Low-light/night focusing tips

[CJK]

I apologize if this has been covered, but my search results were empty.

Does anyone have any tips about focusing during low-light/night shooting? I have used a high powered flash light before but that only gets me so far, and can get super frustrating quickly.

On that same note, now that I have discovered the focus stacking method, would that same technique work during these conditions? Focus closest object which is easy with a flash light, then progressively changed from macro to infinity?

Do these techniques of focus stacking and F-stop stacking work for night photography or is the longer shutter speed going to cause to much 'blur' (clouds and stars) for them to work?

Cheers!

[jcuknz]

It would help to know what equipment you intend to use becuase probably my experience with contrast detection is likely to be irrelevant to your situation ... with CD if there is any contrast AF snaps into focus and when I deliberately tried to stop it I had a hard job to find a no contrast area to place the focusing area on [ the target area perhaps in the middle of the screen].
Does your camera have a focus lock?
Before you do your idea of focus stacking it would be worth while checking your depth of field tables so you can conservatively arrange the focus point of each shot. There is a problem that often cameras these days do not have focus distance marked on them and you are expected to use AF or manual focus the lens.
As to you other idea it would depend on the speed of the clouds.
Since most cameras have a 'black frame' system which they automagtically do with slower shutter speeds, on one of my cameras this cuts in at 1/15 second, you could find considerable differences between exposures as the camera makes the exposure and then the same length BF 'exposure' before you can take the second frame. etc.

Assuming that you are working with digital I would remind you that you have instant review which is very useful for finding out if something will work or not. When working in a non-deadline situation I do not bother to work things out, say using remote flash, but make an exposure and adjust from its result. I had this siutation with the start of a race recently, 6am in the dark, and took a few trial shots of the crowd prior to the start ... only problem I was mis-informed as to which way they were going to go and following the start they all ran away from me

[shreds]

Jcuknz,

That made me howl with laughter, maybe my overactive imagination, but your face must have been the picture of the day!

Back on topic, I do a lot of night photography and always work on manual focus and everything else, the same as I did thirty years ago. Since in those conditions I normally work around f8-11 the DoF is usually reasonable and if I need more then I adjust accordingly. If focus is crucial, I usually have a tape measure or Leica digital measure with me that will provide an accurate distance. The Leica Disto D5 laser will go to 200 metres with an accuracy of +/-1mm which is more than enough for any photography project that I do.

[Colin Southern]

Hi Chris,

There are a few techniques, but it does depend on what you're doing and how you're doing it to a large extent.

- If you've got your composition early and are just waiting for the best light then you can auto-focus then switch to manual focus - and just leave it there (I often reverse the lens hood so that it covers the focus ring so I can't bump it accidentally in the dark.

- If you're photographing lights in the distance then you can manually focus with liveview -- just go for whatever gives the smallest dots.

- If you calculate hyperfocal distance then you can use a distance scale on your lens.

- Or as a last resort, just use a narrow aperture - long exposure - focus at infinity (per the scale) - and just let the DoF take care of it (checking the image after the exposure) (magnified).

[CJK]

jcuknz:

Sorry, the would have been helpful. I have a Nikon D5000, I use the lens that came with it, a AF-S Nikkor 18-55mm (1:3.5-5.6G) and a AF-S Nikkor 70-300mm (1:4.5-5.6G). As far as focusing, I tend to be in manual the entire time, although with the 18-55 lens there are no markings so its more of a guess, the 70-300 does have the markings.

Not sure what you mean by CD, but I have used AF and it has worked occasionally, as long as there is something withen the reach of the flashlight. Yes the camera has focus lock, although I have never used it and really only read about its uses once.

Also, BF I assume is 'black frame', can you explain that?

[CJK]

Shreds:

Have you ever got to a location and set up before losing all natural light and got your focus that way?

[CJK]

Colin:

Good tip about the lights, I'll remember that although I usually only have natural light to deal with.

As far as the narrow aperture, I have never tried that, I have always been wide open so I could speed up the shutter time to reduce noise.

I guess with the DoF, I was curious about getting lake rocks at 1-5 feet in focus as well as the mid range of the lake and the mountains in the distance all in focus. I've seen the layering techniques done on how to do that but just wasn't sure if you could do that during night photography.

[shreds]

In answer to your question, no. Whilst I might have a good idea of the location beforehand, I will usually shoot from the hip and work on what I have on the night.

(CD = contrast detection, its how your camera focuses. It looks for a sharply differing contrast in the scene eg a black and white edge and then works it magic from there. Its also the reason why that kind of focusing doesnt work on the sea or snow or other scenes where there is no contrast. Try it out, try and focus on a bland wall, then move the lens towards something with a sharply contrasting edge and just watch it latch on).

[Colin Southern]

As far as the narrow aperture, I have never tried that, I have always been wide open so I could speed up the shutter time to reduce noise.

If you're at your base ISO - and getting a good exposure - noise isn't really an issue unless you're exposing for many tens of minutes.

I guess with the DoF, I was curious about getting lake rocks at 1-5 feet in focus as well as the mid range of the lake and the mountains in the distance all in focus. I've seen the layering techniques done on how to do that but just wasn't sure if you could do that during night photography.

At 1 foot you'll be pushing it, but with a wide-angle lens you'll be able to get close. This one is probably a good example - shot at F16

[CJK]

Gorgeous shot Colin, love it, I tip my IPA to you good sir.

So F/16, how long was that exposure and ISO? I usually do try to keep my ISO down around 200, try not to clip 800 ISO. I will start experimenting more with a narrower aperture. Thanks

Did you use a polarizing filter to get the rocks beneath the water to show?

[Colin Southern]

Gorgeous shot Colin, love it, I tip my IPA to you good sir.

So F/16, how long was that exposure and ISO? I usually do try to keep my ISO down around 200, try not to clip 800 ISO. I will start experimenting more with a narrower aperture. Thanks

Did you use a polarizing filter to get the rocks beneath the water to show?

Thanks Chris - just one of a few I've taken over the years.

That image was exposed for 2.5 seconds @ ISO 100.

For landscape - especially when shooting into the light - you need all the dynamic range that the sensor on your camera can capture - and that means shooting at your camera's base ISO. Higher ISO settings use progressively less and less of the sensor's range - so the higher you go the less dynamic range you'll be able to capture and the closer you'll be operating to the noise floor (so exposure is critical). For this kind of work you'll need to have a good tripod though.

No - I'm not a big fan of polarisers (I've got 2 rather expensive ones and I NEVER use them). They're not particularly effective (or necessary) when shooting into the light and generally cause more issues than they solve with wide-angle lenses. I did use a 3-Stop hard-edge Graduated neutral density filter on this shot though.

[CJK]

Thanks for the info, did the graduated neutral density filter take the glare off the water revealing the submerged rocks? I guess the only way I know how to remove reflections from shallow water is a polarizer.

[Colin Southern]

Thanks for the info, did the graduated neutral density filter take the glare off the water revealing the submerged rocks? I guess the only way I know how to remove reflections from shallow water is a polarizer.

No - GNDs attenuate a brighter portion of the scene (in this case the sky) so that either (a) the sky doesn't blow, or (b) the foreground details don't fall into shadow.

Whether or not you can see into water depends on the angle of the light hitting it. Polarisers are - in my opinion - over-rated. Not everyone agrees with that, but that's how I see it. With wide-angle lenses like this, all they achieve is an uneven sky.

[jcuknz]

Chris
CD stands for Contrast Detection and I don't think you have it as most DSLRs use Phase Detection. CD seems to have an advantage that whatever the level of light if it spots the faintess degree of contrast it will focus on it. I played around one night out in my suburban street with a line of street lights down one side and the only place it didn't snap into focus was under a parked car lit by street lights.

Black frame is where the camera makes an exposure of the same duration as what you took following your exposure but with the shutter closed. It then compares the two images to reduce the amount of noise. So for every exposure you make there is a delay of the same duration plus presamably a short time while it does its magic ... I have not measured it but just wait as the camera gives me a countdown on the LCD/EVF as it makes the BF.

The quetion to me is as to if your lens has focusing distances marked on it and does it stop at infinity or go past ... that affects some of the advice you have been given. Otherwise you need a long tape measure or guestimate.

Building on your own idea of focus stacking, if there is no movement in the subject then you might be able to walk out to the distances you have worked out from Depth of Field tables and place the torch facing the camera or better have somebody do it for you :)

A further idea for you is 'Painting with Light'. With film which doesn't build up noise with long exposures it was possible to open the shutter with the camera on a firm support and walk out around the subject matter and use a flash light or even just a powerful torch to light up different keys part of the view ... making sure the light doesn't even shine back towards the camera.
I have only had cause to do this once back in 1954 when the USAF sent one of their planes to New Zealand for the first time.
Headwinds delayed it so it was dark before the official doings were over and the boss and I were free to get a shot of the plane itself, the one the paper used. I placed my Speed Graphic on the ground and walked around the front of the plane shooting off flash bulbs according to their guide number and the aperture I had sent the lens to. The boss did the same with his electronic flash unit but unfortunately his camera, a Rollieflex, was perched on a silly lightweight tripod and with the wind blowmg he got camera shake. My shot was sharp but the plane has flat tires from curvature of the airfield cutting off the bottoms.

So wind and what sort of tripod you have is something else to think about ... it may be awkward but it can help considerably if you do not use the centre column but just the basic three legs.

With digital and noise from long exposures I believe it is a better idea to shoot a separate frame for every flash and combine in editing using layers but I have not had the need to do it yet. It could be an idea to set the camera to one second or bulb and have an assistant open the shutter on your command/ count down as a photographer did at the Cumbres and Toltec Scenic RR 40th celebrations back in 2010 for a group of photographers ... I shot from behind to his flash to show him, with the broad brimmed hat and what was going on.


All I and the others had to do was open my shutter to his countdown after he gave us the ISO and aperture to use. There were a whole lot of Canikons on tripods off to the left which helped to avoid blurred engine headlight etc

[jcuknz]

On another thread, don't think it was on CiC, a photographer was wondering about dark marks across the ripples of the sea and it seemed pretty obvious to me that it was the reflections of dark clouds as opposed to breaks in the cloud. We could see similar cloud breaks in the top of the photo and my estimation of angles made me think the broken cloud continued toward over his head.

I suspect something similar with Colin's photograph that the bright reflections come from the break in the cloud and very nicely Colin organised the pool in foreground to reflect the dark cloud which permits us to see into the water and the rocks. If there is no light reflected then you don't need polarisers which is applicable to photographing objects through glass.

[Colin Southern]

I suspect something similar with Colin's photograph that the bright reflections come from the break in the cloud and very nicely Colin organised the pool in foreground to reflect the dark cloud which permits us to see into the water and the rocks. If there is no light reflected then you don't need polarisers which is applicable to photographing objects through glass.

Not quite.

With any reflection, the angle of the reflection equals the angle if incidence; thus the water close to the camera (keeping in mind this was with a wide-angle lens so the angle is actually a bit steeper than it looks) is reflecting the sky that's more overhead - and there's no incident light in that portion of the sky - thus no glare. As you follow the water further back though you'll see quite clearly where the angle is inside what we call the "family of angles" and starts reflecting the light from the setting sun -- and that's where the glare starts (and continues).

[jcuknz]

Whoever tidied up message 14 for me thankyou very much ... I was having a lot of trouble last night trying to get things to work

[Colin Southern]

Whoever tidied up message 14 for me thankyou very much ... I was having a lot of trouble last night trying to get things to work

Um - nobody that I can see. All 5 versions are all yours