I have a Canon EOS 2000D DSLR (crop factor approximately 1.6). As the lenses, I have 18-55 mm IS zoom (f/3.5-5.6) and 50mm non-IS fixed focal length (f/1.8), and have ordered a 55-250 mm IS zoom which hasn't arrived yet.
I'm having a hard time selecting between Canon EF 35mm f/2 IS USM and Canon EF 28mm f/1.8 non-IS USM lens for the second fixed focal length lens.
The prices of these two lenses are approximately equivalent, yet the prices are so high (at least compared to the 50mm lens -- they are 5-6x as expensive) and the focal lengths are so close together that purchasing both is not an option. The dimensions and weight are so close to each other so that I can't use size and the weight as the deciding factor. Both use USM focus motor so no difference there either.
28mm has a wider aperture (f/1.8) than the 35mm (f/2), relatively speaking, and a 28mm lens is more distinct from 50mm than the 35mm lens. Also, 28mm offers a wider angle of view, which I can always crop to be equivalent to 35mm angle of view.
However, the 35mm lens has image stabilization. I'm not 100% certain that I absolutely need the image stabilization. At least for typical light levels, I often manage without IS on the 50mm lens, and IS on the 35mm would therefore be even less necessary at these light levels.
However, the 35mm lens because of the IS would expand my options towards low-light photography when not using a tripod. I live in a country where the length of daylight is highly variable: in the winter on weekdays, I don't have options for outdoors photography except when it's so dark out that the streetlights are on (my profession is not a photographer, and my working hours are regular). So far, I haven't tested the camera outside when it's dark, because I have had the camera only for little more than a week, and it has been raining often. So I really don't know how much benefit IS would be.
Let's also say that I have absolutely no plans whatsoever to purchase a full frame camera in the future. 28mm would be perhaps a bit too wide-angled in the full frame camera, but I don't use this as the deciding factor as I don't have full frame plans.
How should I choose the next lens for my situation? I already listed some similarities and differences of the lenses, but are there some I failed to list? Which lens overall would be better to complement the 50mm non-IS lens?
Or should I instead invest in a better zoom such as 17-55mm IS f/2.8? It would cost 1.5-1.6x as much as the 28mm or 35mm lens, weigh more and be larger, but would be much more useful in low-light non-tripod outdoor photography than the 50mm non-IS f/1.8 or the 18-55mm IS f/3.5-5.6.