Welcome! Log In Create A New Profile
Show your ad here! Mail admin@walletfriendlywatchforum.com for rates
Show your ad here! Mail admin@walletfriendlywatchforum.com for rates


Advanced
Capturing lightning in a lens.
avatar July 03, 2018 09:16AM
It had been 10 or 11 years since I last really tried hard to do this. Photographing lightning storms is not a particularly pleasant activity, but can be rewarding. It works best after sunset. You have to have locations planned ahead of time. The storm needs to be blowing by at the right place for the location at the right time. And you have to stay safe yourself.

About an hour or so before sunset a thunderstorm warning set off my weather radio on a Saturday evening. I had a location in mind, but was not overly sure how it would work. I gathered my Nikon D7000, Sigma 18-35mm f1.8 Art lens, the good tripod, and a remote shutter release. I really should buy some of the plastic rain covers for future work, but on this trip the camera was aimed out of an open window of my Jeep. There was some rain, but the storm actually moved by like a freight train a couple of miles south of my location. I could have done this outside of the vehicle if I had the rain cover (and a rain poncho for me).

Cellphone pic of my setup.


Note to self, my good tripod has long, 3-segment legs. It was hard to configure to work inside of a Jeep Wrangler. If I do it this way again, I will go with my less-stable shorter tripod that uses 4-segment legs. It will give me better flexibility in tight quarters. But the good tripod is the way to go outside of the truck.

I had to position so I was aimed at the lightning action. The live view mode on the back of the camera was put to good use because it was impossible to contort to use the viewfinder. I aimed in the daylight, let the autofocus work, then I flipped the switch to manual focus and left it there. I guessed a WB setting of "cloudy", but was set to RAW+JPG and I planned to correct that later. Camera was set to Manual exposure, ISO 100 (lowest setting), f16 (smallest aperture), and the meter said to use 2.5 seconds shutter initially. Again, I used the screen on the back of the camera to read all this. I had the remote shutter release plugged in. I took test photos, and waited for it to get darker. The D7000 has a built in intervalometer which makes the job easy. I set to snap an exposure every 30 seconds and started it. I also had the picture review turned on so I could see each shot after being taken.

Two and a half second exposures every 30 seconds meant I pretty much missed all the lightning bolts early in the series. The goal is to do this with much longer exposure times. As the sun set and it got dark, I kept moving the shutter speed slower until I had it down to 20 seconds. I then had to start adjusting the f-stop wider, and settled in at about f10 and stayed there. The picture review was showing that as not blowing out the highlights from the foreground lighting.

So once I was taking 15 to 20 second exposures every 30 seconds, I started capturing lighting. Sometimes 2 bolts in one exposure. What you cannot control is where it will strike, and my series produced basically 1 strike that may have hit within 6 miles in-frame. But there were 13 images overall out of over 150 images taken that had some lightning action in-frame. Of those 13 images, the best 4 are shown below.









The last one was the closest ground-strike, but some of the sky lightning made interesting patterns. I had to correct white-balance, the sky looked purple on the camera setting I used (RAW files to the rescue). I also applied some color and lens profiles with RawTherapee to match my setup.

I also used my Jpeg files, bad white balance and all. I just assembled them with Picasa3 and used the "make a movie". The time-lapse is 2 frames per minute taken, down to displaying a frame every 5 seconds.





This location is good as far as being a high point that can overlook the city of Madison, WI. But this storm did not track the way I expected and I had change the aim south (city downtown is south-west of this point) to see any lightning. The surrounding is not as interesting that direction. I also did not capture a true "WOW!" strike. But let's see if that can be fixed in GIMP.

I have done simple overlays of photos before. I experimented with HDR images. I created the night-day watch lume shot which is done with an overlay and a layer mask. Here I thought about how do I take 13 images and combine into 1? Alignment was not really an issue since the photo series was taken from a pretty stable tripod setup and I stayed in 1 place. I just processed each RAW image with RawTherapee and exported into GIMP. Once all images were in GIMP, I picked a base image and started copying all the other images as individual layers on the base. Now I just had to figure out how to combine them. I made all but 2 layers invisible, then I started trying out all the layer blend modes to see how they made the layers combine. I needed an additive blend, but also one that maintained the the overall exposure of the sky and foreground. I found that "Luma/Luminance-lighten only" worked about like I hoped to see. I wound up with a brighter foreground than individual photos, but the sky was not blown-out and I could darken the overall image after flattening it to 1 layer. After watching some videos on how people do this in Photoshop, I think I could have added layer masks for a better blend, but the work would have been another hour to 90 minutes. I saved my work at the full 13 layer point and I can revisit that sometime.



And the final image here. Now this is a scene from Frankenstein! For fun you can look for all the little ground-strikes that happened way out on the horizon. Smile





BF Hammer - the new and improved screen name of Chris L
Subject Author Views Posted
Capturing lightning in a lens. Jpeg Attachments BF Hammer 68 July 03, 2018 09:16AM



Sorry, only registered users may post in this forum.

Click here to login

  Our thanks to our WF-WF Sponsors!
Show your ad here! Mail admin@walletfriendlywatchforum.com for rates