Lenses: Sample variation

It is well accepted from experience in the past that there is some

sample variation in the manufacturing process of lenses. many people

seem to agree that is is specially observed in very wide angle lenses

and complex zoom lenses. many of us think that sample variation is

less severe with the more established (and more expensive) brands as

e.g. leica, zeiss, canon or nikon.

 

my question is, if there is any recent study on sample variation as

one might expect that with more advanced possibilities for quality

control sample variation may today be less of an issue. any

information availble of specific brands quality control?

 

any comments other than speculation?

 

cheers

walter

You know, I wonder about this. I have a digital rebel and got a 70-200 f4 lens and didn't think it was as sharp as I expected. Sent it and the camera back to have it callibrated. Now I'm thinking of getting a 300 f4, and maybe a macro lens and wondering if I will need to have those callibrated as well? What are your thoughts? Virginia

You can go to the Zeiss.de site and see exactly how their lenses are tested. The reason that there is NO sample variation among Zeiss lenses is that they do NOT sample. Every lens is tested and every lens must meet specs or it doesn't ship! You pay extra for that kind of assurance.

A lens may meet the manufacturer's specifications, but that doesn't mean that there is no difference from sample to sample. There are tolerances allowed on everything from the chemistry of the various glasses to the excentricity of the mounting. In the worst cases there is something called "tolerance build-up" where many of the allowed errors contribute to an out-of-spec final product, though this should be caught in the final testing. If you have access to old "Modern Photography" mags, you can sometimes find variations in "identical" lens tests when mounted on different model cameras from the same manufacturer.

One would like to think that with modern manufacturing methods and the general consumer expectation of consistancy would ensure that the latest lenses are the most consistant ever.

<br>I deal in 2nd hand camera gear and for my personal interest i test alot of the lenses that come through.I get enough recent model,good condition canon kit zooms to make a valid comment on them....and they do seem to be VERY consistant

<I>"general consumer expectation of consistancy"</i>

<P>

Consumers dont expect consistancy! They expect bright and shiny things in colorful packaging.

<p>

Pros(or people with OC) expect consistancy, which is why they pay more for pro-film, or anything else.

LOL,yeah maybe i said that all wrong