DavidP wrote:
smaug wrote:
If it does happen, the 70-200 F4L will need more elements in more groups so by definition it cannot be as sharp as the original.

A common fallacy. More elements does not necessarily imply less sharpness.


More glass equals more barriers to the light traveling through. The highest quality UV filter on the market degrades image quality to some slight degree and that's just adding one more piece of glass... a thin one at that. It's not fallacy, it's physics. Now consider adding 5 or 6 more lenses for the IS group... I don't see how the optics would improve.

Of course if the entire lens is re-worked and higher grade glass is used throughout (maybe flourite or...) then maybe it wouldn't be hampered.
THAT is the real question. Will they use the same glass and just add elements for the IS or re-work the whole she-bang?

Of course you can just write this off as my opinion an prompty forget it if you wish. I'm not trying to start a flame war. I'm just defending my cherished fallacy.

-Steve

smaug wrote:
Of course if the entire lens is re-worked and higher grade glass is used throughout (maybe flourite or...) then maybe it wouldn't be hampered.
THAT is the real question. Will they use the same glass and just add elements for the IS or re-work the whole she-bang?


The entire lens has been redesigned in the past, when going to IS.

It's not like they took the same lens design and used it again, slapping some IS elements in there.

So, it doesn't have to follow that the IS lens is less sharp.

DavidP wrote:

The entire lens has been redesigned in the past, when going to IS.

It's not like they took the same lens design and used it again, slapping some IS elements in there.

So, it doesn't have to follow that the IS lens is less sharp.


Oh, sure. Spoil my fun.

I just might have to upgrade if they do make an IS version. While I truly love my lens as it is, the IS would be quite handy in a lot of situations.

(crossing fingers)

-Steve

I know one thing: whatever degradation in sharpness there is from the extra elements is FAR less than the increase in sharpness due to the IS, at least for me.