Updated 2nd December, 2021 by @cacatman
I've always wondered how people rate their lenses. Is there an objective measure?
At the request of @TheStig, I'm going to give it a shot.
A rating without pictures of actual lens is not helpful either. Here’s a great guide by @saulsaul which shows how to take good lens pics - Lens condition pics (thanks @Oak Heel for the heads up).
Please comment with reasons if you agree/disagree with the below scale. I will adjust accordingly (with acknowledgement and grateful thanks).
Personal Opinion re: Weighting of Defect from Best to Worst
No defect
Defect that cannot be seen when mounted (e.g. on edge of lens that is hidden by frame)
Defect that does not affect field of vision and not seen externally
Defect that does not affect field of vision and seen externally
Defects that affect field of vision and not seen externally
Defects that affect field of vision and seen externally
Proposed Rating System
10/10 - Factory perfect without blemishes
9.5/10 - Any imperfection that cannot be seen on correct mounting of lens
9/10 - 1-2 swirl marks not able to be felt with fingernail that are outside the field of vision
8.5/10 - >2 swirl marks not able to be felt with fingernail that are outside the field of vision
7.5/10 - "Pock" marks/divots on lens <0.5 mm outside field of vision
7/10 - Any scratch able to be felt with fingernail <0.5 cm in diameter outside field of vision
6/10 - 1-2 swirl marks not able to be felt with fingernail that interfere with the field of vision
5/10 - > 2 swirl marks not able to be felt with fingernail that interfere with field of vision
5/10 - Delamination of any kind on edge of lens
4/10 - Any scratch able to be felt with fingernail <0.5 cm in diameter that interferes with field of vision
Still working on this!!! But taking a break to do some other work!
I've always wondered how people rate their lenses. Is there an objective measure?
At the request of @TheStig, I'm going to give it a shot.
A rating without pictures of actual lens is not helpful either. Here’s a great guide by @saulsaul which shows how to take good lens pics - Lens condition pics (thanks @Oak Heel for the heads up).
Please comment with reasons if you agree/disagree with the below scale. I will adjust accordingly (with acknowledgement and grateful thanks).
Personal Opinion re: Weighting of Defect from Best to Worst
No defect
Defect that cannot be seen when mounted (e.g. on edge of lens that is hidden by frame)
Defect that does not affect field of vision and not seen externally
Defect that does not affect field of vision and seen externally
Defects that affect field of vision and not seen externally
Defects that affect field of vision and seen externally
Proposed Rating System
10/10 - Factory perfect without blemishes
9.5/10 - Any imperfection that cannot be seen on correct mounting of lens
9/10 - 1-2 swirl marks not able to be felt with fingernail that are outside the field of vision
8.5/10 - >2 swirl marks not able to be felt with fingernail that are outside the field of vision
7.5/10 - "Pock" marks/divots on lens <0.5 mm outside field of vision
7/10 - Any scratch able to be felt with fingernail <0.5 cm in diameter outside field of vision
6/10 - 1-2 swirl marks not able to be felt with fingernail that interfere with the field of vision
5/10 - > 2 swirl marks not able to be felt with fingernail that interfere with field of vision
5/10 - Delamination of any kind on edge of lens
4/10 - Any scratch able to be felt with fingernail <0.5 cm in diameter that interferes with field of vision
Still working on this!!! But taking a break to do some other work!
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