Should I buy a used Canon lens with small scratches?

Maybe — a used Canon lens with small scratches can still be a good buy, but it depends on where the scratch is, how deep it is, what the lens is, and the price.

• Small scratch on the front element: often has little to no visible impact on photos, especially if it’s minor.
• Scratch on the rear element: more concerning, because it has a better chance of affecting image quality.
• Lens type matters: some scratches are more likely to be noticeable in certain situations, but the exact impact is hard to predict without testing.
• Price matters: a scratched lens should usually be cheaper than a clean copy, but there isn’t a reliable universal discount percentage.

Before buying, check for:

1. Actual photo impact — take a test shot at a few apertures and look for softness, haze, flare, or odd artifacts.
2. Scratch severity and location — a tiny front scratch is far less worrying than damage near the rear element.
3. Other issues — fungus, haze, dust, autofocus problems, and aperture issues can matter more than a cosmetic scratch.

If the scratch is only on the front and the lens otherwise tests well, it can still be worth buying for personal use. If it’s on the rear element or the seller won’t let you test it, I’d be cautious.