I thought I'd share. Last week I received a copy of this lense I didn't feel was up to snuff. Today I just received my replacement copy. I'm happy with the performance of the new lens. The new lens is on the left of each crop. The old on the right. These are all wide open at f/4. 70mm, 100mm, 135mm, 200mm, and finally 1.2 meters at 200mm for those whore are interested.
Edited by Jammy Straub on May 17, 2007 at 06:25 PM GMT
135mm f/4 New lens on left. This one is strange the new lens is slightly less sharp than the old, but the differance clears up by f/5.6 - f/8. I've seen one review where they noted a resolution drop at 135mm so perhaps it's normal.
I'm gonna redo the 1.2 meter test later with a better target. The reason I got a replacement was mainly the 70mm test and my old lenses close focusing performance. The lens is super tasty, love it's handling.
Oh yeah, and hello everyone! Is there a better way to post multiple photos in post other than grafting them all together in photoshop?
Edited by Jammy Straub on May 17, 2007 at 06:29 PM GMT
Nope it wasn't an autofocus problem. I tried several different focus variations, and the AF was always the best. I've had no autofocus problems with the lens in testing or in field use.
I'm incredibly releaved this whole ordeal is over. All that's left is to send the bad lens back. UPS messed up two overnight deliveries in a row during this whole scenario, first the original delivery, and then they temporarily lost the second lens due to a "computer glitch"...my ass.
Unfortunately I'm not all that impressed with Canon's quality control as this point, it's the first problem I've ever had with them though.
Hopefully as more 100% crops from this lens get posted on the net people can test their copies and make sure they are perfroming optimally.
The quality control of zooms is disappointing to say the least. And this lens is a new design. I ordered a 100-400 this morning. Seeing reports like this make me wish I hadn't.
I had the non-IS and the IS version both for awhile, and tested to see which one was better. I noticed that there is variation in AF accuracy at different focal lengths, which I could consistently repeat. All within a few mm of actual focus point, but at different zoom settings it snaked around the actual focus point. I found the IS version was more accurate than the copy of the non-IS version I had.
Oh, IS on/off also makes a difference.
After testing with these two lenses, I also tested the 100-400, and found the same thing. Interesting.
IOW, there is AF focus shift in these lenses at different focal lengths.
I have both the IS and non-IS 2.8 lenses, and just purchased the f/4 IS as it is supposed to be the best optically of the lot. The first one I got was equal or just slightly better from 70mm to 135, but decidedly softer at 200mm than my non-IS 2.8. Took that copy back to Samy's and tested out a second, which was actually sharper at 200mm (all apertures) but soft at the shorter end. Two random lenses from Samy's were completely different and neither, overall was better than what must be a very good copy of a non-IS 2.8. I'm going to try one more and see if I can get one that lives up to what I've seen published about it. Canon CPS says to send it to them for calibration, but why, oh, why am I so picky.
One other note: I inadvertantly left the IS on while on the tripod on one round of testing, and then I reshot without the IS, it was noticeable sharper without, so at least with this lens, it does seem to make a difference when on a tripod.
"Did either of your guys try this test with manual focus to determine if it was the optics or the AF"
Yes, the first thing I did was to do another test manually focusing in the smallest increments possible to determine if there was a front or back focus problem. The single autofocus point that I had been using on the 1DsMKII was still the sharpest focus obtained. This thousand dollard lens is going to end up costing several thousand in my time by the time I find a good one - or I might decide to just give it back and live with what I have.
Once again, I found no AF fault in either of the tested lenses. After the Initial AF shots I manually focused fore and aft of the indicated AF. It was a resolution problem not an AF problem.
Yep there was a distinct color difference between the two lenses. Wierdness.
That looks similar to the performance of my new lens. Nice ain't it!?! I haven't used mine with tubes yet. The zoom, 1.4x, and tubes, sounds like a nice bit of travel kit.
Jammy Straub: Unfortunately I'm not all that impressed with Canon's quality control as this point, it's the first problem I've ever had with them though.
Thank you for the tests.
I realized that buying new lenses became a very stressful and time consuming experience for me. The most recent one was 70-200 f/4.0 L IS and some know that it was not a success for me. I, for instance, bought three copies of 85 f/1.8 lens in the last three years and only the last one is finally sharp wide open (and very sharp already at f/2.2).
I prefer to use the lenses I have even if I would benefit form getting new ones. I returned all the zooms, I have bought in the last 4 years (tried three 24-70 f/2.8 L).
By the way, the "200 mm, 1.2 m sharpness" problem must be residual spherical aberration:
