Sony FE Planar T 50mm f/1.4 ZA MTF and Variance Testing
OK, you probably know I don’t like ultra-long lens names. I don’t like lenses that are expensive (who does?). So when you throw out a 50mm lens with a long name, like the Sony FE Planar T* 50mm f/1.4 ZA, and price it at $1,500 I’m a bit predisposed not to like it.
Seriously, that’s a lot of money for a 50mm f/1.4 lens. Let’s take a quick price comparison of some common 50mm lenses.
| Zeiss Otus 55m | f/1.4 | $3,990 |
|---|---|---|
| Sony FE Planar | f/1.4 | $1,500 |
| Canon L 50mm | f/1.2 | $1,350 |
| Sigma 50mm Art | f/1.4 | $950 |
| Sony Sonnar 55mm | f/1.8 | $998 |
| NIkon 50mm G | f/1.4 | $447 |
I say all this just to point out that going into this test my thinking was it had better be really good or I’m going to mock it. For those of you who don’t like to read the articles, I’m not mocking it anymore. This lens is really, really good!
MTF Tests
This is our usual ‘average of 10 copies, each tested at 4 rotations’ graph. In order to keep the graph sizes reasonably large I’ll do a series of comparisons with the Sony FE 50mm f/1.4 MTF chart on the left, the comparison lens MTF on the right. We’ll start with the one that shut me up, comparing the Sony to the Zeiss 55mm f/1.4 Otus Distagon lens.
Compared to the Zeiss Otus 55m f/1.4
ADDENDUM: The original article contained our original Zeiss MTF curves, done about a year ago. After a polite inquiry and suggestions from Zeiss, we redid the MTF tests for the 55mm Otus and did, as they thought we would, bet better results. Here is the MTF graph showing the difference with new testing methods (on the right), which is, indeed, better than our original methods.
This doesn’t change my conclusions that the Sony has a better MTF in the center than the Otus, but does show that the Otus is better in the middle third of the image. I have left all other text and images unchanged and it continues below.
The Sony is phenomenally good in the center; just absolutely superb. From a resolution standpoint it is clearly better than the Otus in the center, and just as good as the Otus away from the center as well. There is a little sag of the Sony’s MTF halfway to the center but then improvement out to the edges.
One note about that ‘halfway sag’ for both of you who actually read the articles and don’t just look at the graphs. This may be an artifact of sensor cover glass. We are limited to a full mm cover glass increments when testing, so for Sony lenses we use 2mm, which is close, but not exactly the same optical thickness as what covers the sensor. (It’s probably about 0.25 thicker). We generally don’t think of a 0.25mm difference as significant for SLRs, but that may not be absolutely true with the short back-focus distance of the FE mount. In other words, the Sony lens may actually be a bit better than what we see here. Or they may not, we aren’t certain yet.
Compared to the Sony FE 55mm f/1.8
Remember for this comparison the aperture difference is significant. The f/1.4 lens has been tested wide open and that half-stop (Actually 2/3 of a stop. It was late. I was tired.) of aperture makes a lens significantly better.
The Sony FE 55mm f/1.8 ZA Sonnar is a really good lens, but even giving up a half stop of aperture, the 50mm f/1.4 is better in the center and generally nearly as good away from center. This is most impressive.
Compared to the Sigma 50mm f/1.4
We’ve evened up the apertures now, with two f/1.4 lenses, comparing the Sony to the Sigma 50mm f/1.4 A1 lens. The Sigma is significantly less expensive and in my mind the best ‘bang for the buck’ among 50mm lenses.
The Sigma is really good, and I won’t argue if the Sony is worth the financial difference. But from an MTF standpoint, the Sony is better.
Compared to the Nikon 50mm f/1.4 G
This is another unfair comparison, the Nikon 50mm f/1.4 G AF-S costs only a fraction of what the Sony does, but I thought it was a good “what you get for your money” comparison. The Nikon is a very nice, decent quality, usable lens. But the Sony is dramatically better, which at the price it should be.
Quick Summary:
The Sony Planar 50mm f/1.4 is expensive and not everyone needs to plop that much money down for a 50mm lens. But, if you do need one, it’s worth the money; it’s really superb. The center sharpness in particular is unheard of in a 50mm lens. This seems to be a pattern we’re seeing with some of the new Sony lenses, too: The fine resolution (at higher frequencies) is higher than we’re used to seeing.
From a pure value standpoint, the price is reasonable. Best quality prime lenses tend to cost well over $1,000 and some up to $2,000, and this is a best quality prime lens. Your shooting may not require a top-of-the-line 50mm lens and there are lots of other options in that focal length for FE shooters. But if you require the best one, then this would be the one you buy, at least based on bench test results. (Remember, I never suggest buying a lens based solely on test results. Go check out pictures, too.)
Optical Field
You may have been, like I was, impressed with how well the Sony maintained a high MTF away from center. The optical field helps show why, and it is also very impressive. Both the sagittal and tangential fields are almost perfectly flat from one side to the other. For some photographers that will be more important than absolute sharpness. But for those of you who aren’t aware, a field this flat is really an accomplishment. We rarely see it.
Variation
There was a time, early in the history of FE lenses, when I used to wince mentally before I pulled up the Variation graphs for a new lens. That time seems to be past, with excellent results from the more recent Sony lenses. So I was looking forward to seeing how the Planar 50mm f/1.4 lens did.
I have two things to remind you about. First, remember our variation graphs now show only 1 Standard Deviation, rather than 1.5 that we used months ago. Also remember that our bench cuts off about half of the 20mm (edge) readings on Sony FE lenses, so take the extreme edge variation with a grain of salt. I’ve put a 50% gray box over the questionable area to help clarify this.
The first comparison I pulled up was against the Sony 55mm f/1.8 ZA Sonnar, which is one of the better and more popular Sony primes.
The new 50mm f/1.4 ZA Planar clearly has less variation than the 55mm f/1.8 did. It’s really nice and consistent.
To give you a more general comparison, here is the 50mm ZA Planar matched up against the Sigma 50mm f/1.4 Art lens, another really good 50mm lens with very reasonable sample variation. The variation is very similar; both lenses are quite consistent. (As always, a reminder to please not confuse autofocus accuracy with optical consistency. They have nothing in common.)
Overall, the Sony FE 50mm f/1.4 Planar has very reasonable sample variation, about what we see in most other high-quality 50mm prime lenses from other manufacturers.
Summary
MTF tests like this give you a good idea of how sharp the lens might be and how much sample variation you should expect. On the basis of these, the Sony 50mm f/1.4 Planar is as good as anything available. For those of you who need a really high-quality 50mm lens on an FE mount camera, it looks like your best choice.
The very flat field with almost no curvature is another plus, and one that may appeal to photographers every bit as much as the excellent MTF does.
But of course the proof is in the pictures. We’re starting to see some sample images online and that will explode shortly, giving you a chance to evaluate the bokeh and the lens’ performance in various lighting conditions. But unless those greatly surprise me, I think a lot of people are going to love this lens.
Roger Cicala, Aaron Closz, and Markus Rothacker
Lensrentals.com
July, 2016
89 Comments
disqus_FQr0oPsUDS ·
Thanks for the super-quick review of this new Sony Lens. I can imagine this would also be a great ’75mm’ portrait lens (via Sony’s APS-C mode on their A7 Cameras)… Can’t wait to rent it!!
Jimmy Andino ·
Thanks for the super-quick review of this new Sony Lens. I can imagine this would also be a great '75mm' portrait lens (via Sony's APS-C mode on their A7 Cameras)... Can't wait to rent it!!
Lee ·
I have some questions for Zeiss.
Lee ·
I have some terse questions for Zeiss about the size/weight of the Otus 55 and especially Milvus 50.
Joel Benford ·
Do you happen to measure transmission and vignetting, Roger?
Some of us available darkness dwellers are interested in 50/1.4s more for the light gathering more than the shallow DoF. 🙂
Roger Cicala ·
Joel, we can’t directly measure transmission and vignetting, our bench has a work around but it’s time consuming as can be.
Joel Benford ·
Do you happen to measure transmission and vignetting, Roger?
Some of us available darkness dwellers are interested in 50/1.4s more for the light gathering than the shallow DoF. :)
Roger Cicala ·
Joel, we can't directly measure transmission and vignetting, our bench has a work around but it's time consuming as can be.
S.Yu ·
Any chance on testing a few copies on 1mm sensor glass? If we see a much worse dip then that pretty much explains it.
Roger Cicala ·
1mm is worse and 3mm is worse, but that doesn’t show us that 2.3mm wouldn’t be better than 2mm, I’m afraid.
S.Yu ·
How much worse is 1mm?
Roger Cicala ·
It’s significant off axis.
S.Yu ·
…and significant means p<0.05? So the mean difference would be?
Roger Cicala ·
S. Yu, I apologize, I didn’t realize you wanted statistical analysis of significance. We didn’t do a multiple copy anaysis of the sensor stack difference – we’ve done it on some lenses in the past as we fleshed out technique but we don’t have the extra 10 hours to do that on every lens. We simply take a single lens, check that it’s a well centered copy, then measure it with and without glass in place to determine if it is better with glass. Then proceed with our testing.
Roger
S.Yu ·
lol ok, I just wanted the mean value of the few tested lenses at the data points at the dip actually.
Roger Cicala ·
S. Yu. I understand and that’s a pertinent point. In the fall, when things slow down for us a bit, I’ll try to do a short series with the common lenses at both 1 and 2mm to at least give some ideas. I’m still getting used to the increased sensitivity to stack thickness that the short backfocus distance of the mirrorless mount gives. We did our initial work with SLR lenses and things weren’t as sensitive.
S.Yu ·
Great, thank you!
Roger Cicala ·
It's significant off axis.
S.Yu ·
...and significant means p<0.05? So the mean difference would be?
Roger Cicala ·
S. Yu, I apologize, I didn't realize you wanted statistical analysis of significance. We didn't do a multiple copy anaysis of the sensor stack difference - we've done it on some lenses in the past as we fleshed out technique but we don't have the extra 10 hours to do that on every lens. We simply take a single lens, check that it's a well centered copy, then measure it with and without glass in place to determine if it is better with glass. Then proceed with our testing.
Roger
S.Yu ·
lol ok, I just wanted the mean value of the few tested lenses at the data points at the dip actually.
------
Of course, I meant with 1mm glass because I'm interested in the Kolari mod...
Roger Cicala ·
S. Yu. I understand and that's a pertinent point. In the fall, when things slow down for us a bit, I'll try to do a short series with the common lenses at both 1 and 2mm to at least give some ideas. I'm still getting used to the increased sensitivity to stack thickness that the short backfocus distance of the mirrorless mount gives. We did our initial work with SLR lenses and things weren't as sensitive.
Roger Cicala ·
1mm is worse and 3mm is worse, but that doesn't show us that 2.3mm wouldn't be better than 2mm, I'm afraid.
Paul Gero ·
Thanks Roger for your test. I’ve been fortunate to have one to test and shoot and the look is so nice….thanks for reaffirming what I suspected — it’s a FINE piece of glass.
Paul Gero ·
Thanks Roger for your test. I've been fortunate to have one to test and shoot and the look is so nice....thanks for reaffirming what I suspected -- it's a FINE piece of glass.
Carleton Foxx ·
I hope both your customers AND your investors realize what an amazing value you provide with this kind of reportage. The only way you could improve upon it would be to mount OLAF in a Sprinter van and take your show on the road. Dancing girls and the Marine Corp Band optional.
Roger Cicala ·
Thank you Carleton. I’m working on dancing girls.
Edna Bambrick ·
You got that all wrong. It’s the dancing girls that work on us. : )
timerickson ·
Oh boy… can we please not use women as sex objects? Let’s stick to just the Marine Corp Band for entertainment on this hypothetical roadshow
Roger Cicala ·
Thank you Carleton. I'm working on dancing girls.
Arthur Meursault ·
You got that all wrong. It's the dancing girls that work on us. : )
timerickson ·
Oh boy… can we please not use women as sex objects? Let's stick to just the Marine Corp Band for entertainment on this hypothetical roadshow
Edna Bambrick ·
How are the Otus results so far off of the Zeiss advertised measurements and consistently so? If an Otus lens performed as badly as OLAF is indicating then those lenses would be dramatically out of spec.
Roger Cicala ·
Edna, I can’t tell you that because we don’t know Zeiss’ testing metrics. Do they use white light? Photopic light? Green light? How many points do they measure? More importantly are their MTFs the average of numerous copies? We have some Otus lenses that are about as good as what the Zeiss graphs show. It’s not all of them, though, and when we average multiple copies this is what we get. Or if I test with monochromatic light, the MTFs are better. Even using a different reticle (pinhole versus cross versus separate lines).
You bring up a good point though: what is spec? We don’t know. No manufacturer releases what their acceptable spec are. (I know a few but I’m under nondisclosure about them, and I don’t know Zeiss’ at any rate.)
Edna Bambrick ·
Roger, I appreciate the response but the DPR article brings in more doubt to the overall story here. What I ventured over there as a possibility (and a credit to LR) that it’s possible that lenses sent to LR are cherry picked knowing your advanced testing capabilities and the popularity of this blog. If I were the manufacturer, I’d go the extra step to ensure that the supply chain for LR is fed with the best examples. (a good reason that you will be my retailer going forward)
If DPR gets their lenses the same way as most consumers do then their results more closely resemble what the average photographer may get.
Although, I understand DPR was provided the lens as part of a media event. So one would expect that lens to be an exceptional copy.
Since getting OLAF have you taken any of these exceptional lenses and tested then with Imatest or other testing to confirm their performance inline and correlated to OLAF results?
S.Yu ·
That’s why it would be best for reviewers to test using samples acquired at random retailers, preferably offline, it would be much harder to rig an entire area’s inventory than a single order 🙂
Roger Cicala ·
Edna, that is a very good point. With the vast majority of lenses that’s exactly how our copies are obtained: we buy everything from US retailers and there’s no way the manufacturer could pick our copies. In this particular case, though, you are correct and I should have pointed that out: these are Sony’s own copies, not mine, we just had the opportunity to test them. This is the first time we’ve done that but I was excited about getting into them. It will also be the case with the 70-200 f/2.8 GM.
On the other hand, and I don’t mean this to sound snarky but it’s true: Sony doesn’t have the capability to test to our standards or even close to them. They’re as interested in our results as anyone else. That’s not saying they might not have cherry picked to some degree.
Roger
hb ·
Hi Roger,
you may want to contact Zeiss to find out. Their support is great
HB
Arthur Meursault ·
How are the Otus results so far off of the Zeiss advertised measurements and consistently so? If an Otus lens performed as badly as OLAF is indicating then those lenses would be dramatically out of spec.
Roger Cicala ·
Edna, I can't tell you that because we don't know Zeiss' testing metrics. Do they use white light? Photopic light? Green light? How many points do they measure? More importantly are their MTFs the average of numerous copies? We have some Otus lenses that are about as good as what the Zeiss graphs show. It's not all of them, though, and when we average multiple copies this is what we get. Or if I test with monochromatic light, the MTFs are better. Even using a different reticle (pinhole versus cross versus separate lines).
You bring up a good point though: what is spec? We don't know. No manufacturer releases what their acceptable spec are. (I know a few but I'm under nondisclosure about them, and I don't know Zeiss' at any rate.)
Arthur Meursault ·
Roger, I appreciate the response but the DPR article brings in more doubt to the overall story here. What I ventured over there as a possibility (and a credit to LR) that it's possible that lenses sent to LR are cherry picked knowing your advanced testing capabilities and the popularity of this blog. If I were the manufacturer, I'd go the extra step to ensure that the supply chain for LR is fed with the best examples. (a good reason that you will be my retailer going forward)
If DPR gets their lenses the same way as most consumers do then their results more closely resemble what the average photographer may get.
Although, I understand DPR was provided the lens as part of a media event. So one would expect that lens to be an exceptional copy.
Since getting OLAF have you taken any of these exceptional lenses and tested then with Imatest or other testing to confirm their performance inline and correlated to OLAF results?
S.Yu ·
That's why it would be best for reviewers to test using samples acquired at random retailers, preferably offline, it would be much harder to rig an entire area's inventory than a single order :)
Roger Cicala ·
Edna, that is a very good point. With the vast majority of lenses that's exactly how our copies are obtained: we buy everything from US retailers and there's no way the manufacturer could pick our copies. In this particular case, though, you are correct and I should have pointed that out: these are Sony's own copies, not mine, we just had the opportunity to test them. This is the first time we've done that but I was excited about getting into them. It will also be the case with the 70-200 f/2.8 GM.
On the other hand, and I don't mean this to sound snarky but it's true: Sony doesn't have the capability to test to our standards or even close to them. They're as interested in our results as anyone else. That's not saying they might not have cherry picked to some degree.
As to 'exceptional lenses' thats a really interesting and fairly secretive area. It only makes sense that the manufacturers would hand pick copies sent out for review, etc. and that's why I totally agree with using off-the-shelf copies for testing. On the other hand, none of the manufacturers admit to having 'special copies'. One interesting aside, though, is most people greatly overestimate the metrology (lens measuring capability) available to manufacturers. Most of them still test on a lens projector or with a simple test target, although that has been changing in the last year or two. While I can't disclose specifics, we've started doing testing for some manufacturers as they determine how accurate their own testing methods are and improve their own techniques.
Anyway, forgive the too long answer, but yes, I agree with you :-)
Roger
hb ·
Hi Roger,
you may want to contact Zeiss to find out. Their support is great.
The MTFs which Zeiss publishes are actually measured results.
What Sony does is a joke in my eyes, diffraction is completely ignored in what Sony publishes. Nobody does such nonsense. Canon and Nikon publish measured results.
HB
Leslie Feigin ·
Would I see a difference between these lenses in a 20″ x 30″ print hanging in my hallway from two feet away photographing a scenic at about f/8 ?
Steve Waldstein ·
Roger, Aaron, and Marks thanks for the work. I do have a question about your sample variation testing. With a new lens in limited supply how do you ensure your not testing lenses that came from the same manufacturing cycle that will tend to be fairly close to each other. In my industry you need to take 3 samples form 3 to 5 independent manufacturing lots to validate process variation. Anything manufactured on the same day is disqualified.
I just don’t see how you get a good representation of true variation on a new lens. Maybe after 6 months of buying samples to use but the lens just became available.
Roger Cicala ·
Steve,
It’s a really good point, but remember how lenses are made: the assembly line sets up, makes a run of a given lens, then tears down and sets up for a different lens. It may be months (and in some cases we know it’s over a year) before that lens is made again. With the Sony lenses I would guess months, but at any case, there won’t be another cycle for quite some time, so we have to do the best we can.
While it is a limited finding and not done with the Sony brand yet, we have, with some other lenses, done repeat runs many months apart. We haven’t noticed any real difference in general. On the other hand we do know that sometimes things have been changed in different runs so I hesitate to generalize too much. For example, Canon 85 f/1.8s have different electronics in newer runs, although we haven’t seen optical differences. There have been similar minor changes in other lenses.
Edna Bambrick ·
RC, Any thoughts around the idea that production quality and variance are highest in the first production run or later as times goes on? Differences between manufacturers?
As a side note, I shoot the 7mm REM MAG Sendero and the rumor was at the time of the release that the first run was all supervised and QC by the Custom Shop. I believe it. I shoot 1/4 to 3/8″ MOA groups with my own hand loads.
Steve Waldstein ·
Roger, Aaron, and Marks thanks for the work. I do have a question about your sample variation testing. With a new lens in limited supply how do you ensure your not testing lenses that came from the same manufacturing cycle that will tend to be fairly close to each other. In my industry you need to take 3 samples form 3 to 5 independent manufacturing lots to validate process variation. Anything manufactured on the same day is disqualified.
I just don't see how you get a good representation of true variation on a new lens. Maybe after 6 months of buying samples to use but the lens just became available.
Roger Cicala ·
Steve,
It's a really good point, but remember how lenses are made: the assembly line sets up, makes a run of a given lens, then tears down and sets up for a different lens. It may be months (and in some cases we know it's over a year) before that lens is made again. With the Sony lenses I would guess months, but at any case, there won't be another cycle for quite some time, so we have to do the best we can.
While it is a limited finding and not done with the Sony brand yet, we have, with some other lenses, done repeat runs many months apart. We haven't noticed any real difference in general. On the other hand we do know that sometimes things have been changed in different runs so I hesitate to generalize too much. For example, Canon 85 f/1.8s have different electronics in newer runs, although we haven't seen optical differences. There have been similar minor changes in other lenses.
Arthur Meursault ·
RC, Any thoughts around the idea that production quality and variance are highest in the first production run or later as times goes on? Differences between manufacturers?
As a side note, I shoot the 7mm REM MAG Sendero and the rumor was at the time of the release that the first run was all supervised and QC by the Custom Shop. I believe it. I shoot 1/4 to 3/8" MOA groups with my own hand loads.
Thinkinginpictures ·
I had the 50mm 1.4 ZA in A mount. It was a pleasure, but wide open performance was lackluster. Excuse me…it actually sucked. Outside of that however, the colors, contrast and bokeh rendering where top notch. It too was 1500.00 fat ones. Since selling it off at a massive loss, I’m not sure I’d give Sony another go at that price point. So many releases these days with mirror less…best to wait it out a bit and do what I call “The 30 percent rule.” Buy it used when you can grab it for 70% of retail. With Sony, it’s the most practical thing to do.
Thinkinginpictures ·
I had the 50mm 1.4 ZA in A mount. It was a pleasure, but wide open performance was lackluster. Excuse me...it actually sucked. Outside of that however, the colors, contrast and bokeh rendering were top notch. It too was 1500.00 fat ones. Since selling it off at a massive loss, I'm not sure I'd give Sony another go at that price point. So many releases these days with mirror less...best to wait it out a bit and do what I call "The 30 percent rule." Buy it used when you can grab it for 70% of retail. With Sony, it's the most practical thing to do.
Daniel ·
I’m sure you’re aware of it, but you didn’t mention, that the mtf chart is misleading, if you forget to think about the sensor area covered by a certain region on the chart. The values between 0 and 2 cover an area on the sensor of about 12,6 mm^2, the values between 8 and 10 cover an area of about 113 mm^2.That’s probably why Zeiss sacrified some center performance, I guess the Otus is still sharper by a good margin if you consider the area.
Thanks by the way for your excellent and entertaining blog!
Daniel ·
Looking closely, the Otus seems to be a clever tradeoff: The mtf curve rises (almost) until the 12mm mark (the short edge of the sensor, after that the covered area stops increasing with r^2 due to the cuts in the circle). It looks like a carefully designed optimum of sharpness per area.
Omesh Singh ·
Agree it is a good compromise. I generally prefer a lens with best midframe performance. If a lens performs well in the midframe region then you can use it for off-centre and rule-of-thirds compositions which allows you to apply rules of space.
There are two exceptions for me, the first is for sports/wildlife applications when I would likely frame my subject centrally (where there is AF point coverage) and likely crop in for final use so this would bias me towards centre performance. The other exception is astro-photography, where I’d want good resolution and low astigmatism in the corners when shooting wide open.
Omesh Singh ·
Agree it is a good compromise. I generally prefer a lens with best midframe performance. If a lens performs well in the midframe region then you can use it for off-centre and rule-of-thirds compositions which allows you to apply rules of space.
There are two exceptions for me, the first is for sports/wildlife applications when I would likely frame my subject centrally (where there is AF point coverage) and likely crop in for final use so this would bias me towards centre performance. The other exception is astro-photography, where I'd want good resolution and low astigmatism in the corners when shooting wide open.
Roger Cicala ·
Very good points Daniel, and that is exactly how it looks.
Ilya Zakharevich ·
Actually, this leads to a very useful (and simple to calculate) 1-number digest-metric of these curves (code-named “the total MTF50 resolution in ‘megapixels’”):
• inter/extrapolate to get MTF50;
• combine tangential/saggital to get the area of MTF50-ellipse-of-confusion at given distance;
• Again, interpolate to calculate the number of these ellipses covering the assumed frame size of this lens.
One can repeat this for MTF10 ellipses. (It does not matter mach how one recalculates the value in lp/mm into an axis of ellipse?—?this would just rescale the number?—?independent of the lens.)
I think it would be a very valuable addition to the curves you publish!
Dmitry Anisimov ·
MTF curves would change if anothing focusing point was chosen
Daniel ·
I'm sure you're aware of it, but you didn't mention, that the mtf chart is misleading, if you forget to think about the sensor area covered by a certain region on the chart. The values between 0 and 2 cover an area on the sensor of about 12,6 mm^2, the values between 8 and 10 cover an area of about 113 mm^2.That's probably why Zeiss sacrified some center performance, I guess the Otus is still sharper by a good margin if you consider the area.
Thanks by the way for your excellent and entertaining blog!
Ilya Zakharevich ·
Actually, this leads to a very useful (and simple to calculate) 1-number digest-metric of these curves (code-named “the total MTF50 resolution in ‘megapixels’”):
• inter/extrapolate to get MTF50;
• combine tangential/saggital to get the area of MTF50-ellipse-of-confusion at given distance;
• Again, interpolate to calculate the number of these ellipses covering the assumed frame size of this lens.
One can repeat this for MTF10 ellipses. (It does not matter mach how one recalculates the value in lp/mm into an axis of ellipse — this would just rescale the number — independent of the lens.)
I think it would be a very valuable addition to the curves you publish!
Frode Bergeton Nilsen ·
“The fine resolution (at higher frequencies) is higher than we’re used to seeing.”
The 10 score is sky high, but the 30 and 50 score is lower of center than the other two. How does this translate into my real life results?
Roger Cicala ·
Frode, I’m not sure I understand your question. The 30 and 50 lp/mm scores are among the highest 30 and 50 lp/mm scores we’ve tested.
Frode Bergeton Nilsen ·
The tangential results for the Sony is lower from 3-4mm compared to the Sigma. The scores just seem relatively low to me, compared to Sigma, at MTF50. The sagittal results appear to even it out from about 6mm at MTF50. I have no clue what sag and tan performance differences would imply for real life.
I read this post of yours, after posting my question, as my understanding of how to interpret MTF charts is pretty poor:
https://www.lensrentals.com/blog/2014/05/mtf-the-english-translation/
“However, the MTF10 is lower (about 69 LP/mm compared to 77) and the MTF90 is higher (30 LP/mm compared to 22). So this lens should be more contrasty but not resolve tiny detail as well as our first lens.”
Given that, at MTF50, we have about even results for sag, but close to double the numbers for tan from 6-14mm, does that not translate into the Sigma being more contrasty and even at that, across the frame? The Sony being more contrasty in the very center and the extreme edges? Given the MTF translation post, the Sony should have better resolving power, given its higher MTF10 score? Resolving power seem pretty even across the frame, more so than the Sigma.
I also guess that we are comparing a Ferrari with a Lamborghini? They are both great. Really great.
Roger Cicala ·
Frode, that gets a little confusing because MTF50 and MTF10 are really quite different than the MTF in Line pairs/mm graphs. But in this one case, we are concerned that the tangential lines are not as good as they should be because our glass thickness is slightly different than the Sony sensors. On axis, the Sony is amazingly sharp. Off axis it may be a little better or a little worse than the Sigma, which is an excellent lens, but the difference is going to be small.
Frode Bergeton Nilsen ·
Thanks Roger, for taking the time to answer me. Really appreciate it.
Frode Bergeton Nilsen ·
"The fine resolution (at higher frequencies) is higher than we’re used to seeing."
The 10 score is sky high, but the 30 and 50 score is lower of center than the other two. How does this translate into my real life results?
Roger Cicala ·
Frode, I'm not sure I understand your question. The 30 and 50 lp/mm scores are among the highest 30 and 50 lp/mm scores we've tested.
Frode Bergeton Nilsen ·
The tangential results for the Sony is lower from 3-4mm compared to the Sigma. The scores just seem relatively low to me, compared to Sigma, at MTF50. The sagittal results appear to even it out from about 6mm at MTF50. I have no clue what sag and tan performance differences would imply for real life.
I read this post of yours, after posting my question, as my understanding of how to interpret MTF charts is pretty poor:
https://www.lensrentals.com...
"However, the MTF10 is lower (about 69 LP/mm compared to 77) and the MTF90 is higher (30 LP/mm compared to 22). So this lens should be more contrasty but not resolve tiny detail as well as our first lens."
Given that, at MTF50, we have about even results for sag, but close to double the numbers for tan from 6-14mm, does that not translate into the Sigma being more contrasty and even at that, across the frame? The Sony being more contrasty in the very center and the extreme edges? Given the MTF translation post, the Sony should have better resolving power, given its higher MTF10 score? Resolving power seem pretty even across the frame, more so than the Sigma.
I also guess that we are comparing a Ferrari with a Lamborghini? They are both great. Really great.
Said AZIZI ·
How about a teardown @roger_cicala:disqus ?
Previously you’ve mentionned when disassembling the 35mm 1.4 that there isn’t much to adjust in the lens assembly if it is decentered. I’m curious to know what Sony did to keep the lens variation on this 50mm lower the its 35mm sibling.
Thank you
Roger Cicala ·
Said, it will come. It will most definitely come.
Said AZIZI ·
Thank you !
hb ·
Dear Rodger,
where can i find the disassembly report of the Sony-Zeis SEL50F14?
Best regards
hb
hb ·
Dear Rodger,
where can i find the disassembly report of the Sony-Zeis SEL50F14?
Best regards
hb
Said AZIZI ·
How about a teardown @roger_cicala ?
Previously you've mentionned when disassembling the 35mm 1.4 that there isn't much to adjust in the lens assembly if it is decentered. I'm curious to know what Sony did to keep the lens variation on this 50mm lower the its 35mm sibling.
Thank you
Samuel H ·
These results don’t look good to me. Center resolution may be great, but its definition of center is way too narrow to be useful for me! Also, the first reveiws of the samyang say it’s really, really nice
http://www.sonyalpharumors.com/big-new-50mm-lens-battle-zeiss-50mm-f1-4-fe-versus-samyang-50mm-f1-4-fe-surprising-conclusion/
Gabriel ·
I just got the Samyang today and already is being returned. The 55mm is superior not to mention the GM
Samuel H ·
These results don't look good to me. Center resolution may be great, but its definition of center is way too narrow to be useful for me! Also, the first reveiws of the samyang say it's really, really nice
http://www.sonyalpharumors....
Mark Harris ·
I just got the Samyang today and already is being returned. The 55mm is superior not to mention the GM
Tom Rosencrantz ·
Granted the focal length is narrower for a Sony 85mm G f 1.4, would you purchase this over the 85mm G when it comes to the do all Portrait lens??
Roger Cicala ·
Tom, I’m not the person to ask on that one: I think bokeh and smooth out of focus rendering are so important with a portrait lens, and MTF doesn’t give the whole story there. But I’d consider it, along with the Batis 85 as fast horses in the race.
Roger
Roger Cicala ·
Tom, I'm not the person to ask on that one: I think bokeh and smooth out of focus rendering are so important with a portrait lens, and MTF doesn't give the whole story there. But I'd consider it, along with the Batis 85 as fast horses in the race.
Roger
Lester Lefton ·
I rented it from LR, then bought one, and it’s not only sharp as heck, it has a certain quality–zeiss. Pop?–that I love.
Lester Lefton ·
I rented it from LR, then bought one, and it's not only sharp as heck, it has a certain quality--zeiss. Pop?--that I love.
Erik Johansson ·
Since you’re the experts on testing in my opinion. I’ve had three of these and they’ve all been soft on the right side (all from the 06/16 batch). How do you feel evenness is on this lens, I assume you’ve been through a few.
I actually thought it was my camera (an a7r2) but it was replaced (six months between manufacturing dates). From what I gather the chances for a tilted sensor on the A7 bodies are slim to none thanks to a very rudimentary design (a good thing).
I’ve tried another lens on the body and it was sharp on the right side (a bit soft on the left though).
Alpha Omega. ·
Can anyone explain why Sony FE lenses have extra height compare to other lenses? Is it for edge to edge sharpness or?
Steve Solomon ·
Excellent review as always, Roger! I may be splitting hairs, but is there anything to the “slightly sharper in center” measurement of this Sony/Zeiss 50 over the new Nikkor S 50? In other words, after post-processing, would the difference be noticable in a relatively large (24″ x 36″) print made with these lenses on a tripod-mounted Sony a7rlll or Nikon Z7 respectively? Thank you sir, and be safe!
SteveTQP ·
Excellent review as always, Roger! I may be splitting hairs, but is there anything to the "slightly sharper in center" measurement of this Sony/Zeiss 50 over the new Nikkor S 50? In other words, after post-processing, would the difference be noticable in a relatively large (24" x 36") print made with these lenses on a tripod-mounted Sony a7rlll or Nikon Z7 respectively? Thank you sir, and be safe!