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-   -   using lights (https://www.dvinfo.net/forum/photon-management/78242-using-lights.html)

Baris Ustun October 26th, 2006 03:04 AM

using lights
 
I am a newbie.
Can anyone tell me what is the difference between shooting under powerful lights and shooting under standart room lights.
It seemed to me, In either case i can adjust the aparture and shutter speed settings to get the same light levels.

in other words changing the shutter speed from 1/500 to 1/1000
makes a similar result with switching from 1K to 0.5K light source.

Gareth Watkins October 26th, 2006 03:41 AM

Hi Baris

Good lighting is not so much to do with the power of the lights... (although the larger the area you need to light the more powerful your source will need to be)... but the control you have over lighting..In fact your average interview video light kit is not that powerful at all with lamps usually in the 250w - 1000w bracket.

Standard room lights give you no control, lighting will be flat and uninteresting, even if your camera can capture in these conditions your pictures will lack punch. Take even a basic lighting set up and light your model correctly and your results will look so much better.

Google 'Three point lighting' and search this site, there is loads of good info

Also check out these sites:
John Jackman's excellent tutorial http://www.pqhp.com/cmp/dvxe05/
Guy Cochran has a briefer but useful one too on his site: http://dvestore.com/theatre/index.html# (scroll down to 3 point lighting...)

Photography is all about light and how you use it...

Finally unless you want specific effects leave your camera on 1/50th.

cheers
Gareth

Baris Ustun October 26th, 2006 04:59 AM

Thanks Gareth,
the links seem to be very useful. I am gonna review in the evening.
I will try and see the results of different type of lightening setup.
I think my problem is the light source; I use a general purpose 500 watt halogen.
When I turned it on almost everywhere in my little room gets lightened.
I think I need more directional light.

Don Donatello October 26th, 2006 08:58 AM

in general ...
1st put light into the scene/room .. next you start to take away some of the light ( you shape it using barn doors, flags, nets , black wrap , whatever you can use to shape the light - you take some light off specific walls , little light off shirt .. little light off forehead , perhaps soften light on subject etc )
500 watt light is good amount to work with for interview and you need items to control that light ....

Baris Ustun October 27th, 2006 05:57 AM

Yes, I tried that way yesterday evening. The results were absolutely different and better than what I had experienced earlier. I used an aluminium folio (the one used in cooking) to wrap around the halogen lamp. I hope it wont catch a fire. maybe I should get one of those with barn doors.
thanks for the replies.

Emre Safak October 27th, 2006 08:39 AM

Baris,

You absolutely should get one with barndoors, if possible. For one, it will enable you to prevent, as you say, "lighting the whole room". Second, it will enable you to use gels (by providing a place to attach them with clothes pegs, aka "C-47s").

You will find that once you have gelled and flagged a 500W light, you will not have much illumination. This is why film-makers measure light in kilowatts.

Heat is also an issue. Use garden gloves to handle the lights, and make sure they are not too close to anything that may catch fire (or break/crack under heat, such as glass/mirrors).

Baris Ustun October 29th, 2006 01:24 PM

Emre,

thanks for your comments.

Jaron Berman October 30th, 2006 09:02 AM

Inverse square law. If you double the distance, you get 1/4 the output. Let's say you get an exposure of f/8 with your 200watt lamp 5' from the subject. If you put another subject 5' behind that person, the light hitting the rear subject will be about f/4. That's a BIG difference.

Now, put a 10,000 watt light 100' from the subject. The second subject is only 5% further back from the light than the first, not 100%. The difference in exposure between the two subjects is basically nill.

Big lights let you get the same exposure, but they allow you to move the light further away. Also, they let you bounce, diffuse, and heavily modify the light to better fit your needs. Let's say you need a diffused light source 10'x10' in dimension. You could put up a silk that size and place a light behind it. Then, it goes back to the inverse square law. To cover that entire silk with light, the lamp itself must be a certain distance away from the silk. The farther away the light is, the less powerful it is.

Paul R Johnson October 30th, 2006 09:44 AM

It's pretty important to recognise the difference between hard and soft light. A bright light source aimed directly at the subject is also going to produce very hard shadows. Video finds these shadows difficult to deal with, so you need another lightsource the other side, but one that is softer, so as to not create another shadow once the shadow on its side has been filled in partly. If you have light walls or ceilings you can bounce light off it, which works well. as another poster said, 3 point lighting is a very use technique. In this case, there is no backlight, but if equipment is available it really does just lift the subject from the background. Illumination is a very different thing to lighting.

Don Donatello October 30th, 2006 10:41 AM

get a roll of blackwrap ( it's heavy aluminum foil and it's black ) ..
also use it as a heat shield ( if you have open face 500-1000 watt light inches from ceiling/walls - put a 15x15inch piece on wall/ceiling ( use press pins not tape) to reflect heat


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