Archived posting to the Leica Users Group, 2009/09/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Geoff, The CCD is an analog to digital conversion device and on a die to die basis there will be variations that while within the manufacturer's, (Kodak), specifications could be characterized on a die to die basis. A designer could simply design for the nominal spec and not worry too much about the effects of variation as a result of the CCD manufacturing process. However the ultimate would be to measure the characteristic of each individual die and use those parameters in the control logic that is processing the digital output of the die. To do this the parameter of the die have to be stored somewhere. In watching the video it's stated that the control board is "paired" with the sensor assembly. That tells me that characteristic parameters for the sensor is stored on the control board, not on the sensor assembly, (where I think they should be stored). I would put them on the sensor assembly because it makes repair much easier. If the cost of repair is not an issue then fine, it's usually the customers money anyway. I assume that Jenoptik made this decision and Leica accepted it but I think Leica should have pushed back on this one. Maybe it would delay the introduction of the camera, I don't know. The ultimate objective would be to have the algorithms and equations in the control board driven completely by parameters from the sensor assembly. If achieved, then you could upgrade a camera by changing just the sensor assembly. Could it be done? I don't know, but I do think it should be a design objective. An extreme upgrade could run into a processing power issue where the speed of the control board doesn't allow the camera to meet the design objectives, too slow. In either case, depending on how much firmware is involved, you can come away with general purpose firmware so that new models don't entail firmware rewrites, and that can save a lot of time and money. Shims are undesirable in any manufacturing process. Good design will almost always obviate the need for shims. At first I thought the issue was the frame the sensor is mounted it, it looks like a sheet metal stamping. But I wondered about the mechanical specifications on the Kodak sensor. Looking at the KAF-10500 data sheet, I just picked one available online, the mechanical specifications are surprisingly loose so it seems to me the shimming is not within Leica's control. I realize this is probably an issue that all digital camera manufacturers have. I have no doubt about Leica's use of technology to measure I also have no doubt about Nikon, Canon, etc., ability to measure. Most likely the difference in use of those measurements is use of robotics to make adjustments, possibly using screw based adjustment mechanisms. Geoff Hopkinson wrote: > Dennis the matching of the sensor to its board is performed by Jenoptik and > there is no insight in that video as to Jenoptik's processes at all. > What is the issue in your opinion with the shimming process?. It is a Leica > response to the criticality of sensor placement to extract the best from > the > lens performance. Leica are using very modern precision measurement > processes that report the shimming adjustments needed and down to one > hundredth of a mm increments at three points. I would be very surprised if > any other camera company works to that level of accuracy. Can you provide > examples of how it should be done differently? > You might like to read some of the reporting that has surfaced recently > regarding the digital back sample variations in high end medium format > cameras for comparison. > > > 2009/9/15 Dennis <dennis at hale-pohaku.net> > > >> Ok, Luminous Landscape titled it "M9" but all I saw was M8s. >> >> From what I saw Leica needs to look at improving their manufacturing >> processes. The matching of the sensor to the control board would be a good >> place to start. No wonder it costs a fortune to replace a control board. >> The sensor assembly should include all the sensor parameters needed by the >> control board. I could talk a lot about this but doubt anyone is >> interested. >> >> The shimming of the sensor is another issue. >> >> Well, it was about the M8, maybe the M9 has improved processes. Somehow I >> doubt it. >> >> >> Vick Ko wrote: >> >> >>> See the video about the M9 at Solms? >>> >>> http://www.luminous-landscape.com/videos/m9-video.shtml >>>