S lenses performance

[edwardkaraa]

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Hi All,

 

Sorry in advance for the blasphemous question, but I have been considering for a while to get into the S system with a used 006 and a couple of lenses. I hear everyone raving about the quality of the lenses and effectively, I see a lot of great shots with the S.

 

However, looking at the published MTF, provided by Leica at both close range and infinity, I really don't see anything extraordinary. In fact, most MTF look below average, and some really bad, with sag. and tang. curves on opposite ends. M lenses have some stellar MTF, and even the average ones look better than S lenses.

 

I know there must be something else going on beside the MTF, so I would be grateful if someone could point out what I'm missing.

 

Thanks

 

 

[Guest NEIL-D-WILLIAMS]

Just go rent one and find out for yourself whether you like it or not. And if you can't rent one just buy one as they are cheep as chips right now.

[edwardkaraa]

That's not what I'm asking, Neil. Obviously I like the handling of the camera and the look of the photos I've seen from it.

[RVB]

Here is a quote from Lloyd Chambers regarding the S120mm MTF,I judge the Glass by the results and the color/contrast is excellent and performance at the edges is very good!

 

"MTF

Wide open at f/2.5, performance is very high over the entire frame. A lens this good would be the wish of many a 35mm DSLR shooter. However there is a drop in contrast at the frame edges into the corners. Stopping down to f/5.6 improves contrast slightly over most of the frame, but with worthwhile improvement in the corners. How f/4 behaves is unclear. Overall performance is astonishingly high."

[John McMaster]

I have never found (well OK the zoom a little bit) the S lenses lacking in quality. Not looked at relative MTF, but I know that the S2 with S lenses will produce shots (of suitable subjects) that the M cannot compete with. I have lenses like the 35mm Summilux FLE, 50mm APO Summicron and 75mm Summicron so have some of the best M lenses. Main thing I find with the S, even with the S 35mm, is that I sometimes get less DoF than I would like when hand holding...

 

john

[jaapv]

Hi All,

 

Sorry in advance for the blasphemous question, but I have been considering for a while to get into the S system with a used 006 and a couple of lenses. I hear everyone raving about the quality of the lenses and effectively, I see a lot of great shots with the S.

 

However, looking at the published MTF, provided by Leica at both close range and infinity, I really don't see anything extraordinary. In fact, most MTF look below average, and some really bad, with sag. and tang. curves on opposite ends. M lenses have some stellar MTF, and even the average ones look better than S lenses.

 

I know there must be something else going on beside the MTF, so I would be grateful if someone could point out what I'm missing.

 

Thanks

It is useless to compare MTF curves between different formats, the results will always be misleading.

[jip]

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MTF curves of small format lenses are usually 'better' than those of medium format lenses due too the smaller image circle.

[edwardkaraa]

MTF curves of small format lenses are usually 'better' than those of medium format lenses due too the smaller image circle.

 

Yep, I forgot about that one. Small format lenses have to resolve more per millimeter than medium format lenses.

[jip]

Yes, and still if you'd count the MTF curves of the S lenses on the small format image circle, they are equal if not actually quite a bit better than M lenses. Especially in close focussing range on the 70mm for example.

[edwardkaraa]

Yes, and still if you'd count the MTF curves of the S lenses on the small format image circle, they are equal if not actually quite a bit better than M lenses. Especially in close focussing range on the 70mm for example.

 

Agreed. But the 35mm for instance has a huge dip wide open at close range. I guess it's just field curvature.

[Jeff S]

http://www.cambridgeincolour.com/tutorials/lens-quality-mtf-resolution.htm

 

The section near the end (Comparing Different Cameras...) expands on some of the above comments.

 

The last section also lists various lens qualities not indicated by MTF.

 

Jeff

[menos I M6]

Next to comparing two different formats (hence having to compare MTF charts with different references) the one thing many people quickly forget when used to shoot 35mm format is that with larger formats you definitely have to stop down much further in order to get a usable DOF.

 

With medium format your usual usable wide aperture you start from shooting is f4 - f5.6 and you still have a very slim DOF.

If you shoot landscapes or product shots you are easily wandering into f11 - f22 territory with medium format while f8 is considered stopped down A LOT with 35mm.

 

When looking at the Leica S system many people completely forget how fast these S lenses are all across the board - generally f2.5 on all major lenses - that is screaming fast and not always appropriate to shoot at (less so compare charts at)!

 

What I find amazing with the S is just how good the S lenses are already wide open, compared with any other lenses. It is perfectly normal to see a major difference between wide open and one or two stops down with other adapted lenses on the S - even normal to see such a difference with really great lenses on the Nikon D800 and also pretty normal with older generation (1970's - 1990's) Leica M lenses.

 

With S lenses it is shocking how good they are already wide open - it really is. With other systems you have a handful of lenses which behave similarly good (like the Nikon 300/2.8 or the Leica M135/3.4 APO Telyt or the Contax 645 120/4 or the Hasselblad 80/2.8 Planar, … but there is no other system where consistently all lenses are like this).

[edwardkaraa]

Next to comparing two different formats (hence having to compare MTF charts with different references) the one thing many people quickly forget when used to shoot 35mm format is that with larger formats you definitely have to stop down much further in order to get a usable DOF.

 

With medium format your usual usable wide aperture you start from shooting is f4 - f5.6 and you still have a very slim DOF.

If you shoot landscapes or product shots you are easily wandering into f11 - f22 territory with medium format while f8 is considered stopped down A LOT with 35mm.

 

When looking at the Leica S system many people completely forget how fast these S lenses are all across the board - generally f2.5 on all major lenses - that is screaming fast and not always appropriate to shoot at (less so compare charts at)!

 

What I find amazing with the S is just how good the S lenses are already wide open, compared with any other lenses. It is perfectly normal to see a major difference between wide open and one or two stops down with other adapted lenses on the S - even normal to see such a difference with really great lenses on the Nikon D800 and also pretty normal with older generation (1970's - 1990's) Leica M lenses.

 

With S lenses it is shocking how good they are already wide open - it really is. With other systems you have a handful of lenses which behave similarly good (like the Nikon 300/2.8 or the Leica M135/3.4 APO Telyt or the Contax 645 120/4 or the Hasselblad 80/2.8 Planar, … but there is no other system where consistently all lenses are like this).

That's a great post with excellent points. Thank you!

[wattsy]

When looking at the Leica S system many people completely forget how fast these S lenses are all across the board - generally f2.5 on all major lenses - that is screaming fast

 

Agree that it is fast (and consistently so) but don't forget that the S lenses are designed for a format smaller than traditional medium format (compare 30mm x45mm with even 645 film size). 

 

 

With S lenses it is shocking how good they are already wide open - it really is.

 

I don't wish to open the whole "digital corrections" can of worms but does anyone know what the 'native' (uncorrected raw) performance of these S lenses is like? I'm sure it is very good indeed but the S lenses do have a design advantage in that they can only be used in the relatively narrow digital S (and, soon, SL) "ecosystem" compared with lenses originally designed for film (Contax 645, etc.) or for multiple digital platforms. 

[menos I M6]

Ian, the benefit the Leica S lives from (being the most compact system of it's kind) comes due to the fact that the lenses indeed are designed to J U S T cover it's smaller sensor.

This is something quite irritating in use sometimes (I am used to hold a lens at slow shutter speeds sometimes by the front rim and partly hold a fingertip into the frame which is not a problem at all with Mamiya, Hasselblad and other lenses. With the S, just a fingertip on the lens' front rim will net you a finger tip in the frame.

 

The performance of the Leica S lenses surely is founded in it's slightly smaller format then traditional 645 or even 6x6 or 6x7.

The main reason why it performs so well it surely that it is the very youngest MF system, entirely designed from ground up around this new sensor size by some of the greatest optical engineers (I have no doubt, Mamiya, Hasselblad, Rollei, Zeiss, … could have pulled of this feat as well).

 

Due to the lens' relatively small image circle (and it's tight image circle regarding sensor size) the S lenses are actually at a disadvantage, as they have to perform into the very corners so well, while other MF lenses do have some excess glass to cover corners and edge illumination.

 

Interesting that you mention the digital correction component here.

I myself do disable ANY lens correction features with ANY camera system upon ingestion into Lightroom.

I do make use in single shots where I can benefit from lens corrections I deem necessary but generally I have switched this function off in my import profiles.

My view therefore is based on seeing images side by side, made on the S2 body with lenses from different makers.

 

Optically the Leica S lenses are the best lenses - which doesn't mean that those are the ones I generally prefer ;-)

 

For example do I generally tend towards using a 80 Planar on the S2 or a Schneider Xenotar 80/2.8 but do grab the 70/2.5 Summarit S when I think I just want the best optical quality over lens character (I am a person why would choose a f1 Noctilux over an APO Summicron any day after all).

I treat the S lenses generally as my modern aspherical Leica M lens set. I do prefer vintage lenses mostly but I do find the modern, more perfected lenses useful for a purpose.

 

There is one other great advantage of the Leica S system: it is the most adaptable system of all MF systems - due to it's smaller sensor size - hence smaller mirror box and flange distance you can adapt so many lenses without modification to it.