HD Pentax-DA 55-300mm F4.5-6.3 PLM WR RE

Vignetting

Vignetting is the darkening of corners that occurs in images shot at wide apertures. The effect is usually especially prominent in lenses with very wide maximum apertures, and those with extreme focal lengths. Given the HD Pentax DA 55-300mm F4.5–6.3 ED PLM WR RE's focal range and narrow max aperture range, we didn't expect it to be a huge issue here.

Vignetting Test

Taking advantage of our location in the beautiful desert southwest, we used a cloudless blue sky as our canvas for the vignetting test. We simply pointed the camera at a section of the sky high and away from the ground, and opposite the sun. Then we fired off shots at 55mm, 120mm, 200mm, and 300mm, using all f-stops from wide open to f/16.

All images were shot in JPEG + RAW, and we used the RAW files to judge the lens's performance.

	55mm	120mm	200mm	300mm
f/4.5			N/A	N/A
f/5.6 or f/6.3
f/8
f/11
f/16

Verdict

Vignetting is visible but not severe when shooting wide open at 55mm, but becomes insignificant by f/8. The situation is a little worse at 120mm, where it doesn't really go away until f/13, and 200mm, where you have to stop down to f/10 or so. Vignetting is, predictably, worst at 300mm, where it doesn't completely go away even at f/16.

The 55-300mm PLM performs well for a consumer-grade zoom, with only moderate vignetting at its most vulnerable settings. In most cases, this corner darkening won't be a serious issue, and when it does become a problem, it's easily corrected either in-camera or through your editing suite of choice. The 55-300mm PLM also offers noticeably better vignetting performance than its predecessor, which is a heartening development.