teekay wrote in post #17562832
In contrast, I don't see any vignetting at all with similar shots from my SX50 even at full zoom (1200mm equivalent) at the same aperture. Why?
Because sensor size. The sensor on your DSLR is ridiculously large compared to the SX50. Here's a comparison chart:
See that red box? That's your SX50, with a 1/2.3" sensor. Your DSLR is the big blue box. Thus, it takes little to no lens to project a full image onto your SX50 sensor and a much bigger lens to project a full image onto your APS-C sensor.
Consequently, that's also why that tiny little lens can get you "1200mm" of zoom, because of its extreme crop factor of 5.2. So that lens is actually "shorter" than your 55-250 STM, at ~230mm You just get "1200mm" because of the insane crop factor. (APS-C sensors have a crop factor of 1.6, so your 250mm is equivalent to 400mm on a full frame sensor.)
teekay wrote in post #17562832I don't see any tool in DPP for correcting vignetting, nor is there one in my favourite editing software, the venerable Paint Shop Pro9. Is there such a tool in LR?
LR does correct vignetting, yes. That said, DPP should have that capability, but it's probably called something different - Peripheral Illumination Correction. That should be an enable-able feature on your camera for SOOC JPEG images and definitely should be present in DPP.
From Canon:
Peripheral illumination
Otherwise known as corner-shading or vignetting. Digital cameras are very susceptible to light not striking the sensor at the correct angle, and with some lenses it is possible to see a slight fall-off in the corners of the image where it looks darker than the rest of the frame. This adjustment aims to even out the lighting across the frame.
