Lens Tests

[Brad Rippe]

Hi Everyone,

After reviewing the excellent lens tests performed and posted by Chris Perez and Kerry Thalmann, I noticed that many lenses tested showed signifiant variation in resolving quality among samples of the exact same lenses by the same manufacturers. One example is the Schneider 110 mm SS XL lens on the list. There are 3 tested with very different results. My question is this: Are there tests we can perform ourselves on newly acquired lenses? If we determine we have a dud, what is the return policy for used and new lenses? Are there lens testers out there who can perform this test if it requires special knowledge or equipment? I suppose I could just start using the lens and see how it performs, but it might be more effecient to know its quality before spending (or wasting) time attempting to make sharp images.

Thank You,
Brad

[Craig Schroeder]

I've culled a few things over the years by using the old Modern Photography Lens Test Kit. I never got too hung up on splitting hairs about which good lens was sharper than another but I think everyone has a curiosity about what they interpret from actual usage. Some simple testing can confirm suspicions. I've got the manual for the testing at

Go Here

It's interesting reading and one only needs a set of the targets to put it into use. It has some ideas for measuring astigmatism and field curvature, too. To do this correctly, you need to truly control camera movement, vibrations, critical focus, etc. It's pretty ancient and certainly doesn't give the total information about an optic but it's been interesting and fun to play with over the years.

[Andre Noble]

"Schneider Super Symmar XL f/5.6 110mm

f/11 24 38 42

f/16 42 48 42

f/22 54 48 42

430g Copal 1 1485xxxx 1990's "

This is the lemon lens of the three. You would be underwhelmed with it's performance after a quick general test, and hopefully get up the courage to return it.

[Paul_5410]

Hello folks, I just wanted to say thanks to Craig Schroeder for posting the pdf file I am downloading it now and looking forward to reviewing it. . . Paul