Pham Minh Son wrote:
Andy,
Thanks for sharing with us your results with the lens as Lotusm50 has showned images from the 24-85. The overall data really give us the first look into these lens as I expected to see them. I believe these lens can handle the diffraction limit better and give nice results with higher F stops at infinity. In mid distance and closer distance these lens should performs even better.
I would like to make a few comments regarding your nice results:
1. the 15 mm is a bit far away thus it would be nice to see the frame with the similar magnification.
2. There seems to be an issue with the slight CA from the 15 mm and I believe this has to do with the adapter thickness issue. My lens that I sold recently show no CA with the proper thickness. Thus beside the slight CA the resolving power may not be optimized to its peak.
3. I also would like to see some mid distance and close up shots if possible.
Very good eye Son, I used a CQ adapter, as the one copy of yours that I had picked up in previous lens purchase was sold. This 15mm was serviced & focus adjusted by Zeiss about a year ago, so it can be considered a reference sample of the lens as it is at factory spec. I'll PM you about another adapter.
Andrew Gough wrote:
The Contax lens seems to perform differently in the field at longer focal lengths. Here is an Architectural shot taken at 31mm/F13 hand held. It was processed the same way as the other samples, DPP sharpening set to Zero.
The lens may perform better at close to medium focus distances than at infinity. Perhaps additional tests might look at comparative performance at distances of 6-12 feet (2-4 meters).
hubsand wrote:
Reviewing the results of the 16-35L v Nikon AFS test, the Nikon similarly improved on the Canon's performance in most areas (particularly with regard to outer image circle resolution), so it will be very interesting to put them head to head.
I agree and I would add that a comparison should include the 15-30mm from Sigma too: from your tests it seems a good lens.
Andrew Gough wrote:
The Contax lens seems to perform differently in the field at longer focal lengths. Here is an Architectural shot taken at 31mm/F13 hand held. It was processed the same way as the other samples, DPP sharpening set to Zero.
cut...
Well, thanks again for your effort, Andrew! Unfortunately (IMHO) the shot above isn't ideal to see effective distortion (a front view of a building, shot at various focals should be better suited in showing eventual issues on the image).
Always IMHO!!!
One thing is for sure: we need more and more real-world testing to come to a first conclusion BUT all your input is really invaluable and I would like to thankyou for the time you've spent to help us.
Do not apologize for dust spots! My display is so dirty that I'll not see them!
Lotusm50 wrote:
The lens may perform better at close to medium focus distances than at infinity. Perhaps additional tests might look at comparative performance at distances of 6-12 feet (2-4 meters).
In my testing, I've found some lenses perform excellent at closer ranges, but are surprisingly poor at infinity.I always check for performance at minimum focus, infinity, and a midpoint. I've also found that zooms usually have weak points in them where they can perform much worse than expected given the right (or should I say wrong) focal length and distance.
Very nice comparison pics. Thank you, I know lots of work went into those. Considering the limited range of high quality results one might also consider the Oly 18/3.5 and Oly 21/2 (or even 21/3.5) combo. Of course, no AF or zoom but the results should be at least as good, and the package is a whole lot lighter/smaller.
Lotusm50 wrote:
I've posted a few examples of images from the Zeiss 24-85 over the past couple of months already, and will get around to posting a few more tomorrow morning.
I was pleasantly surprised by how close it ran the Distagon 21mm: I had no hopes of the zoom matching the prime, but it came closer than just about anything I've seen or used.
Reviewing the results of the 16-35L v Nikon AFS test, the Nikon similarly improved on the Canon's performance in most areas (particularly with regard to outer image circle resolution), so it will be very interesting to put them head to head.
Again and again I get the impression that when Nikon's glass gurus are briefed on a new design, they have set before them a Zeiss lens as a benchmark, and that in the Canon factory they strive to match Leica optics . . .
It's easy to see the Canon 16-35L as a Leica 21-35 with less demanding constraints in play. Leica evidently knew they couldn't extend their zoom's performance (on a budget) below 21mm or to f2.8 without compromising IQ, so they didn't. Remove the quality control, add some mass marketing savvy, and you have the wider and faster Canon L: a Leica 21-35mm without the fat trimmed.
Similarly tuned for saturated colour and microcontrast, and similarly optimised for wide angle and small aperture performance, initial results from the Contax N have much of the flavour of the Nikon AFS. ...Show more →
Hi Mark,
It is about as close as anything that I have seen as well. The 15mm is better than in my shots with Son's adapter.
The thing that I like about the Zeiss glass is how ther glass controls both CA and Contrast. I feel that I can add contrast in various different ways in post image processing, it is harder to lower contrast in post. I find that the Canon and the Nikon WA Zooms both exhibit a steeper contrast gradient which makes the images have that plasticy (sp?) feel to them. The images look better initally because of this, but in the final post production they are less flexible and simply don't print as well.
Well, I don't have my 17-35 back yet (probably next week), but I did get my 85mm f1.4 N-Planar and 100mm f2.8 N Makro-Sonnar back -- those, however, would be for another thread.
OT:
I have been using my 24-85 for a few days/shots. It is generally very good and I certainly prefer it to the Canon L standard zooms. One thing I would criticise though is that it doesn't seem to have the acutance of the CY 28-85. I could be wrong - it's just an impression I get rather than a test conclusion.
It also seems to have less DoF at the same aperture as the CY primes. Can someone tell me if this is a known feature of zooms? Or is there another reason for this impression, i.e. bokeh or contrast?
I have also noticed more CA in the top right corner than in the others. I am slightly worried that my lens/camera geometry may not be right.
Well, I don't have my 17-35 back yet (probably next week), but I did get my 85mm f1.4 N-Planar and 100mm f2.8 N Makro-Sonnar back -- those, however, would be for another thread.
I was wondering if Andy did some other shots (at medium and close distance for example); I'm also curious to hear from him an early field report to know his feelings about this lens in real-world, everyday shooting.
brainiac wrote:
OT:
I have been using my 24-85 for a few days/shots. It is generally very good and I certainly prefer it to the Canon L standard zooms. One thing I would criticise though is that it doesn't seem to have the acutance of the CY 28-85. I could be wrong - it's just an impression I get rather than a test conclusion.quote]
It might be a subject for a separate thread, but it would be nice to compare 24-85 with CY 28-85. I have a remarkably good copy of 28-85. It misses AF and full exif though. Is it worth spending almost double price of 28-85 just to get those two features? Which of the above lens is superior in terms of lens quality? ...Show more →
PLOG1964 wrote:
It might be a subject for a separate thread, but it would be nice to compare 24-85 with CY 28-85. I have a remarkably good copy of 28-85. It misses AF and full exif though. Is it worth spending almost double price of 28-85 just to get those two features? Which of the above lens is superior in terms of lens quality?
From the Zeiss MTF's and data charts that I looked at a little while back, it seems that the 24-85 is better at 24mm than the 28-85 is at 28mm. They are comparable at 85mm. The 24-85 should also have better flare resistance. But a test between the 2 would be interesting.
brainiac wrote:
OT:
I It also seems to have less DoF at the same aperture as the CY primes. Can someone tell me if this is a known feature of zooms? Or is there another reason for this impression, i.e. bokeh or contrast?
I have seen a similar result using various prime/zooms. Some lenses (especially wide angles) seem to snap the whole picture into the frame at f5.6-8 while others require further stopping down. I tend to think it has to do with a combination of good flat focus field, bokeh, and contrast.
Emanuele_C wrote:
I was wondering if Andy did some other shots (at medium and close distance for example); I'm also curious to hear from him an early field report to know his feelings about this lens in real-world, everyday shooting.
Waiting to see your report too...
Ciao,
Emanuele
Emanuele,
The lens seems to perform quite well in day to day use. It's autofocus works exactly like a Canon Lens and is very accurate. The lens seems to perform slightly better at mid-distances. The lens also exibits a very flat field curvature at the wide end, compared to the much more curved field curvature of the Canon. When the Zeiss goes long then the field curvature becomes significantly more curved, whereas the Canon goes flat. CA is definitely much better on the Zeiss, but it is still there, however, it is much much less.
first of all thanks for sharing your opinions/findings: really appreciated!
So it seems that this Contax performs at its best on the ultra-wide/wide end, the exact contrary of Canon's counterpart, in every respect (distortion too). I think Hubsand was right when referred to Nikon and Canon benchmarks in developing lenses: Contax for the first one and Leica for the second one.
Glad to read that autofocus and other functions work flawlessly (as Canon glass on Canon bodies); I'm glad also to hear that there's some slightly improvement on medium distance subjects at longer focals. Control over chromatic aberration is always welcome, too.
Looking forward to see more test shots from you, Lotus and hubsand.
Unfortunately (IMHO) the shot above isn't ideal to see effective distortion (a front view of a building, shot at various focals should be better suited in showing eventual issues on the image). 
