lens because so many photographers shoot with a 50mm as opposed to a 35mm) is that IT IS SHARPER wide open. So--it's true--you can open that f-stop to 1.4 and not worry that you might snap too many out-of-focus shots. (As such, this is a super great low-light lens.)
I might still snap on my 50mm in a field for a different kind of bokeh that I really do like, and I would definitely use my 105mm macro for newborn shots or shots of older individuals (such as high school seniors) standing and posing from a distance, but I really can't see taking my 35mm off that much. But, we'll see.
You might wonder why I don't just buy the 24-70mm, which gets rave reviews and covers a nice focal range. I have rented it. But. It's not a prime lens, and it's definitely not as sharp or as fast as a prime lens. And I like sharp and fast. So, I'm sticking prime around here.
One thing I've learned through the purchase of this lens is that, if you have the right tool for what you're doing, you can actually learn more about who you are as an artist. In other words, you can gain more VISION about what you're trying to accomplish as a photographer. Which is completely amazing, right?
So, cheers to you finding the right lens to hone YOUR vision.