How do you manually focus at night?

[adversus]

I was at a local pond that has a water fountain/fall in an attempt to shooing long exposure water during the night. Upon my arrival I found the spot I wanted to focus on darker than expected. As such I couldn't really see well enough to focus.

I ended up taking a 15 to 30 second exposure, then adjusting focus manually based on the previous shot, then try again. Here are the results.

How do others tackle this? I thought about bringing a high powered flashlight, using the flashlight to illuminate the subject for focusing, then going for the exposure.

Thoughts? Comments on how they DID turn out with my bizarre focusing technique

1:

2:

3:

 

[fokker]

I like the first two.

You're pretty much on the money with the flashlight - that's why AF at night will either use the built-in AF lamp (little red light in some cameras), fire the popup flash during focusing, or use the AF assist lamp on your external speedlight if you have one.

 

[IgsEMT]

Flashlight
I like #1, it's just over all a warm image to look at.
#2,3, honestly not to sure what I'm looking at.

 

[Vautrin]

you can just focus on infinity or use the hyperfocal distance...

 

[Amocholes]

I am a caver. I have a little P&S that I take into the caves with me. The auto focus has a hard time with this environment. I will often aim my headlamp at the object that I want focused. Allow the camera to focus (this could be done manually with a DSLR but I'm not taking mine into a cave). I then turn off the headlamp and snap the picture. I've gotten some pretty good results by doing this.

The flash will wash things out at close range. I've also gotten gotten some decent pictures by turning off the flash and using just my headlamp.

On a recent trip to Hawaii, I did take my Nikon into the Hana Lavatube. (a tourist cave). This was taken using a 30 second exposure with the camera sitting on a rock. The only lighting was 4 high powered LED flashlights used to "paint" the walls.