willie_901
Mentor
The IR filter film is chemically unstable in the presence of water. This is the root cause of the corrosion.
While average humidity varies significantly among climates, water vapor is ubiquitous in our atmosphere. So climate variations are relevant. Even if a camera is stored in a near zero humidity environment, when it's making photographs water vapor in the atmosphere will react with the IR filter layer film. For this reason - sooner or later - every original sensor will corrode.
Another variable is sensor cleaning. Wet cleaning solvents can contain water. For example, isopropyl alcohol is hydroscopic. Sensor cleaning can cause very shallow scratches that have no optical consequences. But these disruptions in the cover-glass surface increase the rate of water vapor penetration. So even dry cleaning methods can affect the corrosion rate.
Yet another variable is the photographer. Corrosion artifacts are most obvious with narrow lens apertures. Those who rarely use narrow apertures will not notice obvious artifacts until the corrosion regions become large. Those who never view highly cropped images will not notice obvious artifacts until the corrosion regions become large.
I typically shoot at wide apertures. Once the problem was announced, started checking the cameras stopped down to F16 and against the inside of a lamp shade- "uniform" lighting. The M Monochrom and M9 were operated in the same environment, same operation. Yet- the M9 went years longer before the first sign of corrosion appeared.
What surprises me about the MAXMAX service- Dan is using a glass closer to that of the M8. The transmission is different, and IR leakage is a problem. Other repair shops are using BG60 or BG55, the transmission curve is not as efficient as S8612, but the shape is about the same. I'm not sure if the different shape of the transmission curve is causing the problem, or if the process itself introduces other changes in the sensor. In the case above: the grey camera has an almost 10% difference in the right vs left half: that is huge.
ALSO- the change in analog gain for ISO1250 requires a different set of coefficients for the correction. As the ISO is stored in the DNG file, a version of code can select the correct coefficients. BUT- the calibration needs to be done for ISO 1250/2500 images and 160/320/640 images: two sets of coefficients.
What surprises me about the MAXMAX service- Dan is using a glass closer to that of the M8. The transmission is different, and IR leakage is a problem. Other repair shops are using BG60 or BG55, the transmission curve is not as efficient as S8612, but the shape is about the same. I'm not sure if the different shape of the transmission curve is causing the problem, or if the process itself introduces other changes in the sensor. In the case above: the grey camera has an almost 10% difference in the right vs left half: that is huge.
ALSO- the change in analog gain for ISO1250 requires a different set of coefficients for the correction. As the ISO is stored in the DNG file, a version of code can select the correct coefficients. BUT- the calibration needs to be done for ISO 1250/2500 images and 160/320/640 images: two sets of coefficients.
willie_901
Mentor
This is hardly a control experiment. Were the cameras purchased at the same time? Is the sensor cover glass construction and composition precisely identical for both cameras? Does one sensor generate more heat than the other? And, were the IR filter films from the same manufacturing run?
luuca
Well-known
I will give you the sample shots as soon as possible, I'm in trouble with my job and no free time!
in the meantime no news from the credit card company and no news from Dan
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kbg32
neo-romanticist
I just received my M9 back from Dan at MaxMax, and I can fully vouch that he is top notch and knows what he is talking about. It is so nice to have my M9 back in my hands and working like it should. Kolari had my camera for over three months before they got to it, only to tell me that the sensor was cracked, a common occurrence on sensors with corrosion, and the sensor could be scratched on removal of the old cover glass. They could not guarantee the repair. They asked me how I wanted to proceed. I told them to send my camera back, which they did, minus a 30% handling fee and additional shipping. During this time I had multiple conversations with Dan, and he went through the whole process with me. Once my camera was returned I sent it to Dan and the camera is now fully repaired with no scratches on the sensor, which according to Kolari, could be taken care of with post processing. Can you imagine having to post process a scratch in every image you wanted to keep?
Hats off to Dan. I am sorry some have had a different experience. I feel Dan is an extremely qualified technician. Kolari has been doing the sensor cover glass replacement for just a short time, while Dan has had years of experience. He is not the best on the phone, but my emails with him have been most informative.
Hats off to Dan. I am sorry some have had a different experience. I feel Dan is an extremely qualified technician. Kolari has been doing the sensor cover glass replacement for just a short time, while Dan has had years of experience. He is not the best on the phone, but my emails with him have been most informative.
Out to Lunch
Menteur
If anyone had their M9 sensor replaced by Kolari Vision, I would appreciate your feedback. Cheers, OtL
Ronald M
Mentor
I took the new camera route. Ordered a M10p silver. Waited 4 months and no new camera, no promise. Leica Miami gave me a M10R from stock with price increase.
The R is incredible and at this point glad the M9P is gone.
The biggest shock after 3 months is my 3.5 Elmar red scale and 1.5 Summarit take way better pics than they ever did on film on many M film cameras. The 1.5 on film was always soft at 1.5 and now it is much sharper. Contrast is a tad low on both, but a small fix in Capture One make them really nice.
50 2.0 APO , well you would not believe it. Beautiful colors , nice contrast, very sharp with DGN right from the camera with Capture One. Makes me think JPEG might be ok, never tried.
The R is incredible and at this point glad the M9P is gone.
The biggest shock after 3 months is my 3.5 Elmar red scale and 1.5 Summarit take way better pics than they ever did on film on many M film cameras. The 1.5 on film was always soft at 1.5 and now it is much sharper. Contrast is a tad low on both, but a small fix in Capture One make them really nice.
50 2.0 APO , well you would not believe it. Beautiful colors , nice contrast, very sharp with DGN right from the camera with Capture One. Makes me think JPEG might be ok, never tried.