[slip]

In your opinion, what is a good used lens that would be the sharpest wide open (at least F2.8) low light/portraits... manual is good too!

any opinions welcome as long as it doesn't cause a divorce

cheers

[twitch]

There are many many possibilities, but without knowing your budget and focal length preference (50 too short for instance?) all you'll get is a random listing of lenses.

[paperbag846]

If you want the sharpest at lower apertures I'd wager you can't do better than the FA 43.

If you want a longer focal length, DA 70, FA 77, or D FA Macro 100.

[BigDave]

If manual focus is OK, then a nice 50mm 1.7 or better (1.4, 1.2) should be good. You can pick these up all over the place for a song (especially the f1.7 lenses). On digital this becomes the equivalent of a 75mm, a nice focal length for portraits.

[RioRico]

I have an M42 Sears-Tokina 55-135/3.5 that cost all of US$8 shipped, and is quite sharp wide open. If that's too cheap for you, a Super Takumar 55/1.8 might cost US$50, and its twin the ST 55/2 with the same optics but a slightly tighter aperture might go for US$15. A Helios-44 58/2 might cost US$35 and is pretty nifty. For easier usage but more money, the A50/1.7 is super-duper. For working further, almost any cheap 135/2.8 will be fine. For a small group, try a Vivitar-Komine CF-WA 28/2, probably well under US$50.

NOTE: You didn't specify what you mean by 'portrait'. Full body, 3/4, head & shoulders, facials / headshots, eyes only - what? Shooting close, medium, far - how? In-studio, in parks or back yards, on the street - where? I've shot portraits at 10mm and 1000mm. Different focal lengths are appropriate for different situations. 'Portrait' is a tactic, not a specification.

[Emacs]

D FA Macro 100.

Please, not again. It's macro, macro is not for portraits.

[lguckert79]

this i have found to be false you can use a macro lens for portraits and they do work really good in my opinion but, in my suggestion i use a old pentax 50mm f2 A lens u can get them pretty cheap to from like 20-50 usd

[jaieger]

Please, not again. It's macro, macro is not for portraits.

Simply because it is designated a macro lens doesn't mean it can't be used for portraits .

In fact, I've found that since it's designed with stopped-down bokeh in mind, and is as sharp as can be, it has a great combination of smooth bokeh and the detail retention attributed to macro lenses. Sure you won't get the dreamy look from, say, a Super-Tak 50 wide open, but not every portrait needs to have that. Plus it's nice to have the ability to have the detail if you want, and do some post on it if not, instead of wishing it weren't so soft.



EDIT: to the OP, I agree with paperbag - wide open and relatively budget friendly (compared to some other options), the FA43 is hard to beat for (center) sharpness wide open. Off-center is okay too, but once you get towards the edges it might not be as great until 2.5 or 2.8 (as the center). Other cheaper options are old manual/screwmount lenses, the Super-Tak 50/1.4 comes to mind (1.4 is soft unless exact-exact-exact-super-exact focus is nailed, also very sensitive to fringing I've found, whereas at f2 (still quite fast) is pretty sharp already). Or, maybe even the DA L 35mm f2.4, which if you're using wide open, has pretty nice bokeh (the fewer aperture blades don't come into play wide open), and is pretty damn sharp.

[Eagle_Friends]

For something cheap that get the job done, try a M 50mm f1.7

If you don't mind manual =]

[Pentaxor]

too many to mention.

[freewheeler]

A50/1.7 @2,4/2,8 is great.
Helios44 58/2.0 is special wide open.
K55/1,8 @4.0 is sharp all across the frame.

[hoanpham]

too many to mention.

That's right ;-)

Wide open or equivalent stepped down?

The best oldies sharpness, colors and contrast are excellent at one click down.:
K50f1.2 step down one click to be f1.4, at portrait distance.
K85f1.8 step down one click to be f2.0, any distance

Portrait with bokeh and soft skin:
All primes, wide open

[m42man]

You need to be careful about DOF when talking about portraits. For instance, if you're thinking of a classical head-and-shoulders portrait, then you'll need to stop down to at least f8 in order to ensure most of your subject is in good focus (f8 would give you about 5 inches DOF).

On the other hand, for a head and upper body shot (taken either from twice the distance or with half the FL), you'll be OK with f2.

Incidentally, if you want the most realistic sense of perspective, you would need to be only 3-4 feet from your subject (choose the FL according to how much body you want to include; 50mm would be OK for a head-and-shoulders portrait).

For a greater camera-to-subject distance, you'll find the subject's features will appear somewhat flattened (depending on how far away you are).

[Spotmatic]

If manual focus is OK, then a nice 50mm 1.7 or better (1.4, 1.2) should be good. You can pick these up all over the place for a song (especially the f1.7 lenses). On digital this becomes the equivalent of a 75mm, a nice focal length for portraits.

+1 and it sells for little $$$.

[Lowell Goudge]

In my opinion, if you want sharp, take the K135F2.5, if you want soft, take the K105F2.8