How do you check whether the lens is good or bad copy? [Archive]

View Full Version : How do you check whether the lens is good or bad copy?

fiery360

15th of June 2005 (Wed), 20:42

In this forum, I read several posts where one stated that his/her lens is good copy or is bad copy. How do you check this? What are some easy tests I can try? I am very curious to find out what people are doing to test the lens quality. As a beginning amateur, I don't think I can tell the difference.

I have following equipments:
Canon XT
50mm f1.4
28-135mm
75-300mm USM
Kit lens

Thanks

velvetjones

15th of June 2005 (Wed), 21:29

If you can't tell the difference, then don't worry about it! ;)

Your stuff is probably ok...people usually just do basic tests with photos and enlarge them to 100% and see how sharp they are. It is best to use a tripod for this particular and pretty basic test, so that you rule out any chance of camera shake.

tim

15th of June 2005 (Wed), 22:56

With this (http://www.canon-dslr.com/Canon_Jan05/Canon_SLR_Focus_Test.htm).