The D50 is not an older D40 or D40x, although those 2 models seem to have replaced it in the lineup.
The key differences: - D50 has an autofocus motor built into the camera body. Neither the D40 nor the D40x has this motor, which ultimately means the D50 will autofocus on all Nikon AF lenses, while D40/x requires newer Nikon AF-S lenses for autofocus. - D40 & D40x share a smaller camera body & grip, so this might be a plus or minus depending on the size of your hands. - D50 has 5 autofocus points while D40 & D40x has 3. - D50 has a top-mounted LCD that shows all important settings at a glance. - D40 & D40x have no top LCD but a bigger and better rear LCD. - D40 shares the same 6MP sensor as D50 but D40 has newer noise reduction algorithms, so the D40 has better high-ISO (low light) noise performance. - D40x shares a 10MP sensor with D80 & D200 - D50 has more external buttons so there's more features at your fingertips where D40/x might have you diving into a menu to change settings. - D50 has auto exposure bracketing, D40/x doesn't
This list could go on and on into obscure features you might not understand. For lens compatibility, it's not simple but the lenses that come with D40 & D40x work perfectly on D50. As I said above, D50 will autofocus on older AF & AF-D Nikon lenses where D40 won't. There are some very old manual focus lenses that can be mounted on D40/x and not D50 but I doubt these are lenses you're asking about.
The table might be generally true, but not necessarily true for all lenses. For the old manual lenses (pre-AI) and the D50, the table said "No!". That meant "Definitely do not use, for it may damage the camera body."
I carefully tried my old Nikkor 50mm F1.4 on my D50 and it fit and worked just fine. Manual focus and manual exposure, of course. It's such a nice piece of glass I didn't want to get rid of it.
Hi Louis and welcome to the D50 family!!! I can't speak to the differences between the D50 and the 40s, I can just tell you that after having a D50 for about a year, I haven't had a moment when I've said, "Boy, I wish I had a D40/x instead of this "old" D50. The best advice I've gotten has been that any time that I spend second guessing what I have is time that I'll later on realize I could have been taking pictures.
I started with lenses from my film camera (one new nikon and one ebay 3rd party), bought a new nikon lense, and recently a new 3rd party lense. In the order of how much I use them: 1. $250 Nikon (new); 2. $60 Quantaray (ebay); 3. $95 Nikon (new); and 4. $400 Tokina (new).
I use AF lenses from Nikon, Tokina, Tamron, Sigma, Quantaray and some manual lenses from Vivitar, Soligor and various Korean brands. The electric contacts on the rear of the lens come in three varieties; one is the AF for D50, 70, 90 etc which is in the pattern . .....; one is the pattern for D40, 40x, 60, 3000 etc ........... and mostly have plastic mounts and will also work on the D50,70,90 etc. No electric contracts mean it is manual focus; many of them will work on the D50 in manual focus/manual aperature mode only.
Sun 22-Jul-12 05:00 PM | edited Sun 22-Jul-12 09:57 PM by briantilley
This is a 4-year-old thread, but it's probably worth pointing out a couple of things - for posterity, if nothing else
It's true that "screwdriver" AF lenses have a pattern of electrical contacts that differs from the AF-S lenses that will not autofocus on the D40, D40X, D60, D3000, D5000, etc. The pattern on AF lenses is one contact, then a gap, then four more contacts. AF-S lenses have no gap and have between 7 and 10 contacts in one group.
Whilst the absence of contacts does mean it's an MF lens, the presence of electrical contacts does not guarantee it's an AF lens. There have been a couple of so-called "Ai-P" manual focus Nikkors (such as the 45mm f/2.8), which have the same "one-gap-four" contact pattern as screwdriver AF lenses.
Lastly, all the top "pro" Nikkors have the same contact patterns as the cheaper, plastic-mount, lenses that you mention. The number of contacts is not an indicator of quality.