Camera Labs

You can basically only use AF-S lenses on your D5100. You an use other lenses too but you will loose certain features such as autofocus or 3d-lightmetering or stuff like that. (your camera manual also explains this somewhere).

If you want to buy a 50mm lens then I suggest you go for the Nikkor AF-S 50mm F1.8G. I believe there is a review about that lens also. Basically it is the best 50mm lens you can buy for the money. It is better then the AF-D 50mm F1.8 and also better then the AF-S F1.4G (you only should buy that one if you really need F1.4 aperture, but i am sure F1.8 will do just fine for most people).

My review of the 50/1.8G is here.
My review of the 50/1.4G is there.

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Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Keep in mind that you can't use all lenses on all bodies, though. AF-S lenses will work flawlessly, AF lenses will work sans-autofocus, AI/AI-S lenses will mount and that's about it (no metering), and original Nikon F-Mount pre-AI lenses will mount as well (but again, no metering here either). However, keep in mind that pre-AI lenses will NOT mount onto the D7000 or any higher level bodies, as they have an AI coupling mount to add metering ability for AI lenses, but will snap off if you attempt to mount a pre-AI lens on. So, NEVER try to mount any pre-AI lens onto a higher end body, unless you get it converted. Otherwise, it will damage the mount.

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-Evan

Gear: 7 Nikon Nikkor AI-S and AF-S lenses, SB-700 flash, Nikon D7000, Nikon FM, variety of accessories

"There are no rules for good photographs, there are only good photographs."
- Ansel Adams

thanks friends

hey plz select the best combination among the following two combinations


1. dslr with built in focus motor + lens without focus motor (AF lens)

2. dslr without built in focus motor + lens with focus motor (AF-s lens)

If the AF-Motor is in the lens you normally have
- a quieter AF
- less play in the gears and thus a little more precision in focusing
- If the AF-motor in one lens fails you can still use another lens

The AF-Motor in the body gives you the following advantages:
- can use older lenses which you can probably buy cheaper than their newest incarnations
- The AF-motor in the lens cannot fail, so your valuable investment in lenses lives longer. Bodies come and go: So normally you get a new body before the in-body AF-drive fails on you.

As you see, there's no clear-cut answer. And you shouldn't underestimate the risk of a failing AF in a lens and Nikon (or any third-party manufacturer) not replacing it if the lens has been discontinued for more than 10 years.

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Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

thanks friend
but am confused

ok can u tell me which one u pick if u get a chance from the above two options?

It does not matter. If the DSLR-body has a built in motor you still can use AF-S lenses too (and the motor in the lens will be used). The latest AF-S lenses are usually better then their AF-D equivalents anyway.

So just buy AF-S lens and buy the DSLR body that you like the most and start making photos.
Just buy the body that you want and the built in motor is not that important unless you havea bunh of old lenses that you still want to use. But the newest AF_S lenses outperform almost all of their older brothers so don't invest in anything old (maybe there are some exceptions but not that many).

You already have a D5100 body so go buy that AF-S 50mm F1.8G lens and show us some photos that you made.