SEM 21 vs Loxia 21 shootout

[CheshireCat]

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Got out today with my M240 + SEM21 (Leica) and A7R2 + Loxia 21 (Sony body / Zeiss lens).

Took several shots with both combos at f/3.4, and here is what I learned:

 

- Both combos are amazing. You can stop reading here.

- Leica combo is much more compact, thanks to the SEM21 size. Yes, size matters

- The SEM does some magic for higher DoF at the same f-stop. See trees in example (may be field curvature, but it is useful).

- The SEM requires both RF and EVF: RF for focusing and EVF for framing. This is a real PITA. The EVF sucks. It is very difficult to nail critical focus with either the RF or the EVF (even at 10x magnification).

- The Sony/Zeiss combo can be focused surprisingly easy with the Sony EVF. Even without focus-peaking, you will see the focus "pop" at the pixel level. Difficult to describe. The magnification works great. Be sure to disable the nonsense auto-magnification when focusing and rather map it to a manual button.

- Switching between the medieval Leica (Oly) EVF and the Sony EVF is like switching between a 1990 CRT TV and IMAX theatre.

- IBIS really helps with low shutter-speed also at 21mm. Especially when the sun goes down.

- The A7R2 has an awesome higher resolution sensor. ISO performance is awesome. Noise patterns are awsome. Push is awesome.

- Colors/gamma SOOC are better on the Leica (Adobe profiles). Sony raws must be processed for same (or better) goodness.

- SEM has classical purple/green LoCa. Zeiss has red/cyan LoCa (special glass ?).

- Sometimes I miss a couple less stops for DoF.

- A7R2 drinks batteries faster than I can drink a Bloody Mary. Remind me to buy a fourth battery. Leica is great with just one spare.

 

Example below.

I made some magic to color/gamma-match both shots as per my liking. Seems I am pumping up magenta as I grew older.

Apart from color/gamma, shots are SOOC (no sharpening).

 

Hope this helps. Feel free to insult me as usual. I'll be glad to help if you need more info.

 

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[Guest JonathanP]

Thanks, exactly the comparison I was hoping someone would do. I had the 21SEM on my wanted list for a while and bought a new one in December (production date Oct '15) but it was decentered and just didn't have the bite that I was expecting given the gushing comments seen on here. Certainly wasn't resolving anything near my 35FLE. So I sent it back for a refund, rather than try another from the same batch.

 

Now I'm at a bit of a crossroads - I really like my M240 but really coming to the conclusion that its better at mid focal ranges 35-50 and perhaps rather than expanding out my lens collection I'll shrink it back and buy an A7RII for landscape use (no artificially crippled long exposure limitations, better dynamic range, etc). So the next go at trying to find a good 21SEM is on hold for now.

 

Jonathan

Edited January 19, 2016 by jperkins

[Guest JonathanP]

Do you have an example comparison at f/5.6 or f/8? Would be interested in how the edges clean up.

 

Thanks,

Jonathan

[jaapv]

Ummm.. The RF for focusing and the EVF for framing? If you don't like the EVF just use an optical viewfinder - the Zeiss one is brilliant, the Leica one more accurate, but admittedly not the WYSIWYG of an EVF.

I'm surprised at the difficulty of achieving focus by the RF. It should be dead easy - have your calibrations checked.

 

However, nice to see rigorous testing, very informative

[Tmuussoni]

Thank you so much for the comparison. A very important lens for the Sony system. Finally a compact and high performing ultra wide angle prime. Based on all the samples I have seen, Loxia 21 is right up there with SEM 21 and A7r II Sensor is truly awesome. And I love my SEM 21 with M.  My only complaint about Loxia 21: why on earth they had to go with 10 bladed diaphragm? It should have been 9-bladed diaphragm like SEM 21 for superior sunstars. Oh well, for most people they don't seem to mind about this

[jaapv]

It probably was to create some extra smoothness in the OOF areas. Judging by this test, it was needed too, it is still a bit harsh on the Loxia it seems. (Or is that the extra resolution?)

[jdlaing]

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It probably was to create some extra smoothness in the OOF areas. Judging by this test, it was needed too, it is still a bit harsh on the Loxia it seems. (Or is that the extra resolution?)

 

I have a couple Loxia lenses. It's not the lenses that are harsh. That's for sure.

[jaapv]

I have a couple Loxia lenses. It's not the lenses that are harsh. That's for sure.

In that case, Cat, could you please repeat the test with the lenses on the same sensor?

[jrp]

  My only complaint about Loxia 21: why on earth they had to go with 10 bladed diaphragm? It should have been 9-bladed diaphragm like SEM 21 for superior sunstars. Oh well, for most people they don't seem to mind about this

I think that you will also get stars with the Loxia.

 

I think that it has a curved (forward peripheral) field of focus, but you may not notice.

 

I'm waiting to see what the 18mm Batis and the new wide angle Voigtlanders are like before deciding.

[Rick]

Questions - 

 

I've read this lens has coma at the edges.  Is that true?

Does infinity stop align with infinity or does it fall short?

It looks like the Loxia shot displays smearing at the edges.  Do you see this?  If so, is it the lens or the sensor?

Would you shoot the 21 SEM on the A7rII or the A7?

Your choice of subject matter is poor, don't you think? (I thought you would feel something is wrong here if someone didn't insult you by the 10th post).   

 

RickNonretroshooter

[CheshireCat]

Do you have an example comparison at f/5.6 or f/8? Would be interested in how the edges clean up.

 

Sorry, I had a comparison at f/8 but then realized the Leica shot was motion blurred (my bad).

Plan to do this again the next days and will keep you posted.

[CheshireCat]

Ummm.. The RF for focusing and the EVF for framing? If you don't like the EVF just use an optical viewfinder - the Zeiss one is brilliant, the Leica one more accurate, but admittedly not the WYSIWYG of an EVF.

I'm surprised at the difficulty of achieving focus by the RF. It should be dead easy - have your calibrations checked.

 

Yes, the M240 EVF at 21 does not allow precise focusing. Not with focus-peaking, and not with 10x maginification. I was also surprised.

I don't use optical viewfinders, as I think that the EVF is much better for framing, especially in low light.

 

My camera is perfectly calibrated, and in any case, calibration won't affect EVF focusing.

[jaapv]

Yes, I would not use the EVF for focusing wideangles  either although the thing is fine (not pretty ) for my use, i.e. long lenses, but not much else, I agree - my  real surprise was that you found focusing an 21 difficult with the RF. To me, it is really easy. If that gives you trouble there must be a cause.

[CheshireCat]

I have added numbers to your questions, so it is easy for response-mapping

 

Questions - 

 

1) I've read this lens has coma at the edges.  Is that true?

2) Does infinity stop align with infinity or does it fall short?

3) It looks like the Loxia shot displays smearing at the edges.  Do you see this?  If so, is it the lens or the sensor?

4) Would you shoot the 21 SEM on the A7rII or the A7?

5) Your choice of subject matter is poor, don't you think? (I thought you would feel something is wrong here if someone didn't insult you by the 10th post).   

 

1) Haven't noticed any coma, even in the far corners. Will try some astro exposures (infinity) tonight though.

2) Infinity stop works great.

3) That is because the focus field is different in the two lenses. In normal shots, corner performance is comparable to the SEM (i.e. excellent).

4) I would not shoot the SEM an any Sony camera, as the thick sensor filter stack destroys performance even mid frame. I wish it worked decently, but it is totally unusable.

5) For the purpose of this test, I don't think so. I shoot Lego blocks for testing because they make sharpness, distortion and color issues quite evident.

[CheshireCat]

my  real surprise was that you found focusing an 21 difficult with the RF. To me, it is really easy. If that gives you trouble there must be a cause.

 

For normal shooting, the RF is perfectly fine.

Indeed, at 21mm the focused subject will have acceptable sharpness also with strong front or back focus.

And this is the problem: for testing, you need to nail perfect focus to correctly compare depth of field and out-of-focus rendering between the two lenses.

[CheshireCat]

Sorry, it's been awfully overcast these days here, so I could not try any proper coma test.

 

Though, I tried shooting directly at the sun, and the Loxia is amazing.

[adan]

RE: Coma test

 

The sun is too big a light source to be useful (even with a 21). (Good for flare tests, though)

 

Look for some decorative "fairy lights" in the evening - someone may have failed to take down their Xmas lights, or your town may have some year-round, on trees/pillars in public areas.

 

Shoot them in various parts of the picture at various apertures. Coma (sometimes combined with astigmatism and CA) will show up as consistent "moth wings" or other odd shapes around the point light sources.

 

http://2.bp.blogspot.com/-VaJDcEcHYAI/USeMN1rSCgI/AAAAAAAADKM/4cRbKXIWpMM/s1600/24mm-coma-test_800px.jpg

 

http://3zgehi1uaxi23dphbrgqa50r6z.wpengine.netdna-cdn.com/wp-content/uploads/2014/05/abellucco_coma.jpg

 

I wouldn't expect slowish 21s to show much - it is more of a problem with fast wides. The Leica 35 Summilux ASPH is notable for having virtually none. My 35 Summicron pre-ASPH has tons of it @ f/2.

[pgk]

I wouldn't expect slowish 21s to show much - it is more of a problem with fast wides. The Leica 35 Summilux ASPH is notable for having virtually none. My 35 Summicron pre-ASPH has tons of it @ f/2.

 

To see an example try: http://marinewildlife.co.uk/info/leica-35mm-f1-4-pre-aspheric-summilux-m/ - the evening photo of the boat shows it very clearly even as a small jpeg.

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[MarkP]

Cheshire, thanks for posting this but the lighting in your two sample photos is different. The first one was shot in sunlight (you can see the long shadows on the ground including of yourself), but the second in shade. Do you think this has affected your interoperation of the colour differences?

[helged]

FYI: Coma example of SL+21LuxM at f1.4 / 20 sec, showing the upper 1/4, or thereabout, of an image (the starts are in focus, albeit not in the attached jpg...).

 

 

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