Canon 5DS + 24-105mm Skyline Drive, Virginia

[Tom Caldwell]

Tom, thanks very much again for your informative replies. I broke down and ordered a used Tamron 28-300 as mentioned above. It should arrive today and I'll try it out on the 5DS, especially looking for sharpness in fine detail and in corners. I'll post some comments asap with photos.
Sandy Fleischmann at flickr

Sandy,

Unfortunately* I am always interested in new lenses and would like to see you report on how you find this one.

It occurs to me that making lenses for EF mount might remain proportional to the amount of Canon EF dslr bodies remaining in current use. But here should be a huge amount of them on the resale market for quite a long time.

*Unfortunately = costly