24-70 II and Circular Filters

I have recently purchased a pair of Hoya Pro ND filters as I wanted to try some long exposure photography.

When using them for the first time today, my first experience using filters, I noticed that the glass on the 24-70 II is a quite bulbous. The centre of the lens appears to be level with the threads on the lens that the filter screws on to. It seems to me that there is very little clearance (if any) between the lens glass and the filter, and I am concerned about the possibility that the filter's glass could possibly come in to contact with - and damage - the glass on the lens. I have seen a webpage which refers to some 24-70 II's being scratched and damaged by "cheap filters" touching the glass. It doesn't say which filters, but does say that that the "branded" filters they tried didn't have this problem.

Thankfully, I cannot see any damage to the lens or to the filters to indicate that they are touching, so it seems to me that everything is fine, but it is still troubling me.

Is there any way to check to see if the glass on the lens and filter are touching? I am also wondering about the best way to create a little more separation between the lens and the filter to avoid any risk. i was wondering whether It was possible to buy a cheap slim filter and remove the glass, so I could stack my ND filter on to the glass-less frame to create a little separation? I have also seen a spacer which is supposed to give an create 6mm of separation would seem to do the trick. Any advice/thoughts/commen​ts would be welcome.

ukfalc wrote in post #17475222
I have recently purchased a pair of Hoya Pro ND filters as I wanted to try some long exposure photography.

When using them for the first time today, my first experience using filters, I noticed that the glass on the 24-70 II is a quite bulbous. The centre of the lens appears to be level with the threads on the lens that the filter screws on to. It seems to me that there is very little clearance (if any) between the lens glass and the filter, and I am concerned about the possibility that the filter's glass could possibly come in to contact with - and damage - the glass on the lens. I have seen a webpage which refers to some 24-70 II's being scratched and damaged by "cheap filters" touching the glass. It doesn't say which filters, but does say that that the "branded" filters they tried didn't have this problem.

Thankfully, I cannot see any damage to the lens or to the filters to indicate that they are touching, so it seems to me that everything is fine, but it is still troubling me.

Is there any way to check to see if the glass on the lens and filter are touching? I am also wondering about the best way to create a little more separation between the lens and the filter to avoid any risk. i was wondering whether It was possible to buy a cheap slim filter and remove the glass, so I could stack my ND filter on to the glass-less frame to create a little separation? I have also seen a spacer which is supposed to give an create 6mm of separation would seem to do the trick. Any advice/thoughts/commen​ts would be welcome.

Heya,

The front element of your lens is stronger.

What COULD happen however is the coatings could be muffed or scruffed. But not the glass.

Use the filters without worry. Canon didn't make the lens to take filters and think make it so that a $2k lens and their reputation ends up plastered on every website for being made poorly and having cheap filters ruining L's left and right. It's fine. If you're really paranoid, take out insurance, and don't tighten filters down all the way and you're good.

Very best,