We've been right on a lot of things that people didn't (initially) believe. The M-A, the M-E, the APO-Summicron-M 50mm f/2 ASPH... The specs for cameras before release, etc.
I should add that I'm assuming the glue is reacting with the glass; I don't know that aspect for sure. Just that it's the glue's fault.
Don't you think it's more ethical to mention the source instead of pretending to have your own secret sources? I have always defended your antics on other forums but this time I think you're being dishonest. I'm sorry but that's the way I see it.
edwardkaraa wrote:
Don't you think it's more ethical to mention the source instead of pretending to have your own secret sources? I have always defended your antics on other forums but this time I think you're being dishonest. I'm sorry but that's the way I see it.
See it however you wish. I can't reveal my source(s) for very valid reasons. If I did, they would no longer be sources - and potentially suffer consequences. Rest assured that I have contacts in the know - both in and out of Leica.
on a more informative note:
I suppose we should say "cement"
"Okay- the cover glass is cemented into place, it can not easily be removed. Soaking the sensor in solvent is required to remove it, and that would very likely destroy the microlens array. So, the KAF-18500 must be revised to use a different cover glass. I already contacted one company for an IR conversion.
I've read comments on other forums stating that the coatings are the problem, that the cement used to hold the cover glass in place is the problem, etc. As an engineer- the root of the problem is that the S8612 cover glass corrodes due to humidity. The sensor stack must be thin for the Leica M-Mount lenses. The traditional method of using an AR-coated clear cover glass with the same coefficient of expansion as the sensor itself and using a separate IR absorbing filter between the sensor and the lens is not optimal. Leica/Kodak chose to go with the very efficient S8612 glass and to seal it from humidity. The seal is breaking down, and humidity is getting to the glass. To me- the easiest way to solve this problem is to use glass that is not sensitive to humidity. As an added bonus- the BG-18 has a coefficient of thermal expansion that is lower than S8612, ie closer to the sensor. I do not know the relative strength of this glass compared with S8612, another important factor.
One other thought: CCD's and sensors in general heat up as they are used. The glass will expand and contract as a result. The S8612 expands and contracts at a different rate than does the sensor. The problem of the seals breaking down "could be" related to shooting style. Someone that is shooting as fast as possible will produce larger expansion/contraction cycles than someone that uses single-mode, rarely fills the buffer.
I worked with digital imagers throughout the 1980s, switched to optical networks in the 90s. We had custom sensors built to our specs, custom glass made to our specs. In the 90s- custom components and boards to our design, "Gallium Arsenide" chips for speed, stamped "prototype". 36 years into it now. Still can't help looking at a problem like this and wanting to task engineers to trade-off between components. "My style" was to read the data sheets, pick some candidates, hand it to one of my engineers and ask if there was a reason why it could not be used, or if they could find one that was better. Sometimes, just had to tell them - "Use this one". In something like the S8612, the warning about corrosion in humid environments should have been enough reason not to use it. Always looking for Murphy's Law to get you wherever possible. The S8612 cover glass seems to be Murphy's Law at work. As best as I can tell, The KAF-18500 is the only sensor in ON's current offering that uses it."
I've seen Jaap's responses, on a couple of forums, claiming "it's not the glue." And he would know... How? That's right, he doesn't. There is no doubt it was causing the cracking, and that it was changed. The cracking stopped happening. Then these spots started appearing. Some coincidence, eh?
Now my source didn't remember all the details, I'll say that much. But the glue was mentioned throughout the conversation. And I trust my source more than a dentist any day of the week.
Fully covering a major, known manufacturing defect like this for only 3 years from the date of original purchase doesn't seem too reassuring or customer friendly. I remember when a number of the Fuji S2Pro's were affected by a bad batch of sensors, Fuji replaced these for all affected cameras free of charge until they ran out of sensors (even 5 years later, Fuji was still honoring this recall). I would think Leica needs to come up with a much better, long term solution for their customers (and potential customers).
Buy a set of Summiluxes and ND filters and just shoot everything wide open. Should avoid the problem!
Charlie's link to Brian's comments is informative. Could Leica and TrueSense/ON Semi substitute this other glass type in future production batches. Could this be a reason there don't seem to be any sensors currently available?
In the longerterm, Leica is probably better off to steer M9 users to discounted refurbed M240s. There's just too much troubling 'history' in the M9/M8 cameras and I'm sure they're feeling haunted by these seemingly never ending problems. That said, the M9 did pull them from the brink.
I have no problem with shooting Summilux (or Noctilux for that matter) lenses wide open and being done with it. Pretty much do that already.
As for being offered a discounted (refurbed?) M240... Not interested. I decided NOT to buy an M240; I sure won't be trading my M9/MM (which I bought new) for a refurbed camera, let alone one I'm just not interested in.
The Achilles heel of the M9-class is what makes them great for many - the CCD sensor. And the rub is, there is currently no MM replacement (though an MM240 is in development).
DoubleNegative wrote:
I've seen Jaap's responses, on a couple of forums, claiming "it's not the glue." And he would know... How? That's right, he doesn't. There is no doubt it was causing the cracking, and that it was changed. The cracking stopped happening. Then these spots started appearing. Some coincidence, eh?
Now my source didn't remember all the details, I'll say that much. But the glue was mentioned throughout the conversation. And I trust my source more than a dentist any day of the week.
I guess we'll find out tomorrow.
It sound to me as if neither you nor jaap are in a position to provide coherent information. Dentistry notwithstanding.
Your source didn't remember any details besides glue, glue glue? If that's the case, I'd say your source is also not in a position to relay more than vague information. This is not rocket science so not remembering any details seems emblematic of low technical understanding, or at the very least someone with little interest in the subject.
But, I hope he's right anyway, as glue is something easily altered. I fear the issue may be more complex especially in light of the various factors which Brian lays out in detail.
Tariq Gibran wrote:
Fully covering a major, known manufacturing defect like this for only 3 years from the date of original purchase doesn't seem too reassuring or customer friendly. I remember when a number of the Fuji S2Pro's were affected by a bad batch of sensors, Fuji replaced these for all affected cameras free of charge until they ran out of sensors (even 5 years later, Fuji was still honoring this recall). I would think Leica needs to come up with a much better, long term solution for their customers (and potential customers).
I also remember D600 and those perfect AF points (outer) on D800.
Anyone else? I mean, Nikon was soo fast to admit its their fault.. riiight?
To be fair, dSLR history is full of such flops. And if Im correct, this "cover glass" issue took pretty long to actually show.. not issue from day one (unlike some others, from other manufacturers).
Mescalamba wrote:
I also remember D600 and those perfect AF points (outer) on D800.
Anyone else? I mean, Nikon was soo fast to admit its their fault.. riiight?
To be fair, dSLR history is full of such flops. And if Im correct, this "cover glass" issue took pretty long to actually show.. not issue from day one (unlike some others, from other manufacturers).
Big fail on Nikon's part, no doubt. Nikon seems to have learned their lesson the hard way as they later were completely replacing affected D600's. Leica should particularly take note of how that all went down for Nikon with regard to bad PR as Leica is perhaps even more vulnerable if they piss off their extremely brand loyal high end customers.
If I'm following the trajectory of this issue, it appears that the first problem that affected the M9 sensor was cracking, which happened with the M9 of a colleague of mine early on. Something was changed to address that issue which it appears has resulted in this current problem. Thus, this could be traced back to a day one issue.
