Frames or Barndoors?
Posted 23 December 2006 - 02:37 PM
What are some of the differences (effects on lighting) that adding gel/diffusion directly to a barndoor Vs adding the diff/gel to an open frame afront of the unit? And vice versa?
Are there certain effects that one can acheive better/only with either method?
Are there any immediate aesthetic differences to using either?
Any comment / direction is greatly appreciated.
Thanks in advance,
Posted 23 December 2006 - 04:41 PM
However, when using diffusion it's a very different story. First of all i have never seen diffusion burn on a barn door. But more importantly the further you take the diffusion away from the source the softer the effect will be. The rule of thumbs is the bigger the diffusion the more wrap it will have therefore the softer it will appear. For example if you take some 216 and put it on the barn doors of a 2K Fresnel to light a subject 10 feet away it will not appear as soft as the same 2K going through a 4' X 4' frame of 216 placed 4 feet away from the source. Furthermore the larger source (the 4X4) will be much more difficult to cut with solid flags than the former set up with 216 on the doors. Another rule of thumb is that when ever using a frame it is best to have the source fill the frame. In other words, it is not optimum to see the spot of the beam in your frame. You can also place the diffusion "on the inside of the doors". Which is right right next to where the scrims would go. now here you can control the beam with the doors but also may see some burning if the diff makes contact with a hot scrim.
This is a fundamental exercise that should be practiced by all students on day one.
Posted 23 December 2006 - 05:57 PM
But with diffusion, the distance you put the diffusion is mainly about how soft you want the effect to be versus how easily you want to be able to flag it (larger sources require larger flags, etc.) A larger frame of diffusion farther away is a softer source than a smaller piece of diffusion on the barndoors.
Posted 24 December 2006 - 10:14 AM
Posted 24 December 2006 - 11:08 PM
Thanks very much for your contributions. I really appreciate it.
I'll be doing a few tests with distance of diffusion in the near future... I'm also curious to see the correlation between fall-off and distance -- assuming that there will be less, the further the diff moves from the light.
But again, thanks a lot.
Posted 25 December 2006 - 12:23 AM
If you are talking about the loss of light output due to the diffusion, that partially depends on the heaviness of the diffusion material and how well the light spreads to fill the frame. Since the frame of the diffusion becomes the source, one of the backwards things to note is that when you flood the lamp behind the frame, the source (the frame) becomes brighter because it is filled more completely, compared to when you spot the light into the frame and only use a small area of the frame.
Posted 02 January 2007 - 12:43 AM
I was speaking in reference to lose of intensity.
And as always, your post is very educational + helpful.
Posted 07 January 2007 - 10:29 AM