One of my favorite subjects is when I go to a local drag strip and work track side by the burnout box and starting line. You can get an idea of the area I'm dealing with in
THIS POST. I primarily used my 15mm Limited (max f/4) and 35mm macro (max f/2.8), but did break out my 18-135mm WR for a few shots too. I'm starting to window shop for something more appropriate for the track and so far kind of leaning towards the Sigma 18-35mm f/1.8 DC HSM Art lens due to good reviews on sharpness when shooting wide open. I also considered the Pentax smc DA* 16-50mm f/2.8 ED AL (IF) SDM lens, but reviews say it isn't very sharp unless stopped down. Because I shoot from afternoon until night, having a small zoom with a constant wide aperture is pretty much required in my shooting position. What has me flipping back and forth between those two is do I go for the extra sharpness of the Sigma, or the longer focal range of the Pentax at the expense of poor low light performance? I need a good wide angle ability, and having a bit more than 35mm on my K3 II would be handy. I know I can shoot at 35mm and crop in, but doing that on my current lens still loses a fair bit of quality if I need a tight crop.
I wouldn't be surprised if there are other options out there, so feel free to fire away any other suggestions, or opinions on those two. If these two had a baby and there's a lens out there that has the range of the Pentax but the sharpness of the Sigma, I'd love to know. I've never shopped for a lens before because I've only bought kits so far, so this is all new to me.