<p>I have a Canon 70-210 f/3.5-4.5 that I brought second hand. The previous owner sold the lens as-is as they dropped the lens in water. Luckily the lens' auto-focus motor works fine. But thanks to the water residue, it leaves any picture I take with it soft, especially at 210mm.<br>
<a title="Boston Mug by Duy Nguyen, on Flickr" href="
src="https://farm6.staticflickr.com/5585/15016017918_7f5b23b38b_z.jpg" alt="Boston Mug" width="427" height="640" /></a><br>
This picture taken with my Canon 70-210mm at f/4.5, ISO100, 210mm at about 6' from the mug. The left side of mug is fairly sharp, but the right side where flash comes in is soft.</p>
<p>While I was able to remove and clean the two front elements and clean the rear element, I was unable to access the insides of the rear elements. Here's how the rear elements look like.<br>
<a title="More Water Residue by Duy Nguyen, on Flickr" href="
src="https://farm4.staticflickr.com/3875/15016089828_a927d74d78_z.jpg" alt="More Water Residue" width="640" height="427" /></a><br>
You can see the residue under the catch light on the glass.</p>
<p><a title="Possible Fungus by Duy Nguyen, on Flickr" href="
src="https://farm4.staticflickr.com/3914/15016091557_bec9c52552_z.jpg" alt="Possible Fungus" width="640" height="427" /></a><br>
I'm not sure if this spot is fungus on the element.<br>
Can anyone provide advice for cleaning the lens' inner rear elements?</p>
<p>Thanks,<br>
Duy</p>
I like the balance of light and shadow on your subject. It gives a wonderful gradient along the natural curvature of her body. The background is a bit distracting though. The frame and what appears to be moulding on the wall pulled my attention away a bit. The moulding can possibly work to your advantage if you use it as a leading line. Overall a good job. Keep it up!