contrast differentiation between few lenses

[jaeger]

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I shoot 30+ years and recent few years gone serious in photography.  I am a Leica noob, I've been using M for only 1+ year (since last March) and I've finally got the focusing issue fixed, and now I can see the IQ at different distant, lighting, aperture, etc...  I own 4 Leica lenses on MP240 and I shoot wide open most of the time unless over exposure, shooting product, studio or shooting landscape.  My work are mostly portrait & headshot.

Here are my observations when shooting wide open.

1) 24mm lux, IQ is fine when uncropped, however, if I start to crop, then detail and contrast are badly diminishing as going further and further.

2) 35mm lux last version I think it's V3?, same as 24 but better.

3) 50mm lux, I cannot complain.  I wish all my Leica lenses perform like this.  It's sharp, high contrast and I can crop and crop and still good.

4) 90mm cron, as sharp as 50mm lux but must lower contrast in comparison.  However, it's fixable using LR. 

My question....

I might have wrong expectations because I kind of using the 50mm lux as standard and expecting other lenses perform similar.  I know wide angle lenses can't go as sharp but I was expecting better because it's price tag.  Anyway, are my observations true or something is wrong with these lenses (or something wrong with my brain lol)?

I wish to hear your thoughts if your shooting style is similar and owning similar lenses.  Thank you.

 

Edited July 10, 2019 by jaeger

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Hallo,

Look here: Leica M

[lct]

No experience with the Summilux 24/1.4 asph but do you mean 35, 50 & 90 asph or pre-asph lenses? If you mean pre-asph it's normal that your pics look a bit soft at full aperture but not that much with the 90/2 if it's a v2 (big lens).

[dkmoore]

3 hours ago, jaeger said:

I shoot 30+ years and recent few years gone serious in photography.  I am a Leica noob, I've been using M for only 1+ year (since last March) and I've finally got the focusing issue fixed, and now I can see the IQ at different distant, lighting, aperture, etc...  I own 4 Leica lenses on MP240 and I shoot wide open most of the time unless over exposure, shooting product, studio or shooting landscape.  My work are mostly portrait & headshot.

Here are my observations when shooting wide open.

1) 24mm lux, IQ is fine when uncropped, however, if I start to crop, then detail and contrast are badly diminishing as going further and further.

2) 35mm lux last version I think it's V3?, same as 24 but better.

3) 50mm lux, I cannot complain.  I wish all my Leica lenses perform like this.  It's sharp, high contrast and I can crop and crop and still good.

4) 90mm cron, as sharp as 50mm lux but must lower contrast in comparison.  However, it's fixable using LR. 

My question....

I might have wrong expectations because I kind of using the 50mm lux as standard and expecting other lenses perform similar.  I know wide angle lenses can't go as sharp but I was expecting better because it's price tag.  Anyway, are my observations true or something is wrong with these lenses (or something wrong with my brain lol)?

I wish to hear your thoughts if your shooting style is similar and owning similar lenses.  Thank you.

 

I’ve owned or still own these lenses.

Trade 24 Lux for 28 Lux for sharper and higher contrast rendering wide open to be similar to 50 Lux  

Trade 35 asph for the FLE version for sharper and higher contrast rendering wide open to be similar to 50 Lux  

If you have the 90 APO it should be just as sharp and in my experience about the same contrast as the 50 Lux so maybe you have a prior version lens. 

*i personally like that my lenses have different renderings so that I can mix things up a bit but if you want a homogenous workflow I recommend the above. Above assumed 50 Lux Asph 

[jaeger]

8 minutes ago, dkmoore said:

I’ve owned or still own these lenses.

Trade 24 Lux for 28 Lux for sharper and higher contrast rendering wide open to be similar to 50 Lux  

Trade 35 asph for the FLE version for sharper and higher contrast rendering wide open to be similar to 50 Lux  

If you have the 90 APO it should be just as sharp and in my experience about the same contrast as the 50 Lux so maybe you have a prior version lens. 

*i personally like that my lenses have different renderings so that I can mix things up a bit but if you want a homogenous workflow I recommend the above. Above assumed 50 Lux Asph 

Thanks Moore.

I need to see if I can financially accomplish that for 28 and 35 FLE trade in.  =P

My 90 APO is s current version serial number start with 470xxxx.  Any thoughts?  Actually all lenses are current expect the 35mm is a previous version.

 

 

 

[jaeger]

35 minutes ago, lct said:

No experience with the Summilux 24/1.4 asph but do you mean 35, 50 & 90 asph or pre-asph lenses? If you mean pre-asph it's normal that your pics look a bit soft at full aperture but not that much with the 90/2 if it's a v2 (big lens).

answers on my reply to Moore's post.  Thanks.

[Jeff S]

The 28 Summicron ASPH also pairs well with the 50 Summilux ASPH.  In fact, so does the 35 Summicron ASPH.  And for a slower but still excellent lens, the 35 Summarit exhibits less flare and focus shift than the Summicron.

Frankly, most all Leica options are fully capable when combined with a suitable shooting and PP workflow.

Jeff

[lct]

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2 hours ago, jaeger said:

My 90 APO is s current version serial number start with 470xxxx.  Any thoughts?  Actually all lenses are current expect the 35mm is a previous version.

Your 90/2 apo should be sharp at all apertures including f/2 at the centre of the frame. Edges and corners are softer at f/2 though. Beware that this lens is not far from the limits of the rangefinder's accuracy at full aperture so better use an EVF to get sharper results at high magnifications. As for your Summilux 35, depends if it is an asph or pre-asph version. If it is an asph version it should be sharp at the centre of the frame but less so at edges and corners below f/2.8.

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Hallo,

Look here: Leica M

[pico]

One self-claimed impression is just one. Not significant. Discard.

[dkmoore]

2 hours ago, jaeger said:

Thanks Moore.

I need to see if I can financially accomplish that for 28 and 35 FLE trade in.  =P

My 90 APO is s current version serial number start with 470xxxx.  Any thoughts?  Actually all lenses are current expect the 35mm is a previous version.

 

 

 

90 APO is as sharp if not sharper than 50 Lux. It is just as contrasty as well. I have the 90 APO currently. 

What may be deceiving your eyes is the more shallow DOF of the 90 Cron. Having less in focus may give off the impression of less contrast but overall the 90 and 50 newer versions should be very close. 

If the 90 isn’t extremely sharp in center I would check it with the EVF and to confirm if it needs to be adjusted. 

[adan]

The Short version - I agree with the OP's evaluations. 24/35 lux and 90 APO don't quite measure up to the 50 Summilux ASPH at full aperture. Nevertheless, they are extremely good for what they are (fast wide-angles/teles).

But......

The Long version - "normal" lenses are almost always the easiest to design well (thus in most systems other than Leica are relatively inexpensive). And as can be seen by the fact that the first general-use 50mm f/1.5 lens (Zeiss Sonnar 1932) was available about 30 years before the first 35mm f/1.4 lens (Summilux 1961) and nearly 50 years before the first 24mm f/1.4 (Canon FD L SSC ~1980).

It depends on how much the light is being bent (to achieve wider angles of view), or how much the world is being magnified (which also magnifies some contrast/resolution-reducing aberrations).

It's been my experience over nearly 50 years using most 35mm camera systems that fast wides/teles rarely measure up to a 50mm of the same aperture and era and maker.

Leica M lenses in particular face limitations - size (mount diameter and rangefinder blockage), and weight/balance on the cameras - that constrain what tools the designer can use to better approximate optical perfection, such as more or larger glass elements. What Canon could achieve around 1980 with a 72mm-diameter, 450g lens, it took Leica another 30 years to surpass (or even attempt) with a 61mm-wide, but still 500g, lens.

There is also often a trade-off in center performance vs. corner performance. The 35 Summilux ASPH (either version in my experience) sacrifices some center resolution performance, but maintains that performance farther into the corners. Compared to the rare original double-ASPH hand-made lens (which is more old-school (similar to Mandler/Canada) in behavior - sharper in the center, but clearly softer in the corners - at f/1.4). Mandler (and Kölsch with the double-A) were designing for photojournalists - get it sharp where the RF focuses, and let the corners go hang.

There is also the question of subject distance - the mathematics of light rays is different when they come from a close distance (not parallel) and when they come from near infinity (virtually parallel). The only way to fix this is a floating element - a subtle changing of the optical formula as the lens is focused. The 50 ASPH (and the 75 Summicron ASPH) have that floating element - the earlier 90 APO ASPH does not, and is reported to (and in my experience does) get a bit blurrier at f/2.0 and distances under 2.5 meters or so (i.e. at portrait distances).

Lens design is an art of balancing the many things glass can do to to light rays. The designer sits at her computer and plays with variables to see what improves performance X a lot while only degrading performance Y a little: lens curvatures, "cheap" spherical surfaces vs. "expensive" ASPH surfaces, glass types (also cheap or expensive), spacings, "good bokeh" vs. maximum correction for contrast/resolution, etc. etc. And then makes a creative decision as to which mix is most preferable.

[jaeger]

2 hours ago, pico said:

One self-claimed impression is just one. Not significant. Discard.

yes Jedi.  lol

[jaeger]

2 hours ago, lct said:

Your 90/2 apo should be sharp at all apertures including f/2 at the centre of the frame. Edges and corners are softer at f/2 though. Beware that this lens is not far from the limits of the rangefinder's accuracy at full aperture so better use an EVF to get sharper results at high magnifications. As for your Summilux 35, depends if it is an asph or pre-asph version. If it is an asph version it should be sharp at the centre of the frame but less so at edges and corners below f/2.8.

My 90 APO focus is dead on now at all distant.  it's sharp but not as contrasy as the 50mm lux.  I just wonder why because 90 is an APO lens but 50mm lux is superb in all aspects and not even APO.  

 

[jaeger]

1 hour ago, adan said:

The Short version - I agree with the OP's evaluations. 24/35 lux and 90 APO don't quite measure up to the 50 Summilux ASPH at full aperture. Nevertheless, they are extremely good for what they are (fast wide-angles/teles).

But......

The Long version - "normal" lenses are almost always the easiest to design well (thus in most systems other than Leica are relatively inexpensive). And as can be seen by the fact that the first general-use 50mm f/1.5 lens (Zeiss Sonnar 1932) was available about 30 years before the first 35mm f/1.4 lens (Summilux 1961) and nearly 50 years before the first 24mm f/1.4 (Canon FD L SSC ~1980).

It depends on how much the light is being bent (to achieve wider angles of view), or how much the world is being magnified (which also magnifies some contrast/resolution-reducing aberrations).

It's been my experience over nearly 50 years using most 35mm camera systems that fast wides/teles rarely measure up to a 50mm of the same aperture and era and maker.

Leica M lenses in particular face limitations - size (mount diameter and rangefinder blockage), and weight/balance on the cameras - that constrain what tools the designer can use to better approximate optical perfection, such as more or larger glass elements. What Canon could achieve around 1980 with a 72mm-diameter, 450g lens, it took Leica another 30 years to surpass (or even attempt) with a 61mm-wide, but still 500g, lens.

There is also often a trade-off in center performance vs. corner performance. The 35 Summilux ASPH (either version in my experience) sacrifices some center resolution performance, but maintains that performance farther into the corners. Compared to the rare original double-ASPH hand-made lens (which is more old-school (similar to Mandler/Canada) in behavior - sharper in the center, but clearly softer in the corners - at f/1.4). Mandler (and Kölsch with the double-A) were designing for photojournalists - get it sharp where the RF focuses, and let the corners go hang.

There is also the question of subject distance - the mathematics of light rays is different when they come from a close distance (not parallel) and when they come from near infinity (virtually parallel). The only way to fix this is a floating element - a subtle changing of the optical formula as the lens is focused. The 50 ASPH (and the 75 Summicron ASPH) have that floating element - the earlier 90 APO ASPH does not, and is reported to (and in my experience does) get a bit blurrier at f/2.0 and distances under 2.5 meters or so (i.e. at portrait distances).

Lens design is an art of balancing the many things glass can do to to light rays. The designer sits at her computer and plays with variables to see what improves performance X a lot while only degrading performance Y a little: lens curvatures, "cheap" spherical surfaces vs. "expensive" ASPH surfaces, glass types (also cheap or expensive), spacings, "good bokeh" vs. maximum correction for contrast/resolution, etc. etc. And then makes a creative decision as to which mix is most preferable.

I guess my lenses are fine after few confirmations by different veteran users.  My observation is the same, the 50mm lux is superb, the 90 APO comes second, then 35 lux and 24 lux.  The 24 lux is actually rendered beautifully but I just better don't crop, so I need to frame carefully as I can't see the whole frame from the RF. 

 

 

[UliWer]

vor 33 Minuten schrieb jaeger:

I guess my lenses are fine after few confirmations by different veteran users.  My observation is the same, the 50mm lux is superb, the 90 APO comes second, then 35 lux and 24 lux.  The 24 lux is actually rendered beautifully but I just better don't crop, so I need to frame carefully as I can't see the whole frame from the RF. 

 

 

If you look at the MTF-graphs of the 50mm Summilux asph. and the 90mm Summicron Apo. Asph. - the 90mm should show at least the same  micro-contrast at equal f-stops avoiding some drop off in the corners which the 50 Summilux shows. This is also my experience with both lenses - though not on short distances: then the 90 AA looses a lot of its tremendous contrast while the 50mm stays stabile. The 90mm is also more sensitive to flare which can reduce the contrast (in brightness and colours) in certain situations.

If you want maximum contrast with a wide angle lens like 24mm a highly opened Summilux would not be the first choice.  The 1:3.8/24 Elmar-M shows sharpness and contrast which is sometimes frightening with no need to stop down for improvement. - It gives you the impression that you don't need another lens, as you can crop eternally and still have the finest details. Though of course it is only 1:3.8 and you can't expect much "bokeh" since the depth of focus is very big even fully opened.. 

[adan]

24 minutes ago, UliWer said:

If you look at the MTF-graphs of the 50mm Summilux asph. and the 90mm Summicron Apo. Asph. - the 90mm should show at least the same  micro-contrast at equal f-stops avoiding some drop off in the corners which the 50 Summilux shows. This is also my experience with both lenses - though not on short distances: then the 90 AA looses a lot of its tremendous contrast while the 50mm stays stabile.

Exactly.

1) Leica's MTF charts are calculated. That is, they are a print-out of the MTF as predicted and charted by their lens design computer. Not tests of real lenses on an optical bench.

2) And more importantly 2) calculated for infinity performance, usually assumed to be greater than 1000x focal length (for a 90mm, at 90000mm/90m).

(Both of which are fairly standard practice these days, although Zeiss still provides close-up MTFs (5x image magnification) for their Makro lenses, as well.)

There's no question the 90 APO is a phenomenal lens at "landscape" distances, or even 4-5m/12-15 feet on the street (as evidenced by many examples on this forum). It just gets progressively - weaker - under 2.5m

Meanwhile, the 24 shows a large sag in MTF away from the exact center at 40lppm compared to the 50. And the 35FLE has a smaller sag.

But as mentioned above the 28 Summilux almost matches the 50mm - the hills and valleys of the f/1.4 MTFs are a bit different, but average out very close.

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Hallo,

Look here: Leica M

[RayD28]

I can't speak to why the 50 asph is so contrasty but I can say it's my best lens.  I usually carry a 50 2.0 because it's is part of my light weight kit, but if I have a special project, the 1.4 never disappoints.  

[jaeger]

Regarding 50mm lux VS 90mm APO.  I might have been confused between contrast and color saturation (or brilliance).  I played around my photos taken by these 2 lenses in LR, I realize pictures from 90 APO needs to increase color saturation most of the time.  Increasing contrast is not needed on every photos but when it's needed it would be just a little bit.

I apologize if I confuse you too...  basically, images taken from 90mm APO looked "anemia" comparatively speaking, but details are there.  They look great again after some LR adjustment. 

So if contrast was not the suspect, I think it's the color saturation... I am soo sorry.  I'm coming from a world that used to have "burning and dodging" only and all these digital things are new luxury toys to me.  I am sure kids with an iPhone knows this photo tweaks more than me.  =P

[jaeger]

57 minutes ago, RayD28 said:

I can't speak to why the 50 asph is so contrasty but I can say it's my best lens.  I usually carry a 50 2.0 because it's is part of my light weight kit, but if I have a special project, the 1.4 never disappoints.  

are you referring to 50 f/2 APO?  I heard tons of good thing about it (especially with monochrome).  and it's price tag....  I don't think I can afford it any time soon so I can only admire it. 

Edited July 11, 2019 by jaeger

[RayD28]

10 minutes ago, jaeger said:

are you referring to 50 f/2 APO?  I heard tons of good thing about it (especially with monochrome).  and it's price tag....  I don't think I can afford it any time soon so I can only admire it. 

No, I was referring to the non-APA asph.  Sorry I was not clear.  

[UliWer]

• vor 2 Stunden schrieb jaeger:

Regarding 50mm lux VS 90mm APO.  I might have been confused between contrast and color saturation (or brilliance).  I played around my photos taken by these 2 lenses in LR, I realize pictures from 90 APO needs to increase color saturation most of the time.  Increasing contrast is not needed on every photos but when it's needed it would be just a little bit. ...

Your distinction is  important and very often it is not clear what is meant if one talks of "contrast".

In optics contrast means the distinction between black lines (very dark) and white (very bright) spaces between these lines. This contrast can be measured if one counts how many of these black and white lines on one single millimeter the lens can resolve: if you have 10 black and white lines on one millimeter, can it resolve 50 percent of them (medium contrast), 30 percent (low contrast) or 90 percent (high contrast)?

When we talk of contrast of a photo we mostly talk about brightness contrast. You see the differences in the histogram: when the histogram goes from deepest black on the left side to brightest white on the right side and on the whole field the curves are high, we have a very contrasty photo where all colours (or grades of grey) are very saturated (the photo may be totally blurred and.unsharp taken with a bad lens  but its brightness contrast is high.

Your  observation that this brightness contrast is - generally - much lower for a 90mm lens than for a shorter focal length is right. The reason for this is not the lens but your subject. The  view for 90mm is much narrower than for 50 mm. The photo with a narrow field of view (usually) has fewer very dark and/or very bright parts and less different colours, just because there isn't as much on the photo. So the histogram will show a tower-like peak in the middle, but the curves on the left and right will be very flat or not existant. Of course this is only a generalisation, since you may get a huge peak for the dark colours on the left if you underexpose or for the brights on the right  if you overexpose. And of course you may find a motive with extreme bright and dark and all the colours you can imagine crammed together in the field of view for 90mm: your histogram will look like one with a much larger field of view.

I can also follow your observation that a photo with a 24mm looses brightness contrast if you crop it: you reduce the field of view. The shadows on the sides which may be underexposed are cut off by cropping: you loose saturation on the left of your histogram. Same with the bright clouds in the sky and the lights on the right of your histogram.

Where I cannot follow your observation is that your 24 and 35mm lenses generally show less brightness contrast than your 50mm. According to my theory (and my experience) it should be highest for 24mm and then decreasing with the lenses of narrower field of view. You might start an experiment: look for a landscape with lots of brightness contrast and many colours all over the field. Put your camera on a tripod and take a well exposed picture with all your lenses from 24 to 90mm at the same f-stop (f/2.8 or f4/). Look for the histograms of each picture with different focal lenses in your raw converter. If my theory is right the brightness and colour contrast you see in the histogram will get narrower by increasing the focal length. Then crop your example taken with 24mm to the field of view of 35mm, 50mm and 90mm. And compare the histograms of the results with your original pictures taken with different lenses. I am rather sure you'll find out: it is not the lens, it is the field of view of your subject which makes the difference.