50mm Summilux ASPH Edges

[UliWer]

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Well, I wouldn't assume it's self-explanatory to me.  I will have to research how to read this. ...

Those graphs are only a specific way to illustrate the character of a lens. The don‘t show the reasons why an object at the edge cannot be revealed on a photo as sharp as an object in the center, but only show the result, which you already saw on your photo.

 

The reason for this result is the lens. The lens is submitted to just a few physical laws. Even Leica is not above these laws. You may find the laws under the header „optical aberrations“. There you will find the sentence, that refraction of light rays which hit the edge of a lens is higher than refraction for rays which hit the center. You cannot change this. All you (or a lens designer) can do, is trying to correct this, i.e. making the difference of refraction between the center and the edges less obvious. The easiest way to correct this aberration is an f-stop: you cut off the edges and get only the rays from the center.

 

With a wide opened lens not stopped down, you need more sophisticated methods for correcting the problem: use different types of lenses combined. Though the more lenses you add the more different types of aberrations you get - so you have to correct them as well. This is complicated - and expensive. A lens very well corrected in all regards - like the 50mm Summicron apo. asph is extremely expensive - though it only has f/2 as max. opening.

 

Of course with the Leica brand on the lens you pay an extra amount - even if the pains the maker took to correct the aberrations as well as possible does not legitimize the price. Though one has to remember, that whatever price you pay or whatever effort the producer made to correct the aberration, the laws of physics will always prevail: edges are less sharp than the center.

[jmahto]

Reading this thread last night, out of interest I picked up my M240 & Summilux 50mm ASPH and took the screenshot below. f1.4, 1/180sec, ISO 200, hand-held at min focus distance.  Now of course, it may be that the camera was not perfectly square to the screen but one can see that there is a change in sharpness from centre to edge.

 

But in real life I have not noticed problems with field curvature...

I would rather state that the field curvature contributes to the character of the lens. I have noticed in some pictures that for "normal" distance, the background blur in the center (behind main subject) is more than the blur on the side. This contributes to (IMHO) little more pop and subject isolation to the center subject in focus. I will post example when I get home tonight.

 

All these small things (size, sharpness, curvature, handling) put together make 50 lux a great lens for me. I also use it on Nex6 with good results (albeit with stop down a little) and that makes it more versatile for me. My 50lux picture (on Nex6) is currently third best on 500px.

 

https://500px.com/gear/lenses/leica/summilux-m-50mm-f-1-4-asph-/best_100

 

BTW, I like this lens enough to have my macho portrait taken holding this lens.

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[jmahto]

Thank you for the reply.  I did indeed use the magnified view and also focus peaking.  I tried the same set up shooting a ruler at an angle at the side as well.  At f/1.4, nothing on the ruler was in perfect focus.  It just tells me that it's a characteristic of the lens.  I'm not faulting the lens, just trying to understand it.  I also understand what you are saying about making adjustments when recomposing, but even if I do everything perfectly and my subject is too far to the side or top (portrait orientation), it will never be perfectly sharp at f/1.4.

 

 

 

I often orient faces in the left or right 1/3 of the image.  The closest eye is usually the one nearest the edge and there is a good chance it may look a little blurry or out of focus at 1.4.  I'm not sure I could comment as to the style or artistry, but I do know I really like razor sharp eyes and even more so razor sharp reflections in the eyes.  Maybe to a fault.  I do also realize that this manual rangefinder and not autofocus with it's own set of compromises.

 

Below is another picture that shows the orientation I often use.  I doubt this one is at f/1.4, and the eyes are pretty good, but not perfect.  You can see how close her left eye is getting to the edge.  Maybe not everyone's cup of tea, but I like it.  I think shutter speed was OK at 1/350th, but maybe I never got the focus right to begin with.

 

I'm just trying to understand my gear, get the most out of it, and get better at what I do.  Thanks for all the comments.

Very nice picture. What I see is the smile and not sharpness (lack off).

 

And I bet the loss of eye sharpness in this picture may not be even visible in A3 size print.

Edited February 28, 2018 by jmahto

[Nordvik]

I find it difficult focusing using the rear LCD-screen. It was a disappointment for me coming from M9. I had so high hopes for Live View.

The magnification is greater in Play than in LV. Why is that? Is the magnification greater with the EVF?

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[Nordvik]

This is what it look like in LV. 1024x683 in LR (I am guessing)

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[Nordvik]

Using Play. I use B&W for the LCD, and I do not use Focus Peaking (I find it better without for precise focus).

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[jhgnag]

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This is normal for this lens. It's not suppose to be sharp at the edges @ 1.4. Even if use a camera with live view such as an SL and move the focus point to the far edges to confirm sharpest possible focus, the results will be the same. 

 

That's what I was hoping to confirm one way or the other.  Thank  you.  The SL is no permanent yet and I don't have the M adapter, but I think I accomplished the same test with the Live View on the M10.

 

 

I love the photo of your daughter on the gate, and I don’t think it suffers from being a little soft. That is really the nature to the 50 Summilux-M at 1.4, I’m afraid. If you want it sharper you need to stop down a little (the impact on the out of focus area won’t be too bad) or switch to the 50 Summilux-SL - it’s portable, but big.

 

Thank you for comment.  I'm not unhappy with sharpness on the picture of my daughter, but was really trying to show how my subject is near the edge of the frame where it may be softer.  I'm sure I can live with and work with the character of the lens.  Like you said, I can stop down or change it if it really bothers me.  I was really just trying to make sure there isn't a problem with the lens itselft, which I'm understanding there is not.

[Nordvik]

Leica says:

 

3” color -TFT LCD monitor with 16 million colors and 1,036,800

pixesn, approx

 

What does that mean? I think that in both LV and Play they are showing more than 100%

[Nordvik]

Look at this: https://www.lensrentals.com/blog/2014/06/comparing-rangefinder-and-slr-50mm-lenses-version-0-7/

Those lenses are tested at infinity. Most Leica-M lenses do less well at/ or near minimum focus distance (but I think your lens should be among the best because of FLE?).

[lct]

Look at this: https://www.lensrentals.com/blog/2014/06/comparing-rangefinder-and-slr-50mm-lenses-version-0-7/

Those lenses are tested at infinity. Most Leica-M lenses do less well at/ or near minimum focus distance (but I think your lens should be among the best because of FLE?).

 

There are mistakes in this article as neither 50/1.4 asph nor 50/2 non apo are as sharp at edges as at the centre of the frame, at full aperture i mean. Now the Summilux 50/1.4 asph does pretty well there at all distances provided focusing is made properly. Of course edges are softer but the results i get this way are way sharper than with my Summilux 50/1.4 v2 or v3 or Nikon 50/1.4, let alone Sonnar 50/1.5. 

Edited March 1, 2018 by lct

[Nordvik]

From the article:

 

I think this is the important take home point of this type of testing. If we just looked at the MTF50 numbers in the first part of the article the Summilux probably seemed the best of the three. It had higher MTF 50 numbers in the center, middle, and edges of the lens, although it also had higher astigmatism. Looking at the MTF curves with a slightly different test, the case isn’t quite as clear and you could certainly make an argument that you preferred any of the three lenses.

 

(One point I want to make clear is the testing methods differ – the MTF50 tests are done at ‘best focus for that point’. In other words the bench individually focuses at the center, mid point, and edge to generate the highest possible numbers. With the MTF tests we’re showing here, the bench focuses in the best position for the center of the lens and all other measurements are done at that focus. So field curvature will affect these graphs, but not the MTF50 tests done earlier.)

[jmahto]

If we really want to compare 50lux ASPH with other excellent RF and SLR lenses then this article by Roger Cicala of lensrentals is relevant.

 

You can scroll down for resolution numbers.

https://www.lensrentals.com/blog/2014/06/comparing-rangefinder-and-slr-50mm-lenses-version-0-7/

 

If you don't want to take trouble to read the article then let me tell you that Sigma art and Otus have marginally inferior numbers wide open. Only 50APO is better (marginally) across the frame (at f2 lux edge performance catches up to APOs).

Edited March 1, 2018 by jmahto

[lct]

If we really want to compare 50lux ASPH with other excellent RF and SLR lenses then this article by Roger Cicala of lensrentals is relevant. [...]

 

Problem is mistakes in this article as suggested above. In no way can wide open 50/1.4 asph and 50/2 non apo be as sharp at edges as at the centre of the frame IMHO.

[jmahto]

Problem is mistakes in this article as suggested above. In no way can wide open 50/1.4 asph and 50/2 non apo be as sharp at edges as at the centre of the frame IMHO.

There is enough explanation in the article about testing method. Whatever is the mistake, it applies to all the lenses since they are tested the same way (along with averaging sample variations). We can't dismiss the entire article.

 

For me the simple takeaway is "50lux is damn good" and I should not worry about sharpness. There could be a sample variation in one's copy but I haven't read about any complains.

Edited March 1, 2018 by jmahto

[jaapv]

Problem is mistakes in this article as suggested above. In no way can wide open 50/1.4 asph and 50/2 non apo be as sharp at edges as at the centre of the frame IMHO.

Carefully explained testing methods are not mistakes

[jmahto]

Another takeaway from Roger's article is that any in depth testing has so many variables that need to be controlled and explained in the results. At the end, these results become academic and what matters is what is good for our own use. I do my own testing based on what I shoot and if it is good enough then I am happy with it, irrespective of what others say. For example, Konica 57hexanon 1.4 is certainly "inferior" wide open to all these other super 50s but I love the soft wide open look of hexanon with bokeh as soft (or even a little better) than 50lux (since hexanon is close to 60mm). Then I shoot with 50lux and love the center sharpness wide open with velvety bokeh in a super handling package.

I am sure others have their own reasons to love their own fav 50. And that's all what matters.

Edited March 1, 2018 by jmahto

[lct]

There is enough explanation in the article about testing method. Whatever is the mistake, it applies to all the lenses since they are tested the same way (along with averaging sample variations). We can't dismiss the entire article.
For me the simple takeaway is "50lux is damn good" and I should not worry about sharpness. There could be a sample variation in one's copy but I haven't read about any complains.

Carefully explained testing methods are not mistakes

 

 

Sorry to disagree with you folks. I have nothing against LensRentals and i like both my 50/1.4 asph and 50/2 non apo but the boxed results below are simply incredible to me that's all i meant to say.

 

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Edited March 1, 2018 by lct

[jmahto]

 

 

 

 

Sorry to disagree with you folks. I have nothing against LensRentals and i like both my 50/1.4 asph and 50/2 non apo but the boxed results below are simply incredible to me that's all i meant to say.

 

Mistakes.png

 

I don't understand. I may also feel that Otus should have better numbers than Summilux in the center but why my feeling should take precedence over an objective test results. It seems like you are not trusting the results simply based on ....?

To be fair, I have no idea whether Roger Cicala messed up in his test but I don't have anything else to think otherwise.

[jaapv]

 

 

 

 

Sorry to disagree with you folks. I have nothing against LensRentals and i like both my 50/1.4 asph and 50/2 non apo but the boxed results below are simply incredible to me that's all i meant to say.

 

Mistakes.png

 

Hmmm.. What did you measure then?

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[Nordvik]

Sorry to disagree with you folks. I have nothing against LensRentals and i like both my 50/1.4 asph and 50/2 non apo but the boxed results below are simply incredible to me that's all i meant to say.

 

Mistakes.png

The numbers for the Summicron is obviously wrong, but I do not see anything wrong with those from the Summilux. It depends on how you define Edge. 12mm or 18mm from center?