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sbeecroft

sbeecroft

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Stephen
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Hi,
I am new to studio photography, and have tried to find another thread on this but cant quite get one which I fully understand.

I have a black background and 3 lencarta Smartflash 200W lights.

I want to shoot portraits that give a pure black background, but so far my postioning and settings of both lights and camera, I am generally making some of the portrait black, but for instance another section of the shot would show light on the backdrop.

Thanks for your help.
 
If some of the light is showing on the background then you have one of two problems, or both.
1. The subject is too close to the background, so light that has missed the subject is reaching the background. If you move the subject further from the background then, because of the effect of the inverse square law, much less light will reach the background.
2. The lights are so far away from the subject that nearly as much light is reaching the background as is reaching the subject - again, the Inverse Square Law is working against you.
 
As Garry said above, but also place the lights more to the side, if you can. Are you in a completely darkened room? If you have some ambient light coming in (say, from a window) that could affect the background, because if your exposure is say 1/125s the flash may only be 1/1000s, and the remainder of the exposure time can pick up ambient light if strong enough. You can normally select the background in Photoshop and use levels to darken it.
 
MacroMania said:
As Garry said above, but also place the lights more to the side, if you can. Are you in a completely darkened room? If you have some ambient light coming in (say, from a window) that could affect the background, because if your exposure is say 1/125s the flash may only be 1/1000s, and the remainder of the exposure time can pick up ambient light if strong enough. You can normally select the background in Photoshop and use levels to darken it.
Click to expand...
Placing the lights more to the side, so that less of the light reaches the background (and so that the light that does reach it is at an angle that reflects away from the lens) will help.

But it's not something that I advise, because lighting needs to be arranged to suit the subject. Moving it to suit the background will affect the all-important lighting on the subject, and isn't something that I would do.
 
In addition to the wise words above to check for ambient on a black background I take a shot with no lights then check the histrogram to see how it looks. During the day I try and draw curtains at least partially to lower the ambient anyway and at ISO100 at typical apertures of F4 to F8 normally it is ok.
 
Garry Edwards said:
Placing the lights more to the side, so that less of the light reaches the background (and so that the light that does reach it is at an angle that reflects away from the lens) will help.

But it's not something that I advise, because lighting needs to be arranged to suit the subject. Moving it to suit the background will affect the all-important lighting on the subject, and isn't something that I would do.
Click to expand...

What about using barn-doors on the front main light to try and contain it on the subject?
 
Marcus Geezer said:
In addition to the wise words above to check for ambient on a black background I take a shot with no lights then check the histrogram to see how it looks. During the day I try and draw curtains at least partially to lower the ambient anyway and at ISO100 at typical apertures of F4 to F8 normally it is ok.
Click to expand...

That's a very good idea. You know for certain then.
 
Getting the light closer to your subject would mean that you can drop the flash power and less light would hit the background. Useful if you are limited for space and can not move your subject away from the b/g.
 
MacroMania said:
Yes. You should also get a softer quality light if it's closer.
Click to expand...

Yes, which is fine if you happen to want the light to be softer. If you don't, you can still move the light closer but will need to mask the light source (softbox?) to make it smaller or use a smaller one.
As I said before, light positioning must suit the lighting effect you want to achieve, not the background.
 
MacroMania said:
As Garry said above, but also place the lights more to the side, if you can
Click to expand...

Rather than moving the lights to the side, you can feather the light a little more. That is turn the light away from the backdrop and light the subject with light from just the edge of the softbox. This provides a nice soft light on your subject and minimises the light in the direction of your subject. But there's plenty of useful advice above.
 
Thanks for all of the responses.

The room is almost completly dark.

I think the problem could be that the subject was too close to the background.

I dont have barn doors available.

But as has also been mentioned the current lights do have on the subject is preety much how I want it.

I will be having another attempt on tuesday and will try to get the subject further from the background.

Also in terms of where the lights were positioned, they were out wide of the camera and subject.

Thanks again for your help.
 
Thanks, I will make sure modelling lights are off.
 
sbeecroft said:
Thanks for all of the responses.

The room is almost completly dark.

I think the problem could be that the subject was too close to the background.

I dont have barn doors available.

But as has also been mentioned the current lights do have on the subject is preety much how I want it.

I will be having another attempt on tuesday and will try to get the subject further from the background.

Also in terms of where the lights were positioned, they were out wide of the camera and subject.

Thanks again for your help.
Click to expand...

Get the light in closer - Light fall off will mean it won't reach the background - meter the light too so exposure is correct.
 
I had another attempt tonight and the results are much more pleasing. I kept the subject further away from the background, and moved the lights closer in.

In all pictures the BG was pure black.

I think now i need to work on where to position the lights around the subject to light the subject differently.

has anybody got any suggestions on if using umbrellas or soft boxes is more suitable? and the difference between the two in terms of the effect you get.

Thanks in advance.
 
See this article on the Lencarta website, which explains the differences between softboxes, shoot through umbrellas and reflective umbrellas. Click on the various pics in this article to see examples
 
sbeecroft said:
I had another attempt tonight and the results are much more pleasing. I kept the subject further away from the background, and moved the lights closer in.

In all pictures the BG was pure black.

I think now i need to work on where to position the lights around the subject to light the subject differently.

has anybody got any suggestions on if using umbrellas or soft boxes is more suitable? and the difference between the two in terms of the effect you get.

Thanks in advance.
Click to expand...

Using the brolly you get more spill - not as easy to control as a softbox generally. Softbox is a more directional light
 
Garry Edwards said:
If some of the light is showing on the background then you have one of two problems, or both.
1. The subject is too close to the background, so light that has missed the subject is reaching the background. If you move the subject further from the background then, because of the effect of the inverse square law, much less light will reach the background.
2. The lights are so far away from the subject that nearly as much light is reaching the background as is reaching the subject - again, the Inverse Square Law is working against you.
Click to expand...


All very good advise

Paul
www.photographybyriddell.co.uk
 
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