Are Leica sensors made for Leica lenses?

[Big John]

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Hi all,

Often read discussions about which is the best 35mm M mount lens with debates comparing the Zeiss distagon 35/1.4 against the 35 Summilux FLE Asph. 

Comparing the lenses to each other is fine but I don’t read much about whether the combination of Leica glass and Leica camera/sensor is an optimal pairing yielding special results. I am shooting the distagon on an SL and wonder, for example, if I would get greater micro contrast with an Lux FLE. 

Any thoughts?  Thanks. 

[Gregm61]

The sensors are definitely made specifically for Leica M cameras. The M lenses are obviously made to be used with those sensors, but Leica also often seems to include compactness as part of their calculation. Otherwise, several of the M lenses would be physically larger to maximize optical performance. 

The 35/1.4 Zeiss Distagon vs. the 35mm f1.4 Summilux FLE is the perfect comparison. In my personal case, a similar comparison of two lenses I own would be the Leica 35mm Summicron f2 ASPH vs. the Cosina-Voigtlander 35mm f1.7 Ultron VM. My opinion, in both of these cases, if the ultimate optical performance is your one and only aim, just buy the Zeiss f1.4 or the Ultron 1.7 and be done. Of course, lens flare to me sucks while others consider it "character" so I may be a little too practical-thinking on this for many on one level, LOL. On another level, one of the biggest treats of shooting Leica cameras is using the Leica lenses.

The finder blockage will be higher with the Distagon and Ultron, especially if you use the lens hoods.

Edited May 9, 2019 by Gregm61

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[adan]

Big John - that takes a little unpacking to explain.

1) on an SL - all bets are off. The SL is designed primarily with SL lenses in mind, which themselves were/are designed "in the digital era" (within the past 10 years) to be digital-friendly (and quite large to be so). Using M lenses on the SL is "a nice feature," but not the primary design goal.

2) The sensors in M bodies are "made for" short-focus rangefinder lenses, with special microlenses over each pixel to account for legacy wide-angle lenses that sit very close to the sensor, but were designed long before the special needs of digital were even imagined. As such, the M sensors are "better" for such lenses of any brand/type: Leica M, Leica screw-mount, 1950s Canon/Nikon RF lenses adapted to the Leica mounts, some C/V or Zeiss ZM lenses of similar design.

But not perfectly - Leica still has to massage the picture data to get rid of wide-angle color edge stains, in between getting the signal off the sensor, and onto the SD card.

And Leica does not measure or provide those "massaged-data" corrections for any lenses except their own. You can't select a non-Leica lens in the lens menu. Sometimes, the corrections for a given Leica lens are "close enough" to use them with non-Leica RF lenses, but one just has to do experiments to figure that out.

For example, I tried a Zeiss ZM 28 f/2.8 Biogon on an M10 - and none of Leica's corrections for four different M-Mount 28mm lenses (v.3, v.4, ASPH f/2.8; ASPH f/2.0) completely removed a blue tint in the corners. Just not the same optics.

None of that specifically addresses resolution or micro-contrast, however.

What Leica has always done regarding resolution, from their very first in-house digital cameras (DMR digital back for the R8/R9, M8) is 1) keep the sensor stack (glass layers on top of the silicon sensor chip: protective cover glass, anti-IR filter, anti-alias filter) as thin as possible, and 2) delete the AA filter (which blurs picture detail slightly to prevent aliasing and moiré) altogether. Doing that minimizes the amount of blurring (intentional in the case of the AA filter, incidental in the case of thick cover or anti-IR glass) and makes for a sharper sensor package. (Other makers (e.g. Nikon D800E) followed Leica's lead, once the success of Leica's bodies showed that a lot of photographers just didn't care about occasional aliasing/moire, if they got sharper resolution as the trade-off).

But again, the advantage of Leica's technique affects any lens mounted on Leica cameras - they all show more resolution than on cameras that retain an AA filter.

I guess the short version of that would be - a Leica 35 FLE will not necessarily show more resolution or micro-contrast than a Zeiss Distagon f/1.4 on the same Leica sensor. Unless the lens itself is better in the first place. There's nothing about the Leica sensors that will benefit only Leica lenses, as far as resolution is concerned.

[Ko.Fe.]

I'm not in FLE income brackets, but after trying some Leitz and Leica lenses on M-E, plus some CV/ZM lenses I'm hesitant to use something else. Yes, even my FSU lenses are fine on M-E, but...

[CharlesL]

Does Leica assert in a datasheet that the M sensors have "special" microlenses, and does Leica provide any technical detail about them?

[Gregm61]

https://the.me/the-leica-m-max-sensor-explained/

[adan]

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A datasheet per se for consumers? I haven't seen one. The overall M-System brochure doesn't dig that deep, nor do the single-page tech-specs for individual cameras.

But in introducing the M8 CCD, they gave dpreview.com and other reviewers tech data on its offset microlenses. And explained the challenges of making a sensor that could handle their raft of "designed before digital" lenses. Up until about Nov. 2005, Leica's company line was that a digital camera that could handle those lenses couldn't be made at all - sensor architecture was incompatible. Epson's R-D1 M-mount APS-C camera tended to disprove that, but Leica had work to do to make APS-H (M8 crop) and then FF cameras that worked.

See second image and surrounding explanations: https://www.dpreview.com/reviews/leicam8

A repeat when the larger-sensor M9 was introduced: https://www.dpreview.com/reviews/leicam9

When the MAX CMOS sensor was introduced in the M (typ 240), Leica gave reviewers another illustration, showing new, tall, egg-shaped microlenses to handle rangefinder wides even better, along with other tricks to reduce the color cross-talk that created the color edge stains (light going through a red pixel filter at such a shallow angle that it actually landed on the next-door "green" pixel's silicon).

https://www.eenewsanalog.com/news/high-dynamic-range-cmos-image-sensor-deliver-24mpixels-across-36x24mm-area

The M10 CMOS sensor is a further development of the M240's MAX CMOS (somewhat extended ISO range, somewhat different color rendering).

BTW, Greg - Thanks. I hadn't noticed the tall MAX microlenses now do away with the need for offsetting them.

Edited May 10, 2019 by adan

[adan]

BTW - I suppose we should mention the Monochrom sensors, which are an idea relatively unique to Leica at the moment, and also improve per-pixel resolution and edge contrast/clarity, by removing the necessary sharing (read, slight blurring) of data between neighboring red, green and blue pixels to get full RGB color in all pixels in color pictures.

But again, a third-party lens that is good enough will also benefit from the Monochrom sensor - the sensor is "lens-brand-agnostic" and won't necessarily give Leica lenses a special edge, unless the lens is simply sharper in the first place.

https://gearpatrol.com/2018/05/02/best-monochrome-digital-cameras/

Edited May 10, 2019 by adan

[Gelatino]

48 minutes ago, adan said:

the sensor is "lens-brand-agnostic" and won't necessarily give Leica lenses a special edge, unless the lens is simply sharper in the first place.

So obvious!

[Big John]

7 hours ago, adan said:

Big John - that takes a little unpacking to explain.

1) on an SL - all bets are off. The SL is designed primarily with SL lenses in mind, which themselves were/are designed "in the digital era" (within the past 10 years) to be digital-friendly (and quite large to be so). Using M lenses on the SL is "a nice feature," but not the primary design goal.

......

Adan, thank you so much for such a helpful and detailed response.  Huge amount of information in that post, thank you.

Basis for my posting is that I have the SL and am using Zeiss glass primarily as I find my 24-90 to be too heavy a package.  Am contemplating buying an M10P and hence also thinking if I would benefit from buying Leica glass at the same time - or whether to try out the M with Zeiss, at least initially.  I referenced micro contrast to avoid the term 'Leica look' (!)