Leica Lens MP Resolution?

[stephengv]

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1 hour ago, jaapv said:

Yes, but the lens produces contrast gradients in diminishing thickness and the sensor records in discrete points.

 

Can you expound on this? I'm a bit confuse, considering the statement of  A. Kaufmanm that  SL lenses could probably go up to 60 or 80 MP. What about our M lenses. 

[jaapv]

That is rather beyond the scope of the forum. A good resource for basic lens design explanations is Erwin Puts: Leica lens Compendium, pages 50 ff.

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[250swb]

I use M lenses from 21mm to 35mm on my Nikon Z7 (47mp) without any problem or concerns about quality, to me they seem perfect. I know some photographers can't get their heads around post processing much larger files and don't understand what they are looking at when pixel peeping, but when the sensor eventually does out resolve the lens we'll simply have the opposite of the lens out resolving the sensor, which is what we've had until now, and you'll still be able to take photographs.

[250swb]

I should have said in my post above 'M lenses from 21mm to 135mm' Doh!

Edited July 19, 2019 by 250swb

[Jean-Michel]

All interesting, but what always misses in these conversations and considerations is the size of the prints we make from our files. And, if we do not print an image, it does not exist. With film, I rarely printed larger than 9 by 12 inches from 35 mm negs; since going digital I now print as large as 20 by 30 and am happy with the “resolution “ from all my lenses including the ones dating from the 1960’s. 

[M11 for me]

Well, DXO invented the P-Mpix (perceptual megapixels) as a metrix of sharpness of a lens. So they measure the sharpness in MPix; in percepual ones . . .

Edited July 19, 2019 by M10 for me

[250swb]

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5 hours ago, M10 for me said:

Well, DXO invented the P-Mpix (perceptual megapixels) as a metrix of sharpness of a lens. So they measure the sharpness in MPix; in percepual ones . . .

Which sort of implies in a roundabout way that as mp's go up so does everybody's print sizes, which is absurd. Do people keep on moving into bigger houses with more wall space, has the atheistic of 'small is beautiful' entirely been usurped, no of course it hasn't. The DXO mp debate is just blowing smoke where the sun doesn't shine. However what more mp does for the average photographer is to give them more to work with, whatever the final size of reproduction.

[adan]

I'm not atheistic about "small is beautiful" - just agnostic.

[adan]

On 7/17/2019 at 1:03 PM, ChicagoMatthew said:

The new Sony A7r4 was just announced and it’s touting 61 mp. As my GAS gets going I’m wondering what the MP limit is on modern Leica lenses... anyone have an idea how these would perform?

Let's do the math:

I can't find the exact pixel dimensions online, but it would appear to be very close to 9500 pixels wide and 6333 pixels tall (landscape format).

A sensor 36mm wide and also 9500 pixels wide will have 264 pixels per mm. Which means it can - theoretically - accurately render lens resolution up to ~132 lppm without Nyquist frequency errors (aliasing or moire).

That's really overkill for most lenses from anyone - it takes an exotic, not just excellent, general-photography, 24x36 lens to top 120 lppm. Unless one uses the absolute best aperture, on an absolutely rock-solid tripod, at a time of day where there aren't any strange atmospheric distortions (heat waves and such). Most manufacturers quit measuring lens MTF at 40 lppm, let alone 132. (The Leica M APO-Summicron 50 nudges the exotic range - at an exotic price).

OTOH, a better sensor resolution makes any lens perform better than a lower sensor resolution, and a better lens makes any sensor perform better than a poorer lens. Total system MTF = MTFlens x MTFsensor.

But since no lens or sensor has an MTF of 1.00 (100%), and 0.99 x 0.99= 0.98, that means as soon as you combine any lens with any sensor, you end up with the whole being less than the sum of the parts, measured separately. As the old saying goes, "You can't win, and you can't even break even!"

Put simply, it requires an infinitely-perfect sensor to get everything out of a lens, and an infinitely-perfect lens to get everything out of a sensor. In the real world, all one can say is that a 61mp sensor might possibly get 93% out of a lens, while a lesser sensor might get only 89% out of the same lens.

And all that leaves out such practicalities as sensor stacks and AA filters and so on.

[otho]

According to DxOMark, even many native FE Sony / Zeiss lenses have poor resolution on A7R body (especially FE 50/1.8 and some zooms) or have some problems with distortion and aberrations (e.g. FE 28/2). Even the new Sony FE 35/1.8 have some troubles on A7RIV. In general, the best results with A7RIV will be from Sony GM prime lenses, Zeiss Batis and so on and - I think - APO-M 50, 75, 90, 135.

I use APO 75 & APO 90 on A7RIII (42 MP without Kolari MOD) - both leness are super sharp, any aberrations etc. Focusing is easy thanks to magnification and focus peaking in EVF. M-lenses wider than 50mm for me are unacceptable on A7RIII body.

I think that APO 50 - 75 - 90 - 135 are superb also on 61MP's A7RIV (I planned to buy one after real users reviews appears).

[otho]

11 hours ago, adan said:

I can't find the exact pixel dimensions online, but it would appear to be very close to 9500 pixels wide and 6333 pixels tall (landscape format).

 

  A7RIV, 61MP = 9504 x 6336 px.

Edited July 20, 2019 by otho

[otho]

Sorry, accidentally doubled post.

Edited July 20, 2019 by otho

[ChicagoMatthew]

On 7/18/2019 at 8:21 AM, jaeger said:

I'm not quite understand the question... unless the sensor pixel count is greater than how many light particles(or wave "quantum physics") landing on 36mm x 24mm surface, which is like trillion billion of a trillion dots tight?  I think even the smallest iphone lens will let trillion and trillion of dots thru. 

 

What’s not to understand? Lenses have a limit to what they can precisely translate to the focal plane... higher quality glass and engineering will result in an image that is sharper, has higher contrast, better color reproduction and generally more detailed image. If that wasn’t the case I don’t think we would be spending so much money on Leica lenses. So, I am asking if Leica lenses, in all their Leica glory, can take advantage of the 61mp of this new sensor.

[ChicagoMatthew]

23 hours ago, otho said:

According to DxOMark, even many native FE Sony / Zeiss lenses have poor resolution on A7R body (especially FE 50/1.8 and some zooms) or have some problems with distortion and aberrations (e.g. FE 28/2). Even the new Sony FE 35/1.8 have some troubles on A7RIV. In general, the best results with A7RIV will be from Sony GM prime lenses, Zeiss Batis and so on and - I think - APO-M 50, 75, 90, 135.

I use APO 75 & APO 90 on A7RIII (42 MP without Kolari MOD) - both leness are super sharp, any aberrations etc. Focusing is easy thanks to magnification and focus peaking in EVF. M-lenses wider than 50mm for me are unacceptable on A7RIII body.

I think that APO 50 - 75 - 90 - 135 are superb also on 61MP's A7RIV (I planned to buy one after real users reviews appears).

Do get any smearing when you use the 50mm on the A7r3? 

[otho]

Lux 50 asph on A7R3: corner color casts, yes, but very little; corner smearing, not at all. Lux 50 asph on A7R3 is a very good performer, but I'd prefer APO 75 & 90 on that body. The 50/1.4 has a some field curvature wide open on A7R3. I'm not trying APO 50, but many reports excellent results with A7R3. 

Edited July 21, 2019 by otho

[farnz]

On 7/19/2019 at 10:44 PM, adan said:

A sensor 36mm wide and also 9500 pixels wide will have 264 pixels per mm. Which means it can - theoretically - accurately render lens resolution up to ~132 lppm without Nyquist frequency errors (aliasing or moire).

I agree with your maths for the ideal sensor, Andy, but since there's no direct sensor pixel to image correlation owing to the Bayer Matrix and de-mosaicing can 132 lppm realistically be claimed? 🤔

Pete.

[pico]

On 7/19/2019 at 4:44 PM, adan said:

A sensor 36mm wide and also 9500 pixels wide will have 264 pixels per mm. Which means it can - theoretically - accurately render lens resolution up to ~132 lppm without Nyquist frequency errors (aliasing or moire).

Monochrome, perhaps. Might that 9500 pixels be closer to int 3160 with a Bayer filter? I do not know. Just asking.

 

[bags27]

On Sony's current and everlasting desire to score best on DXO, this is a fun, if somewhat weird, screed. By the way, the guy posted a strongly anti-Leica video (hates the service) which got terrific blowback from Leica lovers. I think he's a Nikon guy.

 

Edited July 21, 2019 by bags27

[pico]

On 7/19/2019 at 3:41 PM, 250swb said:

Which sort of implies in a roundabout way that as mp's go up so does everybody's print sizes, which is absurd.

A+++

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Hallo,

Look here: Leica M

[microview]

The gent [pictured above] who declared Voigtländer's 50mm f1.2 M mount "the best 50mm lens in the world". Yes it's a very good lens but some tests I took today versus a newly purchased 50mm Summicron showed, at f2, better corner resolution at closest focus and 5ft with the Leica.. 

Edited July 21, 2019 by microview