[Brightcolours]

I get that if you are interested in LENS performance you can compare numbers within a system, or to some degree charts.

 

My question was whether if you are interested in SYSTEM performance (i.e. lens+sensor) you can compare raw numbers. Thus if the we see the same numbers for a lens on a 16MP system an a different lens on  36 MP system we can infer that we will see similar resolution in a print of the same size (or if we normalise the two images and view on screen). 

 

This is supposed to be how perceptual megapixels work with DXO; if one lens+sensor gives you 13PMP at a certain location and a different lens+sensor gives you 13PMP they will look the same printed to the same size (at that location). Of course if the first sensor is 16MP and the second 36 you might want to say the second lens is 'bad' - it isn't giving you the potential of the 36MP sensor. But it's still giving you there same performance in one sense as the much better lens on the smaller MP sensor.

 

In some way these are the numbers that are of most interest: to me, for example, in figuring out if the a lens and sensor from one system can give the same appearance of sharpness in a certain print size and a different lens mixed with a different sensor.

Photozone reviewers use sharpening in their MTF workflow. Sharpening is not linear (to a point unsharp results will benefit more that sharp results) soyou can not really compare cross platform like that. Another thing the sharpening prohibits is judging the real impact from diffraction.

[H. J. Simpson]

Pricing around the world is weird. Canon 24-70 F4 is selling for $900 on ebay, while this Sony/Zeiss lens is at least $1000, so the Canon is actually cheaper than this one. At least for those of us that don't have to pay customs fees.

[Klaus]

Photozone reviewers use sharpening in their MTF workflow. Sharpening is not linear (to a point unsharp results will benefit more that sharp results) soyou can not really compare cross platform like that. Another thing the sharpening prohibits is judging the real impact from diffraction.

 

Actually we select the parameters according to the metric that the best results are neither under- nor oversharpened (which is provided by Imatest in %).

Please note that an AA filter is essentially a negative sharpening filter that have an impact on diffraction just as sharpening. Essentially we are just equalizing the forces by introducing a similar amount of counter sharpening.

The same metric is actually used across all systems.

 

The idea is also to provide real world results. No user on mother earth is using RAW data as is.

[ficofico]

soyou can not really compare cross platform like that

yes, but you can compare slrgear VFAtarget and watch your self that zeiss 24-70 at 24 f8 have really more resolution at lest 90% of the frame than zuiko 12-40 at 12 f8 if you resize both images at 3000 px 

 

zeiss

https://dl.dropboxusercontent.com/u/8602032/test/zeiss%2024%20f8.jpg

 

zuiko

https://dl.dropboxusercontent.com/u/8602032/test/zuiko%20f8.jpg

 

download, open in photoshop, bucubic resize heigh=3000, save quality=11

 

 

It's obvious that zeiss 24-70 f4 it's not able to match the 36 megapixel sensor, but it's quite obvious that, resolution wise, combo a7r + 24-70 f4 it's better that 16 megapixel sensor + zuiko 12-40 f2,8.... see your self or try to replicate download the file

[ficofico]

zeiss 70 f4

https://dl.dropboxusercontent.com/u/8602...0%20f4.jpg

 

zuiko 40 f2,8

https://dl.dropboxusercontent.com/u/8602...f2%2C8.jpg

 

What do you think it's better? Only in the very extreme corner zuiko lens have a bit more resolution but, again, in 90% of the frame 24-70 lens it's better resolution wise..

[youpii]

Thanks for the review.

Could you please add a photo of the rear of the lens ?

 

I think Sony should stick to small prime lenses for the A7, like Leica did with the M mount. Although the Tri Elmar 16-18-21mm f/4 is a fine lens too.

 

In my case, I have the A7r with adapted Contax G lenses. The combo with the G35 G45 & G90 works fine for me (but it's crap with G21 & G28).

[Guest]

Gianluca

 

This was my point; and comparing the raw numbers gives a (very fallible) guide to the kind of thing you were saying.

So in my case I wanted to know if the total system resolution of the Panny 12-35 on OMD I used to use when hiking was better than the FE on A7r; and it looks like the total system resolution of the FE/A7r is in fact between just better and much better at different points.

 

Of course it's disappointing that it's not much better everywhere given that we are talking a 36MP sensor; but it means that I can be confident that I've not lost anything while hiking by using this system, and gained a lot when using the primes.

 

The Oly 12-40 is better in the corners than the Panny; so the total system resolution for Oy+16MP is likely as you say very slightly better for that combo in extreme corners at the extreme focal lengths, but much worse elsewhere (though if a higher MP M43 sensor came out this might change!)

[peterottaway]

Unless there is a change in technology. once you get above 24 MP with m43 sensors then I suspect that things may fall apart on you. Sure you have 20 MP 1 inch sensors but I don't usually go above an EI of 400 unless desperate. Do you want to be limited to EI 400 - 500 ?

 

Probably better to tweek the sensor,processor,AF and exposure performance than go for broke. Perhaps not as sexy but the boys in PR should still be able to sell a 20% improvement in AF speed and accuracy. If not then they should be back to copy and pasting the second hand car ads.

[Guest]

Unless there is a change in technology. once you get above 24 MP with m43 sensors then I suspect that things may fall apart on you. Sure you have 20 MP 1 inch sensors but I don't usually go above an EI of 400 unless desperate. Do you want to be limited to EI 400 - 500 ?

 

Probably better to tweek the sensor,processor,AF and exposure performance than go for broke. Perhaps not as sexy but the boys in PR should still be able to sell a 20% improvement in AF speed and accuracy. If not then they should be back to copy and pasting the second hand car ads.

Hey, I wasn't advocating higher MP M43 sensors; just saying that if they happened then the low ISO resolution of the Only12-40/sensor combination might be greater than the current system resolution of FE2470/36MP. Whether that would be worth any tradeoffs is another matter.  Having said that, it seems these days that overall sensor size (rather than no of megapixels) that determines high ISO limitations, so it might not make much difference. That is, it's not the pixel density of the I inch sensor which limits it, but it's size (unless of course you are looking at non-normalised 1:1)

[Rover]

Finally, a review... and a sad one at that.

Klaus, do you think this one is going to be better on, say, A7?

 

P.S. SLRGear has reviewed this lens around the same time. Their results and conclusion were, of course, fairly similar.

P.P.S. Are you going to test the 28-70 sometime? I wonder what that one is like... some people say it's at least as "good" (or as bad, depending on the viewpoint).