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camera lens center to video light center

padmanaban's picture
Last seen: 1 year 2 months ago
Joined: 12/15/2012 - 4:13am

dear friend

  Past five year i am doing video work for my family and social function.I am having a nikon camera p500 in which i am not able to mount the vieo flash.I have purchased a standard flash light and modified to use in my camera. I have fabricated a frame and fix the hard light i have purchased. I have used this for an important function i got the problem for lighting. When i switch on the light the source of light does not fall on the object that i require to shoot. I feel that the lens center to flash center distant found not correct.I want your guideline to solve the problem.

padmanaban   from India

 


Wildcat Video's picture
Last seen: 1 year 6 months ago
Joined: 01/09/2013 - 10:20am

Padmanaban, the problem is one of geometry. Picture a triangle with your lens at one corner (Point A), your light source at another corner (Point B), and your subject (what you are filming) at the third corner (Point C). The angle of the corner at Point C tells you how much to tilt the light down (assuming the light is above the lens) so that the beam of light meets the focus of the lens at that distance. HOWEVER, the angle at Point C will change as the distance from the lens (Point A) and the subject (Point C) changes. For objects very close to the lens, the angle will be fairly large. For more distant objects, the angle will be small. If your subject will always be a constant distance, the problem is easily solved. Unfortunately, most of us shoot at different distances, and can't always predict what that distance will be.

 

If I understand you correctly, the real problem may that you are using a flashlight (a "torch" as the British call it) as your lighting source.  Most flashlights project a fairly narrow beam of light, and the light is not evenly spread over the area it does cover. There will be spots of very pright light and other spots (especially at the edges) where the light is very dim. If you must use a flashlight, try to find one with a very wide beam. Spreading the light out will help with the triangle problem above. 

The other suggestion I have is to place some kind of diffusion material over your lens. This will help to spread the light further, and it will even out the bright and dim light into more consistent coverage.

 

I hope this helps. Video on a budget is always a challenge, but if you understand how things like light work then you are halfway to coming up with a solution.

 

Richard Wright


chuckzootz's picture
Last seen: 9 months 2 days ago
Joined: 02/07/2012 - 7:16pm

Get some used light stands to save money and read an article here on three point lighting. and if you want an on camera light, go to e-bay and search there, I found a nice LED light to use in my viideos for under $35.00 american, if thats to much money get some bowl lights from a hardware store and you will have much better control of your lights. Or use your current set up and put some diffusing material over you light, this will spread the light over more area co cover what your lens sees.