How to achieve proper focus of stars at night?

[wedding photographer]

I would like to take some photos of stars at night. I have found the location. No problem., I have to keep an eye on the alligators while I am doing this because the location is in the Everglades. No problem. The only problem I am facing is that I have hard time focusing at the stars because the viewfinder is black. (It is 1:00am at night after all.... )

I manually focus at infinity and the stars are out of focus.

I have tried to use the screen in video mode after increasing ISO. No luck. Even the screen on the back of the camera is dark so I am not be able to see the stars for proper focusing.

My question: How do you focus in total darkness? Did I miss something?

[wfooshee]

First thing to consider is that any exposure over 10 seconds will show streaking, which you may be seeing as a focus problem. The longer the lens, the more visible the streaking. Second, your lens (for manufacturing tolerance, just to make sure it can reach infinity) may actually be able to focus beyond infinity, so just cranking the focus over to the stop may not be what you want. In my own feeble attempts at astrophotography I've never been out of sight of something artificially lit, so I pick a distant light and focus on that. A few mile is effectively infinity for equipment of dSLR size. You get something a few hundred inches across to gather light, it'll be a different story. From my back yard, the full moon near Jupiter, January 14 of this year: Jupiter is the 'star' above and left of the moon, and Orion is plainly visible. From a session a group in my local photog club had, the Milky Way from a beach near here, dark but still not far enough away from lights:

[wfooshee]

Edit button just gives me a spinny wheel..... Carriage returns got yanked somehow, I was going to fix, and I was going to add exposure info. The moon/Jupiter was only 1 second at f:3.5, ISO 400, and boosted just a little bit in Photoshop. The Milky Way shot was 30 seconds at f:1.4, ISO 200.