M9 and Red Edge Redux--Part II, with 28mm Elmarit?

[ho_co]

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... Possibly also nice for making CornerFix profiles, better than a white wall for example

In addition, Sandy asked ExpoImaging about using the ExpoDisc for generating a CornerFix profile, and was told that it should not be used for that purpose because the ExpoDisc itself vignettes.

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[wlaidlaw]

Wilson you never saw a problem in real world photographs with that Biogon lens. Then you shot an artificial target specifically intended to show the effect at its most visible. I can see a solution in there

 

Geoff,

 

I think you can see from my post that I would have been happier in ignorance as well ;-}}

 

However the WATE is a different matter and I can see it easily in shots. Life is too short to go into menus and alter settings as you are changing focal lengths as you shoot to get the view you want. I just set to menu to 18mm and forget about it.

 

Wilson

[wlaidlaw]

Interesting if that's so. When the lens was introduced with the M8, the explanation was that it had been designed so that all three focal lengths would need the same correction IIRC. Only when the IR-Cut filter was introduced did the three focal lengths need different corrections.

 

I'm not disagreeing, Geoff, just curious. Maybe someone with a WATE could shoot a neutral target without changing the focal length, but changing the lens ID information given the camera manually.

 

 

 

I think Sandy and KammaGamma indicated that it is a different color.

 

Howard,

 

I will shoot some tomorrow. I will use an Expodisc which although it may exhibit some vignetting, the results look pretty similar to my shots of white walls, so not significant. I think it is best for this purpose to use out of camera JPEG's as this avoids further variables in DNG development.

 

Wilson

[hoppyman]

No no Wilson You REALLY don't want to be introducing the additional variables of the in-camera JPEG corrections and the Expodisc to your experiment:)

[sabrewolf]

I used a hotshoe flash diffuser sock made from fabric and just plug it into the lens and then shoot at the afternoon sky.

[wlaidlaw]

No no Wilson You REALLY don't want to be introducing the additional variables of the in-camera JPEG corrections and the Expodisc to your experiment:)

 

Geoff,

 

Your word is my command; white wall, DNG developed in C1 V6 Pro, then size changed and text added in CS5. Images are as per text. I think it does show that the camera is correcting more with the length in manual lens detection to 16mm, than 18 or 21 but it is pretty subtle. The next three taken with the lens and correction matching, I think show that correction is insufficient. 6th photo on the post below.

 

Wilson

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[wlaidlaw]

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...and the final photo of the set:

 

Wilson

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[hoppyman]

Most interesting Wilson. To my eye there are visible differences in the corrections which validates my theory:)

As an aside that 'moustache' distortion drives me crazy! Yes I know it is exacerbated by the subject (like the vignette too). Always something new and interesting to learn, thanks for contributing.

[ho_co]

Thanks from me as well, Wilson, for taking the time to do and post the test. As you said, the differences certainly are subtle.

 

In fact, just looking at the monitor, I'm afraid I don't see any difference at all in the camera-applied corrections.

 

 

Geoff, as for the "mustache distortion," I think Wilson was shooting a very subtle work of masonry. I find it often in my test shots. You never notice it when just walking by, but it shows up clearly in photographs. It illustrates the subtle skill a stonemason or bricklayer must have to choose the right pieces, each of a slightly different shape, to fit together properly over the wall's full height and breadth.

 

Or, if you prefer the 'glass half empty' version, it illustrates that there await yet higher degrees of correction for future lens designs.

 

 

 

Drat. I hate to return to the mundane thread topic after such an extended delectation, but here goes:

 

Edit: BTW, I just noticed the following comment in another thread in regard to the correction applied with manual settings of the WATE. I differ with a number of statements in the post, but the poster's contention in regard to the vignetting correction agrees with mine:

... When using the Tri-Elmar-M 16-18-21 Asph on the M9 with the automatic lens detection on then the focal length recorded on the EXIF data will always be '16 mm' and the vignette correction applied will always match the 21 mm setting. With the manual lens recognition set properly to match the actual focal length, the EXIF data will record the focal length selected, and the vignette correction applied will still always match the 21 mm setting.

[wlaidlaw]

Howard/Geoff

 

I had to rush this slightly since the rain clouds were rolling in, as I was shooting this test set. The sun was still rising though the trees at the edge of the field at that side of the house, so that the lighting was changing somewhat as I was taking photos. I just felt that the red extended slightly more towards the centre of the image from the left at 18mm lens/21 mm correction than it did at 18mm lens/16mm correction and mousing over the image, taking readings confirmed that. However it was 2 or 3 points out of 256, so that changing lighting could account for that. On the other post is "01af" posting from definitive knowledge supplied by Leica or received wisdom (I have read that someone said that he had heard........). I would have thought it more likely that if the correction does not alter, the 18mm correction would be applied as the mid point of focal lengths. Would Leica go to the lengths of giving us three settings on manual lens adjustment, solely so this would show the focal length on the EXIF - I have my doubts.

 

Wilson

[hoppyman]

Wilson the test frames are not lit nor balanced identically of course and I may be just seeing what I expect (hence my smiley) In any event any difference if present is subtle. My view is that any difference is academic in light of your examples and all of the other influencing factors. However those custom made asymmetric brick walls complicate the analysis.

 

Still I found this little branch of the discussion very interesting and again I appreciate examples and verifiable facts in these discussions

[photolandscape]

Hello again from the person who initiated this very informative and reasoned train of postings. I have learned a lot. It sounds like we are all making progress in comprehending what we are seeing and why it happens. The really intriguing question still remains for me--why does the situation vary so much from body to body?

 

I wanted to update my original post, and say that I sent my M9, 24mm Elmar, 35mm Summmicron ASPH 90 Elmarit to Leica NJ. They logged it in a week ago today, and I have spoken with Sarah Mayville, who has been most helpful. I received a repair estimate (no charge, still under warranty) yesterday. I also had a concern about a very small spot (or possibly a tiny crack developing in the corner) on the sensor, but other than needing focus checks/adjustments for each lens, I only asked them to address the red edge issue, and it is described in the repair estimate. I sent 3 prints, the same images on a DVD, and a thorough letter about the problem.

 

The repair estimate states, "REPLACE CCD, REPLACE CIRCUIT-BOARD, ADJUST R/F, and CHECK AND ADJUST FOR GOOD WORKING ORDER." Two repair parts are listed--"M9 CCD/CIRCUIT BOARD, and VULCANITE for M8/M9 BLACK."

 

It is possible that they have seen a bigger problem with the sensor (a small crack developing), but it's interesting if they are replacing it to see if another sensor might solve the problem (don't know if it's relevant, but my camera was purchased one year ago this week, so it is a fairly early one). And a whole new circuit board. Wondering why?

 

I will call Sarah tomorrow to see if she can shed any further light on their approach. I am pleased thus far with Leica Service in NJ. The only downside is that while they said they could finish the body possibly on 12/23, they'll be closed afterwards until the 1/3, and then will do the 3 lenses/rangefinder adjustments. I wonder if I could pay a bit extra and get the grippier M8.2 vulcanite instead of the standard vulcanite when they replace it?

 

To be continued. Keep the illuminating posts coming.

[jaapv]

I'm sure you can get the finish of your choice,albeit at a price. Leica treats the leather finish in repair service as an a-la-carte item nowadays.

[hoppyman]

If you had a sensor cover glass crack, however tiny, you are getting a complete new sensor assembly. As I understand it the sensor asembly is matched to the circuit board (they stay together). So that will be new too.That means you need to completely forget whatever conditions you saw from your camera as it was. Don't guess and stress:)

The new unit must be installed and calibrated and the rest of the camera functions are tested to spec as a matter of routine.

 

Just like a new unit only gooder

[thighslapper]

I suppose we could put the following by Erwin Puts as a generic reply to most of what gets posted about the 'problems' with Leica M9's........

 

M9 final verdict

 

Sums up everything very succinctly without being defensive or apologetic......

 

I'm sure I read this before ags ago but somehow most of it didn't sink in.....

[hoppyman]

That summary is really so good it ought to be a Sticky in the M9 FAQs!

 

Erwin's Leica Lens Compendium (currently out of print) is an extremely good resource for the enthusiast. Used copies are offered for sale at horrendous prices.

Take note that he has a new, expanded and updated Compendium in the works which will be a very limited print run. You need to let Erwin know if you want to be on the list to be offered one for purchase.

[wlaidlaw]

That summary is really so good it ought to be a Sticky in the M9 FAQs!

 

Erwin's Leica Lens Compendium (currently out of print) is an extremely good resource for the enthusiast. Used copies are offered for sale at horrendous prices.

Take note that he has a new, expanded and updated Compendium in the works which will be a very limited print run. You need to let Erwin know if you want to be on the list to be offered one for purchase.

 

Erwin used to have the older version of his compendium available as a download from his website but no longer and I have a copy of that. I am not surprised he wants to make some money out his Leica work by selling copies of the next edition; he certainly deserves to. I have asked to go on his waiting list.

 

Wilson

[Peter Lea]

How does one get on his waiting list??

Thanks

Peter

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[wlaidlaw]

How does one get on his waiting list??

Thanks

Peter

 

Use the contact button on his website

Home

 

Wilson

[OttoG]

Sorry, I have no idea. I am wary of all these vague supposed “explanations” and “the pixels of the ccd sensor are not symmetric” is just more of the same.

 

Yes, the sensor pixels aren’t symmetric in that their microlenses are offset from the center by some amount that depends on the pixel’s distance from the optical axis. But is it really this kind of asymmetry that Leica refers to, and if so, how is this supposed to explain the red edges phenomenon? The effect of microlens shifting should be symmetric around the optical axis which doesn’t agree with the known facts of the red edges issue.

 

Hi,

 

You forget to take into account that the microlens layer is not necessarily perfectly positioned on top of the sensor layer. If, in assembly, the microlenses are offset even a single micron to the left or to the right, compared to the ideal position, it creates an asymmetry that would be significant to the result. Almost certainly, this is the asymmetry that the Leica representatives have in mind, even though they are reluctant to pinpoint it explicitly, as admission that it is a sample-variation issue might cause buyers to demand sensor replacement, in order to get an "ideal" sample.

 

In case it is not immediately obvious how such an asymmetry could cause the problem, consider a situation where, at one edge of the sensor, red light hits ideally placed photosites a bit to the left and blue light a bit to the right. Obviously, at the opposite edge of the same sensor, red light would hit photosites to the right and blue light to the left. Then think about what would happen if all photosites were offset a bit to the right. Compared to the ideal sensor, less red light would be collected at the first edge and more at the second edge. For blue light, the opposite would be the case.

 

Obviously, Leica engineers are well aware of this situation and have come up with various ways of compensating for it, by testing each camera for the amount of this and other sample-related issues and writing compensation parameters to some type of non-volatile digital memory. But the farther off a particular camera is from the ideal, the harder it will be for the software algorithms to give the correct amount of compensation in all situations. This is what they apparently hope to handle even better with even more sophisticated algorithms. (Most likely, they will let the camera analyze each captured image, in order to come up with better approximations of lens decentering, if it matters, and aperture setting.)