Summilux-TL 35mm 1.4 v. Summicron-M APO 50mm 2.0

[Agent M10]

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Now that Leica has introduced an APS-C camera with a viewfinder, I'd be interested in hearing of anyone who has compared the performance of the Summilux-TL 35mm 1.4 to the Summicron-M APO 50mm. I've read elsewhere that M lenses have been designed to resolve 40 lines per inch while the TL lenses have been designed to resolve 60 lines per inch. I understand that the APO is probably way ahead of other M lenses (I love mine), but I am just curious to know of anyone who has made the comparison and what his conclusions came out to be. 

[scott kirkpatrick]

I suspect that resolution is the wrong comparison.  I've tried comparing a TL zoom to an S macro lens on the SL, matching up the APS-C portions of the images from each, and the answer is that both lenses have the ability to resolve images down to a scale finer than the SL's 6 micron pixel pitch, and probably both can outresolve the ~4.5 micron (don't know exactly) pixel pitch of the TL and CL.  But the claimed difference between the latest primes from the M and SL line and the lenses created by ordinary mortals are special rendering characteristics such as the transitions between sharply resolved and out of focus areas of an image.  Peter Karbe has claimed that he can make an SL Summicron shape a scene in a way that previously was only seen on an M Summilux.  Both, I presume, wide open.  If that would matter to you, it is not likely that Leica has shown an outside lens maker how to do it.

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[thighslapper]

40 lp/mm is what the MTF charts use for measurement if finest details  ..... most of the current M lenses probably are capable of greatly exceeding that figure with acceptable contrast. 

[ropo54]

Now that Leica has introduced an APS-C camera with a viewfinder, I'd be interested in hearing of anyone who has compared the performance of the Summilux-TL 35mm 1.4 to the Summicron-M APO 50mm. I've read elsewhere that M lenses have been designed to resolve 40 lines per inch while the TL lenses have been designed to resolve 60 lines per inch. I understand that the APO is probably way ahead of other M lenses (I love mine), but I am just curious to know of anyone who has made the comparison and what his conclusions came out to be. 

 

FM member Chaemono did comparison shots taken by the SL 50 summilux and the TL 35 1.4.  Here is a link to his comparative shots. 

 

https://www.smugmug.com/gallery/n-m8cbnV/

[jaapv]

40 lp/mm is what the MTF charts use for measurement if finest details  ..... most of the current M lenses probably are capable of greatly exceeding that figure with acceptable contrast. 

Nothing new there; the Apo-Telyt R 280/4.0 for instance resolves over 300 lp/mm in the centre. Leica has exceeded those numbers for a long time, the figure of 40 lp/mm comes from Zeiss and refers to the resolution on film...

Erwin Puts addresses the subject at length in his old "Lens Compendium". Well worth reading.

[wlaidlaw]

Zeiss claimed that their ZM Planar 50/f2 exceeded 200 lp/mm over most of the frame at f5.6. I was hoping to use it with my Leitz BEOON for film scanning but for some reason, cannot get it to focus with any combination of extension tubes (I have 8 different tubes), so using a Schneider Kreuznach 50mm Componon S instead, which focuses perfectly. 

 

Wilson

[jaapv]

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The figure of 40 lp/mm represents the minimum needed over the entire field for average film. All decent lenses will exceed it.

[Agent M10]

I suspect that resolution is the wrong comparison.  I've tried comparing a TL zoom to an S macro lens on the SL, matching up the APS-C portions of the images from each, and the answer is that both lenses have the ability to resolve images down to a scale finer than the SL's 6 micron pixel pitch, and probably both can outresolve the ~4.5 micron (don't know exactly) pixel pitch of the TL and CL.  But the claimed difference between the latest primes from the M and SL line and the lenses created by ordinary mortals are special rendering characteristics such as the transitions between sharply resolved and out of focus areas of an image.  Peter Karbe has claimed that he can make an SL Summicron shape a scene in a way that previously was only seen on an M Summilux.  Both, I presume, wide open.  If that would matter to you, it is not likely that Leica has shown an outside lens maker how to do it.

This is along the lines of my question. Why would Peter Karbe even mention lines per inch if the measurement doesn’t mean anything these days? He says he started the redesigns with the TL line. That is why I am curious.

[Jared]

Well, since Leica is kind enough to publish the MTF charts for both lenses, it’s easy enough to compare them. Basically, the 50 APO coupled with a 24 megapixel sensor like that on the M10 or on the SL is a significant upgrade on the 35mm coupled to a CL or TL2. Both are quite good, but the APO is significantly better as you move away from the center of the field.

 

Even at the center of the field, the APO has a significant advantage, both wide open and stopped down—probably enough to tell on a large print under ideal conditions (tripod, optimum aperture, perfect focus, little or no motion blur, etc.).

 

The charts only go to 40LPM, but all current Leica lenses are significantly above the 10% contrast level which is required to say something is resolved, even in the corners and even wide open.

[scott kirkpatrick]

FM member Chaemono did comparison shots taken by the SL 50 summilux and the TL 35 1.4.  Here is a link to his comparative shots. 

 

https://www.smugmug.com/gallery/n-m8cbnV/

That's an enjoyable set of 50 SX shots supplemented by several rephotographs from the same positions using the TL and its 35/1.4.  Love the old wing-fendered Mercedes sportster, and I wonder if the Chauseegespenst from the 1930s Remarque novel is to be found there.  There was even a first-born Corvette from 1954.

 

The most obvious difference is that the DOF in a 50/1.4 on 35mm falls off faster than with a 35/1.4 on APS-C, but we knew that.  Actually, for this material, where the second plane in the image (cars further away) could be rendered softly but clearly, the APO SC operating at f/2.0 would have been perfect.  The 50 SX renders the distant objects as blurs of bright color.

 

My takeaway from this example is that the TL 35/1.4 just got  more interesting, and it will be fun when my CL finally arrives to try it, as well as the Fuji X-Pro2 (I have the 23/1.4 and 35/2.0 for that family) in contrast with the SX and SC on an M10.  But each of those combinations is so appealing to work with that a disciplined test may not ever get completed.

Edited November 25, 2017 by scott kirkpatrick

[scott kirkpatrick]

And just a note... On EBay this week, the TL 35/1.4 lens is selling for its MSRP of $2400.  Last week there were a few that were MUCH less expensive.