Hi, I bought an ef70-300 L series lens around 6 months ago and I've noticed what looks like some sort of fungal bloom spots developing on the inner front glass element. On further inspection I can see one such bloom/spot on the edge of the outer front glass too. I;ve always had a filter on the front from new and stored the lens well. Here are a couple of photos. Ignore the 5 or so yellow spots, they're just light reflections, but you can clearly see the bloom marks on the glass. One large one n the edge of the front glass and several smaller blooms on the inner, 2nd glass from the front.
<a href="http://www.flickr.com/photos/28448513@N03/8389792344/" title="IMG_5513-2 by sanderspics, on Flickr"><img src="http://farm9.staticflickr.com/8373/8389792344_1a17b252bb.jpg" width="500" height="333" alt="IMG_5513-2"></a>
<a href="http://www.flickr.com/photos/28448513@N03/8389792718/" title="IMG_5506-1 by sanderspics, on Flickr"><img src="http://farm9.staticflickr.com/8511/8389792718_db13fddef4.jpg" width="500" height="333" alt="IMG_5506-1"></a>
Surely this is totally unacceptable, especially for a pro series lens that is supposed to be sealed from both moisture and dust. I feel this shows that something got in the lens during production or this lens has a problem somewhere in the sealing.
I'm currently travelling in Thailand. I purchased the lens in a BKK mall when I found the quality of photos from the 70-300 kit lens (MkIII non IS) were poor to say the least. They lacked contrast and colour and were generally lack lustre and required a lot of post production to be anywhere near acceptable. I bought the L series lens believing I was getting a really good quality lens that would last me a long long time.
I'm certain the blooms are causing some flaring when facing strongish light, and despite all the reviews quoting rediculously low shutter speeds, I can't get a sharp image at 300mm with anything less than 1000th of a sec and better still at 1250th. I'm not a shaky guy and I'm a long experinced camera user.
I travel to India in just over 2 weeks and then back to the UK a month later and my warranty will be useless, having bought the lens in Thailand, so I'm stuck with a duff lens, which surely should not be the case, I paid for a high end Canon product.
Any suggestions anyone?