About to shoot sunrise in 3 hours. Need help for approx. calculations of exposure.

[Thomas Koba]

I´m about to shoot a timelapse of a sunrise in 3 hours. Have never done this before, and I plan to use 1 FPS on 4K on my scarlet.

I have not done any measurements or calculations yet, so I need some approximisation advice from you guys.

I´m no expert on sunrises, but I expect to be filming for 1 hour or so. I want to get the sun approx. 3 x width of sun above the horizon. Anyone know how long this takes?

And then there's exposure. If I expose for when it's black right before the sun starts to pop out from the horizon. How far into the blacks should I go, to protect my highlights? (Don't mind the sun blowing highlights, but I need a nice gradient sky. There'll be no ramping on the F-stops.

It's going to be a clear sky.

To summarize questions:

1. How long does this sunrise take, to go from below horizon to 3 times the width of the sun above the horizon
2. How little exposure should I start from, to get a little bit of texture in the mountains, but still protect the highlight for when the sun is up?

I´m planning on starting the exposure on the lower 20% of the histogram. Running with 800 ISO.

Am I in the ballpark, or what?

 

[Thomas Koba]

I´m on the northern hemisphere, if that makes any difference.

 

[Robert Hart]

My personal preference is to fix lens aperture for light levels likely at end of sequence and shutter speed you have selected. My personal preference was for about one frame every eight seconds or so but I was using film. My personal preference would also be to allow the recording to roll for much longer, say to when the sun is about one hour risen. In mountains, you will get some wonderful shadow travels which will start initially fast and slow down as the sun gets higher. I also shot my hills facing north or south which did not put the sun itself in the shot. I would be a bit wary of having a focused sun on my sensor for a timelapse as unlike film, there is no closed shutter to protect it between frames.

Allow time for the camera temp to stabilise and to do a black balance. As environmental conditions change after sunrise, the light will have brightenes so any sensor fixed pattern noise due to temperature change will be less apparent. I understand the Red camera family is pretty good in this respect anyway so I may be barking at shadows here.

Please take more heed of comments which follow mine as they likely will be more valid.

 

[paulherrin]

well, to start - you could try to use hdrx and max it out. you'd be surprised at how hard what you're trying to capture is - there are a lot of variables for correct exposure... do testing next time. the change from dark to light is absolutely huge... obviously. it's known as the 'holy grail'

you can try to do calculations from this starting point: http://en.wikipedia.org/wiki/Sunny_16_rule

or search around on some timelapse forums - http://forum.timescapes.org/phpBB3/index.php

 

[Thomas Koba]

Well, that didn´t work out well. Just as the sun was about to pop out, everything went totally foggy. So I have to try again.
But do I have to worry about the sensor? Maybe I should use another cheap camera instead, then (Canon 5D with Magic Lantern)?

 

[paulherrin]

sorry to hear that, thomas... check into the timelapse forums. i've found i have to babysit the lens right before the sun peaks over the horizon - often conditions lead to fog on the lens. i wouldn't worry about the sensor too much in this case, but as for now the canon with magic lantern gives you ALOT more control. i do all of my timelapse with the canon. make sure you do a lot of testing and know your equipment and your post. timelapse isn't easy - it takes patience and practice x 70... check out some forums, videos, tutorials, etc. and good luck!

 

[Antony Newman]

A1ex + team has really polished up ML on the 5D.

http://www.magiclantern.fm/releasenotes

Watching him review the Time lapses looked swish too (accelerated playback).

AJ

 

[oliver imfeld]

just did the same, timelaps sunrise with 1 fps: 800 iso, 1/50 or 1/48 (doesn't matter) f 22; let it roll, its a nobrainer; if you can turn hdr on, 1 stop

good luck, o

 

[George Butterfield]

I think the sun rises a distance equal to its diameter about every Eight minutes