- Thread starter
- #21
Mondo Ghulam
Well-known member
Hi,
just returning to the thread as the shoot is now over.
Prior to the shoot I did extensive testing of all of the suggestions here, bar the glowsticks. The only reason for that was that I'd run out of time.
In testing I discovered that the submersible LED's looked like they would hold true to their quoted 48hrs of operation from 2x batteries. In testing, I actually got as far as 36 hours and recorded about a stop's drop in luminance after the first eight hours (as measured with light meter) but then no further drop in luminance.
The laser keyrings were amazing and were legible over great distance even in twilight. In testing, after 4 hours I noticed that he laser dropped significantly in brightness. After power-down and a few hours rest, they were back up to full brightness. My guess is that the laser itself is heating up and losing effectiveness. Due to the low cost of my lasers, they were a bit 'dirty', meaning that as well as a tightly defined dot, I also got some glints and flare from the keyring housing itself. This created an overall 'feature' that was about 6-9 inches in diameter, depending on the colour of the surface it was being shone on.
The glow tape was nice but lost brightness very quickly. The reflective tape was the gloss type, didn't reflect enough light and was too directional. I didn't use either on the shoot. If I ever have to do a shoot in black light however, glow tape will be used!
For the shoot proper, I relied entirely on the LED's and the lasers. The Leds got most use/abuse. At times, people stood on them, kicked them until we got the set 'hot', they took this abuse without problems. I had ping-pong balls at the ready too in case we needed to place markers in the distance, but these were never used. The LED's were all treated with 3M Magic Tape and provided a tight uniform glow to the markers. with about half a stop of light reduction. More tape = more reduction.
I had gaffad every marker-base to greatly reduce light-spillage, but there was still a bit on the ground. This can be sorted when removing the markers however.
A quick test in syntheyes has delivered excellent results - my first attempt produced an error < 0.35 hpix.
Here's one of the setups:
http://www.flickr.com/photos/m_ghulam/10556855254/
The lasers saw less action but when used were a life-saver when we finally used them. Part of the reason for this is that more than half of them hadn't arrived before the shoot.
We had one element in the far distance behind some trees. For the shot the camera was basically 2D panning, so we set up 3 lasers near a group of trees that were almost entirely dark. It took a bit of fiddling but we got a stable triangle of dots high up in the tree and they read clear as day from about 200 metres away. Thanks again Bjorn for this suggestion - I wouldn't have had any way of dealing with this as National Park rules forbade us from putting anything on trees.
I can't show a pic of this setup yet as I only have it in the plate as shot, but I'll try to get a hold of one and update the thread.
Overall the LEDs are a great solution for a shoot like this, you can set them up and forget about them while the crew continue to work. They are cheap (£0.75 each / batteries, 100 for £40). I didn't replace a single battery over the four nights. The lasers are a good choice also, but require more thought & care when positioning (especially if used in a distant config like mine) and take 3 batteries each.
The lasers are genius, especially if you have to extend the reach of your marker coverage beyond what is humanly possible.
Thanks again to all who contributed here, it was a huge help and I learned a few new tricks along the way.
M
just returning to the thread as the shoot is now over.
Prior to the shoot I did extensive testing of all of the suggestions here, bar the glowsticks. The only reason for that was that I'd run out of time.
In testing I discovered that the submersible LED's looked like they would hold true to their quoted 48hrs of operation from 2x batteries. In testing, I actually got as far as 36 hours and recorded about a stop's drop in luminance after the first eight hours (as measured with light meter) but then no further drop in luminance.
The laser keyrings were amazing and were legible over great distance even in twilight. In testing, after 4 hours I noticed that he laser dropped significantly in brightness. After power-down and a few hours rest, they were back up to full brightness. My guess is that the laser itself is heating up and losing effectiveness. Due to the low cost of my lasers, they were a bit 'dirty', meaning that as well as a tightly defined dot, I also got some glints and flare from the keyring housing itself. This created an overall 'feature' that was about 6-9 inches in diameter, depending on the colour of the surface it was being shone on.
The glow tape was nice but lost brightness very quickly. The reflective tape was the gloss type, didn't reflect enough light and was too directional. I didn't use either on the shoot. If I ever have to do a shoot in black light however, glow tape will be used!
For the shoot proper, I relied entirely on the LED's and the lasers. The Leds got most use/abuse. At times, people stood on them, kicked them until we got the set 'hot', they took this abuse without problems. I had ping-pong balls at the ready too in case we needed to place markers in the distance, but these were never used. The LED's were all treated with 3M Magic Tape and provided a tight uniform glow to the markers. with about half a stop of light reduction. More tape = more reduction.
I had gaffad every marker-base to greatly reduce light-spillage, but there was still a bit on the ground. This can be sorted when removing the markers however.
A quick test in syntheyes has delivered excellent results - my first attempt produced an error < 0.35 hpix.
Here's one of the setups:
http://www.flickr.com/photos/m_ghulam/10556855254/
The lasers saw less action but when used were a life-saver when we finally used them. Part of the reason for this is that more than half of them hadn't arrived before the shoot.
We had one element in the far distance behind some trees. For the shot the camera was basically 2D panning, so we set up 3 lasers near a group of trees that were almost entirely dark. It took a bit of fiddling but we got a stable triangle of dots high up in the tree and they read clear as day from about 200 metres away. Thanks again Bjorn for this suggestion - I wouldn't have had any way of dealing with this as National Park rules forbade us from putting anything on trees.
I can't show a pic of this setup yet as I only have it in the plate as shot, but I'll try to get a hold of one and update the thread.
Overall the LEDs are a great solution for a shoot like this, you can set them up and forget about them while the crew continue to work. They are cheap (£0.75 each / batteries, 100 for £40). I didn't replace a single battery over the four nights. The lasers are a good choice also, but require more thought & care when positioning (especially if used in a distant config like mine) and take 3 batteries each.
The lasers are genius, especially if you have to extend the reach of your marker coverage beyond what is humanly possible.
Thanks again to all who contributed here, it was a huge help and I learned a few new tricks along the way.
M
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