Uhoh7 ... why do you keep insisting that people have been saying that RF wides are unusable?
Most folks have said that they will either be more challenged (vignetting/color shift/smearing) by the steeper angle in Zones B & C or that we'll have to be very selective @ which ones will perform well in the edges/corners, with realistic expectations based on their inherent optical projection design that may not produce optimal IQ without additional PP correction efforts.
The CV's seem to be doing rather well as a "brand". I suspect there is something in their design approach that plays well here. Maybe a certain amount of curvature/mustache etc. that they have incorporated for contending with Zones B & C (albeit intended for film) that keeps those angles of incidence within the limits of playing nicer with the sensor (lenses/toppings). Also, one might consider if they are capturing a near/far scene vs. predominantly infinity. They might be better suited for street than for landscape.
Of all that I've seen so far, the CV's have caught my attention the most (as a brand/group) as being pragmatic RF WA/UWA glass options ... imo, they're worthy to explore with more fervor and microscopy to ascertain those applications to which they are well suited.
NOTE:
After learning of undisclosed crops being posted ... my assessment of CV's may warrant reconsideration.
'Of all that I've seen so far, the CV's have caught my attention the most'
Agree, they seem to deliver better.
I'm not sure many would be happy to endure a high degree of functionality loss such that a lens costing $$ is good only for f5.6 and smaller apertures. That is very different to choosing that aperture range yourself rather than having it imposed on you by IQ loss - imagine you are out and see something you need a fast aperture for and 'oh no'.
...maybe if you already own it, and have nothing else you want to use it on; but to buy to use on one of these cameras? Just peering at corners/colours would drive me spare in no time.
it is symptomatic of the fact that we are closing in fast on the exacting science of system lens-sensor imaging solutions. The days of shoe-horning a V8 into a four cylinder car and making a mess of weight distribution and handling are long gone. And that is the real take home lesson of the FE lenses (and more quietly, the RX10 and its signal processing).
Zeiss (and other makers) hold the solution, no doubt, and this schemozzle can then melt away into a last quarter 2013/first quarter 2014 problem. The lenses themselves almost know they do not belong and hope for a Leica solution.
IMO - crops should not be posted here. It gives a false impressions that some lenses are sharp when (perhaps) they are not. I also don't really care to see shot's heavily corrected for color shift and/or vignetting...
p.115 #10 · A7/A7r - performance with WA RF lenses
My conclusions so far :
Corner smearing is the same with the A7 and A7R.
Colour cast ist much higher on the A7R!
Chromatic Aberations are higher on the A7R !
Tested this on both production cams with an
Leica Elmar-M 24mm f3.8
Contax G 28mm 2.8
Contax G 35mm 2.0
Leica Summilux Asph 35mm 1.4 non-fle
and longer lenses.
Have a nice day !
p.115 #14 · A7/A7r - performance with WA RF lenses
Despite the stellar MTF, the SEM 24 has a surprisingly heavy vignette, even compared to the ZE 21/2.8. It retains only 40% of illumination at f8 - which by the above image and the data sheets seems to be as good as it gets - whereas the ZE 21mm retains 70% at f5.6 and further improves at smaller apertures, as do other Distagons such as 15/2.8 and 25/2.
Noise shows up when low tones are lifted, of course, and we see variations in skies rather easily. I believe I would find it unacceptable because the vignette is stronger than the 21/2.8 at its frame edge by the image height of 12mm! And since it is a long slow increase to the vignette you get the effect of an APS-C lens on a full frame sensor. I just looked up the 21mm and 18mm SEM and they are the same or worse. You really would need to rely on excellent shadow lifting profiles for these to work acceptably.
Being curious, I took a look at two ZMs - 21/4.5 and 21/2.8 and found that neither of these puts more than 40% illumination at the corners either, at f8 and f5.6 respectively...this appears to be an RF M mount lens issue. Then I did a google search for vignette and ZE21/2.8 and found loads of threads full of complaints, including our friends at photozone...repeating the search for the SEM and ZM lenses with virtually no mention at all - draw your own conclusions...
p.115 #15 · A7/A7r - performance with WA RF lenses
There was a very interesting comparison on LUF between the M and A7r in a controlled studio setting using the 35 cron on both cameras, and the 35 FE on the A7r. I am not talking about lens performance here because both lenses performed almost identically in this close up shoot out. But what I found very important and essential to understand how these cameras work is that there was a black synthetic fabric gear bag in the frame. It was rendered as purple in the M shot, while it is a pure black in the A7r shot.
Now to put things in perspective, for those not familiar with this issue, the 1.3x crop factor M8 had a very thin UV/IR cut filter to minimize corner smearing, but that introduced what is called IR contamination, causing black synthetic fabrics to become purple, as well as screwing the colors up completely in situations with high IR. The M9 is said to have a thicker filter, and exhibits this problem to a much lesser extent, but still visible in some situations. the M filter is suspected to be slightly thinner to take in account the higher mp and the new microlens design, hence the higher IR contamination.
Now it has to be that Sony decided to put a proper strength/thickness IR filter in front of the sensor, first because color is very important for Sony, second because the lenses are specially designed for the sensor, so a problematic ultra thin filter is not really needed. The result of which is high fidelity color and corner smearing with RF wides, but why should Sony care. So, as Kent likes to say, pick your poison, would you like smearing, or IR contamination, or a bit of both?
p.115 #16 · A7/A7r - performance with WA RF lenses
edwardkaraa wrote:
There was a very interesting comparison on LUF between the M and A7r in a controlled studio setting using the 35 cron on both cameras, and the 35 FE on the A7r. I am not talking about lens performance here because both lenses performed almost identically in this close up shoot out. But what I found very important and essential to understand how these cameras work is that there was a black synthetic fabric gear bag in the frame. It was rendered as purple in the M shot, while it is a pure black in the A7r shot.
Now to put things in perspective, for those not familiar with this issue, the 1.3x crop factor M8 had a very thin UV/IR cut filter to minimize corner smearing, but that introduced what is called IR contamination, causing black synthetic fabrics to become purple, as well as screwing the colors up completely in situations with high IR. The M9 is said to have a thicker filter, and exhibits this problem to a much lesser extent, but still visible in some situations. the M filter is suspected to be slightly thinner to take in account the higher mp and the new microlens design, hence the higher IR contamination.
Now it has to be that Sony decided to put a proper strength/thickness IR filter in front of the sensor, first because color is very important for Sony, second because the lenses are specially designed for the sensor, so a problematic ultra thin filter is not really needed. The result of which is high fidelity color and corner smearing with RF wides, but why should Sony care. So, as Kent likes to say, pick your poison, would you like smearing, or IR contamination, or a bit of both?
That's the best explanation I have found anywhere. Thanks Edward!
I think I'm gonna go crazy and try to find a Leica 19mm R. Life is short, right?
This + my 28 R could be a nice setup for wides....
p.115 #18 · A7/A7r - performance with WA RF lenses
philip_pj wrote:
Despite the stellar MTF, the SEM 24 has a surprisingly heavy vignette, even compared to the ZE 21/2.8. It retains only 40% of illumination at f8 - which by the above image and the data sheets seems to be as good as it gets - whereas the ZE 21mm retains 70% at f5.6 and further improves at smaller apertures, as do other Distagons such as 15/2.8 and 25/2.
Noise shows up when low tones are lifted, of course, and we see variations in skies rather easily. I believe I would find it unacceptable because the vignette is stronger than the 21/2.8 at its frame edge by the image height of 12mm! And since it is a long slow increase to the vignette you get the effect of an APS-C lens on a full frame sensor. I just looked up the 21mm and 18mm SEM and they are the same or worse. You really would need to rely on excellent shadow lifting profiles for these to work acceptably.
Being curious, I took a look at two ZMs - 21/4.5 and 21/2.8 and found that neither of these puts more than 40% illumination at the corners either, at f8 and f5.6 respectively...this appears to be an RF M mount lens issue. Then I did a google search for vignette and ZE21/2.8 and found loads of threads full of complaints, including our friends at photozone...repeating the search for the SEM and ZM lenses with virtually no mention at all - draw your own conclusions... ...Show more →
It's likely an RF issue because it's a tradeoff made by the lens designers to take advantage of other benefits offered by these lens designs not possible with typical SLR lenses of similar focal lengths. Namely, I think, size. The vignetting is likely a factor of the exit pupil and the steeper light ray angles towards the edges of the image area, which is compounded by digital sensor design (compared to film).
When I shoot the 21 Lux against the 21 SEM, the Lux, which vignettes A LOT wide open, is brighter at the edges than the SEM, when both are at f/3.4 or f/4.
As for vignetting at f/8... no, it doesn't bother me. I have yet to view one of my images from the SEM, ZM21, etc., in this aperture range and think it was ruined by vignetting. Like bokeh, high ISO noise structure, etc., vignetting seems to be a subjective like or dislike. My feeling, being a recent RF 'convert' is that SLR shooters are more sensitive to this 'problem' and more apt to point it out.
Just one more reason not to specifically buy RF wides for the Sony cameras.
My feeling is that for those coming from the digital RF world, the main problem with these cameras and RF lenses will be the potential for smearing, followed by the hassle of cleaning up color cast. While vignetting is much like color cast, but just a luminance 'defect', it is less objectionable.
p.115 #19 · A7/A7r - performance with WA RF lenses
snowboarder wrote:
That's the best explanation I have found anywhere. Thanks Edward!
I think I'm gonna go crazy and try to find a Leica 19mm R. Life is short, right?
This + my 28 R could be a nice setup for wides....
Thank you snowboarder. Someone at LUF quoted this passage from Leica FAQ. I think it is very relevant to this issue:
"5. Do I have to use a UV/IR filter on the new M? How infrared sensitive is the new M?
All image sensors for Leica M cameras are designed and constructed to provide the best possible image quality with Leica M lenses. One prerequisite for this is the use of an extremely thin infrared filter on the image sensor to ensure a full corner-to-corner rendition of details. The consequence of this thin filter is that infrared light is not completely absorbed. This may result in slight color variations in certain lighting situations. This can be particularly critical when photographing dark-colored textiles in incandescent light. The infrared sensitivity of the M8 is so high that we strongly recommend the use of a UV/IR filter. The infrared sensitivity of the M9 and M (Typ 240) cameras is approximately 5% of that of the M8; these cameras can therefore be used without an IR cut filter. Nevertheless, when shooting critical subjects, it cannot be completely ruled out that corrections in post processing may be necessary."
So we now fully understand why Sony used a full strength IR filter even if it jeopordizes the use of M mount wides.
p.115 #20 · A7/A7r - performance with WA RF lenses
Uhoh7 wrote:
"somebody forgot to tell this guy his glass was unusable. Do you think he missed this thread, or what? PS I'm told both are cropped"
I am with Rustybug in this one, judging FF by cropped photos??!
Whenever a new camera/sensor solution arrives it is mandatory to pick it apart to find out it's strengths and weaknesses so that one can balance them out and see if it is a worthwhile investment. Your mileage may and will mostly vary. Posting sample shots that are cropped and hiding the defects introduced _by the sensor_ is doing nobody a service.
Nobody said the glass was unusable but we are talking judging a FF camera with FF lenses. A crop is a compromise and for some an unwanted one. Your defending the A7/R on false premises is getting a bit long in the tooth.
Having said that there are a few select RF wide angle lenses that seem to work fine with the A7/R and I'd like to see more. Uncropped, of course. If there are at least a few different wide angle lenses that work good enough it would serve as a stop gap solution until Sony/Zeiss/Sigma/Voigtländer churns out a new great wide angle lens for the system.
The samples that have been posted with shots from the Leica 75/1.4 and "tricky" lenses like the ZM 50/1.5 Sonnar look beautiful on the A7R indeed. It looks like the lens character really comes out well on FF.
A set of a few different wide angle lenses the A7R, for the most part not so impressive but two lenses fare better than the others:
Crops for evaluating FF 
