Canon 100-400mm f/4.5-5.6 USM IS II

Started Jul 2, 2019 | Discussions thread
photonius Veteran Member • Posts: 6,895
Re: Canon 100-400mm f/4.5-5.6 USM IS II

ohthatgirl wrote:

I love DPReview and how helpful everyone is. Honestly didn't know what to do. I called Canon and discussed with them the issue. Not surprised to hear they need me to send it in and they can make the call. As I mentioned, the dust (or even the crack I saw) does not seem to impact my images and I more or less consider dust to be part and parcel of a long lens over time. It's the crack that I saw that concerns me more. I have been back for a few days from my road trip and looked under a flashlight and other lights and cannot see the crack. I know it's there. It was very clear. I'm pretty sure it was deep and not the surface - which I have protected with a filter. I'm also very sure it has never even had a low impact. It's pretty protected in my bag and I wear it - shamelessly never use a tripod. I could move on and figure it was an optical illusion on my part, but it does make me wonder why my shots are not as sharp as they were in the beginning. Anyhow, I appreciate all the feedback.

Well, if you cannot see the crack with a flashlight, and don't have an impact on the images, then I suspect it's not a crack. A crack in glass should be pretty obvious with a flashlight. Sometimes a fine line/smear of grease (say if you clean your front element, or filter), can look like a crack, but it is not. Since it is on the inside, as others have said, maybe something else is in there, a tiny spider thread, some dust fiber, which as moved again so you don't see it anymore. Since you saw it in extreme brightness (sunlight), maybe it was just some reflection of a lens edge on a glass element? It's difficult to say what it is, but it does not seem to have the characteristics of a crack.

-- hide signature --

*** Life is short, time to zoom in *** ©

 photonius's gear list:photonius's gear list
Canon EF 100-400mm F4.5-5.6L IS II
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow