What makes L glass different from other Canon lenses?

Don't forget much higher price!

Joslyn wrote: Don't forget much higher price!

lol of course!

KCook wrote: For starters, they are all full frame.  There are not, and never have been, any L labeled EF-S lenses.  Otherwise, everything gets upgraded (not just the glass).

Kelly

While this is technically true, the EF-S 15-85 f3.5-5.6 IS USM comes close to 'L spec" with three aspherical elements and one UD glass element.

Stic wrote: The price!

Yup....

Ain't that the truth !

effron wrote:

Stic wrote: The price!

Yup....

Quality
Price
Reputation

 - any or all....
Although I do have a Canon - camera I'll stick with Tamron lenses!

Stic wrote:

KCook wrote: For starters, they are all full frame.  There are not, and never have been, any L labeled EF-S lenses.  Otherwise, everything gets upgraded (not just the glass).

Kelly

While this is technically true, the EF-S 15-85 f3.5-5.6 IS USM comes close to 'L spec" with three aspherical elements and one UD glass element.

Also, when viewing the images after downloading from camera, all shots taken with the EF-S 15-85 f3.5-5.6 IS USM show up as having an L lens icon in the corner, the same as shot's by my 100-400L do...

Go figure...

Stic wrote: ...when viewing the images after downloading from camera, all shots taken with the EF-S 15-85 f3.5-5.6 IS USM show up as having an L lens icon in the corner, the same as shot's by my 100-400L do...
Go figure...

According to (un)reliable sources Canon is considering making a "L-Lens certification" compulsory for all who wants to use those glasses......

PhotoViking wrote:

Stic wrote: ...when viewing the images after downloading from camera, all shots taken with the EF-S 15-85 f3.5-5.6 IS USM show up as having an L lens icon in the corner, the same as shot's by my 100-400L do...
Go figure...

According to (un)reliable sources Canon is considering making a "L-Lens certification" compulsory for all who wants to use those glasses......

That would certainly ensure the "L" series the lenses of snobs....

PhotoViking wrote: Quality
Price
Reputation

 - any or all....
Although I do have a Canon - camera I'll stick with Tamron lenses!

Are they weather resistant like the canon L's? Plus the resale value on 3rd party lenses tanks.

Scotty wrote:

PhotoViking wrote: Quality
Price
Reputation

 - any or all....
Although I do have a Canon - camera I'll stick with Tamron lenses!

Are they weather resistant like the canon L's? Plus the resale value on 3rd party lenses tanks.

I haven't had any problems with the weather so far whereas I don't tend to shoot too much outside when it's raining or snowing. 
You definitely have a point when it comes to resale value! 

Tamron has come a long way, but they aren't in the same class as Canon's "L" lenses....That is of course, one reason for the difference in resale value...

Sigma and Tamron are really stepping up their game lately.

Sigma has been making great macro lenses for a long time. They are certainly improving...the 24 /1.4 art lens had me stammering....

If you're making a living out of photography (or at least trying to.....) the cost of an "L" - lens might be justified but if, as in my case, you're a "hobby - snapper" I don't think the costs are justified. Unless, of course, money doesn't matter.........
(I'm imagining myself coming home, telling my wife"honey, no vacation this year - but look what a beautiful lens I've bought"...... I don't want to take that risk!)