Night Focusing - DPChallenge Forums

01/22/2008 07:28:18 AM · #1

I was out taking some pictures last night and was finding it very difficult to get the focus right.

With exposures of about 30 seconds the pictures come out much brighter than it actually was (I've yet to upload them) but at the time I could only barely make out shadows across a lake.

I tried a few shots where I just adjusted back from infinity but whilst testing other settings (ISO/shutter speed/aperture) I didn't have time to do this all night. So does anyone have any tips on focusing at night, maybe a really really powerful torch? : P

thanks in advance.

Tez

Canon EOS-5D Mark II

Canon EF 85mm f/1.8 USM

01/22/2008 07:31:26 AM · #2

What I do is get the subject (if you're shooting a group or whatever) to hold a mobile phone or a lighter, or an illuminated watch near their face so the camera can pick it up. Once you have the focus, click the focus to Manual so it doesn't shift randomly and you're good to go.

A torch would probs work for landscapes but on a big enough scene can't you just set to just under infinity and use F13 or so?

Nikon AF Nikkor 28-85mm 1:3.5-4.5

01/22/2008 07:40:56 AM · #3

It was a landscape, but in the day I seem to find just a tiny bit back from infinity is more in focus (for what I was shooting). I might try using infinity then, I don't think my lens has any measurements on it so just all the way to the end?

electrolost

Nikon D200

01/22/2008 07:56:35 AM · #4

If you use a smaller apeture the less ya got to worry about focusing.

dwterry

Canon EOS-1D Mark III

Canon EF 24-70mm f/2.8L USM

01/22/2008 08:07:20 AM · #5

As you start moving to smaller and smaller apertures, please keep in mind Diffraction and the problems it causes.

Due to diffraction, you'll find that you actually have a "less sharp" photo out beyond f/11 than if you stuck to f/8 or f/11. Sure, you will have a greater DOF, with a smaller aperture, but diffraction eats into your DOF and makes everything less sharp. Plus, when dealing with long exposures, the longer it is, the more likely something moves (leaves in the wind, etc), creating additional blur.

With that thought in mind, I'll shoot f/22 to get a nice star effect on a light when I want it. But otherwise I won't go past f/11 without a similarly good reason to do so.

OdysseyF22

Panasonic DC-G9

Olympus 12-45mm f/4.0 Pro

01/22/2008 08:14:23 AM · #6

All my lenses focus best just a hair before the infinity mark on them. That's where I put them when I shoot at night. When possible, using a flashlight/torch to illuminate the subject can work, if the subject is near enough (or the flashlight bright enough). As [user]Tex[zuser] said, it's easiest to get enough light on it to use Auto focus, then switch over to Manual and leave it alone. But of course this isn't always possible.

Smaller apertures do help, as do wide-angle lenses, with a deeper DOF.

Canon EF 24-70mm f/2.8L USM

01/22/2008 08:21:03 AM · #7

Thanks David, that's really useful, I was out from midnight to past 2am last night trying out all sorts of different settings, it's the first time I'd used manual mode.

Cheers Brent, I'll try that.

gloda

Canon EOS-5D Mark II

01/22/2008 10:29:28 AM · #8

What I do in dark stationary situations where small apertures aren't an option is to point a laserpointer at the exact part of the image that is covered by the focus-point that is relevant at that moment. It works across a large distance and actually simulates spot measuring since the only light the camera can pick up on to focus is the tiny dot from the laser.
In moving low light situations (e.g. night clubs) my 580EX helps out by projecting the red grid. Obviously this isn't an option in landscape situations when there's nothing nearby for the light to bounce back from.

EducatedSavage

Canon EOS-400D Rebel XTi

Canon EF-S 18-55mm f/3.5-5.6 II

01/22/2008 11:30:21 AM · #9

The laserpointer is a brilliant idea! I read that suggestion somewhere else and have yet to try it, but it sounds brilliant.

What I've been doing is having someone hold a flashlight and point it back at me from the place I want the focus to be and focus on that light instead and it's actually been working pretty good.

Nikon AF-S Nikkor 28-300mm f3.5-5.6G ED VR

01/22/2008 11:39:17 AM · #10

Originally posted by EducatedSavage:

What I've been doing is having someone hold a flashlight and point it back at me from the place I want the focus to be and focus on that light instead and it's actually been working pretty good.

Unfortunately my missus wouldn't stand on the opposite side of a dark forest at 2am, I dunno...

:O

NikonJeb

Nikon D850

01/22/2008 12:19:06 PM · #11

Originally posted by EducatedSavage:

What I've been doing is having someone hold a flashlight and point it back at me from the place I want the focus to be and focus on that light instead and it's actually been working pretty good.

Originally posted by rob_smith:

Unfortunately my missus wouldn't stand on the opposite side of a dark forest at 2am, I dunno...

:O

I have that same scenario.....going under the ridiculous assumption that she would even be with me on a night photography quest, the idea of her standing across....whatever, to hold a light is pretty much out of the question.

That said, I've had some pretty decent luck just kind of "roughing it" and setting my manual focus just a "skoche" off infinity as

OdysseyF22 mentioned.

The long exposures help, too.

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