Taylor Sherman wrote:
Wow, this is very. . .interesting. It is certainly dampening my enthusiasm.
But, I will be happily surprised if it turns out that one ED lens at the front makes a significant difference!
There are also some minor changes to element shapes/curvatures that could influence performance.
Regarding why the Loxia lenses are larger/heavier than the ZM counterparts asked by someone else: I suspect size is a design consideration to conform to Sony's design as seen with the FE/E primes so far. Generally they seem to maintain the same diameter as the lens mount. Certainly they could be made narrower as the ZM lenses prove. The larger size/volume may result in more weight due to the materials used, assuming mostly metal construction (BTW, a Novoflex M-NEX adapter adds ~35g to the ZM lenses). I think these are also intended to somewhat mimic the size/feel of SLR primes from back in the film days before everything ballooned in size for AF and auto aperture support.
Seriously, if Zeiss themselves published that ZM lenses weren't suitable for the Sony A7*, why would they rerelease them in a different housing with no modifications?
Perhaps also of note is that the ZM50/2 is slightly wider angle than most other rangefinder 50s. As already noted, the Planar has never been noted for exceptionally smooth bokeh, but it also really depends a lot on how you use it. Here are a couple at f/2.8 on the M240:
What I have always liked about the 50 Planar is how no-nonsense it is to use. It's easy to get good results and is quite predictable in performance/character. At wider apertures it's sharp centrally and stopped down a bit, it's very good across the frame. It has simple barrel distortion that isn't a problem to fix in post without a dedicated profile (the two above have been corrected for this, IIRC). Lenses like the ZM50/1.5 or the 50 Lux ASPH are perhaps more special in character, but each present certain quirks/challenges compared to the Planar.
Steve: I like your proposed lens lineup. Regarding a hypothetical 21/3.5, I think it should be possible to design this within the existing Loxia/Sony FE design parameters. If you were to look at the ZM21/2.8 or the Leica 21/3.5, both are 46mm filter mount lenses and not much different in size than the ZM35/2 or 50/2.
A 58/1.4 also sounds interesting. Why not just make it 60 instead along the lines of the Konica Hexanon 60/1.2? It would be a slight but perhaps significant enough of a difference in focal length from the 55/1.8.
xbarcelo wrote:
Seriously, if Zeiss themselves published that ZM lenses weren't suitable for the Sony A7*, why would they rerelease them in a different housing with no modifications?
I'd hope that the Loxia Biogon would be successful, because all my existing 35mm lenses are retrofocal types. It would be nice to have the option of a symmetrical type 35mm design.
It may be that the ZM 35/2 Biogon was an easy re-design to get to work on the A7. The wider lenses may be more difficult, take more time.
Keep in mind the differences in registration distance when thinking about length of the lenses. The ZM is 56mm without caps but Leica M mount is 9.8mm further from the sensor than E-mount, so if you added an adapter to the ZM it would be about 66mm like the Loxia. The longer registration distance of the DSLR lenses make them even longer with an adapter they would be about 110mm (the number you give for length again includes caps).
theophilus wrote:
so if we are dealing with a modified ZM biogon, what is the consensus of the 35/2 ZM version on the right camera? Good wide open?
I have the FE 35/2.8 which I like for landscape, this will have to be nice to use wide open for me to replace it.
a little SA wide open. ugly bokeh at short distance, decent at long distance. from f/4 on it is the best landscape 35mm near infinity. only the sigma and rx1 even come close. i don't really like it's look for environmental portraiture.
douglasf13 wrote:
Where did they state that about the ZM 35 and 50?
You're right about the planar, but the biogon 35 could be included in the famous white paper by dr. Nasse that now, funnily enough, doesn't seem to be so easy to find. However, if you don't remember, you can find the info on ronscheffler's web page, specifically: http://www.ronscheffler.com/techtalk/?p=78
It talks about problems with nearly simmetrical wide angles and, as we can see with the diagram posted, it does seem nearly simmetrical, right? That's why I don't think they would rehouse it and release it without modification. But I'm sorry I was partly incorrect.
xbarcelo wrote:
You're right about the planar, but the biogon 35 could be included in the famous white paper by dr. Nasse that now, funnily enough, doesn't seem to be so easy to find. However, if you don't remember, you can find the info on ronscheffler's web page, specifically: http://www.ronscheffler.com/techtalk/?p=78
It talks about problems with nearly simmetrical wide angles and, as we can see with the diagram posted, it does seem nearly simmetrical, right? That's why I don't think they would rehouse it and release it without modification. But I'm sorry I was partly incorrect.
Xavier
Thanks. I've read that Zeiss paper many times. I didn't know if maybe there was a different source you were referring to. The ZM 35/2 is actually pretty unsymmetrical, for a Biogon, and I'm starting to think that Zeiss must believe that ZM 35/2 design is good enough for the A7 series. They'll probably included software correction to deal with color shift and vignetting. I noticed that the Loxia 35 has a slightly narrower field of view than the ZM 35/2, so maybe they "chopped" off the bad parts, in a sense.
I haven't used the ZM 35/2 on the A7 series, myself. How bad is the smearing?
douglasf13 wrote:
I haven't used the ZM 35/2 on the A7 series, myself. How bad is the smearing?
too bad for zeiss to release it without becoming a laughing stock. i'm sure they've at least recalculated to compensate for the astigmatism caused by the cover glass. hopefully they've done some other tweaks to the design too, as i'm not overly fond of the zm 35/2.
sebboh wrote:
too bad for zeiss to release it without becoming a laughing stock. i'm sure they've at least recalculated to compensate for the astigmatism caused by the cover glass. hopefully they've done some other tweaks to the design too, as i'm not overly fond of the zm 35/2.
Yikes. I'm just trying to imagine how such a subtle tweak would result in such a large improvement of astigmatism. As that Zeiss paper mentions, the ZM 21/2.8 increased the back focus distance of the Contax G 21/2.8 by a few millimeters (at the cost of more distortion,) and, despite having the same number of elements and groups, the designs of the ZM 21/2.8 and G 21/2.8 are noticeably different. I'd be curious to read theSuede's opinion on this.
At any rate, it's a good sign that it's taking longer for the wider than 35mm Loxia lenses to come.
p.s. if anyone is interested in lots of Zeiss lens data sheets, this was posted a while ago: link
douglasf13 wrote:
Yikes. I'm just trying to imagine how such a subtle tweak would result in such a large improvement of astigmatism. As that Zeiss paper mentions, the ZM 21/2.8 increased the back focus distance of the Contax G 21/2.8 by a few millimeters (at the cost of more distortion,) and, despite having the same number of elements and groups, the designs of the ZM 21/2.8 and G 21/2.8 are noticeably different. I'd be curious to read theSuede's opinion on this.
At any rate, it's a good sign that it's taking longer for the wider than 35mm Loxia lenses to come.
p.s. if anyone is interested in lots of Zeiss lens data sheets, this was posted a while ago: link...Show more →
i would imagine rather than focusing on decreasing angle, they could design it to induce similar astigmatism in the opposite direction that the cover glass would correct. no idea how possible that is and of course the astigmatism caused by the filter stack changes with focus distance...
sebboh wrote:
i would imagine rather than focusing on decreasing angle, they could design it to induce similar astigmatism in the opposite direction that the cover glass would correct. no idea how possible that is and of course the astigmatism caused by the filter stack changes with focus distance...
Yeah, it seems optimistic. Am I correct in saying that the A7 and A7r seem to perform differently in this regard, as well?
