wayne seltzer wrote:
Except didn't we have a thread a while back about how the Z* 35/2 was considered to have a FLE design which is not mentioned in the Zeiss description?
I believe so but keep in mind that this is Sony marketing, not Zeiss.
The Sony G 35 1.4 states this about it's features:
"• The double floating element design results in sharp images at all focal lengths."
wayne seltzer wrote:
What do you think causes that microcontrast/contrast difference between the two Zeiss designed lenses?
The design. Which encompasses glass types, element designs, coatings, etc. The whole thing. You could put T* coatings on a sheet of flat Schott glass and you'd end up with a flat sheet of glass, not a lens. Though it would have good transmission
As far as microcontrast, I try not to get caught up in that buzz word. I know it has a specific, real thing, but on this forum, you never know what someone means by it when they say microcontrast, whether a real defintion or some hocus pocus.
Presumably Zeiss has had some input on both lines of lenses. How much, I don't know. It's perfectly reasonable that ZA line has different design goals than the ZS, either due to Sony's urgings or actual design input.
The designation "floating" is more confusing than enlightening. Ignore it.
An I.F. design is by virtue "floating" as per the accepted definition - it has at least two surface>surface distances changing internally with the focusing actuation. The one before, and the one after the focusing group... What is normally designated "floating" seems to be a rear element (or group) that just happen to fail to move as the focusing group (internal or unit) moves forward. :-)
The 35/1.4 is , if I read the drawings in the service manual correctly, an R.F design - with a stationary "float" group sealing the back end of the lens. The difference between this and an "inner focusing" design is in reality very small - you just do the focusing actuation movement behind the aperture in stead of in front of it. OR, you can insert a stationary lens element between the aperture and the rear focusing group - then you'd have an I.F. lens in stead of an R.F. lens.
It's all a play with words and definitions - what parts of the lens changes its' distance related to the focal plane as you focus and what doesn't. If the aperture moves, and if the focusing actuation is before or after the aperture. If the focusing actuation is enclosed between two stationary glass surfaces or not. You can get equally brilliant results with any of the variations, but lenses that are totally unit focusing can only be optimized for one focusing distance.
Simple internal focusing is not what I think of with regard to a floating element designation or, more specifically, FLE. I always thought of this meaning that the elements that are moving internally do so not only with respect to the stationary elements but also with regard to one another such that close focusing ability is improved.
The 24 focuses by moving the rear end group so it is not unreasonable to suspect it does have FLE. Also Zeiss did confirm to me on their facebook page that ZA rendering may be different than their own lines as they design them to fit better in the Sony lens line.
edwardkaraa wrote:
The 24 focuses by moving the rear end group so it is not unreasonable to suspect it does have FLE. Also Zeiss did confirm to me on their facebook page that ZA rendering may be different than their own lines as they design them to fit better in the Sony lens line.
Don't most wide angle lenses focus by moving the rear end group? That seems to be the case with most of the inverted tele wide angle lenses I have used over the years, and not all of them have had FLE.
Good point. Looking at my ZS 25 and 35, they move both the front and rear groups for focusing. There is no indication that the 35 has FLE as the rear element moves harmoniously with the front, unlike my 2 previous 18 and 35 c/y which had FLE.
edwardkaraa wrote:
The 24 focuses by moving the rear end group so it is not unreasonable to suspect it does have FLE.
Not sure that means anything, my ZF 25 also moves the rear element group when focusing -- and we are pretty sure that the ZF 25 doesn't have a FLE design.
edwardkaraa wrote:
Also Zeiss did confirm to me on their facebook page that ZA rendering may be different than their own lines as they design them to fit better in the Sony lens line.
I suspect that mostly has to do with having a consistent color across the lens line. The ZF line has a particular color rendering across the line that is different from the color rendering across the Contax lens lines. It would make sense for Zeiss to match the color rendering of the ZA lenses to the rest of the Sony (née Minolta) lens line. That would make sense.
wayne seltzer wrote:
Except didn't we have a thread a while back about how the Z* 35/2 was considered to have a FLE design which is not mentioned in the Zeiss description?
Wayne is right, we did indeed. And thes info came from a member who is a retired Zeiss employee, and who said that he'd told marketing a few times about the floating element, to no good effect...
philber wrote:
Wayne is right, we did indeed. And thes info came from a member who is a retired Zeiss employee, and who said that he'd told marketing a few times about the floating element, to no good effect...
I would be glad to know that it does, but nothing indicates from the way the rear elements move that it has FLE. In the Contax 35/1.4 and 18/4, the rear elements movement clearly shows they have FLE, but the ZS 35/2 rear element movement is no different than the 25/2.8 or 50/1.4.
Lotusm50 wrote:
I suspect that mostly has to do with having a consistent color across the lens line. The ZF line has a particular color rendering across the line that is different from the color rendering across the Contax lens lines. It would make sense for Zeiss to match the color rendering of the ZA lenses to the rest of the Sony (née Minolta) lens line. That would make sense.
Lotusm50,
I asked Zeiss specifically about why my ZS lenses seem to have different rendering than the ZA, particulary regarding contrast and 3D, and it took them several days to reply, which makes me think they really wanted to chose their words carefully. This was their reply:
" The ZA line is the result of close cooperation with Sony and is optimized to meet the requirements of the target groups addressed by Sony's products. Therefore, it is possible for two similar focal length types to have different designs and deliver different results. What they all have in common is the proven Carl Zeiss quality and the company’s aspiration to ensure the best imaging results in any situation."
This makes me believe there are other differences than color rendering (ZA tend a bit towards Cyan). Perhaps Sony requires softer overall contrast and bokeh to match the existing Minolta designed line up. One thing for sure, while the ZE/F/S are a pure Zeiss product for which decisions about the target IQ and rendering are pure Zeiss decisions, Sony has for sure something to say regarding the ZA line, and it might not always coincide with what Zeiss wants.
28/2 has asph element and FLE.
How does it focus?
I would have thought that the
same 24/2 would be close to thatlens in design maybe without the field curvature at infinity.
wayne seltzer wrote:
These large DOF landscape lens tests are hard to compare if there is some field curvature going on or not which will help the closer corners. I like the planar lens tests against the side of a large building like how Diglloyd and Le monde de la Photo perform lens tests.
Wayne,
As you can see in Steve's test, there are obvious differences in the corners of the tested lenses, so it doesn't seem so hard to compare them. The fact is that the ZA 24 corner performance sweeps the floor with the 24-70, 16-35, Minolta 17-35 and 24/2.8.
In my experience, the ZS 25 corners are better than the 35/2 and 50/1.4. Zeiss MTF also tend to confirm my observation. They also show the 25 being not too far behind the 21 in the corners.
I don't want to comment on the 25 close range performance before I have enough experience with it, but so far, I definitely don't find it unusable. I will definitely post a few images that show its strengths and weaknesses when I have more time to shoot with it in normal conditions, as the weather is still bad in Bangkok, and all what I have done are snapshots around my apartment.
wayne seltzer wrote:
28/2 has asph element and FLE.
How does it focus?
I would have thought that the
same 24/2 would be close to thatlens in design maybe without the field curvature at infinity.
As The Suede said, it is not always possible to tell if a lens has a FLE from the focusing action. But if a lens focuses in a specific manner, you know for sure it has a FLE.
When you turn the focusing ring from infinity backwards, the rear element should start moving inwards. When you reach a certain distance, the rear element movement could either slow down, stop, or reverse direction and start moving outwards. This for sure is a FLE behaviour.
I asked Zeiss specifically about why my ZS lenses seem to have different rendering than the ZA, particulary regarding contrast and 3D, and it took them several days to reply, which makes me think they really wanted to chose their words carefully. This was their reply:
" The ZA line is the result of close cooperation with Sony and is optimized to meet the requirements of the target groups addressed by Sony's products. Therefore, it is possible for two similar focal length types to have different designs and deliver different results. What they all have in common is the proven Carl Zeiss quality and the company’s aspiration to ensure the best imaging results in any situation."
This makes me believe there are other differences than color rendering (ZA tend a bit towards Cyan). Perhaps Sony requires softer overall contrast and bokeh to match the existing Minolta designed line up. One thing for sure, while the ZE/F/S are a pure Zeiss product for which decisions about the target IQ and rendering are pure Zeiss decisions, Sony has for sure something to say regarding the ZA line, and it might not always coincide with what Zeiss wants. ...Show more →
And the FLE is in no way any rock solid guarantee for an improved focal range aberration consistency. A lens totally without FLE (solid unit focus or one-moving-part focus) may have superior performance to a FLE lens at each and every available focal distance - you just don't know, unless you're the designer of the lens...
This is just like the "aspherical" buzzword... Asphericals MAY improve a design - but in many cases it is in stead used to simplify the design, to give the manufacturer a possibility to use one lens in stead of two (or even three) to correct for 'something'. Then it is more of a "profit margin optimization" than a "performance optimization".
I understand your point about asph and FLE being potential over-hyped marketing words like APO but I haven't seen a Zeiss or Leica lens with asph and/or FLE which sucked.
My NIKON 24/1.4 has both and it has great resolution/sharpness both up close/wide-open and at distance stopped-down.Just missing the Zeiss microcontrast/contrast.
It would be a big mistake if the za 24/2 was not excellent close up wide-open.I can see even from the crappy dpreview samples that it looks to be good close up.Just wish they made it f1.4 instead of f2.
wayne seltzer wrote:
I understand your point about asph and FLE being potential over-hyped marketing words like APO but I haven't seen a Zeiss or Leica lens with asph and/or FLE which sucked.
Well, the Contax Zeiss 18/4.0 wasn't all that great and that was an FLE design.
"Asph" and "FLE", as well as "APO", have become marketing buzz work, and their use very loosely applied by many manufacturers. Merely having one of these "features" in your design, doesn't necessarily make a good lens.
wayne seltzer wrote:
Just wish they made it f1.4 instead of f2.
I'm with you there. It would have been the straw that made me switch to Sony.
Much comes down to who Sony thinks its "target groups" are. I wonder if those target groups are more or less will the spend, and more or less demanding than the target groups that Zeiss addresses with its ZF/ZS/ZE lens line.
