The change from FD to EF happened 20 years ago, and back then I am sure it was to some peoples bother that their existing glass wouldn't mount on new bodies, but such is life. I've got a box of old AGP video cards that I paid thousands for over the years, that are now pretty much worthless. Also are you suggesting that Canon should have stuck with a breech-lock mount?
What I am saying is that the "won't meter" argument is practically meaningless in terms of Nikon v. Canon since it's an artifact of lens mount choices made >20 years ago.
And this is my beef with Nikon. You and I may not be confused as to what lenses will work and to what extent with the lower end Nikon DSLR's, but your average soccer mom with a D40 who is looking at buying a fast prime so she can take pictures of her kids in low light, won't.
Once again, which lenses work are documented in the manual that comes with the camera. Every single one of those lenses (except one, but I can never remember which one- I think it's the 35mm AF-D) hasn't had a change since ~1992.
Remember that the D40 is marketed to people with little technical knowlege or understanding of technical photography terms.
Who buy less than 1.2 lenses per camera body. How many people do you know with D40s? I know at least four well- and have spoken to at least a dozen (if I'm shooting in public, the "I have a Nikon too" crowd tend to approach,) and none of them has a lens issue. In fact one of them borrowed an AF-D lens from me to shoot his stepdaughter's track meet and had few problems manually focusing (I was unwilling to lend the fast prime that WOULD AF on the D40, and shooting for the first time in MF mode on a D40 without understanding DoF calculations he missed about the same number of shots that a friend with a D70s misses with AF when they borrow the same lens.)
Frankly the intended audience isn't likely to go out and buy a used lens because of their lack of knowledge, but if they do then they just need to adjust to manual focus or throw it back- every retailer I've seen has heavily advertised lens compatibility for the D40 too, so it's not difficult to get right outside of online auctions.
It's not a big deal to me either, but you've got to understand how other people could be confused as to why their lens has "AF" for auto focus in the name on the lens, yet it doesn't auto focus on their D40.
I never said I didn't understand it- I said it wasn't that difficult to get around, was well-documented and moot for most of the intended audience.
Anything from the last 20 years or so, oh wait that was when Canon changed to EF! Anything that is pre-AI or AI won't meter, how common are these lenses is not something I could tell you, but it is still something that an inexperienced user could run into after hearing that they could find old lenses off ebay for their Nikon because the lens mount hasn't changed in 45 years.
Actually, pre-AI lenses were from 1959 to 1977, so that's more than three decades ago. AI lenses were introduced in 1977, and manufactured until the mid '80s. AI-S was introduced in 1982, you have to go all the way up to 1992 to get lenses with CPUs that meter- but the D40 actually has very good lens compatibility in manual mode (better than some of the more expensive "advanced amateur" cameras.) All that said, frankly the optics of today's consumer lenses are better than most of the venerable old glass, so it's pretty moot too. The exceptions to that are lenses that are in the "advanced amateur" category, not the "soccer mom" category.
A good number of Nikons best inexpensive lenses (50mm F/1.8 anyone) are still AF, the very kind of glass your D40 user might be interested in.
No, the typical D40 user doesn't know what a 50mm prime is, nor do they look specifically for that focal length, because it's covered by the lens that came with their camera body. People who are thrown by the D40 issue are enthusiasts who simply can't afford another DSLR, or people who are given advice by well-meaning folks who don't know the limitation that the three lowest end bodies have. For most people, their first DSLR is their only DSLR, and if they hit "enthusiast" status, they're quickly looking for the next body up anyway. Finally, lots of us happened to shoot just fine before autofocus and autoexposure were created.
I don't know what you consider a "good number" or "inexpensive" but other than the cheap 50mm, almost all of the new lenses that won't work cost more than the D40- and for a budget-conscious buyer, "that dog won't hunt."
(For the record, it's AF-D that you want to whine about, introduced in 1992, not AF introduced in 1986 but no longer in production.)
They're not stuck re-buying, but they're left with the same FOV on their expensive FF body as they were on their APS-C body. Don't get me wrong, I find it nice that Nikon allows the capability, and this is less of a problem than the AF vs AF-S issue, but why not just sell your DX glass at a small loss and rebuy the correct lenses? If you're contempt with a 6MP image at 1.5FOV, you can always crop the ouput later.
Because you often don't want to lose the depreciation if it's a focal length that you don't use frequently, or it may be that the AOV is pretty expensive to do on an FX sensor. For instance, my Sigma 10-20mm lens gives a 15-30mm FOV- that'd mean I'd need a 14mm to get that wide- now you may shoot enough wide stuff to justify a 14mm lens- I don't, so why should I have to pay ~$1400 and lose a ~$900 investment just because I went from one tool (an APS-C body) to another tool (an FX body?) That's at least $1600 of lens inflexibility. I like my tools to be flexible- I don't want to have to buy or rent a tool every time I'm doing a few shots when I don't need to. Surely a champion of the budget-body-buyer can see that?
No, it's that they are smart enough to know better, and aren't likely to be wanting to mount a el-cheapo 18-55 on their 1DsIII anyways...
Odd- on the one hand, you argue it's bad not to be able to AF with an el-cheapo lens, on the other you argue it's good to not be able to use one at all.
There are plenty of good ultra-wides that are crop-sensor lenses from different manufacturers.
I would consider anyone considering taking off their stock lens in exchange for something else to be a "advanced amerature". Take a look at the people on here who own D40's, most of which just can't afford thousand dollar bodies and thousands of dollars in glass like you can. So they turn to eBay and the large variety of second hand Nikon glass to mount on their D40, the question is whether or not it will work like they expect.
Actually, my current body and *all* of my lenses except for my Sigma 10-20mm are second-hand lenses (every Nikkor I've ever owned except one for my 4x5 enlarger when I used to shoot LF film has been second-hand.)
I would argue with your definition of "advanced"- the ability to change lenses on an SLR- is something that takes no skill and little advancement- after all, that's the whole point behind an SLR. If your "advanced" lens-changer ignores their camera manual, doesn't understand that buying the lowest-cost body has an effect, and buys a used lens that works fine in manual mode, they can pretty-much always resell it for what they paid- used Nikkor prices are relatively stable and have been for quite some time.
And yet people are confused. Denying the fact that people are confused doesn't make the problem magically go away. Nikon advertises the D40 to people who want simplicity with the advantage of interchangable lenses, then have other people tell them that they can use any lens Nikon has made since the 60's.
First, technically they CAN use almost any Nikon lens from ~1962, they just have to shoot like people shot in the '60s. Secondly, advice from "other people" who don't use or understand the system is hardly Nikon's fault as you seem to want to say. I've recommended the D40 to several people, and none of them's had a problem- I've met others who made the purchase decision on their own, none of them has had a problem. Four of my regular friends have them, they're not confused- either they read the manual, they don't need anything other than the kit lens or they've gotten good advice.
The question is, why would someone want to pay for an $8000, then throw 50% of that sensor away by using glass that can't provide for the full size sensor? It's not like the "buy in" argument is all that big of a deal on the Canon side as most of the EF-S glass is junk, and the decent lenses (2) hold their value.
Because it's a tool- sometimes you're not building a work of art with the tool- you just need a basic item that the tool is capable of producing. Sometimes, you want a specific AOV with a tool you're used to, and let's not forget that Canon isn't the only lens manufacturer who makes glass in a Canon mount that has a crop factor. The bigger question is why would you want a less flexible tool instead of a more flexible tool? The Swiss Army Knife and Leatherman and their clones all exist because sometimes we're not sure what we're going to need out of a tool, and in those cases flexibility wins over exactitude. If suddenly the AD says "Oh! I need a shot of everything in one frame!" and I've got a 10-20mm with me, I shouldn't have to go on eBay, sell it, go to B&H and order a 14mm, then wait for it to get delivered.