JJ Abrams likes him some lens flares. So does Michael Bay:
These are great examples of the anamorphic lens flare. A lot of Indie filmmakers dream of making images that look like this. In order to get images like this, you need an anamorphic lens. The only problem is though, that those puppies cost thousands and thousands of dollars that said Indie filmmakers don't have.
Recently though (within the last year or so), I have seen a surge of DIY solutions that don't cost much to put together, and you can use the lenses that you already have, and the best part is (I think), that you get the coveted horizontal flare (!).
I put anamorphic in quotations in the title, because technically it's not an anamorphic lens flare. It just looks like one.
So here's the skinny: get some fishing wire (I got the 30 lb. stuff), and run it vertically (yes, you read that right: run the fishing wire vertically for a horizontal flare) in front of your lens. Now, here is the place where I should mention that your lens needs to be at least a 50mm. If it's not, then the flare won't extend across the whole frame.
I tried out this little trick with a lens that I don't really use all that often anymore: the 14-42mm kit lens that came with my Panasonic GH2. I drilled a hole in the top and bottom of the lens hood and threaded the wire through both holes. I knotted the wire on the top and the bottom so that it would be tight.
EDIT:
Here is a few seconds of the test that I did last night:
So it's super noisy (ISO 6400 or so), but you get the idea. The flare is there, and all with my cheapo kit lens! Granted, this was at 42mm with ETC mode on (which works out to be about 100mm or so on a Full Frame equivalent).
This was just a quick and dirty test, and I will update this post once I have done more with it. I currently have some step-up rings coming for my 24-70 and 70-200 lenses to see what this flare will look like on a full frame sensor rather than a Micro 4/3 sensor.
I'll keep you posted.