Should I buy Canon EF 50mm f1.8 MK I

I find a Canon EF 50mm f1.8 MK I and my question is that I`m able to use with my EOS Rebel XT(350D), and it worth the money more than the MK II?

it is better made, and it will work ok, the question is how much more is it?

It will work with a XT, any EOS EF lens will.

Do you have the mkII version now? Do you use it a lot? If you can get a MKI for a good price then I'd say go for it but if not, there is nothing wrong with the MKII version.

Or avoid both f1.8 and go straight to the 1.4 version.

No, I don`t have the MK II version, it will be the first 50mm lens for me.

Just go for the 1.4

the mkII focuses faster but not as well built as the mkI. I think they are both plastics except that the mkI has a metal mount. If you can get the mkI for a good price sure. Otherwise mkII will just be as good and focuses faster.

The Mk I my g/f has doesnt appear to be plastic. It is a great lens, much better than the Mk II. I'd go for the Mk I if you can, otherwise a Mk II is good too. If you really wanna get into it, the 1.4 is better than both the 1.8's.

The Mark I is better built, and has a metal mount. It is heavier - 190g vs 130g for the Mark II, and it takes a different lens hood. It was introduced in March 1987, the Mark II came out in December 1990. optically it appears to be exactly the same - same number of elements and groups in the construction, and same 5 bladed diaphragm.
The Mark I is a bit of a collector's item, so you pay a premium to get one. this status is likely to continue, so you would probably get at least your money back if you sold it on.
But basically the optical performance is the same so i struggle to see the benefits of purchasing this lens. If you want to spend extra for a 50mm lens you are better of spending that bit more for the 1.4mm

MK I is really noisy. big turn off. and yes, nosyier than the MK II

MkI tends to sell for a lot more than it's worth,. unless you can get it for under 100.00 I[d say just go for the 50mm 1.4 USM and get all the advantages of that model.

Thank you all, I`m still not decided but I will try the MK I lens first and maybe than I`ll decide what`s next.

from an image point of view

(Mk1 = Mk2)<1.4

ie buy a new Mk2 or buy a used f1.4 for better image/low light/bokeh

remember, the Mk2 1.8 produces images way way way beyond its cost.....a real example of worth being much greather than cost !