Originally posted by audiobomber A portrait lens uses a slight telephoto focal length (often quoted as 70-105mm in 35mm equivalent) to produce a mild compression in perspective, which is generally seen as flattering to the subject. It's not a hard and fast rule, just a recommendation. With the setup shown in the photo, it doesn't really matter. You're far enough away that the subject's face won't be distorted.
You asked about shooting landscapes, low light and portraits and I recommended the 50mm and your kit lens. I would use a standard zoom for the photo you showed, at f8-f11. You don't need a fast lens for a photo like that. If you're trying to shoot a portrait with a sunset in the background, you'll need to get a little fancier than just using a fast lens.
Indoors, I find 35mm is crowding the person and taking in more of the surroundings than I normally want. Others say the 50mm is too long for indoors and favour the FA 35mm. I have both but I prefer the 50mm 1.4. A kit lens and fast 50 will cover the uses you've listed quite well, IMO. I bought the 35mm because 50mm was too narrow for shooting in crowded museums. I wish it was 28mm. I have a 28mm 2.8, but it's too slow.
Thanks,
Your response is helping me get a clearer idea in my own mind of what I want to try to achieve.
In my OP I never used to word "portrait" I said photos of "people". Everyone wants to shoot a portrait sometimes, but I' tend to be attracted to people in a setting. Thus I might be trying to capture an abandoned factory with a person in it, rather than taking a portrait of a person in an abandoned factory. Actually, I'd like to capture both of those images in separate photos. The 50mm would be ideal for the portrait but a normal or slightly wide lens might be best to capture the image of the abandoned factory with the person in it.
Low light: Maybe I didn't give enough examples but, I am often drawn to scenes that are "poorly" lit. I attempted several shots with the kit lens where the only choice was f4.0 at 1/50. I was very disappointed with the results and stopped taking pictures. (Reflectors or fill flash might have helped.) The 18 - 55 kit zoom seems happiest at f8 - f 11 I think, and is not so good wide open with a slow shutter ;-)
If it weren't for budget I would get a fast zoom or a traditional set of 3 lenses maybe 21, 35 and 50mm
That's why I was thinking the 35 mm would be usable in most settings. I am starting to lean towards the 50mm and accepting that there are some shots I just won't get. I do still have a film camera, with a fairly fast normal lens, maybe I should just throw it in the bag and use it to fill in the lens gap ;-) Hell, that almost makes sense.