I need some video advice. Anyone know how to get good video of persistence of vision LED effects? I recently got a totally amazing LED phoenix hula hoop from spin fx… http://www.spin-fx.com/product/phoenix-hoop … And while I can get good photos the video camera just seems to hate this thing… How does one capture this effect? Is it possible?
With an exposure time arround 1-2 s (for the led “stripes”) and a flash at low power/high distance during that second, preferably at the end of the exposure (for the sharp picture of the human). I would start with ISO 1600 and a low aperture for the beginning.
A second person operating the external flash is helpful for that kind of photo.
A black dress for the model is very helpful too in order to have nothing reflecting the led light.
Oh, sorry, you asked about video. What is your specific problem? You do not get the rainbow stripes in the video? I do not know any way how to achieve that while recording except with software during the postprocessing.
I have a Panasonic HDC TM900. I also have a gopro silver and a couple iPhone 4s.
Can you show some youtube video which looks similar to what you are aiming for?
You know what? Thinking about this I bet it has to be post-process effect. You want lots of overlapping long-exposure frames and you can’t actually do that with a single camera.
yeah you need to blend frames for it. The thing you want is probably called ‘additive blending’ or something similar - the brightest pixels remain - and a bit of fadeout to black as well or to the current frame so you don’t saturate areas for the duration. It’s relatively simple so i expect there is a way to do it in many different programs with many different workflows, i ended up writing my own (in processing) as i couldn’t find something free and easy. There might well be a shader that someone has written available to use in many programs. I’ve done a few test videos but no ‘proper’ ones yet, here’s an example blending with no “fadeout”: https://www.youtube.com/watch?v=Fyqa-Z7_TGQ (warning, slightly overloud music!) - if you fadeout then it looks a bit better for abstract movement etc. check my other videos for some more test examples with and without fadeout.
It’s easy to do if you have the right software — I can do it in 5 minutes with After Effects.
Use the highest frame rate you can - if you have a GoPro then use that. There will be a trade off between image quality and frame rate — you’ll need to try a few different fps.
If you want to try shoot a few (short) clips I’ll stick it through After Effects if you like.
Uploaded a 1 min video (I know that’s longish, let me know if you want me to trim it down) shot with the panasonic at 60fps and a variety of f-stops, which you can hear my husband muttering in the soundtrack to:
I’ve been able to do real time light painting with after effects so for sure it can be done pretty easy. I’ve used a lot of those type of effects in this video http://youtu.be/Kayqs74owFI
@Erin_St_Blaine that video didn’t upload properly— think you might have to try again
I thought that uploaded awfully fast. Trying dropbox:
@Erin_St_Blaine ok — so first thing, you want the camera on a tripod
Erin: the challenge here is that any frame rate lower than about 24 frames per second looks “choppy” to the human eye. So, that means the limit for the longest exposure you can have in a video is about 1/24th of a second. Unfortunately, that’s just not long enough to “naturally” produce the kind of tails you are looking for. You could do some fancy stuff in post processing with frame blending, but I just don’t think you will get the beautiful long tails natively. My best advice is to make the exposures as long as possible and go from there. You said you were filming at 60 fps with your Panasonic; see if it has a 24 or 25 fps mode.
You’re going to have issues getting an exposure time long enough to display it on video- do it in post.