cypilk said:
for nikon's lenses.. why is it that the 70-300 lenses are so different in price... the g type is about 100 and the d type is about 300... whats the big difference...?..
I don't know all the Nikon lense letter abbreviations myself but this is what I have found out so far. Anyone please correct me if I'm wrong. There are basically two type of Nikkor lense...CPU and non-CPU lenses.
CPU lenses are: G, D, non-G/D AF, AI-P
non-CPU lenses are: AI-S, AI, series E
Depending on your camera you might be able to use all of them but some functions may not work on some cameras. It's best to refer to your manual and see which type of lenses is best for it. I believe most current Nikon bodies can use G or D without a problem. So what's the difference between G and D you ask?
Orie basically already pointed it out. G lenses don't have an aperture ring while D lenses do. They are actually very similar aside from that. Just make sure your camera can use it before buying.
The reason for the price difference isn't because one is either G or D but it's that extra letter abbreviation after it. The 70-300D lense also has an ED abbreviation after it which is why it cost more. Here are two quotes I found about ED..."ED Glass: Extra-low Dispersion glass for telephoto lenses that offer superior sharpness and color correction by minimizing chromatic aberration" and this one is from the Nikon website, "ED glass for high resolution and high contrast even at maximum apertures". If you don't know what chromatic aberration is then read
this site.
If you can afford it then go for ED lenses. If you really want to spoil yourself then also go for AF-S lenses, which have very quiet, smooth, and fast focusing motors. AF by itself just stands for auto focus. Just remember that these extra abbreviations and aren't necessarily only found on only G or D lenses. Just think of them as extra features added on to your lenses.
For example, the lense could be:
1. 70-300mm f/4-5.6D ED AF
2. 70-300mm f/4-5.6D ED AF-S
3. 70-300mm f/4-5.6D AF
These are all D lenses but they are different. (Please note that number 1 is the only existing lense. The other two don't exist at the present time but I use them here as an example.) This would be the same for G lenses. Lenses can last you a long time if you take care of them so if you can afford it then go with the one that has ED on it. The one without ED is the budget version. Whether you can live without the ED version is more of a personal preference.
If your camera can support both G and D lense then don't worry about which one to get but do look out for ED versions. That's the one you want.