Some kit lens deficiencies are easily resolved in post and some are just ugly to the core, or is that the iris. For today we consider the factors that can be sorted post shot.
The worst cases of VD ( vignetting disease) seem to occur at the wider end of things, with most kit lenses displaying considerable vignetting between 18-24mm. You may not actually see any vignetting if you're only shooting in JPEG mode, almost all cameras now correct this in processing, but again for Raw files you will need to roll your sleeves up.
The tip to take to the bank is, if shooting RAW files that will need distortion correction step back a bit and give yourself some wiggle room.
Normally the distortion is only really obvious if you are shooting objects with straight lines in them, for example architecture. I must point out that even many fixed wide angle lens have considerable distortion so buying an alternative lens may not solve the problem altogether. From an optical point of view this is a hard thing to eradicate via lens design and usually involves adding more elements to the lens, making it both heavier and far more expensive, and since it is relatively easy to fix in post it removes some of the justification for buying well corrected but expensive alternative lenses.
Currently Photoshop offers a work around for fixing this issue, but an auto option would be just peachy
|And now we have our finished specimen, the CA is gone, the corners sharper, vignetting removed and the distortion but a memory. Of course it is a little cropped due to the distortion corrections, hence my tip to shoot a little wide if possible.|