lens separation

[alice]

what causes lens separation?

 

[oftheherd]

I am no expert on the matter. From what I have read, it is usually just age on older lenses, such as some of the LF lenses, where the balsaam has just basically gotten older and dried up, causing the separation between some of the lens elements.

On newer lenses, I understand that heat, such as leaving a camera lens in a glove compartment of a car, can also cause it.

Probably someone who actually knows more about it can comment.

 

[alice]

thanks oftheherd, i have heard that if lenses are stored in an excessive dry environment, such as in a drybox where humidity is set at 30-ish percent lens separation may happen....
again i don't know how true this is and trying to find out more.....

 

[pvdhaar]

Mechanical stress, both impact stress and mechanical wear, different expansion properties with temperature between materials.

Chemical causes; dehydration, outgassing, chemical reactions due to for instance humidity and/or airborne acids and solvents.

Biological causes; fungi, the dog ate my lens -just checking if you're reading this-, bacteria.

The list is nearly endless..

 

[Kim Coxon]

Hi,
Most older lenses groups are stuck together with Balsam. As this is an organic compound, many things can affect it. M have already been mentioned.

Kim