John Shultz wrote:
the Canon, to my eyes, walked all over the Zeiss in this comparison. I completely disagree with the statement that f 8 and above is more important than f 2.8 - 5.6 (not to mention the ABSOLUTE dominance of the Canon between 1.4 and 2.8)
The Canon demolishes the Zeiss in the corners and only slightly loses out in the center up to f8. If the points system were a 1-10 scale, the corners at f4 would stand with the Canon at a 8 points and the Zeiss at 1 point. This is significant, and I'm surprised the Zeiss was listed as the winner but I understand there is more to it than can be explained over the web. ...Show more →
It's important that you read the conclusion, not just look at the points. I try to make clear that the points are only a broad-brush indication of how the lenses perform relative to each other. I certainly didn't say the Zeiss (this sample, at least) was a better lens. I'd much rather have the 24L in the kit bag for most applications.
The pictures really speak for themselves, but I believe it is useful to notate them with a marking system that can be tallied at the end to indicate a broad range of competence. However, I agree that the current system doesn't allow room to express the magnitude of differences between lenses and several have pointed this out. I will be re-grading the recent tests with a slightly more sophisticated system in the next few weeks. But I must emphasise that the tests only work at all because of the eye's acuity at playing spot the difference – the points element is always going to serve that end, and should never be viewed as anything more in its own right.
hubsand wrote:
According to Zeiss' PR person, one of the company's engineers is looking at the test today, so we should have 'official' feedback soon. The review could be repeated with a different sample, and/or a ZS vesion.
They only have one lens thus far for the ZS mount, 50mm I believe. Is the ZS version "optimized" for FF?
I am sure this observation has arisen before, but surely Zeiss knows that a literal stampede would occur if they put out the 21 Distagon in ZS mount.
According to the Zeiss PR person who arranged the loan of the lens, Zeiss are working on shorter focal lengths for the ZF mount, but she couldn't comment further.
hubsand,
The image on the Zeiss uper coner shows purple fringing. My suspicion is that the adapter is not optimized for the lens and could potentially impact the results greatly.
but unfortunately is this not always the case...the need for adapters on any of these alternative lenses on the canon's will always add such a factor into the fray that almost immediately handicaps these lenses for use on the canons.....it does make it so difficlut to really judge the actual quality of a lens in its own right with adapaters so all we do is see how they work with the best adapters we can find...for instance my tests of the zf 35mm against a canon zoom do not show the differences I would expect in these lenses..but assume if I could fit it directly to the full frame canon the differences would be there..but except for sigmas we'll never know!
Photozone says the ZF25 is soft on the corners and they shot it on a cropped Nikon. If it is soft on the Nikon in the corners, you know it will be even more so on a FF Canon. This would seem to indicate that Hubsand's test were maybe representative and not just a poor sample. Of course, we need more samples to conclude that for sure.
If you look at the MTF curves, the 40/cylces one in particualr, it dips down as you move away from center, then spikes back up right before the edges. This is characteristic Zeiss design. However, on a crop camera, the area where it dips is unfortunately on the edge of that Nikon frame, hence the area of the imnage circle that spikes back up again is not realized on that body.
jjlphoto wrote:
If you look at the MTF curves, the 40/cylces one in particualr, it dips down as you move away from center, then spikes back up right before the edges. This is characteristic Zeiss design. However, on a crop camera, the area where it dips is unfortunately on the edge of that Nikon frame, hence the area of the imnage circle that spikes back up again is not realized on that body.
Yes, but the dip is not that large and the curves are pretty strong to begin with. Even wide open, from the MTF's it should not look that soft in the corners with an APS-sensor, and certainly not at all at 5.6. Full frame, if we are to believe the MTF's, it should only be somewhat soft in the absolute corner of the frame as the curves are still reasonably strong 20mm out from the center.
Pham Minh Son wrote:
hubsand,
The image on the Zeiss uper coner shows purple fringing. My suspicion is that the adapter is not optimized for the lens and could potentially impact the results greatly.
-Son
Like I say, I can't rule it out. However, in Photozone's review, the verdict of which corresponds very precisely with mine, there is also lateral purple/green CA present in the f8 shots made with a DX sensor. Which of your adaptors would you recommend with the ZF25?
Photozone's test sample showed clearly compromised 'corner' performance all the way up to f8, and even vignetting: all this on a little Nikon sensor! I'd like to see more of Bruce's copy, though . . .
marcwilson wrote:
but unfortunately is this not always the case...the need for adapters on any of these alternative lenses on the canon's will always add such a factor into the fray that almost immediately handicaps these lenses for use on the canons.....it does make it so difficlut to really judge the actual quality of a lens in its own right with adapaters so all we do is see how they work with the best adapters we can find...for instance my tests of the zf 35mm against a canon zoom do not show the differences I would expect in these lenses..but assume if I could fit it directly to the full frame canon the differences would be there..but except for sigmas we'll never know!...Show more →
Many here have no problem extracting Canon-beating performance from their adapted Contax, Nikon, Leica and Olympus lenses in demanding situations. It may simply be that the new Zeiss lenses are not as good as the old Contax ones.
I think it is safe to say the designs are different for a reason. Is it because the old Contax designs are off the table because of the Kyocera license, who knows? Whether the new ones are better, worse, etc, will always be subjective. They are different lenses made in different economic times for different markets. I have a gut feeling that performance of many of the Contax classics, whether they were CY or N mounts will never be seen again.
It appears that the end result of obtaining finely crafted images is relying more and more on software solutions rather than optics. Case in point, the new Hasselblad 28mm. Hasselblad has chosen to use software to attempt to overcome the deficiencies of what we have come to call mediocre lens design. This type of software fix will only improve in time. Perhaps in 25 or 30 years, no optics will be used at all, and images will be the result of lasers scaning the scene and creating it virtually.
jjlphoto wrote:
I think it is safe to say the designs are different for a reason. Is it because the old Contax designs are off the table because of the Kyocera license, who knows? Whether the new ones are better, worse, etc, will always be subjective. They are different lenses made in different economic times for different markets. I have a gut feeling that performance of many of the Contax classics, whether they were CY or N mounts will never be seen again.
This really makes me wonder if I should grab as many of the C/Y lenses as I can find NIB for myself. While I think that Cosina will get their things together and produce C/Y-quality lenses, realistically, I see it taking years until then.
They're starting off with lenses relatively hard to mess up (1.4/50, 1.4/85, the Marko-Planars, and, well, I guess the 2.8/25 was too much to ask for right now). As Cosina becomes better able to meet Zeiss' quality standards, I can see them moving on to more complex designs and assemblies. However, waiting a few years is fairly saddening; the supply of C/Y lenses will begin to slowly dwindle.
hubsand wrote:
Many here have no problem extracting Canon-beating performance from their adapted Contax, Nikon, Leica and Olympus lenses in demanding situations. It may simply be that the new Zeiss lenses are not as good as the old Contax ones.
yes..I stand corrected...just my bad experience I think!
I did email zeiss asking them which adapters they had found best from their testing of the zf lenses on full frame canon cameras:
"...we do recommend the Novoflex adapters since we did receive the best results
with this product..."
I'd like to state very clearly that my Zeiss 24mm ZF on its Chineese adapter clearly outresolves my 28mm f2.8 Zeiss for Contax on the same brand of adapter and also every other lens I have now or have had (including the 24L) at the focal length, on full frame and at f8-f11.
The ZF I have is every bit as good as the older in every way and I have sent Mark a complete RAW file to show that. I also do not believe the adapter has anything to do with it given the design and that the adapter is flat.
But it is also clear that Marks lens is'nt the same and so far I don't see images from any other samples.
I'd like to state very clearly that my Zeiss 24mm ZF on its Chineese adapter clearly outresolves my 28mm f2.8 Zeiss for Contax on the same brand of adapter and also every other lens I have now or have had (including the 24L) at the focal length, on full frame and at f8-f11.
The ZF I have is every bit as good as the older in every way and I have sent Mark a complete RAW file to show that. I also do not believe the adapter has anything to do with it given the design and that the adapter is flat.
But it is also clear that Marks lens is'nt the same and so far I don't see images from any other samples.
hubsand wrote:
It may simply be that the new Zeiss lenses are not as good as the old Contax ones.
This would ignore the fact that MTF's published for the ZF 25mm lens by Zeiss show that is the clearly and significantly better than the old Contax 25mm lens. The old Contax 25mm is a 30 year-old design (I beleive it was the same design that was used for the Contarex!) Even the ZF 50mm and 85mm lens, which are refinements of the same designs used in the Contax versions, are shown to be better than the Contax lenses. I suspect that the new Makros will have MTF's that will show them to be superior to the older Contax designs as well.
jjlphoto wrote:
I think it is safe to say the designs are different for a reason. Is it because the old Contax designs are off the table because of the Kyocera license, who knows? Whether the new ones are better, worse, etc, will always be subjective. They are different lenses made in different economic times for different markets. I have a gut feeling that performance of many of the Contax classics, whether they were CY or N mounts will never be seen again.
The Kyocera license would have nothing to do with the Zeiss designs for the Contax lenses. These lenses were Zeiss designs, manufactured and sold by Zeiss (With respect to these lens Kyocera was an OEM supplier, not a licensee). As I suggested above, the 50mm and 85mm are basically the same design as the Contax equivalent lenses. I suspect that the ZF lenses will be accepted as better than the equivalent Contax lenses. There is just something wrong -- and it not to my thinking the design of the lenses. These ARE different times, and there hase certainly been an advance in Zeiss' technology and lens design know-how since the Contax lenses were produced. We can expect these advances to be present in the ZF lenses, and the MTF's suggest that they are.
shiwan wrote:
While I think that Cosina will get their things together and produce C/Y-quality lenses, realistically, I see it taking years until then.
{snip} As Cosina becomes better able to meet Zeiss' quality standards, I can see them moving on to more complex designs and assemblies.
The only issue I have with this is that Zeiss famous (or infamous, if you are Kyocera) Quality Control should be preventing lenses that don't measure up from ever leaving the Cosina factory. Has Zeiss' QC suddenly significantly lowered it's standards and requirements? Unlikely, as that is, above all, what is expected of Zeiss, and it would be quite contrary to Zeiss' corporate culture to do so. Over time, rather than seeing the quality of the lenses improve, we should see (if we have access) Cosina's quality rejection rate fall, and perhaps the supply of the lenses improve.
Edited by Lotusm50 on Feb 05, 2007 at 07:30 AM GMT
Bruceconnelly wrote:
I'd like to state very clearly that my Zeiss 24mm ZF on its Chineese adapter clearly outresolves my 28mm f2.8 Zeiss for Contax on the same brand of adapter and also every other lens I have now or have had (including the 24L) at the focal length, on full frame and at f8-f11.
The ZF I have is every bit as good as the older in every way and I have sent Mark a complete RAW file to show that. I also do not believe the adapter has anything to do with it given the design and that the adapter is flat.
But it is also clear that Marks lens is'nt the same and so far I don't see images from any other samples. ...Show more →
This performance report would seem to be more consistent with the MTF's and the perfornace we should expect from these lenses -- I would like to see these sample images. Perhaps they could be posted somewhere (or e-mailed to me)? But the question remains, why does the test we've seen so dramatically deviate from the published MTF's? Is it poor quality control (and Zeiss' famous QC a thing of the past)? Is it the test methodology? Or is Zeiss and the published MTF's simply lying and/or misrepresenting the performance of these lenses?
I had thought I read that the Canon MTFs were theoretical curves from computer modeling, while the Zeiss CY's MTF curves were actual curves made from actual lenses. Anybody know if this is still the case with regard to the ZF's?
Pham Minh Son wrote:
hubsand,
The image on the Zeiss uper coner shows purple fringing. My suspicion is that the adapter is not optimized for the lens and could potentially impact the results greatly.
-Son
But perhaps valid for Canon users, as husband has several adapters. As a Canon user, I would not expect to get better results than husbands.
As Nikon will go full frame, If I were a Nikon user I would want to see a test on film.
But I expect this lens is representative of what Zeiss is building at this price point. This lens was sent by Zeiss for review. Should I expect to get a better lens at retail?
