Lightning: A Polarizing Story

[Jason Persoff]

I learned something odd on the 25th of May. Bill Hark and I were chasing some beautiful (initially) LP storms in NM. As the storms began to coalesce and become outflow dominant, I began snapping photos of the highly electrically active storm. I was shocked (pun not really intended) to see that photo after photo failed to show any bolts when the bolts clearly had dropped perfectly centered (or so) in my frame.

I shot multiple photos, briefly celebrating the victory of well-targeted lightning, only to find that the photos were virtually devoid of lightning strikes on the images.

I scratched my head and moved on before getting munched by a core. Ultimately I later discovered I'd left a polarizing filter on my 35mm. It suddenly occurred to me that lightning may be polarized light. While I'm not certain about this, it fits the explanation the best. In the shot below a strike does appear but without any step leaders or forks. Anyone else have this experience???

 

[Doug Raflik]

I put a polarizing filter on the camera if there is some day light present, to allow me an extra couple seconds exposer. I have not noticed any problems. Do you remember if there were many return strokes with the lightning? If not, with the polarizer, it may have kept a lot of light from getting to the camera. I only have one image online where I was using a polarizer during the day. The bolt was about 1/4 mile away from me, so it damn well better of shown up. I will watch more closely the next time I shoot in these situations.

Doug Raflik
[email protected]
http://www.wxnut.net

 

[Jason Persoff]

The bolts were both sfc and cloud based. Many of them per a shutter speed of 3 secs max. I wonder if maybe the rain shafts also affect the process by blocking out all but a few light beams which more or less will orient witht polarizer.

I'll probably should some digital video w/a polarizer on to see if the image differ while simultaneously taking stills with DSLR.

 

[Mike Peregrine]

Jason - I use a polarizer on the vidcam often and don't notice any issues capturing lightning on video. My guess is that it is actually the angle you are standing in reference to the lightning bolt behind rain and water shafts, which are then acting to partially polarize the bolt (similar to light refracted through crystal). If this is the case, some bolts will come out okay and others will be partially invisible when you are using a polarizer - it's all in the angle you stand in reference to the bolt. My thinking is that if there is a lot of precip involved without a lot of sunlit portions of the shot anyway, go without the polarizer. Usually it isn't necessary if you are under the base of the storm, and becomes more necessary if you are out away from the storm base and have a lot of direct sunlight in portions of the shot. Just a thought.

This page has a better explanation, but I'm thinking this might be the issue. http://www.glenbrook.k12.il.us/gbssci/phys...ght/u12l1e.html

 

[James Langford]

A different idea

I can maybe offer up a different reason for why there is not much showing. Using the Polarizing filter is going to require you to have around 1 1/2 stops more light enter the camera to get a proper exposure. So, your lightning is going to need to be pretty intense, especially when shooting during semi daylight like you are. Also, the lightning looks to be pretty far away. What Aperature were you shooting at? For lightning that far away, you would need to be using a pretty open aperature (like below F4) to get it to properly exposed. My guess is you were using a higher aprerature due to the lighting conditions, and with the filter on, the lightning just wasn't intense enough to be properly exposed.

Of course, I could be completely off base. ;-)

James

 

[Jason Persoff]

Thanks everyone for your insight. Just to answer James...

Also, the lightning looks to be pretty far away. What Aperature were you shooting at? For lightning that far away, you would need to be using a pretty open aperature (like below F4) to get it to properly exposed.

I indeed was using above f4 for aperture due to the remaining sunlight..probably f12 I think. The one bolt captured was indeed far away. The other bolts seemed much closer, but looking at the posts above suggests I was just plumb unlucky to still have my polarizing lens on. Bummer

Again...I appreciate everyone's collective experiences!

 

[Susan Strom]

probably f12 I think

F12 + polarizer - that'll do it. Commonly I shoot at F4-5.6. One time I shot F8 with 64ASA film and 50mm lens because the lightning seemed so close -the pictures turned out just a shade too dimmed for my liking on the branches - and that was w/o a polarizer. F8 or higher causes lightning branch dimming - that's just my experience.