Archived posting to the Leica Users Group, 2015/12/05

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Subject: [Leica] Which has more central Resolution: Sony 28-70 or Leica 28-70?
From: red735i at verizon.net (Frank Filippone)
Date: Sat, 05 Dec 2015 14:07:52 -0800

Which has more Resolution: Sony 28-70 or Leica 28-70?  The question had
bothered me ever since I got the A7, when either lens would fit on the same
body...

There are really good reasons to not care, including AF and Auto Diaphragm
operation of the Sony.  But which would have would have better glass?

 

My application is mostly travel photography. in which case things like
distortion issues, vignetting, color cast,, etc have a lesser value to me
than brute force net resolution.

 

With a couple of 28-70 in hand I went a'testin.

 

The Sony 28-70 F3.5-5.6 is the "kit" lens usually associated with the A7
bodies.  It is not expensive to buy on its own, and as part of the Kit, is
hard to turn away.

The Leica 28-70 F3.5-4.5 Rom lens is the third model ( first was designed
and made by Sigma, and not considered a superb lens optically or
mechanically, second is the Sigma designed, Kyocera made lens, and the third
is apparently a slightly modified Sigma design, modified by Leica, and built
by Kyocera.  Depending on what you read, the second and third or third only
have a different barrel.  Again, depending, the third is a Leica designed
barrel and has modified optics. FYI, Kyocera is/was the company that brought
back the Contax name..  The third version is the only one with factory ROM.

 

Some will ask, well why not test the Leica 28-90 lens, the one with a
splendid reputation?  Because I do not have access to one, and the price
point is too high for my interest!  35-70?  Different range meaning that a
direct comparison is difficult, not available to me, but I am working on
accessibility...

 

How did I test?

A7 camera,  24MP, no IS.  ( no, I do not own a 36MP camera so the test was
done with existing equipment)

Tripod

Delayed shutter release. no movement introduced errors

Electronic first shutter.. no shutter slap

RAW Files

Manual focusing at 11.3x ( or whatever) magnification.  LCD or eye level?  I
used the eye level.  GG type focusing.  No assist.

Cheap Chinese adapter from R to NEX. cost me $12.  Any questions or dissing
of this cheap adapter, go back to the price point.  It is worth $12 to do a
test,  Not $200 or more.

Only the central area of each lens was tested in depth, spot check
examination of the corners had the same results.

 

What was the control lens?  

50 Summilux ASPH, probably the best lens in Leica's M portfolio, with the
possible exception of the 50 APO ASPH Cron ( which I have no access to). 

It was mounted using a Novoflex adapter.

 

What Focal lengths were tested?  28, 50 and 70 mm

What F stops?  F4 and F8

 

How did I compare images?  Raw files in LRcc, latest version, updated 24
hours before. 1:1

 

What LR settings were used?  None,.  All set to basically un-touched,
neutral

 

What was used as a test image?  A section of the outdoor fence at my house.


It was made from cedar, is 44 years old, and has enough character to allow
minute comparisons of image quality.  Bug holes, wood texture and all.  

Distance was about 15 feet.

 

What ISO?  ISO320 for all.

 

Now that you have read all the caveats.. The results...

 

The 50 ASPH Summilux is the best by a fraction. 

The Leica Zoom lens held its own, and was a CLOSE second.  ( Surprise!  The
Zoom was surprisingly good, especially when the design was done in the late
90's by a company that was supposed to be second rate : Sigma. Proves you
should never believe everything you read, even if it is on the Internet!)

The Sony lens was not bad, but not as good as the Leica lens.

 

The differences were in the fine details, where Leica really did a better
job than the Sony.  This was at all Focal lengths, all apertures.  Center
and corners too.

 

Define "better"?  small details were obviously sharper and clearer in the
Leica at 1:1 in LR.  Edges crisper.. Overall small detail contrast was
higher.

Overall contrast and color were very close in all 3.

 

Is it worth it to switch to the Leica if you have the Sony?  YMMV.  You give
up AF, a big deal for many.  You give up auto diaphragm, a big deal to me.

The Leica lens is a bit longer, a bit more in diameter and a bit more heavy.


The positive?  You get better image quality...

 

No, I did not test for CA, etc.  This was an initial test to see if I wanted
to go further... Which I will not.

 

The difference in IQ was not enough to outweigh the negative user aspects of
the Leica.. IMO.

 

What might change my final decision?  A sensor with more MP may NEED a
better lens.  At 36MP?  43MP? 50MP?  64MP? 

I don't know, but there is a point where more  resolution is needed than the
Sony can deliver.

 

But that is not in the budget for me for the foreseeable future... in which
case, I can worry about it then.

 

Frank Filippone

Red735i at verizon.net

 



Replies: Reply from jayanand at gmail.com (Jayanand Govindaraj) ([Leica] Which has more central Resolution: Sony 28-70 or Leica 28-70?)
Reply from photo at frozenlight.eu (Nathan Wajsman) ([Leica] Which has more central Resolution: Sony 28-70 or Leica 28-70?)