[dycz]

Hi guys,

I just got my lens (tamron 28-75 f2.8) from the cleaning services due to slight fungus inside the lens. Before, even with fungus, the lens was sharp and contrasty wide open. But after it was cleaned (professionally), my shots wide open, starting from 40mm-75mm, were somewhat glowy (or lil foggy). The sharpness and constrast dropped drastically.

However, stopping down to f3.2 the foggy effect starts to drop and the contrast and sharpness went back to normal. at f3.5 ,the fog effect is completely gone. BUT.... I bought the lens for the 2.8 aperture. I am really dissappointed with my lens now.

I checked the lens and it's completely cleaned. no signs of marks or anything. Very clean.

Im yet to visit the person who cleaned my lens. But is it his fault?... Does it only need a lil adjustment or anything? or is it because the lens was damaged by the fungus (It only has 2 tiny spots of fungus)?

[wallyb]

Usually to clean fungus out of a lens, it has to be fully disassembled to clean the elements. This means that it will have to go through re-collimation upon re-assembly. Usually, especially with a zoom lens, especially a modern zoom lens, especially an AF modern zoom lens, the lens can be difficult to properly align. This is almost definitely the problem, and should be easily fixable.

However, if the guy you sent it to wasn't a "professional" cleaner, they may not have cleaned the elements correctly which could cause the same problems. Who did you send it to?

[rhodopsin]

Another possibility is repairman accidentally reversed an element, or improperly seated one in its holder. Definitely return for another try, maybe supply an elements diagram if you can find one online or elsewhere.