How soft is the rear element?

So i was at a buddy's place and a friend (not a photographer) asked to see my camera/lens. Without too much thought, i gave it to him to shoot while i went to use the restroom and grab some food. when i return, i noticed that he had a bottle of lens cleaner (for glasses) and lens cloth (looks like a generic cloth that comes with cases/glasses). he was cleaning my lens! he said he saw finger prints on the lens (i think he accidentally touched the rear element while changing lens) and wanted to clean it up for me. being a meticulous with my stuff, i politely asked him to stop so i can have it clean with the correct materials.

So my question, how soft is the rear element's coating? obviously, the best materials were not used to clean the lens, but after i cleaned it up at home, everything looked. i shined light through it and i got the different color reflections, like on my other lens. pictures look good still. can any harm have been done with his cleaning? how can i tell if the coating was rubbed off?

Canon, or any manufacture, I am sure realizes that at some point you are going to clean the lens with less than ideal materials and makes the lens accordingly. I know several pro photographers that use spit and the t shirt they are wearing to clean the lens. No problems that can be seen. You are being a bit over protective. That can be a good thing at times, it can keep you out of trouble. But is not always needed.

The coating, if correctly applied on the lens during the manufacturing process, should not come off unless you use metal to scratch it.

I've cleaned my rear elements with lens tissues and Windex many times with no adverse effects. No coating loss!

Thanks everyone. I just wanted to check as when I searched on the subject, it seemed that some people say the rear element is quite soft and some rubbed off the rear coating on the glass with some elbow grease. So I wanted look for some reassurance that the lens is still in good condition.

The coloring that can be seen does change from moisture. But it does not rub off. Much like frosted glass is much less frosted when it is wet. You can wipe it "dry" but there is still enough moisture on the glass to make the frosting look a lot less.

Mark1 wrote in post #10254921
The coloring that can be seen does change from moisture. But it does not rub off. Much like frosted glass is much less frosted when it is wet. You can wipe it "dry" but there is still enough moisture on the glass to make the frosting look a lot less.

Is the coating what makes the glass look colored?

What he used to clean your lens was very adquate. Dont see really why you reacted that way.

Brain Mechanic wrote in post #10255791
What he used to clean your lens was very adquate. Dont see really why you reacted that way.

Why shouldn't he?
He didn't know if that was appropriate, and sought help...

Sounds like a proper thing to do!

YseanY wrote in post #10255740
Is the coating what makes the glass look colored?

yes.

Brain Mechanic wrote in post #10255791
What he used to clean your lens was very adquate. Dont see really why you reacted that way.

i would have been pissed. if the rear element was dirty he should have told me.

ed rader

Brain Mechanic wrote in post #10255791
What he used to clean your lens was very adquate. Dont see really why you reacted that way.

i wasn't rude about it or anything, i just told him i'll take care of it. but being very meticulous, i tend to care for my things a little more than others, especially on $1k lens. so i wanted to to check with others to see if there'd be any harm with what he used (mainly glasses cleaning solution) and how i can see if any of the coating was damaged since i read some people rubbing off the coating.

"since i read some people rubbing off the coating."

please provide links. i'm interested in reading into this.

c2thew wrote in post #10257336
"since i read some people rubbing off the coating."

please provide links. i'm interested in reading into this.

I'm not sure if they've ACTUALLY removed the coating, but this is why i'm asking as i'm not sure if it is possible or easily done.

https://photography-on-the.net …hp?p=10000864&p​ostcount=5

https://photography-on-the.net …php?p=5689010&p​ostcount=7

As said before, lenses are harder than people think. It dont mean you should be careless with them of course.

Its similar to the believe that newborns are very delicate when in fact are very resilient...just imagine how traumatic the act of birth is! LOL!