Thursday, October 27, 2016

A Quick Primer On Day To Night Curve With The Pulse by ALPINE LABS

I wanted to quickly throw a post up for a few of my friends as it would seem the Pulse by ALPINE LABS on Kickstarter was very popular. So here goes...

The settings screens are not very explanatory and in my opinion just very simple for someone who understands the day to night slope. The unit automatically manages the slop, you just need to estimate a few points on the timeline.

Click for larger image.

The Promote Control setup is very different so I will keep this specifically for the Pulse setup.

1. Make sure your camera is on, set to manual and set a shutter speed / aperture combo that looks good (take a test shot). A scene in the shade or overcast day is good around 1/20 f-8 @100iso.

2. Plug in the Pulse unit to the camera and switch to "on" (I won't explain how you should be composing the scene but I will tell you unless you are working with ND filters you should not be pointing into the sun).

3. Turn on the app, search for device, once connected go to timelapse screen.

4. Your first screen is your interval (obvious setting) and "duration". The Duration is the full time from A to D above.

5. Upper right menu will bring you to the "exposure ramp" menu. Click enable and make sure it shows start/end shutter and start/end iso.

6. Your Delay is A to B length to set. Your Duration is B to C length to set. And your run out will be whatever time left after after A to B to C is completed (based on Duration set in step 4 above). Don't overthink it, minus A to C from A to D and you have your runout time.

Some thoughts:

Many sites will tell you 30 minutes is a normal sunset slope length but I have found in central Alberta 40 minutes is better. Dusk seems to hang here for a long time after sunset. To estimate your start time just consider B as the "actual" sunset start time for that day in your location (use an app or the web). Then just work backwards. Your starting shutter speed should always be at the beginning of your timelapse, once the ramp starts (B) it will work along the curve until it hits the end of sunset/twighlight generally around 40 minutes later. At this time you can let it runout for an extended time and it will be the shutter speed you figure looks great in that condition. Usually in the city with bright lights or sometimes you have to make your final shutter longer if you are shooting dark sky and stars,

Best way to get some good numbers to start is to go out the day before and take exposures (WITH THE SAME F-STOP) at 20 minutes before sunset, 1 minute before sunset, 30 minutes after sunset, 40 minutes after sunset, and again at 50 minutes after sunset (ideally where you want your final ending shutterspeed to be).

Note on ISO: If you are using 10 second intervals and your exposure lengths are ending at greater than 10 seconds (for example), you can set your "ending" iso to one stop faster (100 to 200) to give like a 10 second @ 100iso a shift to 5 seconds @ 200iso.

Biggest down fall to this unit is you WILL have to use LRTimelapse software to manage the flicker that will appear later on during the encoding process (this happens because the camera sets the shutter speed in steps and less like a high resolution curve or slope. Each time it steps-up you see the jump in exposure and resembles a flicker in post). You should be using it anyways with your workflow. I normally don't need to with the Promote Control. Overall the price is right for this unit and the form-factor is small. With a little software know-how, this unit can create some decent results.

Feel free to find me on facebook or email me for questions. Happy shooting