I'm with you on the QC issues. The conclusion I am coming to over the last couple of years is that there are lenses that are in spec and there are cameras that are in spec but that there are combinations of those that are out of spec. That may not be the case here with the softness at long and wide, but it could be. Most photographers have no way to really easily verify that with either only one lens of a type or one body of a type.
What made me fairly confident in this hypothesis is that the new iDmk3, if I am understanding it right, has the ability to micro adjust the fore or back focus on a given lens. The camera remembers the lens and the user calibration for that lens. The problem comes is if you have two of the same lens, it can only remember one - so it must be remembering based on the lens model and not on a model and serial number.
Why would Canon put this capability into a body if my hypothesis were not correct?
Since all the lenses are manufactured in mass production not every lens gets tested against the lens design specification. Some companies have better Statistical Process Control with tighter control limits than some of the other ones, but they all have some less than perfect samples shipped.
I can assure you based on my personal experience that Canon is one of the companies where the problems are minimized, but even so I had to get a replacement lens on more than one occasion.
I am certain these problems have always existed in the past decade but went unnoticed since nobody was checking the color slides under a microscope only with a 4-10X loupe. Now in the digital age most of us are checking the images on the screen at pixel size (100%) and all the lens defects are magnified and more noticeable. It just all depends on what your tolerances are and what is acceptable on the largest print size you are planning to make.
If you are in the pursuit of the “perfect copy” of a given lens you may need a lot of patience and good luck or the combination of both to accomplish your goal.
Did anyone see the Canon production videos from a month ago where they showed how they make the lenses? Those gave me the impression all the higher priced glass got strapped on a test machine before it left the factory? I guess it could have given me the wrong impression.
You know I would happily pay another $400 or so a lens if Canon would make damn sure they were perfect before they left the factory. I know the size of their production is incomparable but it sure seems like you very rarely hear of these sort of problems with Zeiss.
I'm pretty familiar with the sort of manufacturing technologies that Canon uses and the level of competency required to make this sort of stuff. I'd expect, and would be very, very surprised it I'm wrong, that Canon has probably got a top notch mfg facility for this stuff and is state of the art in SPC.
I do agree with the point that this is maybe a migration in standards from what was industry standard in the film days to the digital age where everything can go under the digital microscope.
So, what's perfect? Is it even attainable on a mass production basis cost effectively? We may be looking at the outlying units in the distribution through the spec range that are 'perfect' as we know it and as what we expect it to be. Is it possible to hold mfg of the lens to the tolerance that is necessary to make it work with a 6 sigma population of camera bodies operating in the field?
DynaSport wrote:
My last word on this which has gone completely off topic. While I agree that QC could and should be better at most companies, I don't think having Canon or any other company reimburse shipping charges is the correct answer. Canon is not the one charging the shipping charges, the retailer is. Canon has no control over how much they charge. In fact, if you walked into a brick and mortar store and bought the lens there wouldn't be any shipping and handling charges. You would likely pay more for the lens and you would certainly pay tax on it, which you may be avoiding by buying online/mailorder. Instead of asking Canon to pay for charges they don't control, a more realistic tactic would to buy a competitors product. If enough people did that Canon would certainly get the message. I hear the response now, "but others don't have any better QC." Probably right. In fact, Canon's may be better than their competitors. Well, at least you can complain on the internet and I hope you have a lens you are happy with now.
I was not suggesting Canon pay for return shipping; it is certainly the retailers responsibility as Canon has no idea what happened to the product after their delivery. I have sucessfully asked for reimbursement for shipping, and will no longer do business with anyone that won't. If every one called and demanded this, the customer service departments of all the major online retailers would have to fall in line. But there has to be a common will or it won't be implemented - except in isolated instances. Those who say it won't work obviously dont have the savvy or the will, or have never tried. Where there is a will, there is a way...
tinke wrote:
I was not suggesting Canon pay for return shipping; it is certainly the retailers responsibility as Canon has no idea what happened to the product after their delivery. I have sucessfully asked for reimbursement for shipping, and will no longer do business with anyone that won't. If every one called and demanded this, the customer service departments of all the major online retailers would have to fall in line. But there has to be a common will or it won't be implemented - except in isolated instances. Those who say it won't work obviously dont have the savvy or the will, or have never tried. Where there is a will, there is a way... ...Show more →
Actually, what would happen would be that the discount retailers would not discount as much and offer free shipping instead. It would be in there somewhere - there is no free lunch on this. It really is pretty much a zero sum game when you are working the discounts outlets. They've taken the margin down pretty far already.
You (personally) are actually better off if you ask for it and get it instead of having them make it a blanket policy. That way you get the discount and the shipping.
