Black Background

[oblivion]

I have recently purchased a projector screen, which is very wide and ideal as it comes with a stand built into it. I was thinking portrait head n shoulder shots at the time but I can squeeze in more due to its size. Not bad for £20 of a ebay.

Anyhow, its white one side and black the other. I can achieve a white background shot very easy using this with my light on the subject and a light on the background. Results are very impressive. However, out of curiosity if I want the black background to show in the shot do I have to light it?

I have been using a fast shutter and softbox directly on my subjects far enough from any current background to not show any spill and this seems to produce very effective black backgrounds. This is the easy option but as I have a black background now I wish to use it at some point, especially if space is an issue. I'm guessing the answer will be not to light the background at all but I thought Ide ask for advice.

On another night, if I wanted the white or black background to appear grey after post production do you have any advice on this. My aim is to produce a grey background and my two subjects in black and white.

 

[kokakaste2]

For black background, try to avoid spilling any light on it. That should make it black. Otherwise you will end up with grey.

Simply put more light on it to make it brighter, or less to make it darker. (hope that makes sense).

 

[oblivion]

Yes I thought that would be the answer. I was just getting a little confused as up till now for any of my black backgrounds I have just been using a fast shutter and softbox light direct onto my subject. I have never actually had a black background to use so was wondering if I used one how this would look if my subject was in front and lit from the front as a second light direct onto the background....but I gather this would probably look more grey unless I put the background on a slight angle to reflect any spill away from the lens.

I need to have a day practising

 

[Garry Edwards]

Firstly, I assume that you're using flash? If so, the shutter speed is all but irrelevant in terms of the effect it has on the amount of light, assuming that you haven't got sunlight streaming into the room - without any sunlight, the ambient light doesn't have enough power to make a difference, so don't use a very high shutter speed. By default, my shutter speed is 1/125th.

The amount of light reaching the background will affect the tone of the background. The Inverse Square Law is your friend here... Every time you double the distance between light and subject you lose 3/4 of the lighting power so, if the light has to travel 2' to your main subject and then another 2' to your secondary subject (the background) then the background will get 1/4 of the light of your main subject - which means that the further the background is from your main subject, and the closer the light is to your main subject, the darker the background will become.

The background should be of a non-reflective material. If it isn't then yes, angling the background will help. Angling the background will also create a graduated effect (especially if the light on the main (front) subject is frontal).

 

[oblivion]

Thanks for your responses. I was going into this shoot blind as I had never been to my friends house before so wasn't sure what to expect. I was working in a smallish space but managed to set up my 2x elinchroms. I used my background (the white side) which is a cine film projector screen on a stand. I used one light on the background and the other on bot my friend and her husband. (note to self... Really need a third light)! These shots came out fine with a little tweak in Lightroom.

I turned the screen to the other side (black) and used both elinchroms on my friend and husband. Test shots were coming out looking ok but when I tried to take a shot say 1/200 sec. F8 ISO 100 the light coming from the garden was too bright and I had no curtain to shut! I had no option to move around and bearing in mind this was my first ever shoot for someone I decided to keep shooting thinking I will just have to manipulate later in Lightroom. Maybe I was a little too shy to start moving furniture around but this was a definite learning curve for me. (note to self....get some black velvet material).

I managed to adapt the light in Lightroom but on my attempt at black background pictures the lights on my subjects were a little too harsh on the face. Maybe they were a little too close. I wasn't using any other light ie a flash as I dot yet have one.

I am taking some shots soon of my mum and her boyfriend so I will give it another go then and use the fact I will feel a little more comfortable around them to practise on. Plus he has a large long living room.

It's all fun n games this but I love it.