16-35L versus 17-85 IS

[arpi]

hi fellows

I just tested the difference between my two lenses. the first pic is from lens is the 16-35mm at 16mm f4. the second pic is from the 17-85 IS lens at 17mm f4. tripod used finger triggered. no posprocessing, 100% size.

http://www.scientificlinux.com/pics/test16-35.JPG

http://www.scientificlinux.com/pics/test17-85.JPG

just as expected, the 16-35 wins with a lot of margin

I got a question. the 16-35 is brand new but has a small spec inside the lens but out of the picture range (to the side). can it drift in the future to the center and then I will have to pay? or should I exchange it for a clean one?

TX

[BrandonSi]

I really hope those weren't 100% size ;) If it's brand new and has a spec in it, i'd return it and get a new one. Yes, the spec can drift later on.

[arpi]

oops, I meant that the pics were not resized (1:1). obviusly, it is a crop

thanks for the advice.

[arpi]

actually, it has many specs!

I have excellent vision and I can see the specs agains the balck contrast of the lense. my question now is how small is considered acceptable? The spec I mention before I saw it on the field when I was going to use the lense, but now that I have taken a closer look, I see a lot more but much smaller. is this normal?

what is an acceptable number of specs?

[BrandonSi]

actually, it has many specs!

I have excellent vision and I can see the specs agains the balck contrast of the lense. my question now is how small is considered acceptable? The spec I mention before I saw it on the field when I was going to use the lense, but now that I have taken a closer look, I see a lot more but much smaller. is this normal?

what is an acceptable number of specs?

7 is the maximum number of acceptable specs. ;) No, really, I don't know. Take it back, ask to look at a new one and then see. I've never seen any specs in my lenses.

[Skip Souza]

I have no experience with specks on the inside of the lens but I would probably be concerned.
My wife has the 16-35 L and she loves it. I've used it once and I can see why. It is currently with her in Hawaii :-)
Is your 17-85 IS still for sale?

[RbrtPtikLeoSeny]

At $1,400.00 I think you deserve a lens with no specs.;) Take it back immediately.

[drisley]

The spec won't affect pictures, but like others have said, if it bothers you, at that price range, maybe exchange it. Then again, if you have a sharp copy of the lens, you might want to keep it because some say there is a quality control issue and it may be hard to get a second copy just as sharp. ALthough, I'm starting to think that may have been with the older lenses as most with the newer ones seem to be very happy (like me).
I am often in awe of the sharpness of the 16-35L. I will shoot pictures wide open, and later think I MUST have stopped down to F8 because there is no way it can be this sharp at F2.8. It really is a great lens, especially on the wide end.

[arpi]

thanks a lot for your guidance.

The problem with me is that in the past I have bought items and I've have looked at them with a very critical eye and sometimes I have overblown microscopic defects and I don't know how sever is a very small spec in the performance of a lens. In this case, the other specs are really really microscopic (eventhough I can see them). I have compared this lens with my other lenses and the problem with this one is that it has a lot of black surface at front behind the glass (the others don't) and you can see any microscopic spec. I have looked at my 70-200 and I can also see some spec halfway down the tube. the 16-35 seems to have a two-hole key to remove the glass and I could maybe clean it myself with a static brush (like for the sensor). I am convinced that if I get a new one, I am probably going to see microscopic specs but maybe not like the single small one (not micro). I want to keep it realistic.

My question to any of the pros is this: how hard would it be to unscrew the front glass (with a two prong key)?

TX

to Skip Souza: sent a pm

[drisley]

Arpi, I'm obsessive/compulsive, much like you sound to be :)
I often will do what you may attempt, and often make things worse. I would say "don't do it".
This spring I noticed a spec of dust under my 20D LCD after a day of shooting in windy conditions.
It really bothered me, and I ended up removing the cover, and removing the spec. But, when I replaced the cover, I discovered I had more specs than I did initially! I thought, here I go again.
Luckily, I removed the cover a second time, used some ROR and a pec pad, and now it's as good as new (and I ordered a replacement cover for down the road).

OCD can be a cruel mistress if you're not cautious :)
.

[arpi]

I guess once you open the door, all kind of microparticles would get inside, so it would be risky. with my keen eye, I could look at any lens and find a 'particle ' inside (if I really look hard). but maybe I would get in trouble with a salesman if I were to show him where it is :D

[drisley]

Arpi, I think even my 70-200/4L had a small spec inside the front element.
If I looked hard enough, I bet my current L lenses have some too. I just learned not to torture myself, and so I don't even bother looking.

[pierrot]

Hehe, and if you keep looking for a long time with your eyes wide open, you'll begin to see plenty of black specks moving all around, too... :mrgreen:

[drisley]

Hehe. Yes, true!