White background lighting

[Hell on earth]

I've read and watched Garry's vids on lighting and while he has advised me to forget this for a while I do need to learn to control it

I'm keeping the lighting under a stop above the main light and today I flagged the lights with about a foot of cinefoil this on to a white wall.

But still the lighting was uneven and am still getting a bounce back on the subjects hair washing it out and her hair is black, she was 6ft from the background

Really not sure what's going on ?

Helen

 

[Phil V]

How are you measuring the 'less than a stop'?

 

[HoppyUK]

White backgrounds are just difficult, and very difficult to do well in a small studio. You may have to fudge it by just getting the area immediately around the subject blown, and clean up the rest in post processing (easy enough).

Aim for half a stop over. Blown is blown, whether it's 1% or 1000%. I use blinkies rather than a meter for setting the background exposure. They will show you very accurately where the brightest areas are. Set it all up, then tweak ISO so that it's just around the blinkies threshold, and then you'll know exactly where you are and can adjust the front light to suit. Get to know your blinkies and histogram, in conjunction with post processing regime. Eg, you'll probably find that there is about one stop of extra exposure headroom available above the blinkies threshold, though that will vary a little according to JPEG pre-sets, particularly the contrast setting (turn it down).

As I've mentioned before, a Lastolite HiLite is an excellent thing for this, especially in a small area. Cost a couple of hundred quid, but if this is something you want to get into, that will be money well spent.

 

[Hell on earth]

How are you measuring the 'less than a stop'?

Light meter.

H

 

[Hell on earth]

White backgrounds are just difficult, and very difficult to do well in a small studio. You may have to fudge it by just getting the area immediately around the subject blown, and clean up the rest in post processing (easy enough).

Aim for half a stop over. Blown is blown, whether it's 1% or 1000%. I use blinkies rather than a meter for setting the background exposure. They will show you very accurately where the brightest areas are. Set it all up, then tweak ISO so that it's just around the blinkies threshold, and then you'll know exactly where you are and can adjust the front light to suit. Get to know your blinkies and histogram, in conjunction with post processing regime. Eg, you'll probably find that there is about one stop of extra exposure headroom available above the blinkies threshold, though that will vary a little according to JPEG pre-sets, particularly the contrast setting (turn it down).

As I've mentioned before, a Lastolite HiLite is an excellent thing for this, especially in a small area. Cost a couple of hundred quid, but if this is something you want to get into, that will be money well spent.

It's the blown area that causes the burn-out on the hair, I have looked at the "blinkies" and they sit right around the victim LOL, turning the stop down and it's all going gray, turn it up and I'm getting flair again and more burnout

Hilite even the big one won't do a group, well only tightly, then you have to free transform the background in pp Grrr

I know it makes sense to get one, just may have to wait awhile

H

 

[HoppyUK]

You can only do so much in-camera. That is, blow the background with the minimum of over-exposure, and get the front light up as close to that as you reasonably can without over-exposing the main subject. Maybe you have the front light a bit low.

But perfection with this technique is almost impossible, it's full of compromise. You can only aim for the best/acceptable compromise, and we've been through a lot of that in previous threads. Don't under-estimate the need for post-processing, or think that you've necessarily done anything wrong by using it.

 

[Garry Edwards]

To add to the above, it also helps dramatically to have a lot of space between front subject and rear subject, so that one doesn't interfere with the other.

I tend to quote a minimum of 8' but personally use as much as I have available, usually twice that. And I have a friend, an excellent fashion photographer who is able to dictate terms to his clients, he flatly refuses to do white background shots with less than 21' of distance.

The use of a Hi-Lite turns this approach on its head, the Hi-Lite does an excellent job in an extremely limited space, as long as you like the inevitable wrap that it produces.

 

[saracenhouse]

The trick to working with white backgrounds is not how just much you over expose it for (your light meter, meters for 18% grey by the way, hence why people suggest a stop or more over exposed to make it go white) but also how much light hits your subject.

It doesn't matter whether you have a few feet or half a mile distance between your subject and the surface of the background, the background acts as a giant reflector, so one more important metering point should be from the back of your subject pointing to the background and as long as this reading is less than the reading from the front (or the setting you're dialling in to the camera) then you shouldn't be blowing highlights of your subject, nor getting a somewhat hazy effect on your image.

 

[HoppyUK]

To add to the above, it also helps dramatically to have a lot of space between front subject and rear subject, so that one doesn't interfere with the other.

I tend to quote a minimum of 8' but personally use as much as I have available, usually twice that. And I have a friend, an excellent fashion photographer who is able to dictate terms to his clients, he flatly refuses to do white background shots with less than 21' of distance.

The use of a Hi-Lite turns this approach on its head, the Hi-Lite does an excellent job in an extremely limited space, as long as you like the inevitable wrap that it produces.

All true. I think it was our JR that said every studio he'd worked in was exactly one foot smaller than he needed. How true

Small space and wrap is another example of compromise. Personally, I think a good amount of wrap is all part of the blown white look, though not everyone agrees and it would be nice to be able choose how much. Distance has a lot to do with it, but so does width of background too which is where screens can help.

Venture are supposed to be the masters here, and whether we like it or not they're extremely popular. Technically, a lot of their stuff doesn't stand up to close scrutiny at all (tons of wrap, over-exposed, completely bleached outlines, massively over-processed etc) but if the customer's happy...? http://www.venturephotography.com/image-portfolio/

 

[TG.]

Hilite even the big one won't do a group, well only tightly

How big a group are you talking ? i have had 10 adults on an 8x7, one guy was about 6ft 4in, it is tight but with the right posing it can be done without looking too tight, i'm fairly sure others have had more too.

I don't think as already has been mentioned, you would ever use a Hi-lite in a smaller space without using PP, it's just part of the course, well it is for me anyway

 

[Hell on earth]

How big a group are you talking ? i have had 10 adults on an 8x7, one guy was about 6ft 4in, it is tight but with the right posing it can be done without looking too tight, i'm fairly sure others have had more too.

I don't think as already has been mentioned, you would ever use a Hi-lite in a smaller space without using PP, it's just part of the course, well it is for me anyway

Thanks everyone
I think I'll take Garry's advice and leave it for now unless it's a small shot, like kids.

H

 

[HoppyUK]

The trick to working with white backgrounds is not how just much you over expose it for (your light meter, meters for 18% grey by the way, hence why people suggest a stop or more over exposed to make it go white) but also how much light hits your subject.

No, if the camera is set to exactly the same as the meter reading, the background should be white anyway (it's already three stops above 18% grey). The additional exposure is just to make sure it's completely blown, which only requires minimal extra.

It doesn't matter whether you have a few feet or half a mile distance between your subject and the surface of the background, the background acts as a giant reflector, so one more important metering point should be from the back of your subject pointing to the background and as long as this reading is less than the reading from the front (or the setting you're dialling in to the camera) then you shouldn't be blowing highlights of your subject, nor getting a somewhat hazy effect on your image.

Light level falling on the back of the subject affects the brightness of the wrap, and the only way to moderate it is with distance. This in turn alters the 'effective width' of the background, and that changes how much wrap there is.

 

[sk66]

Angle. If using strong lights from more to the front to blow the BG, then more is going to bounce right back into the camera. If you use a shallower angle it will spread further across the BG (more even) and not bounce directly into the camera. It may (will) require more power though.

 

[saracenhouse]

No, if the camera is set to exactly the same as the meter reading, the background should be white anyway (it's already three stops above 18% grey). The additional exposure is just to make sure it's completely blown, which only requires minimal extra.

Light level falling on the back of the subject affects the brightness of the wrap, and the only way to moderate it is with distance. This in turn alters the 'effective width' of the background, and that changes how much wrap there is.

If you meter your background at, say f/11 and you shoot at f/11 you will not get a perfect white background. Shooting a white background like this won't make it turn 18% grey of course, if that was what you thought i was saying - as it's a white background, not a grey one! But it won't be perfect white either.

I have also seen Sekonic quoted as measuring 14% grey, which is around 1/6th of a stop lighter if my maths is correct.

Distance is indeed the best solution to avoid wrap.

 

[HoppyUK]

If you meter your background at, say f/11 and you shoot at f/11 you will not get a perfect white background. Shooting a white background like this won't make it turn 18% grey of course, if that was what you thought i was saying - as it's a white background, not a grey one! But it won't be perfect white either.

I have also seen Sekonic quoted as measuring 14% grey, which is around 1/6th of a stop lighter if my maths is correct.

Distance is indeed the best solution to avoid wrap.

Yes, it was. Apologies.

 

[Tunbridge]

One thing I'll add (some advice Garry gave me in an earlier thread) was to use a background reflector on your background light rather than the standard reflector. This makes life much easier, especially in a limited space. I only have 5m in total so getting the space I need between background and subject isn't possible, you just need to work with what you have, but it is much easier to position the background light closer to the background with a background reflector.
Admittedly I'm trying to light a 2.75m wide background with just one light, which again isn't enough to do it evenly (really I need one at each side) but I can get reasonable results with a background reflector and one light which are impossible to achieve without it. Its just another help in trying to get the light to go where you want it to.

 

[Richard King]

I've read and watched Garry's vids on lighting and while he has advised me to forget this for a while I do need to learn to control it

I'm keeping the lighting under a stop above the main light and today I flagged the lights with about a foot of cinefoil this on to a white wall.

But still the lighting was uneven and am still getting a bounce back on the subjects hair washing it out and her hair is black, she was 6ft from the background

Really not sure what's going on ?

Helen

Uneven - read up on the Inverse Square Law. This explains that if you had a "lot" more distance between the light source and wall, the wall would have less, but more even illumination

Bounce back - imagine the wall is a mirror, could you see the light source? if you light the wall more obliquley, you get less bounce back. Watch out however for any texture on the wall

Wrap - you need lots of space between the light source (the wall) and the subject

Wrap - imagine if the wall was a mirror, is the subject in view of the background lighting? if so, this wont help. Not only do you not want your camera to be at an angle where the light from the background lighting bounces straight back at it, neither do you want the subject to be either. Think about the space three dimensionally.

 

[Hell on earth]

One thing I'll add (some advice Garry gave me in an earlier thread) was to use a background reflector on your background light rather than the standard reflector. This makes life much easier, especially in a limited space. I only have 5m in total so getting the space I need between background and subject isn't possible, you just need to work with what you have, but it is much easier to position the background light closer to the background with a background reflector.
Admittedly I'm trying to light a 2.75m wide background with just one light, which again isn't enough to do it evenly (really I need one at each side) but I can get reasonable results with a background reflector and one light which are impossible to achieve without it. Its just another help in trying to get the light to go where you want it to.

Thanks
As I said, I did flag, in the same sort of way that reflector does, ok it was with black cinefoil so not really reflecting

H

 

[Hell on earth]

Uneven - read up on the Inverse Square Law. This explains that if you had a "lot" more distance between the light source and wall, the wall would have less, but more even illumination

Bounce back - imagine the wall is a mirror, could you see the light source? if you light the wall more obliquley, you get less bounce back. Watch out however for any texture on the wall

Wrap - you need lots of space between the light source (the wall) and the subject

Wrap - imagine if the wall was a mirror, is the subject in view of the background lighting? if so, this wont help. Not only do you not want your camera to be at an angle where the light from the background lighting bounces straight back at it, neither do you want the subject to be either. Think about the space three dimensionally.

I have 6 meters so it's hard to get a lot between the BG and subject

H

 

[saracenhouse]

I have 6 meters so it's hard to get a lot between the BG and subject

H

The more the better, but 6m is plenty. Stick a metre between the subject and the background and another metre or two in front of them and you'll be fine. More is better, but this will be fine as long as you don't have your rear lights turned up too much. As mentioned elsewhere, meter your subjects' back with the meter pointing to the background and make sure the reading is lower than the aperture you're shooting at.

 

[sk66]

I like to think of exposure and distance in terms of "aperture stops."

For the sake of explanation lets say your subject is 3ft from the BG and 8ft from the light source. If the subject is properly illuminated at 8ft (f/8) from the light source, the BG will be 1 stop underexposed. 8ft+3ft=11ft; f/11, one stop smaller.
So for the BG to be "properly (equally) illuminated" it must meter 1 stop higher by adding additional light there. If you want it 1 stop overexposed it must then meter 2 stops higher.

The only thing you have to worry about then is the light bouncing back onto the subject (lighting angle/flags).

 

[Hell on earth]

I like to think of exposure and distance in terms of "aperture stops."

For the sake of explanation lets say your subject is 3ft from the BG and 8ft from the light source. If the subject is properly illuminated at 8ft (f/8) from the light source, the BG will be 1 stop underexposed. 8ft+3ft=11ft; f/11, one stop smaller.
So for the BG to be "properly (equally) illuminated" it must meter 1 stop higher by adding additional light there. If you want it 1 stop overexposed it must then meter 2 stops higher.

The only thing you have to worry about then is the light bouncing back onto the subject (lighting angle/flags).

I'm come to the realisation as Hoppy said, my space is to small to get good white bg and to go with a hilite when I can afford one.

H