philber wrote:
I beg to differ with the learned members above. The RX-1 proves how good a lens designed for a specific camera can be when Zeiss get involved (I am not sure if it is a Zeiss or a Sony-Zeiss lens). The Touit 12 shows how good a Zeiss lens can be even when designed for a very touchy camera (the NEX 7). The Sony-Zeiss FE 55 shows how good a lens can be for the A7 camera, even though I don't care much for it and will put mine up for sale tomorrow. My guess is that the Loxia will show that (a) Sony don't mis-design senor covers and glass toppings to the point that even forum members look like experts in comparison (no offence meant, yuo guys have forgotten more in a day than I've leanred in a year), and (b) Zeiss know how to take those parameters into account.
Simply put, their 50 Loxia must outperform the FE 55, or Zeiss will look like complete fools, which is not their custom. Considering how many people thing highly of that lens, the Loxia should be interesting, to say the least. Forget the theory and glass toppings, they are not members of FM anyhow...:-)...Show more →
I think you're over estimating Sony, Philippe. We have seen a lot of stupid decisions in the past, decisions that crippled their output unnecessarily and lost them a lot of clients. The decision to add the glass thickness goes back to the A700 and A900. All UWA are completely screwed by this decision. No Sony or Zeiss wide performs correctly in the image periphery. The decision to remove the mirror and replace it with a translucent one that stays in the optical path cost them their DSLR user base, including myself and many others on this forum. Even with perfect lenses like the FE55 you can see the weird effects of the sensor stack in the image periphery especially on highlights and blur discs. I guess we AA less camera users like the Leica M are spoiled because we are used to the benefits of a thin stack so we get sensitive when we see unnecessary image degradation caused by some stupid engineer at Sony. Add to that the lossy raw compression and no uncompressed format, the mirror like surface causing flare and ghosts everywhere... etc. As for the b part, I have no doubt whatsoever about Zeiss abilities, but the sensor stack will inevitably put many restrictions on the lens design, size and weight that need not be there in the 1st place.
rscheffler wrote:
I see Loxia as a ZM successor because outside of the minuscule rangefinder market, the ZM line, at the wider end, is a poor option for adapting to mirrorless systems. It's pretty much dead in the water and Loxia is a chance for Zeiss to optimize a set of compact lenses for proper digital compatibility.
This is actually what I was thinking as well.. Zeiss dropped their ZM lenses mid-design to focus on what they felt was a growing market and technically the future of photography. FF Mirrorless. If Nikon/Canon/Fuji ever jumped into that market, all Zeiss would have to do is design a new casing. As I'm sure they'll design the lenses with a bit of wiggle room in the casing for distance to sensor changes (sort of like the touit fuji/sony).
As for peoples comments about Zeiss designing lenses for Sony's A7 sensor stack thickness.. I actually don't think they will. I think the lenses will be designed based on less specific parameter. As to keep them as future proof and universal as possible. I also doubt they'll be soulless perfect lenses (55FE). I'd think that Zeiss would build them with character (think 50 1.5 sonnar characteristics), as to draw in photographers, rather then just everyday consumers. Since they'll have to compete with Sony and Sony will always take the majority of the market of everyday consumers.
Mind you, I could just be dreaming But I think it would be hard to top the 55FE, really not much wrong with it other then being a bit boring SOOC.
sebboh wrote:
i hope you don't think anything you wrote is contradictory to my statements above. if you do, i must have worded it poorly. or are you disagreeing with edward from a ways back?
I actually had Edward's approach in mind; Not disaggreing with him, on his approach...
I remember the time when we were told that removing the AA filter would most certainly avoid any corner issue with short-register cameras
edwardkaraa wrote:
I think you're over estimating Sony, Philippe. We have seen a lot of stupid decisions in the past, decisions that crippled their output unnecessarily and lost them a lot of clients. The decision to add the glass thickness goes back to the A700 and A900. All UWA are completely screwed by this decision. No Sony or Zeiss wide performs correctly in the image periphery. The decision to remove the mirror and replace it with a translucent one that stays in the optical path cost them their DSLR user base, including myself and many others on this forum. Even with perfect lenses like the FE55 you can see the weird effects of the sensor stack in the image periphery especially on highlights and blur discs. I guess we AA less camera users like the Leica M are spoiled because we are used to the benefits of a thin stack so we get sensitive when we see unnecessary image degradation caused by some stupid engineer at Sony. Add to that the lossy raw compression and no uncompressed format, the mirror like surface causing flare and ghosts everywhere... etc. As for the b part, I have no doubt whatsoever about Zeiss abilities, but the sensor stack will inevitably put many restrictions on the lens design, size and weight that need not be there in the 1st place. ...Show more →
Edward, I am not defending Sony's every decision as clever, including camera design choices. I am just saying: "give them a bit of credit, they presently design and manufacture the wolrd's best mass market camera sensors, if they choose to design the sensor stack this way, it is not mere ignorance" If your theory is correct there must be trade-offs that we are not aware of IMHO.
douglasf13 wrote:
Whew, this is a good sign. Looks like I may have been wrong about the new lenses simply being recycled designs.
Which designs? Full frame DSLR or M?
Zeiss themselves quite some time ago was dissing their own M designs as being unsuitable for the Sony platform. From that moment on it seemed more logical to assume we'd see all new product.
philber wrote:
Edward, I am not defending Sony's every decision as clever, including camera design choices. I am just saying: "give them a bit of credit, they presently design and manufacture the wolrd's best mass market camera sensors, if they choose to design the sensor stack this way, it is not mere ignorance" If your theory is correct there must be trade-offs that we are not aware of IMHO.
I understand your point Philippe, and of course, we do not know why Sony chose to go this way and not the other. I give them credit for making the 1st small IL FF mirrorless in the world, but what they have done, I really can't use. I tried, but I couldn't. The image degradation in the peripheral area is too severe, even with their own FE lenses. Whatever the reason for this sensor stack, it can't be right from my point of view.
Edward, I agree about the sensor stack. However, I don't think the native lenses really suffer from it. I also see the negative effects you describe, but I blame the lens designs. When I put on an adapted lens that I also used on a DSLR I don't really see a difference in the peripheral area. What I do notice is exaggerated field curvature. This is a result of that sensor stack. With the A7 stack you also get sensor reflections as a "bonus".
Aug 28, 2014 at 05:28 AM
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adamdewilde wrote:
This is actually what I was thinking as well.. Zeiss dropped their ZM lenses mid-design to focus on what they felt was a growing market and technically the future of photography. FF Mirrorless. If Nikon/Canon/Fuji ever jumped into that market, all Zeiss would have to do is design a new casing. As I'm sure they'll design the lenses with a bit of wiggle room in the casing for distance to sensor changes (sort of like the touit fuji/sony).
As for peoples comments about Zeiss designing lenses for Sony's A7 sensor stack thickness.. I actually don't think they will. I think the lenses will be designed based on less specific parameter. As to keep them as future proof and universal as possible. I also doubt they'll be soulless perfect lenses (55FE). I'd think that Zeiss would build them with character (think 50 1.5 sonnar characteristics), as to draw in photographers, rather then just everyday consumers. Since they'll have to compete with Sony and Sony will always take the majority of the market of everyday consumers.
Mind you, I could just be dreaming But I think it would be hard to top the 55FE, really not much wrong with it other then being a bit boring SOOC. ...Show more →
Adam, I think the 55FE is a good lens, but I think Zeiss could improve on it in two important ways. First, I am not overly fond of the bokeh from the 55FE and think a new lens could have a lot better bokeh. The 50 f/1.5 ZM, for example, does, IMO, have quite a bit better bokeh, so maybe that was part of what you meant as well. Second, it is nothing special in terms of correcting for CA. If Zeiss added some APD glass (as their newer ZF/ZE lenses had and the 55FE does not), then I think we could see a noticeable reduction in CA. Maybe not a full APO lens, but they could do much better than the 55FE. So for me, I am hoping that the new 50 Loxia has a lot nice bokeh and a lot better CA control and then even if it is a bit more expensive (as I expect), then I think about getting it eventually.
If either of these things are missing, however, then I probably won't be that interested. If it is a true APO, and the bokeh is only ok, I might get it eventually but I probably won't, and if it doesn't have improved CA control then the bokeh would have to be better than my Rokkor 58 f/1.2 (a pretty tall order) for me to consider it.
Aug 28, 2014 at 08:30 AM
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michaelwatkins wrote:
Which designs? Full frame DSLR or M?
Zeiss themselves quite some time ago was dissing their own M designs as being unsuitable for the Sony platform. From that moment on it seemed more logical to assume we'd see all new product.
All good news for E mount. Yay.
More specifically what Zeiss was saying is that their Biogon designs were unsuitable for the Sony platform (distagon, planar, and sonnar are fine). That suggests that their 21-35 ZM lenses would have to be redesigned, but maybe not their other ones. We still don't know whether the 50, for example, that is now rumoured will be based on the ZM 50 f/2 planar or whether it will be a new design. If it is based on the ZM planar it will come in at a price likely below the 55FE, but if it is significantly redesigned with a floating element and high performance glass then it will cost a lot more. It will be interesting to see which way they went. What would be very disappointing would be a 50 f/2 planar a lot like the ZM, but costing a lot more money. That wouldn't make any sense and I hope it doesn't happen.
Aug 28, 2014 at 08:36 AM
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edwardkaraa wrote:
I think you're over estimating Sony, Philippe. We have seen a lot of stupid decisions in the past, decisions that crippled their output unnecessarily and lost them a lot of clients. The decision to add the glass thickness goes back to the A700 and A900. All UWA are completely screwed by this decision. No Sony or Zeiss wide performs correctly in the image periphery. The decision to remove the mirror and replace it with a translucent one that stays in the optical path cost them their DSLR user base, including myself and many others on this forum. Even with perfect lenses like the FE55 you can see the weird effects of the sensor stack in the image periphery especially on highlights and blur discs. I guess we AA less camera users like the Leica M are spoiled because we are used to the benefits of a thin stack so we get sensitive when we see unnecessary image degradation caused by some stupid engineer at Sony. Add to that the lossy raw compression and no uncompressed format, the mirror like surface causing flare and ghosts everywhere... etc. As for the b part, I have no doubt whatsoever about Zeiss abilities, but the sensor stack will inevitably put many restrictions on the lens design, size and weight that need not be there in the 1st place. ...Show more →
Edward, I think you are right about some of the dumb choice Sony has made (e.g., the translucent mirror in the DSLR "upgrade"), but I don't think the sensor stack is quite as bad as you make it out to be. As I understand the issue from Roger Cicala's excellent analysis with Brian Caldwell and several others, the issues is not as simple as thin stacks are good and thick stacks are bad. That is basically true if we are talking about lenses designed from film cameras. One important point to keep in mind is that it is worse the shorter the exit pupil. So for film lenses, the problems of the sensor stack are reduced if the sensor stack is thin and the exit pupil is long.
Leica which has to deal with a lot of legacy lenses designed for film, when they started making digital cameras smartly made the sensor stack as thin as they could. This was especially important for them because many of these legacy lenses had very short exit pupils. One thing that Leica has also done, however, is that as they have come out with new lenses since going digital it is pretty clear they have lengthened the exit pupil.
Now if I understand Roger and Brian's analysis, however, if you design the lenses for the sensor stack a thick stack does not need to cause problems. I suspect the 55FE is a little under designed to handle the sensor stack fully. I expect, however, these new Loxia lenses to be fully designed to handle the stack, which incidentally won't make them bad candidates for any other possible mirror less formats. Almost all FF cameras and APS-C cameras too (other than Leica), have about a 2mm sensor stack according to Roger's tear down, and the one clear exception is an interesting one (earlier Canon 1 series cameras that had to deal with a lot more lenses designed for film). So, I don't think the sensor stack will completely ruin these cameras. They will work fine for lenses designed for the sensor and although the lens won't quite react optimally even older lenses with a long enough exit pupil will still do quite well especially at narrower apertures. The problems are worse at wider apertures as well as one might expect.
Steve Spencer wrote:
More specifically what Zeiss was saying is that their Biogon designs were unsuitable for the Sony platform (distagon, planar, and sonnar are fine). That suggests that their 21-35 ZM lenses would have to be redesigned, but maybe not their other ones. We still don't know whether the 50, for example, that is now rumoured will be based on the ZM 50 f/2 planar or whether it will be a new design. If it is based on the ZM planar it will come in at a price likely below the 55FE, but if it is significantly redesigned with a floating element and high performance glass then it will cost a lot more. It will be interesting to see which way they went. What would be very disappointing would be a 50 f/2 planar a lot like the ZM, but costing a lot more money. That wouldn't make any sense and I hope it doesn't happen. ...Show more →
My guess is (I might be wrong!) - same 50/2 E-mount design as the Biogon design, just different mount and a higher price tag. Doesn't make sense from a technical improvement point of view, but for marketing reasons since Zeiss might expect to see better sales numbers in small size E-mount MF lenses.
Steve Spencer wrote:
Edward, I think you are right about some of the dumb choice Sony has made (e.g., the translucent mirror in the DSLR "upgrade"), but I don't think the sensor stack is quite as bad as you make it out to be. As I understand the issue from Roger Cicala's excellent analysis with Brian Caldwell and several others, the issues is not as simple as thin stacks are good and thick stacks are bad. That is basically true if we are talking about lenses designed from film cameras. One important point to keep in mind is that it is worse the shorter the exit pupil. So for film lenses, the problems of the sensor stack are reduced if the sensor stack is thin and the exit pupil is long.
Leica which has to deal with a lot of legacy lenses designed for film, when they started making digital cameras smartly made the sensor stack as thin as they could. This was especially important for them because many of these legacy lenses had very short exit pupils. One thing that Leica has also done, however, is that as they have come out with new lenses since going digital it is pretty clear they have lengthened the exit pupil.
Now if I understand Roger and Brian's analysis, however, if you design the lenses for the sensor stack a thick stack does not need to cause problems. I suspect the 55FE is a little under designed to handle the sensor stack fully. I expect, however, these new Loxia lenses to be fully designed to handle the stack, which incidentally won't make them bad candidates for any other possible mirror less formats. Almost all FF cameras and APS-C cameras too (other than Leica), have about a 2mm sensor stack according to Roger's tear down, and the one clear exception is an interesting one (earlier Canon 1 series cameras that had to deal with a lot more lenses designed for film). So, I don't think the sensor stack will completely ruin these cameras. They will work fine for lenses designed for the sensor and although the lens won't quite react optimally even older lenses with a long enough exit pupil will still do quite well especially at narrower apertures. The problems are worse at wider apertures as well as one might expect....Show more →
I think the question is more intersting put this way - what are the benefits/ advantages of having a thick sensor stack? We know the disadvantages - and I tend to agree with Edward on those. One possibility is simply cost, maybe versatility of application. The other, which Leica has shown in the past, is proper IR filtering. Others?
Tariq Gibran wrote:
I think the question is more intersting put this way - what are the benefits/ advantages of having a thick sensor stack? We know the disadvantages - and I tend to agree with Edward on those. One possibility is simply cost, maybe versatility of application. The other, which Leica has shown in the past, is proper IR filtering. Others?
I woudn't be surprised if it is the same sensor stack as now being used also in the D810 DSLR. Simply for cost savings in the sensor production, it might be easier to have the same sensor sourced out both for mirrorless and DSLR cameras. For DSLR lenses the thicker stack doesn't seem to be an issue. Possible that the drawbacks especially with some wide angle rangefinder lenses weren't considered as being worthwhile to make a separate sensor production line with a thinner stack.
retrofocus wrote:
I woudn't be surprised if it is the same sensor stack as now being used also in the D810 DSLR. Simply for cost savings in the sensor production, it might be easier to have the same sensor sourced out both for mirrorless and DSLR cameras. For DSLR lenses the thicker stack doesn't seem to be an issue. Possible that the drawbacks especially with some wide angle rangefinder lenses weren't considered as being worthwhile to make a separate sensor production line with a thinner stack.
Yes, that's exactly what I was thinking. I do suspect there is a performance hit with even SLR wides with the thick stack off axis though.
retrofocus wrote:
I woudn't be surprised if it is the same sensor stack as now being used also in the D810 DSLR. Simply for cost savings in the sensor production, it might be easier to have the same sensor sourced out both for mirrorless and DSLR cameras. For DSLR lenses the thicker stack doesn't seem to be an issue. Possible that the drawbacks especially with some wide angle rangefinder lenses weren't considered as being worthwhile to make a separate sensor production line with a thinner stack.
I doubt it. The D800 has much less issues with sensor flare than the A7, even with the same lenses. The D810 could in theory be worse, but that just doesn't make any sense.
carstenw wrote:
I doubt it. The D800 has much less issues with sensor flare than the A7, even with the same lenses. The D810 could in theory be worse, but that just doesn't make any sense.
A7 is not the accurate serrogate though. The A7r is the one that shares the same sensor - and suffers less with regard to flare compared to A7 btw.
carstenw wrote:
I doubt it. The D800 has much less issues with sensor flare than the A7, even with the same lenses. The D810 could in theory be worse, but that just doesn't make any sense.
Are you referring to the D800 or the D800E? The D800 comes with the AA filter which the A7R (same MP resolution) doesn't have. I am not sure if there is a difference in the sensor design when comparing D800E with D810.
My understanding based on reading everything that's been posted on the subject here and elsewhere is:
1. The filter stack imparts a small amount of spherical aberration everywhere in the image (this was mentioned in discussions about the MB speed booster, which Brian Caldwell claims corrects for this aberration).
2. The filter stack causes "smearing" in the corners when rays strike the sensor at an oblique angle.
3. The design sensor itself causes colour shift in the corners when rays strike the sensor an an oblique angle due to colour cross talk.
Lens designers can counter the first by leaving the lens overcorrected for SA, and the second by increasing the exit pupil distance (the third can be handled in software).
So if you remove the filter or make it much thinner, then the increased exit pupil distance is of no consequence but you will end up slightly overcorrected for SA.
This might go some way to explain why manufacturers are reluctant to change filter stacks. Changes to the registration distance / infinity focus as a result of thinning the stack can surely be solved by moving the sensor.
Tariq Gibran wrote:
I think the question is more intersting put this way - what are the benefits/ advantages of having a thick sensor stack? We know the disadvantages - and I tend to agree with Edward on those. One possibility is simply cost, maybe versatility of application. The other, which Leica has shown in the past, is proper IR filtering. Others?
Exactly.
I refuse to believe Sony engineers that ignorant to the effects of the filter stack. Olympus chose to have a whopping 4mm filter stack and make their lenses telecentric (exit pupil at infinity) as a result. There must have been a good reason to do this.
It could just come down to cost. according to TheSuede thinner filter materials are available but at additional cost. It's possible they want to get the entry level camera body price right down, and assume higher end users will pay extra for lenses as a result. That seems a bit of a stretch, though.
But I think it would be hard to top the 55FE, really not much wrong with it other then being a bit boring SOOC. 
, is proper IR filtering. Others?