Thinking about getting a cheap wide zoom. Keeping this cheap as it wont be a lens I use everyday. If you are a shooter that will shoot at the widest of these 2 lenses and always at f4 (maybe sometimes using a bit of the zoom), would you just go for the cheaper 15-45? Im only concerned about image sharpness/quality for the most part. Will be using this for ho-hum controlled group shots at weddings so I dont need good build quality or AF speed, or bokeh etc.
Have to agree that the 15-45 isn't in the same class as the 18-55. Although the 18-55 is considered a kit lens, it really is much more than that. Since you said you're concerned mostly with image sharpness/quality, then between these two lenses, the 18-55 is the much better choice.
I'll put in a post in favor of the 15-45mm, for image quality. I currently own it, and have previously owned the 18-55 and 16-50 II.
I find the 15-45mm quite sharp particularly at 15mm, even wide open in the center, with the edges sharpening up as you stop down to f/8.
I've found the 15-45mm overall sharper and more consistently sharp than the 16-50.
The 18-55's advantages are primarily aperture, bokeh, and ergonomics.
Used as an f/8 and be there lens, the 15-45mm is great and compact. If you're going to shoot wide open a lot for more subject isolation, I would definitely take the 18-55 instead. Don't really have a use I would prefer the 16-50 for.
For me, the size and range and image quality stopped down makes the 15-45 an ideal choice for light and compact carry on a small X body, making a better all around camera than an RX100. I don't mind the ergonomic trade-offs and aperture sacrifice in that space.
