adding one more lens 135 f.2. Is it worth the money ?

Just going off the images that are posted in the lens archive, I would say yes. I'm looking to save for that lens to shoot indoor volleyball and some portrait work as well.

worth every penny

yes man! Super lens!

I got the lens yesterday. I tried it on my kids, and today I took pics of them at ice skating rink! Nice! The only thing, I hav hard time focusing on both eyes, although both eyes are in the same plane.... can you tell me the trick ?

I just got mines yesterday too. I love the bokeh on just a few quick snaps, but it is really hard to hand hold at this focal length. It's ok when the shutter speed is really high, but around 1/60 I get a little worried.

Very true... but then you're hand holding a 135mm lens at less than half the normal shutter speed, so it should cause some worry... heheh

You want to use at least 1/125th, 1/160 or 1/200 or faster is better. It is a telephoto lens and doesn't have IS so it needs a higher shutter speed. You can make up for this using the wide aperture but as the OP has noticed, at f/2 it can be tough to get both eyes in focus. There is no trick to that I'm afraid other than REALLY getting both eyes into the same plane (if only one is in focus then they are NOT in the same plane) or using a narrower aperture for wider depth of field.