AV mode shutter speed too slow for sunrise timelapse (very low light)

[glimmer33]

Hello all!

Firstly I'm a bit embarressed to ask this as I'm sure its entry level stuff but I've posted in several other forums to work out what the problem im experiencing is and i now have narrowed it down to a simple question... I think..

I am trying to shoot a sunrise timelapse. At dawn when the camera is in AV mode, due to the low light it seems to be frezzing up when i go to take a photo. I realise now its not freezing up its simply tusing a long shutter speed to compensate for the lack of light.

The problem is, I see loads of sunrise timelapse tutorials and they all suggest using the AV mode due to the changing light conditions.  (I had to use manual mode with a low aperture in the end and halfway through once the sun came up my photos were all horribly over exposed)

How can i combat the low light issue in order to use my camera in AV mode for photos with intervals of 4 seconds?

At the moment i cant use it at dawn because the shutter speed slows up so much it makes it impossible to do a timelapse.

Any feedback would be massivly appriecated.

Thanks!

[Skirball]

Why are you using an automatic mode at all?  If you're doing a timelapse wouldn't you want it all to be at the same exposure, showing the sun come up and the brightness increase?  I'd use manual.

[glimmer33]

Yes. The problem is that as the level of light changes, there are very small changes that happen on digital cameras that cause a difference in exposure to the odd image here n there. What results is timelapse flicker when compiling all the images in post production.
There are two main ways to combat this one of them is shoot in AV mode so the shutter speed adjusts to the changing light and should reduce or eliminate the flicker effect or manually disconnecting the lens fro the body so the electrical contacts are uncoupled.
I don't want to do the second option at this stage as I'm a beginner, knowing me I'll drop the bloody lens or something!

I used manual this morning and halfway through as the sun came up my photos started to become over exposed as i had to set the aperture wide earlier in the morning when it was very dark.

No doubt you'd suggest changing the settings as the shoot goes on but not moving the camera is crucial to getting a decent timelapse.
Even just adjusting the aperture or ISO or shutter speed through the menu during the shoot will ruin the final outcome.

Thanks for all your responses though, really appreciate all the feedback.

[glimmer33]

If you're suggesting to have the everything set as if the sun had risen already through manual then just let the scene go from very dark to light then yes, that is something I am also thinking of trying out lol!

[ebiggs1]

Did you notice he moved the lens off contact?  I did not even know this was possible so you guys are way above what this old guy knows. I am not getting why full manual works as expousers change with each minute of the day.  It looks like to me that would cause a problem in manual too. Hmmm.....

I have made a very few TL shots but I admit this is out of my expertise.  Hope you do well with it.

[RobertTheFat]

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@Skirball wrote:

Why are you using an automatic mode at all?  If you're doing a timelapse wouldn't you want it all to be at the same exposure, showing the sun come up and the brightness increase?  I'd use manual.

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That was one of my suggestions, but it has the drawback of not mimicking the behavior of the human eye, which itself changes aperture automatically. The change of illumination in the course of a sunrise is a lot greater than it appears and can easily exceed the dynamic range of the camera.

[RobertTheFat]

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@glimmer33 wrote:
No doubt you'd suggest changing the settings as the shoot goes on but not moving the camera is crucial to getting a decent timelapse.
Even just adjusting the aperture or ISO or shutter speed through the menu during the shoot will ruin the final outcome.

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Maybe not if you did it remotely from a computer.

[Skirball]

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@RobertTheFat wrote:

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@Skirball wrote:

Why are you using an automatic mode at all?  If you're doing a timelapse wouldn't you want it all to be at the same exposure, showing the sun come up and the brightness increase?  I'd use manual.

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That was one of my suggestions, but it has the drawback of not mimicking the behavior of the human eye, which itself changes aperture automatically. The change of illumination in the course of a sunrise is a lot greater than it appears and can easily exceed the dynamic range of the camera.

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That's a good point, you're right.  I guess Av it is.

[Skirball]

Discussions like this are what keep me coming back.  I never thought about the difficulties with taking a time lapse in a dynamic exposure setting.  Luckily however, plenty have.  Looks like there is software to analyze the the variation in exposure and create a smooth transition.  Like so:

http://www.panolapse360.com/rawblend/

[glimmer33]

Hey!
So I went out lastnight to try and do a timelapse of the sunset.

It was mainly cloudy so there was no sun visible really, the morning had been clear skies - typical British weather!

I had the camera on AV mode as I wanted the shutter speed to adjust the the decreasing light.

So it was set to auto ISO. F-stop of 5.0

The first hour of the shoot was ok. Shutter speed was firing away with no problems.

The thing is once it became completely dark, I looked at the LCD screen and the images were coming out very light still.
The shutter speed was obviously over compensating for the lack of light but that was what I was trying to achieve as night fell!

Once it turned pitch black the shutter speed slowed right down do I had to lower the f-stop as low as it would go which was 4.0
Anyway The weather for tomorrow is clear so I'm going to attempt to redo my sunrise timelapse in the same place.

I'm just wondering whether to set the camera to AV mode or full manual and guess the settings needed for when the sun comes up and it is extremely bright.

(Also I experienced condensation on the lens last time so after some research in gonna have to wrap hand warmers around the lens with elastic bands to keep it warm enough to prevent it clouding up!)

What do you guys think?

[RobertTheFat]

I still think you should try Tv and auto-ISO and let the aperture float. Note that while the shutter speed can slow down arbitrarily, the aperture can't open arbitrarily wide and the ISO can't go arbitrarily high. So you shouldn't get the artificially bright result when it gets really dark. Remember that you don't care what the aperture is, but you do care about the shutter speed. So the shutter speed is what you should set manually.