Camera Labs

haii friends
i have nikon d 5100
it dont have a focus motor in it

i wish to buy a 50mm lens
how can i choose best one?
wht r the things i need to check b4 buying it?

plz help

You will need an AF-S lens if you want auto-focus capability. Your choices among Nikkor lenses are the 1.4 and the 1.8, each with strengths and weaknesses. I already had an AF 1.8D, so I elected to purchase the AF-S 1.4G when a local dealer finally received two of them. ( Please notice that the 1.8D will not auto-focus with your camera. ) Plenty of forum posts and reviews have indicated the AF-S 1.8G is an excellent lens, but none were available when I bought my 1.4G. Some feel the 1.4G auto-focuses too slowly, and compared to my 1.8D, there is a difference. My F6 does have a powerful focus motor, so I can chose faster auto-focus with the 1.8D, or a wider maximum aperture with the 1.4G.

Some who have compared the 1.4G and 1.8G prefer the 1.8G. I have never used the 1.8G, so cannot be of help in that regard, except to recommend reading the ample writings available on-line.

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Canon 7D/5D/40D/1D2N; Nikon F6, FM3A, & Coolpix A; Canon 40mm Pancake, 135L, 50L, 35L, pre-II 50mm 1.8, 100mm 2.8L Macro, 10-22mm EF-S, 28-135 EF, 400mm 5.6L; Nikkor 50mm 1.2 AI-S, 50mm 1.4G, 50mm 1.8D, 16mm 2.8D Fisheye, 180mm 2.8D, 100-300mm 5.6 AI-S; Tokina 17mm & 100mm 2.8 Macro

You've got options:

From Nikon:

Nikon 50mm f1.4G
Nikon 50mm f1.8G
Nikon 50mm f1.2 - let's discount that one from the word go!

From Sigma:

50mm f1.4

Then a few leftfield options:

Carl Zeiss 50mm f1.4
Carl Zeiss 50mm f2 Macro Planar
Voigtlander 40mm & 58mm which straddle 50mm


For the Nikons, the f1.8G is cheaper, slightly slower, focuses faster and is possibly slightly sharper. I'd go for that personally if I was buying new. (I went for the f1.4G as I got a mint 2nd hand example for a good price)

For the Sigma, the bokeh is nicer than the Nikons, the image quality sharper in the centre but soft in the corners, it's bigger and heavier. Also, you may have to hunt around for a good copy or send yours back as Sigma QC can be troublesome.

For the leftfield options above you have two manual focus lenses, but they both have their strengths. Ultimate sharpness and the f2 Macro Planar wins. Manual focus alone, let alone cost, will probably put you off. Voigtlanders are also manual focus - if 50mm is a bite too tight, and manual focus doesn't put you off, then the 40mm (dinky) is nice

So out of those main examples, I'd say:
CZ 50mm f2 MP - sharpest, best colours
Sigma - best bokeh, more of a portrait lens in effect, due to soft corners
Nikon f1.8G - best value and better across the whole frame than the Sigma

Cheapest is probably best for your requirements. If you're buying it, then it should be good out of the box (which is debatable with the Sigma - not bashing them, but I've tried several and not just the 50mm and they've had issues - that's enough to put me off)

Me - I'll be swapping my 50mm f1.4G for a Carl Zeiss 50mm Macro Planar

is it possible to focus manually if i buy a 50mm AF lens ( my camera don't have focus motor in its body )?

wht will be the result if i can focus it manually?

did it give good pics?

You can focus manually with any lens.

Nikon f1.8 and f1.4 D lenses will work, but only as manual focus.

They will give good pics, if your technique and eyesight are up to the task!!!!

i have another doubt
am just a beginner so this doubt may be foolishness to others


in kit lens (18-55mm) also 50mm is possible
so whts the benefit of buying 50mm lens separately?

i know 50mm lens give good bokeh effect

is there any other benefit?

Faster aperture = better low light performance.

If you are shooting at ISO3200, f8, 1/100th second with your 18-55mm then you could shoot at:

ISO1600, f5.6, 1/100th
ISO800, f4, 1/100th
ISO400, f2.8, 1/100th
ISO200, f2, 1/100th

Your prime lens will be stopped down a little at f2, very sharp, and considerably better image quality than ISO1600 or ISO3200 with the 18-55

+

Prime lenses are optimised for one focal length (obviously) while zooms are a compromise throughout their focal range. Obviously the compromise is lessened with more expensive pro zooms, and you pay the $$$ as a result. A cheap 50 is just that though, cheap.

"Bokeh effect", as you put it, is not automatically the preserve of a fast prime. At f5.6, closeup with your 18-55 a distant background will be thrown out of focus. Bokeh is generally considered to be the aesthetic quality of the out of focus areas. Some 50mm primes give nice pleasing bokeh, others less so. What you will get with a 50 f1.4 or f1.8 is the ability to make a subject pop from a background - your Depth of Field will be shallower.

For example, 50mm on a Nikon crop sensor DX camera body with a person 2 metres from you:

at f8, DoF is 51cm
at f5.6, DoF is 36cm
at f4, DoF is 25cm
at f2.8, DoF is 18cm
at f2, DoF is 12cm
at f1.4 Dof is 9cm

Now take another portrait with the person 1 metre from you:

at f8, DoF is 12cm
at f5.6, DoF is 9cm
at f4, DoF is 6cm
at f2.8, DoF is 4cm
at f2, DoF is 3cm
at f1.4 Dof is 2cm

As you can see, in lower light you can shoot better quality images due to the faster aperture. However you have to be more careful with your focusing as the DoF can get pretty shallow. There's nothing worse than a portrait where the eyes have just missed focus unless it's very intentional - you have to be careful with your technique