For a lot of photographers, one of the first lenses they will get is some kind of 50mm, usually an f/1.8. For Nikon shooters this is usually the 50mm 1.8 D or the newer 50mm 1.8 G version. I have owned both and both are very good lenses for the money, but in my opinion the D version is a much better piece of glass.(not to mention its about $100 cheaper)
While the G version is by no means a bad lens(it’s actually a bit sharper and the autofocus is ever so slightly more accurate) I don’t personally see a justification for the higher price. Unless your camera is incompatible with the D series of lenses, my advice would be to stay away from the G.
So why is the old and slightly outdated lens better than its newer counterpart? Well there aren’t any monumental differences between the two, it just does a lot of things slightly better than the G version. At least, in my opinion.
For one thing, The autofocus on the D version is faster. Not by a lot, but enough that if you shoot with each one, you will notice it. Although it is older and a lot louder, it is still somehow quicker than it’s replacement. The downside to the older system is that the autofocus wont work whatsoever on the D3000 and D5000 series, so if you own one of those this feature wont do you much good.
Another HUGE difference in the D version is the aperture. This is probably the single best part about the lens for several reasons. First off, I LOVE the fact that it has the aperture ring. because of this, I can not only use it with my d610, but it will work with just about any film camera like my Nikon f3 as well, which is very helpful and makes it so I don’t have to carry around excess gear. Another nice thing about it is that it stops all the way down to f/22, rather than f/16 like the G version. And although I don’t often shoot at small apertures, its still a helpful feature to have. This last one is just my personal opinion, but I also really like the haxagonal aperture over the (more or less)round one in the G version. I know it wont be popular, but I think it gives photos a more interesting and slightly cinematic look.
As far as optics go, these lenses are almost exactly the same. One of the only upside for the D version is that the G series can have some weird and really ugly flares near the edges of the frame.(see right) The other upside is that I loooooove the way the D version flares when shooting directly into a light source. This can be good or bad depending on your taste, but I dig the flares.
Ultimately its up to you to decide which one to get, though. If you value sharpness over all else, the G version is for you. But I think the D series is a more creative piece of equipment.