50mm Sonnar-C vs. Summilux Asph

[Denton]

I recently did some quick resolution shots comparing the 50mm Sonnar-C vs. a new 50mm Summilux Asph. While the Summilux was clearly sharper on center than the Sonnar, I was surprised to discover this advantage was only maintained in the center of the frame. The Sonnar was just as sharp in the outer thirds at f1.5. The sharpness of the Summilux focused on a flat target on either side fell off rather quickly.
Of course, both lenses are still quite sharp across the breadth of the frame except for very extreme corners. The Summilux also vignettes significantly at the edges, but I can't speak to a comprison with the Sonnar here, don't have any way to easily do a comparison.

However, if I had not already had the Sonnar, I would definitely want the Summilux. But, at that price, I can deal with the front focus of the Sonnar, I've learned how to adjust. If I were still shooting professionally, I'd definitely not have to worry about front focusing, but with more time on my hands I can deal with it and I really like the compact nature of the Sonnar. This lens, coupled with my 50mm Planar, leaves little to be desired and saves cash.

This comparison made me understand why some would want the new 50mm Apo Summicron; there is still room for improvement, however, I would need to put my M240 on a tripod to see the difference.
Loving my Sonnar…
Denton

 

[Pioneer]

I do not have the Summilux Asph but I do have the earlier version. The Sonnar-C performs very well in comparison.

When I am not using my ZM Planar (a better lens than the other two IMHO), I tend to use the Summilux on my M-A and the Sonnar-C on my Zeiss Ikon. 🙂

I wouldn't worry too much. If you have any of these lenses you have some terrific glass. Just use it, get used to it, and enjoy what you get. None of them will let you down very often.

 

[MCTuomey]

Agree with OP's findings. The C-Sonnar is comparatively good mid-frame, especially versus the pre-ASPH version. Also, the Lux suffers from field curvature, making flat field test results look worse than they would be for 3-dimensional compositions.

I recently sold my C-Sonnar as part of my M gear regression. I'm regretting it. It's such a fine portrait lens, and this mid-frame strength makes for nice, reliable off-center framing.

 

[uhoh7]

With respect I don't believe your results. 🙂

Here is a serious test:
http://www.lensrentals.com/blog/2014/06/comparing-rangefinder-and-slr-50mm-lenses-version-0-7

Wide Open:

The 50 Lux asph, as Puts might predict, smokes everything but the 50APO and basically equals the Otus.

The Planar is also behind, with the Zeiss Sonnar way out: as the older design limitations would suggest.

Note the 50 cron non-APO is 1200 1200 1200 🙂 Of course that is f/2, but compare to planar.

Here they all are at f/2:

Very interesting to compare the CV 50/1.1 to the Leica .95 in these tests. Some claim the Cv is a bit 'soft' LOL, but it's better mid and edge WO than the .95 and not that far off in the center. And half the weight 🙂

 

[rscheffler]

What distance was the target?

The Lux ASPH has a mid zone dip and then recovers at the edges. If you're testing at near to medium distances, this becomes quite evident, especially until around f/4. At portrait distances, I find the Lux ASPH difficult to hit focus with at f/2.8 with the RF and the subject's eyes placed in the rule of thirds. It also gives up a bit of sharpness at nearer distances despite the floating element.

At infinity, the Lux is more consistent across the frame. The mid zone dip is still there, but not as noticeable. I have used it to shoot infinity scenes wide open and have been very happy with the results. My experience with the C-Sonnar is that it's not as good here. The center sharpens up but the edges lag until stopped down somewhat. But it's not really where the C-Sonnar is at its best.

Back when I did an infinity distance cityscape comparison of the M9 against the a7R, I also posted links to M9 full rez files from these lenses with the article, which can be found here.

 

[Richard G]

I have a lot of good lenses. The C Sonnar is the only one that is magical.

 

[uhoh7]

I have a lot of good lenses. The C Sonnar is the only one that is magical.

Sharpness is not the source of the magic. 🙂

I love my Sonnetar, and was shooting it all day today, but I have sharper lenses.

 

[Denton]

Surely numbers don't lie?

Surely numbers don't lie?

With respect I don't believe your results. 🙂

Yes, I'm quite aware of those tests and many more done by others. My observations were not numerical but impressions of sharpness. The targets were in a plane about ten feet from the camera and tripod, a distance typical for my captures. Also, the zone of sharpness was not confined to a doughnut centered about the midpoint, but extend well past this and was symmetrical about both sides. My observation is empiracle, and ; therefore my personal lesson is "Try before you buy".

As I mentioned, if I could only have one lens it would be the Summilux. But the Sonnar will now suffice and I'm not left wondering if I could be happy with a new lens.
Denton

 

[ramosa]

"Impressions of sharpness"?

 

[uhoh7]

Yes, I'm quite aware of those tests and many more done by others. My observations were not numerical but impressions of sharpness. The targets were in a plane about ten feet from the camera and tripod, a distance typical for my captures. Also, the zone of sharpness was not confined to a doughnut centered about the midpoint, but extend well past this and was symmetrical about both sides. My observation is empiracle, and ; therefore my personal lesson is "Try before you buy".

As I mentioned, if I could only have one lens it would be the Summilux. But the Sonnar will now suffice and I'm not left wondering if I could be happy with a new lens.
Denton

Hi Denton,

There are many great 50s and it's hard to have just one. I have a CZJ 50/1.5, Elmar 3.5 red scale,, Nikkor 1.4 sonnar, Canon 1.2 1.4 1.8, Leica 50/2 v4, Sonnetar, Cv 50/1.1, and a bunch of SLRs. I should sell some of them.

I'd love to have your zeiss, the CV 50/1.5, Planar and a bunch of others, but that's ridiculous, and my collection is already ridiculous.

But one lens I really do hope to own someday is the 50Lux asph, having drooled over countless images since it came out.

Today they can be seen for 2800, and I have to really keep my heart in check.

The ones I actually use at the moment are the 50 cron and Sonnetar. Maybe you will post some images from your zeiss--I for one would love to see some you like 🙂

 

[Denton]

"Impressions of sharpness"?

Yes, sharpness is an imprecise term. It is a subjective word unless defined precisely. The resolution numerical data is a precise definition; The line pair resolution is higher. But how does this relate to how a photo looks?
May I suggest that my impression of sharpness is related to an effect not obvious from the data presented. Perhaps it is not so crazy an idea that the neurological "impression" of sharpness is not only related to lp/mm but some other optical factors?
Denton

 

[Larry Cloetta]

Sharpness is not the source of the magic. 🙂

It rarely is🙂

 

[EdwardKaraa]

No lens can be considered sharp if the owner can't focus it properly, no matter how theoretically good it is.

 

[Denton]

Characteristics of low frequency resolution?

Characteristics of low frequency resolution?

If one compares two lenses, one with better resolution at high lp/mm but poorer at low frequency resolution, what would be the qualitative difference and when would we prefer one vs. the other?

 

[Pioneer]

I still find it interesting that results from one single lens compared with results from another single lens are taken without doubt as being fully representative of all such lenses.

As much as I respect Roger's work, it may really be more representative for several of us who own these lenses to ship them off to Roger and have him repeat these tests on all of these lenses and see where things play out. I think that people would be quite surprised, maybe even shocked, at the leveling effects from the averages of a group of real life lenses that are being used on a regular basis.

Further, I think that some type of cost effectiveness measure has to be considered as well. I find it extremely instructive to see how closely the $850 Leica Planar and the $2500 Leica Summicron compare.

Finally, how many of you that own a $7,000 Summicron really believe that you are achieving those stellar results from your handheld shots on the street? I think the reality is that we are all realizing very similar results from our various lenses regardless of the actual dollar amount spent. The tiniest amount of focus error or camera movement will totally negate all those terrific test results.

 

[Richard G]

I find the single most important thing for a sharp image is a fast shutter speed, especially with digital. On the M9 this means 1/180s minimum with the 50mm lens, and preferably 1/500s. But I often use 1/45s or slower when sharp is not the key requirement. And Denton is certainly right about the many inputs to the impression of sharpness, a well chosen phrase.

 

[Tom A]

I have the Summilux 50 Asph - and the C-Sonnar 50f1.5 (and Planar 50 etc). The Summilux is sharp and contrasty - but it lacks 'soul" - the C Sonnar 50f1.5 has it - at least in black/white.
Further more, what is interesting in the test is how good the Nokton 50mm f1.1 is compared to the $ 10 000 Noctilux 0.95!
Yes. I would like to have a 50 Summicron Apo - but at $ 7000 I am not getting it. Shooting film you would need to shoot everything with ultra fine grain film to even see the difference.

 

[uhoh7]

I find it extremely instructive to see how closely the $850 Leica Planar and the $2500 Leica Summicron compare.

The 50cron pre-apo optics have not changed since the 80s, so it's easy to find a tabbed v4 for 900USD. It's one of the great values today. 🙂

The APO is like the .95: would be alot of fun to have lying around, but for normal working person, hard to justify. Such money could be used so many ways.

Would I rather have a APO or MM? LOL Or a nice motorbike 🙂

Lastly, while the tests are probably pretty good, Roger calls them preliminary, and not to be taken as definitive. Its a work in progress and we should see some more info from him in the future. His favorite camera? Leica MM. 🙂

 

[john_s]

No lens can be considered sharp if the owner can't focus it properly, no matter how theoretically good it is.

And furthermore, leaving aside for the moment that the rangefinder focus mechanism is at its limit in testing to the degree of accuracy of the lensrental post above, on an optical bench I understand that the best focus is found having no regard to the lens's focus hardware, so no focus shift comes into the results, no field curvature etc.

When the Sonnar-C came out, Zeiss's MFT graphs looked quite ok, but what they didn't reveal is that those sharpness results were not available if you were focusing with a rangefinder camera rather than an optical bench.

 

[uhoh7]

When the Sonnar-C came out, Zeiss's MFT graphs looked quite ok, but what they didn't reveal is that those sharpness results were not available if you were focusing with a rangefinder camera rather than an optical bench.

Unless you actually practiced enough to learn the lens and how much forward or back to go in a given situation.

You really need a digital M of some sort to do that, but once you learn a lens, film results will be effected as well.