Sensor Corrosion Analysis and Fix [Merged]

[Michael Markey]

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15 minutes ago, jaapv said:

Leica's problem was that the corners on the sensor suffer because of the steep incidence angle of some (legacy) lenses, thus they had to use as thin an IR filter as possible. That affected IR sensitivity (the M9 was already much better than the M8, but even the M240 and M10 have similar (mild) IR contamination. )

Thus they could not use the normal thick, even dual-layer IR filter glass available. They did opt for a  0.5 mm ant-corrosion coated glass that was the only thing available to Kodak at the time. Unfortunately it turned out that the coating did indeed exhibit micro-porosities (which you speculated on). It was not a matter of stupidity, but engineering at the limit of the technical possibilities by necessity, which ran into technical difficulties after a few years of use.

That maybe but what sticks in my mind when this problem came to the fore was Leica`s response .

They weren`t what you would call helpful and transparent.

It took them a while to take responsibility and provide a solution .

I thought that disappointing .

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[Einst_Stein]

57 minutes ago, Michael Markey said:

That maybe but what sticks in my mind when this problem came to the fore was Leica`s response .

They weren`t what you would call helpful and transparent.

It took them a while to take responsibility and provide a solution .

I thought that disappointing .

I found the corrosion rather late. But Leica offered trade-up to M240. I paid $600.

That's not disappointing at all. I was actually rather happy with the corrosion! 

 

[dante]

1 hour ago, jaapv said:

Leica's problem was that the corners on the sensor suffer because of the steep incidence angle of some (legacy) lenses, thus they had to use as thin an IR filter as possible. That affected IR sensitivity (the M9 was already much better than the M8, but even the M240 and M10 have similar (mild) IR contamination. )

Thus they could not use the normal thick, even dual-layer IR filter glass available. They did opt for a  0.5 mm ant-corrosion coated glass that was the only thing available to Kodak at the time. Unfortunately it turned out that the coating did indeed exhibit micro-porosities (which you speculated on). It was not a matter of stupidity, but engineering at the limit of the technical possibilities by necessity, which ran into technical difficulties after a few years of use.

I don't dispute this, I think that "stupid" may be a strong word (it was not mine), and I acknowledge technical limitations of the glass - nothing lasts forever. Maybe the impact of glass qualities over long periods was not foreseeable to the camera designers, but what was foreseeable was users damaging sensor cover glasses during cleaning. I have not yet heard the explanation for why changing the filter glass was not addressed in the design. That is why sensor damage has always been an outsized issue. The M9 has a 50-year recycling logo, does it not?

[Einst_Stein]

Slightly off the topic. Anyone has experience with Kolarvision on monochrome conversion? not IR, such as just remove the bayer layer. 

How would it affect raw conversion?    

The candidate camera would be Sony R1, Lumix FZ40, FZ100, or Leica Dlux 4. Most preferred is Sony R1, but it has larger sensor (cost!).

Edited September 12, 2020 by Einst_Stein

[jaapv]

1 hour ago, Michael Markey said:

That maybe but what sticks in my mind when this problem came to the fore was Leica`s response .

They weren`t what you would call helpful and transparent.

It took them a while to take responsibility and provide a solution .

I thought that disappointing .

But don't forget that the rather vehement reaction by senior members of this forum triggered a more customer-friendly response by Leica.

[dllewellyn]

For any camera,  you want the ICF to be as thin as possible.  But there are tradeoffs.  Typically, the ICF is a combination of ionically colored glass that absorbs infrared and vapor deposition coated glass that reflects infrared.  Contrary to previous comments, the Schott glass is not a Hot Mirror.  Hot Mirror refers to the vapor deposition coated filters.  Schott glass makes ionically colored glass absorbing filters (as long as we are talking about ICF types).  With vapor deposition coated filters, the angle of incidence of the light passing through the filter changes the transmission of the filter. 

With a wide angle lens, the light passes at a greater angle towards the edges so: 1: the light travels a further distance through the ICF and the further distance changes the focal plane (i.e. why wide angle lenses have soft corners),  2: the metallic coated filters change transmission properties because the light is not going through the filter at a right angle, 3: so the manufacturers use a combination of IR absorbing glass and IR reflecting glass.

With a 25mm or greater lens, those affects largely disappear.  Use a 50mm lens, you can forget about the ICF thickness.  The light rays are already close to parallel.

[Ko.Fe.]

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So, both mentioned in this thread companies are offering M9 sensor cover repair and even Monochrome conversion.  

https://maxmax.com/maincamerapage/monochrome-cameras/leica-m9

https://kolarivision.com/product/leica_m9_repair/

[analog-digital]

After 27 post's, what is the conclusion?

[jaapv]

That there is a solution for corroded sensors.  

[Michael Markey]

45 minutes ago, analog-digital said:

After 27 post's, what is the conclusion?

Well this is one conclusion  ..... that it was a dumb design decision .

https://petapixel.com/2020/09/12/leica-m9-sensor-corrosion-due-to-dumb-design-decision-report-claims/

[jaapv]

As argued against above... who is to blame, if blame there is?  Leica, who set out the parameters with rangefinder lenses in mind? Kodak,who formulated the production specifics? Or Schott who provided the corrosion-proofed glass? 

[dllewellyn]

Keep in mind that Kodak was faltering and laying off employees.  Their peak was 1988 when they employed 145,000.  They missed the shift to digital and never quite caught up.  The M9 came out in 2009 which is in the period where Kodak had fired 47,000 employees and closed 13 manufacturing plants.  My guess is that the engineers who knew what to do had been fired or where retired.  Not coating the glass is a rookie mistake.  Unfortunately, it was one that takes time to become apparent.

To be fair to Leica, they did replace sensors long past the warranty period, then users had to pay for sensors, then sensors weren't available, and now Leica is still offering credits towards new cameras.  Not many companies would do that.  Sure Leica/Kodak screwed up, but Leica has done what they can at this point.

[jaapv]

Even when the customers had to pay, it was 60%. 

[pedaes]

33 minutes ago, jaapv said:

Or Schott who provided the corrosion-proofed glass? 

If only they had!

 

[dllewellyn]

You can't blame Schott.  They will tell you that certain sorts of glass oxidize.  It is just part of the chemical structure of the glass.  It is up to the user to decide if they want to use the glass raw, coat or do whatever.  Even glass that doesn't oxidize gets haze and such over time.  For that matter, glass is not really a solid (no exact melting point).  Look at old windows, and you can see the glass slowly sags.

[Munik]

Unfortunately the filter replacement service is very expensive and not really a replacement for the Original Leica sensor replacement.

With Leica we had a new sensor, free CLA and 1 year of warranty for 1.6k$.

Here it’s 1k$/1.5k$ with no warranty or insurance if the sensor is damaged.

The better option for corroded sensor is to buy a used « new sensor version » M9 and keep yours for spare parts. Should last you another 12 years

[dllewellyn]

I can offer a 1 year warranty on my work, but I have repaired work long past that gratis.  With the correct glass, the sensor shouldn't be a problem.  Something else will wear out on the camera before the sensor goes.  Most problems are caused by things like camera falls and water damage.  Eventually, electronics will fail, but usually in the camera world, by the time that happens, technology has made the camera obsolete.  Though I do have 10 Leaf backs all with the same problem that are End Of Life that need to be repaired.  Probably faulty capacitors. 

[jaapv]

1 hour ago, dllewellyn said:

You can't blame Schott.  They will tell you that certain sorts of glass oxidize.  It is just part of the chemical structure of the glass.  It is up to the user to decide if they want to use the glass raw, coat or do whatever.  Even glass that doesn't oxidize gets haze and such over time.  For that matter, glass is not really a solid (no exact melting point).  Look at old windows, and you can see the glass slowly sags.

Yes, but this version of the glass was specified with an anti-corrosive coating. Yes, glass sags, like in the Hagia Sophia |it took 800 years...

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Hallo,

Look here: Leica M

[dllewellyn]

But Schott doesn’t apply coatings normally.  You buy the glass from Schott and do it yourself.  I have been buying glass from them since 1996.

[dllewellyn]

Analogy: blaming the lumber mill for rotted wood when the building didn't varnish the wood.