DAY-NIGHT time lapse

[Lee Kelly]

Anyone keen to share some clips with tips about shooting time lapse from day to night?
I shot this amazing sunset over sydney skyline the other night and it looked great. went from hot white arvo sun to amazing orange/purple sunset to dark sky which is perfectly natural however Sydneys city skyline is also amazing with all the bright lights and the harbour and once that sun went down my settings were too dark to capture the city lights.
i was shooting 1 frame every 5secs manual iris set to expose the bright oranges of sunset but once it got dark between frames i tried to slow my shutter down add gain etc but this made it look like rubbish! once played back at 25fps the first 3/4 looks great until i tried to compensate for the low light of night time cityscape.
Id love to learn how to make the transition naturally. ive heard some guys will shoot as i did to capture the magic moment of sunset and then later re-set their settings for the nightime stuff and in post just dissolve the two clips to make a seamless timelapse however maybe someone knows a trick for in-camera techniques.
wish i could show you my clip as i was pretty proud of it but i have noidea how to do that right now.

[Ryan Farnes]

I've also wondered about these kinds of things. I'm about as stumped as you are though. With the light changing that much there has got to be some sort of workaround.

The transition between 2 shots at different iris settings sounds like it would work best...but yeah...dunno

[Stuart Graham]

I am in the same boat. I want to photograph time lapse spanning day to night. I don't want the night shots to be pitch black though. Even if you bracket the shots it will look odd if the video switches from one exposure setting to another.

Anyone know how to do it?

[Stuart Graham]

I just read in a random internet article that auto iris is the way to get decent exposure for day-to-night time lapse.

Use of auto iris in conjunction with fixed focus, fixed shutter and auto ISO I suppose would be best.

I imagine the key is to try and use the longest exposure possible during the daylight, then as darkness falls the camera will open the iris and increase ISO to maintain exposure. Though having auto ISO will increase noise so I'm not sure it's a good idea to use auto ISO.

Fixed shutter is important to prevent changes in motion blur for moving objects.

I'll give it a try if the weather improves!

[Lauri Kettunen]

The trick I've used to tackle this kind of situations is the AEB-mode of Canon still cameras that automatically takes also over and under exposured shots. The amount of over and under can be adjusted. So, say if you set exposure to -3, 0 and +3 stops, then in post you can effectively have 6 stops of relative difference in exposure between day and night.

The over and under exposured frames also makes it also possible to create high dynamic images and this also somewhat solves the issue Lee has in mind.

In all cases some manual work is always involved.

[Stuart Graham]

Weather turned out to be okay today, apart from being rather cold and windy so I had a go at photographing a large building as night fell and the street lights switched on. With my Canon EOS 400D SLR and 17-55mm lens I used:

Aperture priority mode
F5.6
ISO 1600
Manual focus
17mm focal length

PCLix intervalometer set to record images every thirty seconds

Initial shutter was 1/4000 of a second during broad daylight, final shutter was about 4 seconds in the dark. I chose shutter priority because the camera wouldn't be able to get a bright enough image after dark in aperture priority mode even at fully open aperture with ISO 1600.

I've converted all the images into a video in 1080 HD resolution and noticed a number of problems with the animation:

1. The color balance became incorrect as night fell and the sodium street lamps came on, this caused overexposure and a very orange image.
2. During daylight the image suddenly changes from bright to dark to bright again as clouds pass over the sun making the footage appear as if it is not smooth but jerky.
3. During daylight with a fast shutter the people walking past didn't blur so the animation looks stuttery as they teleport from position to position.

Anyone know how to get around these problems during the actual photographic process?

Ideally I would use a longer shutter speed during the daylight to give the images more motion blur and make the animation look smoother. But it's tricky to do this as 1/4000 shutter and F5.6 was the widest aperture I could use during the daylight. Otherwise night exposures would be really long. It's quite a mystery as to how to maintain high motion blur, reasonable colour balance and good exposure for day to night time lapse.

[Lauri Kettunen]

Originally Posted by Stuart Graham

1. The color balance became incorrect as night fell and the sodium street lamps came on

I'm afraid there is no simple solution, but few things to try.

1. Did you try the "Match color" tool in Photoshop? That's a tool to make colors of different images to match.

2. White balance is just meta data, so adjust the white balance in Adobe raw importer when you first open all day time images. Then open one of night time images and set a new white balance etc. in the Raw importer. Thereafter open in batch all night time images. Perhaps you may want to make some manual adjusting with the image taken during dawn exploiting "Match color".

3. To blur you need an ND filter which you have to remove/change between two shots.

Finally, the ISO setting is also meta data so better to keep it on the nominal value of the sensor. In practice you loose quite a lot of bits when the value is increased.

[Stuart Graham]

Thanks for the advice Lauri!

The match colour option in Photoshop worked really well. However, my footage still flickers because of the sudden darkening and lightening of the image as clouds cross the sun. I guess the best workaround would be to take images on an overcast or cloudless day. Might try and correct those images in Photoshop, is there an easy way of doing that? Perhaps the shadows and highlights option would work?

Sounds a bit tricky to change the ND filter without getting a sudden change in exposure. Guess you would have to correct for it in Photoshop?

I didn't use RAW images due to lack of memory card space (I took over 700 images). RAW would give much better results but a lot of processing! I couldn't face all that RAW conversion.

[Lauri Kettunen]

Originally Posted by Stuart Graham

However, my footage still flickers because of the sudden darkening and lightening of the image as clouds cross the sun.

If the cloudes are above the sun only for a few frames, you could try to increase lightness. The problem is that a big change in lightness and contrast is distracting. But although you increased lightness of one or two frames and they appeared bit akward as still images, it is still difficult to spot them in a video stream.

Originally Posted by Stuart Graham

Sounds a bit tricky to change the ND filter without getting a sudden change in exposure. Guess you would have to correct for it in Photoshop?

Yes, but if you open the files with the raw importer in batch, one can set the exposure to counterbalance the effect of the ND filter. If you change the filter twice while shooting, this implies you just have to open the files in three different sets. A challenge is to change the ND filter without moving the camera at all. Heavy tripod etc. turn out to be useful in such cases.

Originally Posted by Stuart Graham

I didn't use RAW images due to lack of memory card space (I took over 700 images).

Yes, I recognize and appreciate the problem.

[Stuart Graham]

Thanks again Lauri. I'll have a go at correcting those problem images. Haven't got any ND filters for my SLR camera, but my XH A1 camcorder has two. Thing is, I don't think I can control it with the PCLix intervalometer :( Though I haven't tried...