Red edges and new firmware......

[sandymc]

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Well, time is moving on, and no new firmware yet. For those interested, and amused rather than repelled by speculation, I've published some thoughts as to why that might be the case on my blog (too long and complex for here).

 

HEALTH WARNING: Speculative content AND deep technical content.

 

ChromaSoft: Will Leica fix the M9's red edges?

 

Sandy

[Mauribix]

Well, time is moving on, and no new firmware yet. For those interested, and amused rather than repelled by speculation, I've published some thoughts as to why that might be the case on my blog (too long and complex for here).

 

HEALTH WARNING: Speculative content AND deep technical content.

 

ChromaSoft: Will Leica fix the M9's red edges?

 

Sandy

 

Very interesting Sandy, I'm reading that carefully.

[Ario Arioldi]

Very clear writing and the questions are very well posed.

Now is up to Leica to give us an answer. I'm confident they will.

Cheers,

Ario

[Mauribix]

BTW I add a couple of things:

As for my personal experience with the M9, I found the "red edges" issue with *every* fast wide angle lens.

I.e.

 

18SE, 21lux, 24lux, 28cron, in my experience, only when they're used at full aperture, i.e. with the strongest vignetting that they can show.

Now, thinking about a new firmware, together with your reflections,it makes me think about one thing:

Since the red edges problem's been noticed from the beginning (and IMHO Leica did know that) they're now developing a new firmware as to fix the problem without the risk of another "incomplete" release.

Some features have to be improved, such as card formatting and hopefully a small improvement in 2500 ISO's noise signal.

Probably, new algorithms have to be used, so that's why I guess it takes a little longer. Probably the beta testing is taking much more time than in the past too, and that could be a fair explanation to the delay.

As for my feeling, I don't think the S2's development is gonna take resources off the M9's.

My 2 cent.

[D&A]

One particular question that lingers for me is the following: Lets assume among other factors, that the red edge that's predominantly found on left side of the frame can be exacerbated by a both a lens design (rear elements proximity to the sensor) as well as how much a particular given sample of a lens is properly aligned. If that's the case, then why most always and prominently on the left side? if a lens is not a well aligned sample or if all samples of a lens has its rear element in very close proximity to the sensor...causing light rays to strike the sensor at an extreme obtuse angle...then it should be random what edge of the frame exhibits "red edge:. This is of course the sensor is symmetrical in comparison to the lens mount, which I believe others have confirmed with Lecia, that it is.

 

This is what perplexes me the most at the moment and I'm also aware that sometimes the bottom edge of a image horizontally framed may also show signs of red..but its this consistant asymmetry in relationship to right side red edge that I'm trying to understand. Any thoughts? Thanks!

[ho_co]

Sandy--thanks for the thoughtful post.

 

 

 

 

A comment on lens alignment: As I understand it, It is virtually impossible for a Leica lens to be misaligned.

 

As I read Erwin Puts, Leica's 'stressed designs' require utmost precision in assembly. That is, without the most exacting effort, the lens cannot be put together. The assembly process itself becomes part of the quality control process.

 

That's one of the reasons that Leica lenses have gained their reputation.

[Bob Ross]

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One particular question that lingers for me is the following: Lets assume among other factors, that the red edge that's predominantly found on left side of the frame can be exacerbated by a both a lens design (rear elements proximity to the sensor) as well as how much a particular given sample of a lens is properly aligned. If that's the case, then why most always and prominently on the left side? if a lens is not a well aligned sample or if all samples of a lens has its rear element in very close proximity to the sensor...causing light rays to strike the sensor at an extreme obtuse angle...then it should be random what edge of the frame exhibits "red edge:. This is of course the sensor is symmetrical in comparison to the lens mount, which I believe others have confirmed with Lecia, that it is.

 

This is what perplexes me the most at the moment and I'm also aware that sometimes the bottom edge of a image horizontally framed may also show signs of red..but its this consistant asymmetry in relationship to right side red edge that I'm trying to understand. Any thoughts? Thanks!

 

I have been quietly following this subject, with a lot of sympathetic feelings and have a speculative thought. The difference between the M8 and the M9 is the IR filter. If the IR filter in the M9 was improperly fabricated....thickness or consistancey of filter effect or if it was consistantly missaligned in relation to the sensor.....would it not explain the gradient like pattern? If the whole batch of sensor IR cut filters was defective, it would explain why everyone is seeing the effect.

One thing that I haven't seen mentioned is the use of an Expo/Disc to provide a uniform plain field to help see the gradient. I checked the M8 + lenses with mine for the lens correction quality. A useful tool.

Bob

[jklotz]

The problem is, no matter what the speculation as to why it is happening, it is nothing but that - speculation. Personally, I'd like for Leica to be a little more forthcoming with the information. Of course they know about it....

[adan]

One comment, Sandy - I notice you sort of attributed my paraphrase of Stephan Daniel's comments on lens corrections ("It's an art form") in a way that makes it looks like those were his exact words (well, to me anyway). I plead guilty if my original post didn't make it clear it was a paraphrase.

 

I reviewed the LL video: An Interview with Leica's Stephan DanielKarbe and the discussion comes up at about 30:45 into the video.

 

You might want to look at it to get a more precise rendition of what he said, if you're going to pin a conclusion on it (not that I disagree with the conclusion or the general trend of your argument). "The vignetting corrections are always made at the lowest level - We need to be careful not to overcompensate - etc."

 

At some point earlier in the video (21:00:-22:30) he does refer rather directly to people "calculating" the corrections needed - as though Leica was in fact using a math model for fall-off and IR-filter drift corrections, rather than actually building profiles off of white background shots as CornerFix does. Perhaps open to interpretation - but you might want to view that part and see how it fits into your case.

 

In looking at the video again, I also noted that Daniels (4:00) says Jenoptik writes the firmware for the M9, as well as building the sensor board and other circuitry. It is not done "in-house".

 

Which may figure into the time involved in firmware changes. They just have to go through several hands - and presumably every update may mean money out of Leica's pocket, so waiting to do one update for several problems likely costs less than producing 3-4 updates as each individual problem gets solved. (i don't know how contracted code-writing works - maybe I'm wrong)

 

Howard, I take you point - but was that technique in effect in 1985 or 1975? And if decentering of lenses is not a possible source, then what DOES account for the assymetry of the red edge drift?

[D&A]

Andy Wrote >>> "And if decentering of lenses is not a possible source, then what DOES account for the assymetry of the red edge drift?"<<<

 

Andy,

 

I've been asking this exact question both in my post above and in a different thread....but with a slightly different emphasis. Lets say there are lenses with slight or pronounced de-centering....if this was a main contributing factor to red edge, then how can it primarily be in most cases on the left edge of the frame. It should be in such cases, random as to which side or edge of a frame it shows up.

 

Dave (D&A)

[noah_addis]

I'm not convinced that there is all that much sample variation between when it comes to the red edge with a given lens.

 

In some cases the problem may be masked by lighting conditions, subject matter, white balance and other factors.

 

I agree, if it were a decentering problem or some other flaw in lens construction, why would the red edge always be on the left?

 

I do think it has to do with the sensor and possibly the arrangement of color filters, etc.

 

Regardless of the cause, I do think Leica has a responsibility to inform M9 owners and prospective purchasers of the cause and plans for how to fix the problem.

 

Assuming it can be fixed in firmware, I would prefer for Leica to take the time to get it right. However, from a company that markets small-volume high-end products for a premium price, I expect a high level of service. Part of that service should be honest answers about problems with the product.

 

Leica must provide an acknowledgement that there is indeed a problem, an explanation of the cause and at least an estimated timeframe for when it may be fixed.

[adan]

D&A: Good point!

 

Let's just say that something seems to be off-center relative to something. And that almost has to mean a physical construction issue, which I doubt will be fixable in firmware unless Leica adds a

"create your own lens profile" module. If something is installed off-center, whether it be Kodak's overlays on the silicon, or Jenoptik's installation of the sensor on the circuit board, or Leica's installation of the circuit board in the bodies, I think we are talking trips to Solms for a real fix - new sensors or a rebuild.

 

Noah: I agree - an acknowledgement of the problem is overdue, even if Leica is still trying to track down the source - or knows the source but is still trying to develop the solution.

 

Personally, I'm going to end my speculations on the subject there. I have put in a query through channels to Leica (very recently). I don't want future posts to appear to be reflecting privileged information (assuming I even get any). I'd recommend that anyone with red-edge samples track down a way to get them to Leica directly and raise the issue at the source. Blogs and forums (fora?) are fine, but only Leica can produce a solution.

[D&A]

I guess I'm getting the impression as some others are, that although the issue of red edge may be caused by a general singular cause...it can be exacerbated by any number of factors...such as lens de centering (maybe primarily non Leica lenses) or rear element proximity to sensor.

 

Dave (D&A)

[marknorton]

Some welcome straight-talking from Sandy who certainly has more insight than any of us into the detail of the processing required.

 

I think we should put to bed any ideas that this is caused by lens centring problems. As Dave points out, if this was the cause, the red edges would appear in random directions; separately, we know that Leica go to extraordinary lengths to centre lens elements correctly because of the impact on IQ of not doing so.

 

The lack of symmetry in what we're seeing surprises and I still wonder how they managed to fit the sensor into the M8 camera body and still mount it centrally. Long-term readers may remember my M9 mock-up which suggested there wasn't room.

 

In any event, you can imagine a briefing document presented to Leica management which defines the cause of the red edges and a range of variously unpalatable options to fix it. A very un-Leica response would be to say: "the camera is selling, we're making money, let's go with Option E, do nothing".

 

I hope I'm wrong.

[D&A]

Mark,

 

I realize you're not going to (at least presently your 're not) repeat your truly amazing teardown of the M8, on a M9 body...but hyperthetically if you did, I presume you might see if physically (along with appropriate measurements) if the full frame sensor indeed had to be mounted asymetrically in relationship to the lens mount.

 

Although I may be incorrect in saying this, but in some respects, it may be easier for Leica to deal with the red edge problem in that it more often than not is confined to the left edge of the frame. Can you imagine if it was random, appearing quite differently with different samples of a given lens? If this was the case, then some custom setting, profile and more would have to be supplied (or input) by each user of the M9 when using a particular lens...sort of like taking a WB prior to shooting in a given situation with a certain sample of lens. I'm in one sense a bit relieved that it's asymmetry seems to be consistent as to the location of the red edge

 

Lastly once in a while I keep hearing that even with the WATE, evidence of red edge can be seen. I thought it was coming from most who own this particular lens, that the WATE is one of the few ultra wide angle lenses that doesn't exhibit the red edge trait. Any conformation one way or another?

 

Dave (D&A)

[viramati]

I have the WATE and have no problem with fringing

this is straight out of the camera with no manipulation

 

 

 

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[Mauribix]

I have the WATE and have no problem with fringing

this is straight out of the camera with no manipulation

 

 

 

[ATTACH]188386[/ATTACH]

 

David, is that at full aperture then?

[viramati]

doubt it probably f5.6

here is one at f4 (LR 2.6, adobe standard calibration)

Mind you I'm not sure how accurate it is to do this on the site as it looks a little different here as to when it's viewed in LR2

 

 

 

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[scott kirkpatrick]

I thought we had hashed this down to some conclusions (but not to answers) in several earlier threads.

 

1) The preferred red to the left (and to the bottom) can't be blamed on an off-center sensor, because moving the sensor away from the battery (Mark Norton observed that this is the tightest dimension in making a full-frame digital M) has the opposite effect. It would tend to cause green to the left and red to the right in the resulting image.

 

2) The effect can be seen faintly in the M8 as well as in the M9, if you take a lens with a really deep rear element and shoot a white wall, wide open, in warm room lighting, so it is not an M9 bug, just a problem that hadn't been noticeable before.

 

3) The only things which are asymmetric in the Kodak sensor family are the pixel cell itself, which has charge extraction gates and circuits that run horizontally, and charge overflow drains that perhaps run vertically. None of these details are public information. And the Bayer pattern of filters. There have been examples of errors that are magnified by the de-Bayering algorithms. The "mosaic" pattern that the KAF-5000 exhibited when a red colored region was slightly overexposed is one case.

 

Making changes in this basic step is a delicate process. If the information needed to do it is scattered between Kodak, Leica and Jenoptik, it may take a little longer. But I wish Leica would be willing to release firmware updates that fix the problems that must have been solved by now, while still working on this tougher problem.

 

scott

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[UliWer]

Thanks a lot, Scott, for your posting, which concisely resumes all we can know and wish for at the moment.