S2 Chromatic Aberration - how big an issue is it?

[brianc1959]

On behalf of Coastal Optics / Jenoptic - or on behalf of Caldwell Photographic Inc ?

At least initially it will be a Caldwell Photographic product, although it will be shown (fingers crossed - still hard at work on the prototypes!) at the Megavision stand with their monochrome MFDB and multispectral imaging system.

 

[NotXorc]

And I thought Leica didn't abuse optical terminology the way some other manufacturers do! What are we designers and manufacturers of *real* apochromats (and superachromats for that matter) supposed to call our lenses?

BTW, if you're interested in a true medium format UV-VIS-IR apochromat with zero focus shift from 330nm out to 1100nm I'm planning to show one at Photokina. It will be 120mm f/4.5, Copal-0 mounted, 100mm image circle, and will have a manually adjustable floating element for infinity down to 1:1.

Brian, I think you answered your own question, even if you didn't realize it. This thread exists because some have called attention to the dissonance between marketing claims and what some users have seen in their images. Those who slap an APO label on their kit when it is undeserved will be tried in the court of user opinion. They will be found wanting and trust in their brand will diminish.

You have described a specialist lens that purports to reveal the emporer's state of undress (especially in the IR wavelengths, where some textiles are very transparent . . . I digress), so you'll have to let the users speak about whether it really raises the bar.

 

[brianc1959]

. . so you'll have to let the users speak about whether it really raises the bar.

Agreed.

 

[jlm]

found this link, his first line in the bibliography credits an Isaac Newton, 1672

http://toothwalker.org/optics/chromatic.html

 

[Jack]

Hi John,

Yes, that's the link I gave above -- very good pot of info

 

[jlm]

i meant to credit your link...mis wrote. meant "found this in the link"

 

[stephengilbert]

John,

Did you see the photographer photo here: http://toothwalker.org/about.html?

Steve

 

[jlm]

looks familiar...even the compatible leaning to match the boat

 

[PeterA]

Interesting link Jack - thanks!

 

[fotografz]

I have a question related to all of this. Please temper this question with the notion that the discussed issues are not omnipresent in S2 files any more than any other MFD system.

Presuming Leica IS good at making lenses, and Leica has done the best possible technical lens design for the format at hand (MFD, whether "tweaner" or not) if not Leica, than who? ...

then what else in the digital imaging chain could be the culprit?

I've found no more of these type issues while using other MFD systems ... even when processing the files in Lightroom, without the benefit of integrated proprietary software corrections other than those also available for S2 files in LR. So, how can a $2,500. lens compare equally to a "designed from ground-up" $5,900. lens made by a renowned optical company?

It doesn't make any sense to me. :wtf:

In a related question, how do those with Schneider lenses for their Phase/Mamiya kit find they compare to the Phase One/Mamiya versions?

For a long time I was using a dual lens system with my H camera ... Fujiblad optics verses Zeiss leaf shutter CF/CFi/CFE lenses (not the faster F series with their unique character). Basically, in actual use I honestly couldn't tell the difference, and neither lens system had many of the issues we are discussing here. The only issue I had was the Chrysler Logo specular highlights with the Zeiss lenses, and that they were much slower to use.

Frankly, setting aside AF advancements, I wonder if much progress has been made in MFD optics beyond what the Contax 645 offered a decade ago? Not on paper, but in use. This suggests to me that MFD is some sort of "equalizer" ... and over-engineering the optics is where the waste of time and money really is ... money better spent on other portions of the imaging chain ... at least to start with, in order to surpass what existing optical design is capable of. Then look to the lenses.

The anomaly to my premiss is that when these backs are used on a tech camera ... the optics from Schneider and Rodenstock out perform everything out there, including the Leica S2 lenses. So, I could be completely wrong about everything. Yet, I know what I see in actual practice ... so I'm confused to say the least.

Your thoughts?

-Marc

 

[tjv]

I wonder if the technology and optical qualities present in the micro-lenses located on the sensor effect the image chain. I mean, if they refract light in any way, then surely they also pollute, in a sense, the image chain. If they are employed to bend light so each pixel sensor receives more light, then does it also follow things like fringing and blooming are also amplified? I have no idea, really! There are several other laters located on the sensor too, are there not?

 

[robmac]

<snip>....

This suggests to me that MFD is some sort of "equalizer" ... and over-engineering the optics is where the waste of time and money really is ... money better spent on other portions of the imaging chain ... at least to start with, in order to surpass what existing optical design is capable of. Then look to the lenses.

....<snip>

-Marc

Still ruminating over the rest of the post, but am starting to think you may be correct - especially on the preceding. I've come to the opinion over the years that there comes a point in a lens's design where perceivable benefit in a design (of a lens) gets passed and it becomes more about bragging rights. Bragging rights that end up costing you $$ with minimal incremental value attached - beyond your own bragging ability of course.

I think it WOULD be no different in SLR world IF they also universally lacked AA filters on sensors sourced from the same 2-3 manufacturers. While in far too many cases, DSLR players never get anywhere near that 'line' in lens performance (;<), in the case of the S2, I do think Leica leaned too heavily on it's reputation for 'dead-man's EKG' MTF charts vs. the end result of the entire image chain - especially the importance of the developing software.

As for their claims that the (S2) lens designs negate the need for "wasting time & money" on custom developing software (when both Hassy and Phase see it as an absolute necessary step in a tightly-controlled imaging chain -- especially Hassy) do more to give LUF die-hards talking points than any comfort to agnostic buyers comfort. It's a claim that should ONLY be HINTED at (why make enemies) let alone stated so bluntly in public IF the proof were violently obvious in the pudding.

I like Leica glass, but the implication that other player's lenses are comparative coke bottles and thus tailored software is needed to compensate (an implication educated shoppers know is hog-wash) comes across as immature and as trying top defend an untenable (to anyone outside the faithful) position.

(On a side note Lloyd Chambers is preparing an S2 review and given the heated reactions to his "I like it, but...." ongoing review of his M9 and glass, it could get interesting.)

 

[fotografz]

I wonder if the technology and optical qualities present in the micro-lenses located on the sensor effect the image chain. I mean, if they refract light in any way, then surely they also pollute, in a sense, the image chain. If they are employed to bend light so each pixel sensor receives more light, then does it also follow things like fringing and blooming are also amplified? I have no idea, really! There are several other laters located on the sensor too, are there not?

If that were universally true, then I would expect those sort of things to show up on with my H4D/40 which, unlike the Phase One P40+, still employs micro-lenses (Kodak verses Dalsa 40 meg sensors). Yet, they do not.

Perhaps Hasselblad has auto corrected for them with firmware or something, because they don't show up even when bypassing the proprietary software and using Light room as the RAW processor.

-Marc

 

[doug]

... suggests to me that MFD is some sort of "equalizer" ... and over-engineering the optics is where the waste of time and money really is ... money better spent on other portions of the imaging chain ... at least to start with, in order to surpass what existing optical design is capable of. Then look to the lenses.

FWIW, Leica has claimed that the S lenses are over-engineered for the S2's sensor, and that they will be fully able to exploit the next two generations of sensors.

 

[NotXorc]

FWIW, Leica has claimed that the S lenses are over-engineered for the S2's sensor, and that they will be fully able to exploit the next two generations of sensors.

The 'over-engineered for the future' claim is pretty cool when you're buying lenses for a crop factor dSLR, and think you might eventually move up to full frame 35mm, however, it may not be so compelling in MF. Yes, it should mean that lenses hold their value better over time, but it does not mean that they will necessarily do more at some future date.

 

[NotXorc]

(On a side note Lloyd Chambers is preparing an S2 review and given the heated reactions to his "I like it, but...." ongoing review of his M9 and glass, it could get interesting.)

I agree that it will get interesting. Several moons ago in this forum, one MFDB dealer accused a specialist Leica dealer of being unfit to compare the S2 to his own products (a very loose summary). It was ugly. Ugly is interesting sometimes, but not where internet fora are concerned.

As with all reviews made possible by a major clearinghouse of photogear, I will have to remind myself, "The author and equipment supplier benefit from a favorable conclusion that induces the reader to buy." Corollary: "Only the handpicked best samples are likely to find their way to a reviewer".

 

[fotografz]

Still ruminating over the rest of the post, but am starting to think you may be correct - especially on the preceding. I've come to the opinion over the years that there comes a point in a lens's design where perceivable benefit in a design (of a lens) gets passed and it becomes more about bragging rights. Bragging rights that end up costing you $$ with minimal incremental value attached - beyond your own bragging ability of course.

I think it WOULD be no different in SLR world IF they also universally had sensors lacking AA filters with said sensors sourced from the same 2-3 manufacturers. While in far too many cases, DSLR players never get anywhere near the that 'line' in lens performance (;>), in the case of the S2, I do think Leica leaned too heavily on it's reputation for 'dead-man's EKG' MTF charts vs. the end result of the entire image chain - especially the importance of the developing software.

As for their claims that the (S2) lens designs negate the need for "wasting time & money" on custom developing software when both Hassy and Phase see it as an absolute necessary step in a tightly-controlled imaging chain (especially Hassy) do more to give LUF followers talking points than any comfort to potential buyers comfort. It's a claim that should ONLY be hinted at (why make enemies) if the proof were violently obvious in the pudding - and it's not.

I like Leica glass, but the implication that other player's lenses are comparative coke bottles and thus tailored software is needed to compensate (an implication educated shoppers know is hog-wash) comes across as immature and as trying top defend an untenable (to anyone outside the faithful) position.

(On a side note Lloyd Chambers is preparing an S2 review and given the heated reactions to his "I like it, but...." ongoing review of his M9 and glass, it could get interesting).

I accept certain limitations and anomalies from the M optics, given my priority for aperture speed ... especially from 50mm on down. Very little image disadvantages while using rarified apertures of lenses like like a M21/1.4 and M50/0.95. However, as others here have said, there is a much stiffer expectation of MFD, especially given the applications ... and the trade-offs one makes in the name of MFD IQ. Not to mention that it's hard to pull the wool over most experienced MFD users eyes.

Perhaps that is the argument that the S2 should hang on ... the form factor justifies a very slight disadvantage ... a disadvantage that would be much greater IF the lenses weren't as good as they are.

Unfortunately, that slight crimp in the IQ, could be lessened by using all of the tools available to Leica in the digital realm.

All said and done, I still have yet to see S2 images that show some sort of aesthetic character that I subjectively like. For me, that is far more important than a bit of fringe and CA in a few images.

-Marc

 

[georgl]

There is noch such thing as a perfect lens, the aberrations can be controlled to a negligible level - I don't think Leica claimed something different.
Fuji makes lenses which simply cannot be used without heavy software correction (it cannot even be used with only a few years old H-boodies!) to implement cheaper optical designs (that becomes ovbious when you compare it to the optical performance to the last new Zeiss-design, the 40IF - it's superior regarding resolution and CA) - that's a big difference in comparison to Leicas approach to make designs as good as possible with the option to later control (most optical defects cannot be fully "corrected" at least not witout trade-offs) remaing aberrations within software.

I have yet to see any MF-lens (or any lens) which performs as well at wide apertures in comparison to the S-lenses, I cannot even see "proofs in the pudding" within this particular thread.
Although the particular fringing problem clearly goes beyond simple lens aberrations.

What proved to be wrong is the fact that not every DNG-capable converter can be used for DNG-files, C1 doesn't create useful files from the S2, for example. So it's an open system but not necessarily completly independent from the converter.

 

[fotografz]

FWIW, Leica has claimed that the S lenses are over-engineered for the S2's sensor, and that they will be fully able to exploit the next two generations of sensors.

In the face of any other contradictions by those more science minded than I am, I would tend to believe that.

However, given Leica's glacial product introductions ... one could pass through two full human life stages before that initial lens investment bore fruit

So, I wonder if that isn't an even more compelling reason to utilize the digital tools available to help out those who invested in the first iteration of the S2? Perhaps the lenses don't need the help, the camera/sensor does? Leica saves face, and the S2 owners get their software :thumbs:

Or perhaps they'll just lose interest, and shovel S2 folks into the same boat as R investors (Sorry, still stewing over that abrupt assault on my bank account :angry::cussing.

-Marc

Ah, arm chair quarter-backing is so much fun when you don't have the subject camera in the race ...

 

[robmac]

<snip>
Or perhaps they'll just lose interest, and shovel S2 folks into the same boat as R investors (Sorry, still stewing over that abrupt assault on my bank account :angry::cussing.
<snip>

Call it a funny feeling, spidey sense, intuition or having the 'eye' as they say, but I'd sadly be willing to bet that has at least an even chance of being the case.

As for lenses being designed for x generations ahead.. that may be the belief/justification in Solms but:

a) Reference Marc's comments about time passing in Solms vs RoW.

b) Many folks are happily using many fine older MF lenses from the film era on high-res MFDBs (some via adapters) most of which of which would probably pale on an MTF basis to S glass.

c) What matters to sway agnostic buyers is the bottom line - what IQ am I getting for giving my $$ to you vs the other guy(s). Having God's own lenses is all well and good and a great bragging right, but clients aren't buying re-prints of Leica's MTF charts. The paycheck (and sense of satisfaction) depends on the end result of the ENTIRE imaging chain and ANY weakness in any link of that chain, such as with the processing software) can have a nasty effect in a market where every wart not only is looked for with a watery eye (as it should be given the $$) but also has no place no hide. This is a concept I think Hassy cottoned on to early (and took much heat for) -- and one I think you're seeing Phase starting down the path of.

Unlike H and P, using shrink-wrap PP software with the S2 places a KEY element of the IQ imaging chain beyond Leica's control and in the hands of a larger player with no vested interest to put effort into it, getting the most out of it (re: the S2), etc. It also gives the user no place to bitch to. In the eye's of Adobe, your $$$$$$$ buys you far less programming man hrs and attention (given the size of the user base) than the Uncle Bob you saw at the last wedding with his yearly entry-level DSLR upgrades.

Given that All RAW digital images need to go through PP in some form or other, what difference does it make if the resulting IQ can be accredited to the lenses+hard/firmware guts+PP software vs laid at the feet of lenses? All that matters is the end result and the lack of undue pain it takes to get there.