Archived posting to the Leica Users Group, 2006/01/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Bill, I think the situation boils down to the difference between "good enough" and "the best material possible". Clearly either the manufacturers are lying, which I do not believe, or are convincing people that the materials are good enough by writing things such as you quote. The shell of a camera is hardly a high tech structural element. It is a cosmetic cover which keeps dirt out. The precision stuff is inside. The worst load case a camera will experience it to be dropped, I expect. Then who is to say what is good enough? With respect to Leica (almost on topic), dropped onto the top plate a brass plate will probably dent, a zinc (probably mazak) will dent or crack and so will magnesium. What actually happens depends at least as much on what angle it lands, what it lands on and from what height than the material of the shell. What I take issue with, and it irritates me a great deal, is that the marketing propaganda presents magnesium as new and superior. It may indeed meet all the criteria somebody has set for a camera - hardly any sort of high tech duty cycle. The fact that magnesium is "rugged, robust and durable" in a camera context only questionable in the durability sense. There is probably a hard cheese being made somewhere in the world which is rugged and durable enough for a camera shell - he joked - but I am sure you get my drift. I won't repeat what I have already written about magnesium but the butt of my concern is the durability issue. I have many Leicas. The lovely old black ones have "brassing". Had they been made from magnesium rather than brass there would be holes in them where it had corroded through. I have seen a magnesium helicopter gearbox casing from an aircraft that had been inadvisably used by its owner to land on his boat. At its first inspection from new the casing was scrap, less than 12 months old. Marinized helicopters have aluminium casings I believe. Chrome plated brass lenses I have are like new, regardless of age. Aluminium and brass are OK if used all the time, the wear rubs of oxide spots. Some of the wartime IIIc cameras have blistering chrome plate where the aluminium is corroding underneath. If they had been magnesium they would be corroded through. I have looked at a few pro photographers C*non long lenses which are painted magnesium too. Where they have chipped the paint off one can see the surface plating. As long as the bangs don't break through this coating they may be OK. They obviously don't care about longevity anyway because they change things frequently. Maybe magnesium can be made adequate anywhere weight is the dominant factor and long life is irrelevant (digicam?). Magnesium can not be made good, even its best alloys make it useable rather than good. If any of my engineers proposed a finishing process which -required- moving through 3 countries I would ask what he had been drinking. That would be of questionable acceptability for a high tech application never mind a dust cover. In the Leica case I would bet that is because the castings are done in France, the cameras made in Portugal and the QC, packaging and attachment of the "made in" sticker in Germany. Well Bill you and I have gone on a bit here, I ask the indulgence of any Lugger who has got this far. I do not doubt that magnesium can be made "good enough" structurally for a camera shell. I do not believe it can be made "as good as" any of the alternatives historically used - including fibre reinforced plastic. An unused component with perfectly applied, undamaged, surface coating MAY be "durable" but a used one with a surface scratched to bare metal, like a typical pro used camera, will not be as durable as any of the traditionally used alternatives. Frank On 21 Jan, 2006, at 18:00, Bill Marshall wrote: > Frank, > > I truly appreciate all of the information that you have presented & > the fact that you have lent your expertise to this discussion. > Thank you for your patience with me who knows next to nothing about > this subject other than what I can learn from reading. I'm just a > guy who likes cameras & who is trying to understand the marketplace. > > I certainly understand that Marketing Departments are paid to hype > their products & that these departments can be prone to > exaggeration. So, I'm not surprised when they claim that something > is "rugged," "durable," or "robust" & it is so only to a very > limited degree. However, it's certainly confusing to read about the > testing that Nikon & Zeiss say that they have done & to read their > claim that magnesium meets the highest standards of professional > use (Nikon's claim) in terms of resistance to corrosion & of shock > resistance and for this not to be true. This would be more than > marketing hype & exaggeration. It would be misrepresentation, a > blatant lie. While I certainly don't put it past the corporate > community to engage in such deceipt, it would be surprising coming > from companies like Nikon & Zeiss. I assume that Canon & Leica have > done similar testing although it is not explicitly stated in their > materials, so it only adds to my confusion when companies of their > stature also represent this material as strong & as fit for its > intended purpose. > > Some time ago, I corresponded with Hasselblad about the Zeiss Ikon, > specifically in regard to the magnesium body plating as well as > other matters. Since they couldn't answer my questions, they > referred me to one of the engineers at Carl Zeiss AG. In an > exchange of several lengthy e-mails, he assured me that they had > subjected the camera to intensive testing in their environmental > test lab for extremes of temperature, humidity, shock, and > vibration, that they had insisted on improvements & modifications > where they felt necessary, & that the camera met all of their > standards in this regard. The tone of his letters bore no > resemblance to someone from a marketing department. > > I don't know if the following sheds any light on the discussion, > but here is what Leica has to say on the subject in a press release > about the R9: > > "Magnesium is particularly difficult to manage with respect to > corrosion resistance and scuffing. Leica for the first time employs > a plasma-chemical process for coating the light metal. This > transforms the surface of the magnesium into a thick ceramic layer. > In the process, special demands are placed on the magnesium alloy > and on the preparation of the surface. Special lacquers are then > applied to achieve an extraordinarily long-lasting finish. A > greater fabrication effort is also required for casting the > magnesium in the molds because this takes place at temperatures of > 700 degrees C (1292 degrees F) as compared to 400 degrees C (752 > degrees F) in the die-casting process." > > More from Erwin Puts on the matter: > > "Magnesium is the lightest of all commercially available metals > with a specific gravity of 1.75. It is in itself not a strong > metal, nor has it good elasticity. You need to create an alloy and > use a considerable thickness or utilize deep sections to obtain > good stiffness. It is a very high cost material and does not > possess good corrosion characteristics. The painting and casting > and shaping of the topcover is a process that takes place in three > countries (Germany, France, and Portugal) before it ends up on the > R9." > > Again thanks for sharing your knowledge & for your patience with me. > > Best regards, > bill > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information