PetKal wrote:
Stu, I am sorry to hear about this problem you are having.
Never seen anything like it. However, two theories already advanced seem plausible to me:
(1) Some sort of corrosive liquid ended up on your lens.
(2) The G1/G2 element doublet optical cement has developed a defect. (in such case you might be able to get a free repair/doublet replacement.)
In either case, you should be able to see if the defect is on the front element (G1) external surface or not, by varying the angle of incident light as well as the visual inspection of the spots.
Hi Peter. I just placed the corner of a piece of paper next to one of the marks and it looked adjacent so I think the marks are actually on the outside. I can't think of any corrosive fluid that could have gotten onto the element, unless its some type of plant sap, but that doesn't sound terribly plausible. From close visual inspection and viewing the semi macro shot at 100% it does appear that the coating is damaged. There are no scuff marks or scratches so wasn't was from being bumped. I've emailed a CPS repair centre to check how much they charge to replace the G1/G2 element. I don't think I can now blame it on a lens defect. Bummer
Unfortunately the funds I have been expecting for some time haven't arrived yet and I'm currently unemployed so I'm loathe to spend any money unless I really need to. The marks don't appear to be affecting the image at this time so if the repair can wait then I'll send it in, in a couple of month time. If they do become an issue or get worse I'll break out Mr. MasterCard.
skibum5 wrote:
Did you shoot around any giant bonfires? I once had a filter (and this why those who say filters never protect anything under conditions expected to be normal are wrong) get some tiny bits of embers apparently land on it and the filter got some odd permanent rings on it, damaged coating, but I think they were a trace different and probably had a center mark too so it's more likely coating going bad or element glue going bad.
I did shoot close to a huge bonfire last year on Guy Fawkes, but that was with my 24-105. I'm pretty baffled, but I think ultimately its just going to be a case of replacement. My main concern was that it might be fungus, but I think has been ruled out. Oh well, such is life
If you have blown on the front element it could be a bit of spittle. It happened to me once and my camera dealer couldn't remove it with any cleaners he had. Then I fogged the lens element with my breath and it came of with a soft cloth immediately. Who knew?
Vancouver47 wrote:
If you have blown on the front element it could be a bit of spittle. It happened to me once and my camera dealer couldn't remove it with any cleaners he had. Then I fogged the lens element with my breath and it came of with a soft cloth immediately. Who knew?
I tried the fogging method this morning and no luck Good result for you though
I had something that looked a lot like that from a drop of swimming pool water that got on the lens as I was shooting. Nothing I did would take it off, including PEC-12 film cleaner, which pretty much takes everything off. I ended up sending it to Canon and it came back clean, but they never said what they did or how they did it.
I was sitting here watching DRTV's Amsterdam Special pt.2 when I had a thought (no not about Alamby ). I got a lens cleaning cloth, dipped it in warm water, gently rubbed in a circular motion on the 70-200's front element and slowly the marks began to fade. All gone now. Amazing how lens cleaning fluid and warm breath (fogging) had no effect. What a relief
Peter Figen wrote:
I had something that looked a lot like that from a drop of swimming pool water that got on the lens as I was shooting. Nothing I did would take it off, including PEC-12 film cleaner, which pretty much takes everything off.
Swimming pool water was the culprit in my case, a few posts above; persistent deposits, eh? Congrats on your success, Bones, definitely something to watch out for...
Jerry
p.2 #11 · Strange marks on 70-200 II front element
You never know when a topic will bring home; to light, a potential problem. Pool water, chlorine and the other chemicals, I've been lucky it seems so far shooting in my backyard. Be it kids, adults or our wild city Mallards, there is always a bit of splashing about going on...my 70-200 is bare w/hood; no more
p.2 #12 · Strange marks on 70-200 II front element
Bones74 wrote:
I was sitting here watching DRTV's Amsterdam Special pt.2 when I had a thought (no not about Alamby ). I got a lens cleaning cloth, dipped it in warm water, gently rubbed in a circular motion on the 70-200's front element and slowly the marks began to fade. All gone now. Amazing how lens cleaning fluid and warm breath (fogging) had no effect. What a relief
Hah great to hear!! I wonder what it was that did it. Anyway glad to hear it is gone.
p.2 #14 · Strange marks on 70-200 II front element
StillFingerz wrote:
You never know when a topic will bring home; to light, a potential problem. Pool water, chlorine and the other chemicals, I've been lucky it seems so far shooting in my backyard. Be it kids, adults or our wild city Mallards, there is always a bit of splashing about going on...my 70-200 is bare w/hood; no more
Use an extender and stay back It is very strange because I cannot think of any instance when anything other than a little water might have got onto the lens.
Hi Peter. I just placed the corner of a piece of paper next to one of the marks and it looked adjacent so I think the marks are actually on the outside. I can't think of any corrosive fluid that could have gotten onto the element, unless its some type of plant sap, but that doesn't sound terribly plausible. From close visual inspection and viewing the semi macro shot at 100% it does appear that the coating is damaged. There are no scuff marks or scratches so wasn't was from being bumped. I've emailed a CPS repair centre to check how much they charge to replace the G1/G2 element. I don't think I can now blame it on a lens defect. Bummer 
Good result for you though 
