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Archive 2016 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!

  
 
Steve Spencer
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p.9 #1 · p.9 #1 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


snapsy wrote:
Playing devil's advocate, if Sony can't supply the largest camera gear review site with a good copy what hope does the average consumer have? A good copy may exhibit great performance but that doesn't help very much if the probability of obtaining a good copy is low.


But it isn't low. Roger's larger sample from Lens Rentals shows that the lens does not show a lot of variability between copies and they typical copy performs quite well. Put that together and if Roger's tests are accurate then it shouldn't be that hard to get a good copy.



Jul 20, 2016 at 10:13 AM
snapsy
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p.9 #2 · p.9 #2 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


I would expect a preproduction unit to have much better QC than a lens that's in mass production. The yields for preproduction would be lower but each copy would receive a lot more attention.


Jul 20, 2016 at 10:14 AM
Matt Grum
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p.9 #3 · p.9 #3 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


rscheffler wrote:
I wonder if the central sharpness of the 50 is beyond what current sensors can discern/resolve?


Definitely.

There is no such thing as sharpness, there is only contrast. Contrast at different spatial frequencies. The lens rentals testing shows contrast of 70% at 50lp/mm, however that's just because they stopped measuring it there (or perhaps due to a limitation of OLAF) - there will also be some contrast at 60,70,80lp/mm etc. and at frequencies above current pixel densities.

N.b. this is also true of lenses that appear to be at the limit of their resolution (i.e. slightly soft when viewed at 100%), they are still delivering nonzero amounts of contrast at the higher frequencies and will therefore still look better on a higher resolution sensor.



Jul 20, 2016 at 10:21 AM
snapsy
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p.9 #4 · p.9 #4 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Steve Spencer wrote:
But it isn't low. Roger's larger sample from Lens Rentals shows that the lens does not show a lot of variability between copies and they typical copy performs quite well. Put that together and if Roger's tests are accurate then it shouldn't be that hard to get a good copy.


From Roger's article:

"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. Iíve put a 50% gray box over the questionable area to help clarify this."



Jul 20, 2016 at 10:22 AM
Fred Miranda
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p.9 #5 · p.9 #5 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


A solution for this is for every lens tester and review site to get 10-20 copies of each lens and average the results. It should not be too hard.


Jul 20, 2016 at 10:22 AM
Matt Grum
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p.9 #6 · p.9 #6 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


snapsy wrote:
Playing devil's advocate, if Sony can't supply the largest camera gear review site with a good copy what hope does the average consumer have?


That sounds like the sort of thing that is handled by the marketing department, rather then engineering, who may not have the ability to test lenses and find a good copy...

Anyway Lensrentals tests are performed with a simulated sensor stack, dpreview are testing with the real sensor and stack, and more importantly Lensrentals are testing at infinity that alone could account for the difference, so I think it's too early to criticise dpreview or Sony.



Jul 20, 2016 at 10:28 AM
Fred Miranda
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p.9 #7 · p.9 #7 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Matt Grum wrote:
That sounds like the sort of thing that is handled by the marketing department, rather then engineering, who may not have the ability to test lenses and find a good copy...

Anyway Lensrentals tests are performed with a simulated sensor stack, dpreview are testing with the real sensor and stack, and more importantly Lensrentals are testing at infinity that alone could account for the difference, so I think it's too early to criticise dpreview or Sony.


I think the latest dpreview sharpness test was done at infinity as well.
We are scrutinizing that image at 1:1 but there is also a possibility of misfocus for one of the lenses. I'm hoping they carefully focused them manually at 12.5x magnification and post the best of 3 or 5 tries.



Jul 20, 2016 at 10:30 AM
rscheffler
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p.9 #8 · p.9 #8 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Well, that scene is close to infinity. I've used a similar scene for my own infinity tests and have been surprised to see sharpness differences at wide aperture values between lenses, where some are obviously calibrated for a farther, perhaps 'true' infinity distance, while others focus slightly closer.

Thinking about the question of copy variation, could it be that a typical good copy, whatever that may be, still will have some minor 'defects' in regional image quality that become more apparent on a 42MP sensor than would be evident at 16-24MP?

I'm thinking of the MTFs Brandon posted a while back showing how individual lenses will vary across the frame, yet are still considered good lenses.

Looking at the DPR 50/1.4 images, the lens is slightly better than the 55 in some areas, but not in others. It seems a bit weaker at 'true' infinity in far distant areas, but slightly better in some areas at nearer distances at the bottom of the frame.

To echo what I wrote in the first paragraph, I saw similar differences when I recently compared a single copy each of the new and old Leica 28/2 Cron. One had a 'far' infinity hard stop while the other had a nearer infinity hard stop. It made a difference in image sharpness in some areas when compared side by side. Viewed independently, it wasn't as noticeable or dramatic.

Edited on Jul 20, 2016 at 10:38 AM · View previous versions



Jul 20, 2016 at 10:34 AM
philber
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p.9 #9 · p.9 #9 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


ecarlino wrote:
Philber @ DearSusan just put up a great piece on "magic" lenses:
http://www.dearsusan.net/2016/07/19/where-does-the-magic-lie/


Thanks, Eric!




Jul 20, 2016 at 10:37 AM
Matt Grum
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p.9 #10 · p.9 #10 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Fred Miranda wrote:
I think the latest dpreview sharpness test was done at infinity as well.
We are scrutinizing that image at 1:1 but there is also a possibility of misfocus for one of the lenses. I'm hoping they carefully focused them manually at 12.5x magnification and post the best of 3 or 5 tries.


Fair enough I haven't actually got round to reading the dpreview article, I had assumed they had done the usual studio test scene...

The fact remains though that dpreview are testing the lens plus the entire signal processing chain all the way through to the RAW converter, which is different to Lensrentals which who are attempting to test the lens in isolation




Jul 20, 2016 at 10:58 AM
hiepphotog
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p.9 #11 · p.9 #11 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Matt Grum wrote:
Fair enough I haven't actually got round to reading the dpreview article, I had assumed they had done the usual studio test scene...

The fact remains though that dpreview are testing the lens plus the entire signal processing chain all the way through to the RAW converter, which is different to Lensrentals which who are attempting to test the lens in isolation



Yet, the same camera body (I sure hope so) and the same processing would not be a concern. It's just that they have only one copy. They might as well have the best FE 55 and the worst FE 50. That and the focusing error would be the bigger factor.



Jul 20, 2016 at 11:16 AM
PanS
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p.9 #12 · p.9 #12 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


I thought it was going to perform on the same level as the FE35/1.4CZ so I was considering about passing on this. Lensrentals is making this hard to ignore though as 50 is my preferred focal length.

I'm not the only one who finds the housing and styling for the 35 and 50mm Zeiss/Sony lenses more appealing than the Sony GM lenses right?



Jul 20, 2016 at 11:26 AM
Steve Spencer
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p.9 #13 · p.9 #13 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!




snapsy wrote:
From Roger's article:

"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. Iíve put a 50% gray box over the questionable area to help clarify this."

I don't see what your point is. Roger exercises due care in explaining his results but they still show good performance and fairly low copy variation. I think it doesn't make sense to assume there are lots of bad copies from the one DP review received and ignore the good performance and fairly low variability from the ten copies Roger received. That's my view, YMMV.



Jul 20, 2016 at 11:30 AM
snapsy
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p.9 #14 · p.9 #14 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Steve Spencer wrote:
I don't see what your point is. Roger exercises due care in explaining his results but they still show good performance and fairly low copy variation. I think it doesn't make sense to assume there are lots of bad copies from the one DP review received and ignore the good performance and fairly low variability from the ten copies Roger received. That's my view, YMMV.


My point was that most of the centering variation seen in lenses is at the corners/extreme edges and Roger's proviso said to take his edge variance results with a grain of salt.



Jul 20, 2016 at 11:42 AM
Steve Spencer
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p.9 #15 · p.9 #15 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!




snapsy wrote:
My point was that most of the centering variation seen in lenses is at the corners/extreme edges and Roger's proviso said to take his edge variance results with a grain of salt.

It is actually just the corners that need to be taken with a grain of salt--18mm gets you all the way to the edge, so if decentering is happening then we should see it in Roger's tests.



Jul 20, 2016 at 11:57 AM
snapsy
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p.9 #16 · p.9 #16 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


Steve Spencer wrote:
It is actually just the corners that need to be taken with a grain of salt--18mm gets you all the way to the edge, so if decentering is happening then we should see it in Roger's tests.


Roger's quote again:

"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. Iíve put a 50% gray box over the questionable area to help clarify this."



Jul 20, 2016 at 12:04 PM
RCicala
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p.9 #17 · p.9 #17 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


A couple of things I know. I'll try to be clear when I speculate.

1. I get to look behind the curtain a lot, and there's nothing I've ever seen to suggest preproduction copies are better than eventual production ones (not 100% certain, but 98%), although 'sample selection' can certainly be practiced before they get sent out.

2. I've seen the manufacturer's sample selection, and honestly most aren't that good at it. They weed out awful ones for sure but that's all most can do.

3. I try to be transparent, but I'm also still trying to figure all this stuff out. I'm still, with the help of people smarter than I am, working on our variation presentation and numbers. But one of the things it doesn't tell you well is how likely a given copy is to have a bit of soft tilt or side. I was originally interested in resolution differences between lenses and it's pretty good at that. But, for example, some lenses that are really sharp, the 'not as sharp corner' is really common but in the variation graphs gets lumped in with copy-to-copy sharpness variation. I'm not shocked at DPRs 55, and honestly I'll bet it was someone's personal copy. I don't know that they keep a stable of lenses there.



Jul 20, 2016 at 12:40 PM
realVivek
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p.9 #18 · p.9 #18 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


It is not the distrust of the reviews from the samples supplied by the manufacturer themselves but the variations even within those review samples that is more telling. As a buyer, that puts me off from any notion of a pre-order or order as it just becomes available.




Jul 20, 2016 at 01:20 PM
ecarlino
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p.9 #19 · p.9 #19 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


i'm generally not a fan of his (tends to be a fanboy but claims he isn't), but Jason Lanier got his hands on the 50/1.4 and if you skip the first 11 minutes of this video, he finally gets around to showing some quick shots he took of his sons. Until it is in everyone's hands, i'll take what i can get to eval the rendering:
http://youtu.be/59sDbYYsEPk?t=10m54s



Edited on Jul 20, 2016 at 05:33 PM · View previous versions



Jul 20, 2016 at 01:55 PM
jankap
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p.9 #20 · p.9 #20 · LensRentals: Planar T* FE 50/1.4 ZA is absolutely superb!


The MTF of the questioned lens (Planar T* FE 50/1,4 ZA) is very good, but only in a circle with a radius of say 3 mm.
Perhaps one should average such values from 0 to 10mm (fourthirds).
Jan



Jul 20, 2016 at 02:08 PM
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