Camera Lightning Trigger - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 31, 2017, 11:17:29 pm
content: Whilst on vacation I came across two photographers who were trying to get lightning photos...They had a gadget on the top of their cameras to capture (I presume) the flash and then trigger the camera.Although we rarely get lightning here I think that might be an interesting thing to try and build...Photo transistor, comparator, delay? opto?Thanks in advanceNivag

author: dave_k
author_rank: Frequent Contributor
timestamp: September 01, 2017, 07:01:11 am
content: A alternative way to capture lightning is to use long exposure (15-60 sec) and just keep taking photos. Some cameras call it bulb mode, other manual exposure.Here is an example of this technique when I was living in the Eastern Suburbs of Sydney:

author: Jeroen3
author_rank: Super Contributor
timestamp: September 01, 2017, 07:28:00 am
content: You don't need to look for light. Lightning is visible in many places on the spectrum.Take this lightning detector is for example:AS3935.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: September 01, 2017, 09:19:25 am
content: Thanks for the sensor link... that took me, with a related google, tohttps://github.com/evsc/ThunderAndLightningwhich is very interesting.

author: dorin
author_rank: Contributor
timestamp: September 01, 2017, 10:17:16 am
content: There is a delay between the camera trigger and the actual start of sensor sampling. Even if your lightning detector had no delay, it's very likely this approach won't work well, because the duration of a lightning strike is so short that when the camera starts sampling, it's already gone.The long exposure method is the only reliable method, also very easy to do.

author: mark03
author_rank: Frequent Contributor
timestamp: September 02, 2017, 11:24:39 pm
content: Maybe this depends on the type of storm? I knew a guy who occasionally worked up on Kitt Peak (astronomy observatory in Arizona, USA). He would take lightning photos by just pointing the camera in a likely direction, then using his own reflexes to trip the shutter when he saw a flash. In the daytime. IIRC most lightning there was ~ a few hundred milliseconds in duration, with multiple pulses along the same channel, so he didn't need an electronic assist.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 03, 2017, 10:57:11 am
content: You just continuously shoot long exposure images. Camera's can do this themselves.

author: SeanB
author_rank: Super Contributor
timestamp: September 03, 2017, 04:28:45 pm
content: You can do it with the lightning sensor, just use it to stop the integration after a short delay, instead of starting it. That way all the sensor has is is the slow build up from ambient light gradually saturating it ( so you will have to limit the aperture down to something silly and set the ISO to something really low, like you are shooting in bright daylight) and it will retain the ultra bright lightning flash as a very bright image. Long open on the sensor will mean you periodically trigger it to get a black and cleared sensor, but it will get good lightning, or just use a video recording mode with low frame rate, which will give similar results without needing any sensor, just manual exposure and no autofocus.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: September 04, 2017, 12:43:31 pm
content: FWIW the people I observed taking the pictures were standing on the edge of the Grand Canyon North Rim during day time (heading towards dusk but still pretty light at the time).I'm feeling that thunderstorms are probably too rare where I live to turn this into a proper project ... but it's quite interesting nevertheless.In fact... it could well have been this guy...https://www.donsmithblog.com/2017/08/17/chasing-bolts-at-the-grand-canyon-with-sony-a7rii-and-a6300s/