Which is better for a Nikon d5100? 50mm 1.8g or 1.4g?

Which is better for a Nikon d5100? 50mm 1.8g or 1.4g?

I own the 50mm f/1.4G. Either one will work. The 1.4G is 2/3rds of a stop faster but it is not really that significant for most purposes. If you are on a budget, the f/1.8G is sufficient, and in some ways better.

Just make sure you don't buy the D version or it will not autofocus on your camera.

I shoot a 1.8 on my Canon and it does everything I want… And, even with Nikon, it's a much less expensive lens.

I'm pretty sure the D5100 wouldn't care whatever is attached to it. Aperture size setting depends on what the photographer wants to achieve. Then again, the maximum aperture size of a lens depends a lot on how fat the wallet of that photographer is.

F/1.8 will do although there's a world of difference between that and f/1.4. If I'm wrong however and you really are talking about something then may I point out to you that the the 50mm lens weighs more than just 1.8 or 1.4 grams.

It depends on what you are trying to do, but for 99% of people I'd say the f1.8 is good enough. If it is a portrait lens you are after then the 50mm f1.8g is a great lens for that.

If you are always working in very low light then the f1.4g might just be worth it as you will benefit from a brighter viewfinder as well as having the ability of shooting at f1.4, but don't forget that the depth of field will be very limited at f1.4. Of course, that might be just what you want! It is hard to know if you don't tell us what it is going to be used for.

I suspect though that the 50mm f1.8g is all that you need. The other question is do you actually need a 50mm lens or would you be better off with the 35mm f1.8g?

The 50mm was the "standard" lens on 35mm cameras because it more or less had the same angle of view as the human eyes. A lot of people still go for that lens on the same advice, however the direct equivalent for a DX camera like the D5100 is actually the 35mm f1.8g because the DX sensor size is only 2/3 the size of a 35mm film frame.

So, if you really need to work in very low light, go for the 50mm f1.8g. If you want a portrait lens then fine, go for the 50mm f1.8g, but for something a bit more general purpose the 35mm 1.8g would be worth considering.

One more lens that might be worth considering is the 40mm f2.8g DX Micro lens. Micro is Nikon's name for Macro or very close up. That would not be as bright, but it is a very sharp lens and would allow you to get some very good close-ups. On most DSLRs I wouldn't recommend a macro lens as short as 40mm because it is very easy to block your own light, but with the swivel screen of the D5100 you should be able to get close without hitting that problem too often. The 40mm would double as a good, sharp, general purpose lens, but obviously won't have the wide aperture advantage of the f1.8 lenses. (The 60mm f2.8 AF/S lens is better for macro, but quite a bit more expensive).

For not much more than the cost of the 50mm f1.4 you could choose 2 of the other lenses…