16 December 2014

Do small scratches on lens front element affect the picture quality?

Long time ago I bought used Canon 24-105mm lens with scratched front element. Scratches were 2-3mm long and I thought they won't affect picture quality at all. And indeed I didn't notice anything until I started the product photography.


I couldn't find any other defect or dust other than those two scratches, so picture quality most likely is affected only by them.
Scratched front element of Canon 24-105mm


Below are two pictures taken with my scratched Canon 24-105mm. I used widest and narrowest apertures - f4 and f22, respectively.
Monitor: Canon 24-105@f4
Monitor: Canon 24-105@f22
Zoomed in. 24-105@f22
Bookshelf: Canon 24-105@f4
Bookshelf: Canon 24-105@f22
Zoomed in. 24-105@f22


Next test picture was taken using Canon TS-E 24mm II with f22 aperture to see if spot on pictures is really caused by the lens or sensor. I tried two more lenses and there was no spot on pictures.
Monitor: Canon TS-E 24mm II@f22














Next pictures are good examples as well. The picture with the tripod, contrast was increased so spot is even better visible.
Lens: Canon 24-105@f22
Tripod: Canon 24-105@f22
Optical drive: 24-105@f22
Changing front element costs around 100-150€. I've decided to get rid of these lens, but got much less money I spent, probably because I was more honest than the buyer I bought from, who didn't even mention a word about the scratches.

Verdict:
Small scratches won't appear on large apertures, but on narrow, even such small scratches are spotable, especially making product photos.

No comments:

Post a Comment