50mm f/1.8G vs Micro 40mm f/2.8G

[Nikoner]

Hi guys, I've a D90 + 18-105mm and am saving up for a new prime lens. I've read that they make you think more about composition because you can't zoom and have to move yourself in order to recompose. Plus they're much faster than my kit lens... So I thought a prime lens could help me in my photography. I want a general-purpose lens that could be used for portraiture, close-ups (but not real macro), maybe street photography, etc. I've been shooting mostly landscapes so far but I'd like to get better at other shooting genres, too. The Micro Nikkor 40mm f/2.8G would be fine for close-ups and general purpose but I'm thinking it might be a bit too short for portraits. Am I right? On the other hand, the 50mm f/1.8G is better for portraits and has a larger aperture but might not be good for other general photography. And another question - if the micro lens is okay for portraits, too, then will the bokeh difference between f/1.8 and f/2.8 on these two lenses be noticeable?
I guess some of you might suggest me to get both lenses but I'm a student and have a limited budget, plus the standard of living here in my country is lower than in Western countries.
Thanks in advance for your replies

[OsmosisStudios]

I have both the 40 macro and the 50 (though 1.8D). I find the 40 to be an excellent general purpose lens, but it's not quite the same as the 50: believe it or not, the difference of 10mm is substantial.

If you're looking seriously into portraits, I'd suggest opting for the 85/1.8 instead of the 50: its just a touch short. having the 40 and 85 would also give you a bit more variety.

It is, unfortunately, substantially more expensive. The 40 will run you about $300, where as the 85 will run about $450. The 50/1.8G is only abut $225.

If you can only afford one, get the 50. If you can afford both, get the 40 and 85.

[Nikoner]

Yeah I've read that the length of 85mm is even better on DX bodies but I'm not really looking seriously into portraits. Thanks for your reply

[Nikoner]

Any other opinions? Which is the better do-it-all lens?

[ravncat]

As prime lenses they're both pretty specialized. In your case, the 50 is best suited to night shooting and the 40 is to macro. While both can be used pretty general purposely, I think if you're really looking for versatility, you should look at something like a 17-55 2.8 zoom, It's going to give you alot of framing versatility and at a good compromise speed, but added weight (if the 40mm is on your list, 2.8 is ok, or you're looking at macro capability.

Of course - one of your goals is to learn via the tool of a prime, ie, framing, forcing yourself to move around (so you learn about perspective) and usually ability to control depth of field with the wider aperture. You don't "need" a prime to do those things, you can actually do quite a bit of that with a cut out card board square, like an old 35mm slide without film in it. The depth of field control, a fast aperture is helpful for, at some point, you may realize that choosing where to shoot from should come separately from choosing the framing. Primes limit your options, and you can indeed learn a lot from working with that constraint. I myself use primes, but I have a bunch, so that I can choose the focal length I want - often times a zoom would be far more practical - but I don't mind changing lenses.

If you're looking for small size and cost, a prime is a good way to go. Of those two (40mm macro and 50mm 1.8) Which is more versatile, is a tough question. The macro is more versatile in an overall subject kinda way, it'll do everything from landscape to macro - but it's optimized for macro of still life, insects and lighting get tough due to lens to subject distance, but such images are possible. While the 50mm is more versatile in a light kinda way - it's almost 2 stops faster. (1.4 would be 2 stops). If you're doing lots of available light and shooting way into the evening and not using a tripod or flash - the 50 is a better choice for you.

So simple questions you need to answer,

1.Which focal length do you like better?
2. Do you want to focus on light versatility or "subject" versatility?

One final note - if you're willing to sacrifice some image quality in your macro (sharpness, distortion, chromatic abberation etc) , you can invest in extension tubes, close-up filter attachments or a lens reversing ring, and use them with your 50mm lens to get into the macro world. Each of those three options are inexpensive and can be found in the 10-100 dollar range, depending on where you look, used or new, major brand or not)

[OsmosisStudios]

Originally Posted by ravncat

I think if you're really looking for versatility, you should look at something like a 17-55 2.8 zoom,

So we're ignoring the $1000 elephant in the metaphorical room? Sorry, no dice.

Between the two, I find myself reaching for the 40 more often. Its just that much wider that it gives me a bit more versatility in framing. That being said, I've basically relegated the 50 to film use and am aiming for an 85... but I'll wait for an updated AF-S/1.8/G version.

[ravncat]

Originally Posted by OsmosisStudios

So we're ignoring the $1000 elephant in the metaphorical room? Sorry, no dice.

Sigma and Tamron versions are between half and three quarters that price yeah? Going used and you start to get into that 400 dollar range. Viable options maybe, compared to the 85mm.

[sk66]

Prime and "do-it-all"? Doesn't exist. A 35mm would be considered "normal" on DX. The 40 is closer to that....

[Nikoner]

Thank you for your comments. I'll probably get the 50mm.