Focus in the Dark

[Two23]

I shoot at night quite a lot, especially in winter. I'm using a 4x5 field camera and my lenses are f5.6. To focus in the dark I usually put a small flashlight on/by my subject, focus on it, then remove it. Sometimes I can't place a flashlight on the subject though, like a waterfall etc. I was wondering if a lasar beam of some kind, point at/on the subject might work? I'm thinking of distances of maybe 40 to 80 ft..


Kent in SD

[Bob Kerner]

The only laser beam I can think of that would be available to civilians would be a laser pointer. I think the point source of light would be too small to focus on, don't you?

Can you walk to the area? In other words, could you set up the camera, walk over to the subject and put a light next to it, focus and then go back and remove the light? Some chem stix might work.

Or could you set up the camera while it's still light, focus and then leave it and come back later? This sounds preposterous, but I just read a blog post by someone who routinely leaves his 8x10 set up overnight in the wild so he won't have to scramble to get it set up at sunrise.

Otherwise, at 80 feet I think you'll need a light with a big honking power source and beam; something like a handheld spotlight used on boats and a portable battery.

[BetterSense]

Laser pointers work very well. I even use them for tabletop photography to check focus. It's very easy to compare the size of the blur spot at different distances, when it can be hard to judge degree of defocus otherwise due to smooth surfaces.

[John Bowen]

My first choice would be the laser pointer. Should that not work, I would seriously consider breaking out the trusty 'ole crown graphic to take advantage of the camera's rangefinder.

Good luck,

[Bob Kerner]

Laser pointer from 80feet?!? Ok. If you'all say so. I've used them for astronomy and couldn't imagine them for focusing a camera. My bad, I guess.

How to you hold the laser and focus, or have you built some sort of mount onto the camera for the pointer?

[John NYC]

What kind of flashlight are you using currently? Flashlight technology has changed in the past few years... a lot.

[Two23]

I have a fair amount of experience shooting at night, but mostly with a Nikon D300 etc. and very fast glass. My preferred way to focus is to place a small 2AA Minimag on my subject and focus on the light. Sometimes I can't do that, such as photo'ing a waterfall at night etc. For that I try to find a spot where there is a gleam reflecting on my subject, but even that isn't fool proof. My main flashlight is a 3D Maglite. Generally that will do the trick, but not always. I'm usually a little hesitant out here shining bigger lights around. Local deputies think I'm deer hunting. I usually do have a rifle in my car somewhere, and the combination of a big light and an automatic rifle makes for some tedious conversations from time to time. I could try a laser pointer, they are cheap enough. I have a 1930s vintage handheld Kodak rangerfinder. I didn't think of using that. It would probably work if I could find an edge to dial in on.


Kent in SD

[ki6mf]

The other thing to do is check a depth of filed scale for your lenses. Preselect an f stop. The DOF scale will tell your where to focus at that f stop to get maximum amount of range in focus. Then use a flash light or laser pointer to illuminate the focus point. for a 90mm up to 150mm at F22 up to F 64 this will be fairly near the camera.

[Robert Hughes]

I sharpen my depth of file in post, until it's a razor.

[Drew Wiley]

Lasers or other point light sources work especially well if you can temporarily set a
reflective metal target at the intended focal distance. Obviously you cannot with a
waterfall, but specular reflective wet spots on rocks would work in an analogous manner.