Time Lapse sunset exposure

[Steve Larsen]

Hi everyone, I recently purchased a Konvas 2m / 35mm camera from russia and have it set up with a Tobin time lapse motor. I am looking for advise on how to expose a time lapse shot that starts an hour before the sun goes down to an hour after the sun has gone down with the sun in the picture. I am shooting at a 10 sec interval, trying to get 30 sec @ 24fps.

 

If your interested in the Konvas camera I have pictures of mine online @ www.konvas.info

 

Steve Larsen

[Stephen Williams]

Hi everyone, I recently purchased a Konvas 2m / 35mm camera from russia and have it set up with a Tobin time lapse motor. I am looking for advise on how to expose a time lapse shot that starts an hour before the sun goes down to an hour after the sun has gone down with the sun in the picture. I am shooting at a 10 sec interval, trying to get 30 sec @ 24fps.

 

If your interested in the Konvas camera I have pictures of mine online @ www.konvas.info

 

Steve Larsen

 

 

Hi,

 

My usual starting point for time lapse is 50 asa /6 seconds exposure/ND 3.0 (10 stops) T5.6, giving 1 stop over exposure to the sunny F16 Rule. You may want to open another stop as you are starting 1 hour before sunset.

 

Stephen

[Steve Larsen]

Hi,

 

My usual starting point for time lapse is 50 asa /6 seconds exposure/ND 3.0 (10 stops) T5.6, giving 1 stop over exposure to the sunny F16 Rule. You may want to open another stop as you are starting 1 hour before sunset.

 

Stephen

 

Hi Stephen and thanks for the advise.

I am wondering the reason you expose for 6 sec ? ( I thought my Min expousre of a 1/2 sec might be a problem, I guess not... )

Do you ever pull the stop and/or pull ND as the suns going down ?

 

Thanks in advance,

 

Steve Larsen

[David Venhaus]

You might try shooting some test rolls with a still camera, bracketing the exposures, of course and writing down all the info. while doing that, then figuring out the correct exposure(s) for the time lapse.

[Stephen Williams]

Hi Stephen and thanks for the advise.

I am wondering the reason you expose for 6 sec ? ( I thought my Min expousre of a 1/2 sec might be a problem, I guess not... )

Do you ever pull the stop and/or pull ND as the suns going down ?

 

Thanks in advance,

 

Steve Larsen

 

Hi,

 

I was assuming you would use a constant speed motor so 6 sec open 6 sec closed, you were talking about a shot every 10 seconds, the maths works better for 12! You want the trees etc to be blured as they move in the wind so a long exposure is good.

With an animation motor offset the shutter by 180 degrees, then the camera stops open. The 1/2 sec 'exposure' is just the film advance, and any delay is the exposure.

 

I don't pull the ND as the sun goes, but time to play in telecine is useful. I do know people who change the T stops with motion control when shooting 24 hour day & night timelapse.

 

Stephen

[Steve Larsen]

You might try shooting some test rolls with a still camera, bracketing the exposures, of course and writing down all the info. while doing that, then figuring out the correct exposure(s) for the time lapse.

Hi David, I have shot some test rolls on my K3 and I have kept very good records of what I took the exposure from (ie: a spot reading and/or an incident reading) and tracked those readings on a graph Taking an exposure reading every 10 min's. When I started shooting with the Konvas I made myself a template table/details page to fill in as I shoot a Time-lapse shot. I have posted it online it might be usefull to someone else:

http://www.vancouvergrip.com/The%20Larsen%...pse%20Table.htm

http://www.vancouvergrip.com/shotreport.htm

 

Steve Larsen

[Steve Larsen]

Hi,

 

I was assuming you would use a constant speed motor so 6 sec open 6 sec closed, you were talking about a shot every 10 seconds, the maths works better for 12! You want the trees etc to be blured as they move in the wind so a long exposure is good.

With an animation motor offset the shutter by 180 degrees, then the camera stops open. The 1/2 sec 'exposure' is just the film advance, and any delay is the exposure.

 

I don't pull the ND as the sun goes, but time to play in telecine is useful. I do know people who change the T stops with motion control when shooting 24 hour day & night timelapse.

 

Stephen

 

Hi Stephen, and thanks again. I have a Tobin time-lapse motor for a Bolex adapted to my Konvas 2m. It has 2 modes; regular @ .75 fps exposure at any interval and long exposure (your interval - 1 sec (2 sec-100hr) )

 

The way I've calculated my shutter speed is: Tobin specs for regular speed = .75 fps = 1.3 spf x Konvas 2m shutter = 150 deg. = 150/360 = .416

1.3 x .416 = .541 sec = 1/2 s.

 

I think I am starting to get my exposure close now, but there is a huge difference in stops between 10 min before sunset and 10 min's after. I have asked quite a few DP's I work with how to expose/shoot a sunset and I don't seem to get the same answer twice. One of my best tests on the K3 I pulled 2 stops as the sun went down (approx 10-15min) watching with the spot meter to make sure I was pulling the stop slower than exposure's drop, so even though I'm opening the stop the picture is still getting darker. I have another 6 sunsets in the can now (on 35mm) and a few of them I've pulled 4 stops. They should be in the lab soon.

 

I created this table to calculate shooting time at various intervals and footage for play back at 24fps:

 

http://www.vancouvergrip.com/footage%20Calculator.htm

 

Steve Larsen

[Stephen Williams]

Hi Stephen, and thanks again. I have a Tobin time-lapse motor for a Bolex adapted to my Konvas 2m. It has 2 modes; regular @ .75 fps exposure at any interval and long exposure (your interval - 1 sec (2 sec-100hr) )

 

Hi,

 

The only time I tried to pull the stop by hand I screwed up the shot! I am interested in seeing your results.

 

Stephen

[Steve Larsen]

Hi,

 

The only time I tried to pull the stop by hand I screwed up the shot! I am interested in seeing your results.

 

Stephen

 

Hi Stephen, here's a link to download the test I did with the K3, I looked over my notes and I pulled the stop from f11-3.5 with a pola filter / 1/30 s. / 50asa as the sun was going down. I had to give up doing time-lapse with the K3 because of the fogging problems and some strobe effect i was getting...

 

Steve.

 

http://www.konvas.info/v/steve_larsen/expo...test_a.mov.html

[Steve Larsen]

Hi,

 

The only time I tried to pull the stop by hand I screwed up the shot! I am interested in seeing your results.

 

Stephen

 

 

Hi again Stephen and anyone else intereted. I just got my first Time-lapse footage transferred to HD, all shot with the Konvas 2m & Russian glass. For the most part I am very happy with the results, no fogging on a 10 sec interval with the sun in the shot. I pulled 4 stop manually on every sunset shot, trying to open slower than it's getting darker. I'm posting my results as we speak on http://www.konvas.info in my album.

 

Steve Larsen