Perfect white background

Sara Anderson

Sara Anderson

Suspended / Banned
Messages
41
Edit My Images
No
Hi,
For most of the studio shoots I do with white background, I can't seem to get a perfect white background. I had a set of 3 strobes. I'd place two on my subject n one in the background but there is always a vignetty effect on the sides so I bought flash guns 580ex II n place two on the sides positioned to the back at hight 1.5 mtrs. However I can only achieve a good white at some parts of the image not whole. Moreover I get a blue grayish halo on the sides of my subject. I use the burn n dodge option in PS to fix that but sometimes even that doesn't help.

Please help :)
 
Sara, it's a tricky subject with so many compromises.

When I started ther were loads of people here who offered really useful advice and help. Where a bouts are you, you'd be welcome to pop in for a cup of tea to my studio and I'll talk you through how I've set up my lighting (my studio is near Swindon).

This is the sort of thing I end up with....

IMG_4065.jpg
 
You need two at the back 1/2 or 1 stop more than the front, keep you subject as far from the back as possible and bingo, easy peasy.

Any stray areas, simply dodge it in ps
 
Last edited:
Hodders said:
Sara, it's a tricky subject with so many compromises.

When I started ther were loads of people here who offered really useful advice and help. Where a bouts are you, you'd be welcome to pop in for a cup of tea to my studio and I'll talk you through how I've set up my lighting (my studio is near Swindon).

This is the sort of thing I end up with....
Click to expand...

Thanks hodders, I'm from wales but currently in the middle east. Would u be able to share a brief on your studio setup Plz?
 
Sara Anderson said:
Brian thanks for the video, I found it on UT few months ago but I don't a light meter. I have a brief understanding of the setup depending on the subject n the surrounding lights. I heard there are many iPhone apps that work as lightmeters any suggestions?
Click to expand...
There are apps for metering light, but not flash AFAIK

You can use the principles from the video and check the evenness of your lights in your processing software.

The thing is many people will tell you that you can get away without a proper meter, which you can, until you want to be very accurate:shake:. I'm afraid you can't have it both ways. It's trial and error and getting it close enough, or metering to get it perfect.
 
have you tried two lights and just shooting that with nothing as your subject? maybe a stool with a plant on it or something and just take some time working your background?
When I've shot groups recently (in an amateurish way) I shoot without anyone there just to see what the light looks like on the background and then work from there
 
Pure white backgrounds are difficult. Lots of threads on this if you scroll down the forum.

You need two lights on the background, and even then it is very hard to get it perfectly even all over. Trying to get it blown all over often results in the central area being far too over-exposed, which is the worst thing you can do. Aim for half to one stop max. Don't worry about all-over evenness too much, just get it nice and even behind the subject area and clean up around the edges in post processing.

Do as Matt says and practise getting the background right. You don't need a meter - use blinkies (highlight warning) that flash black and white on the LCD. It's a very accurate method and shows exactly what's happening all over the background. Adjust the exposure level so it's around the blinkies threshold and it will show the hot spots.
 
The tip I've just remembered is to cross the flashes so the l/h one lights the r/h side and vice versa. Creates a more even light because of the more even fall off. I can't remember who suggested it (Garry?).
 
Phil V said:
The tip I've just remembered is to cross the flashes so the l/h one lights the r/h side and vice versa. Creates a more even light because of the more even fall off. I can't remember who suggested it (Garry?).
Click to expand...

Yes, that's fairly standard practise and usually quite good.

To the OP, when first setting up for a white background, start with one light and see what the light distribution pattern is on the blinkies. Shoot two or three exposures at 1/3rd stop increments to see exactly how the brightness varies. Much easier than taking half a dozen light meter readings everytime.

Then when you add the second flash, you'll have a much better idea of which light is doing what.
 
Lots of great useful tips guys thanks a lot. I guess I'll just need to try positioning the lights at different places to get it right. I however didn't understand Phil's point when he said crossover the right to left ..??
 
Sara Anderson said:
Lots of great useful tips guys thanks a lot. I guess I'll just need to try positioning the lights at different places to get it right. I however didn't understand Phil's point when he said crossover the right to left ..??
Click to expand...

It's not an easy technqiue and there's lots of compromise to be worked around.

In a perfect world, you would simply put one light either side at 45 degrees and get perfectly even light all over. Except no light modifier is like that, and there'll be a hot-spot, so if you point both lights at the centre, you'll just make that twice as bright. Aiming each light to the far side of centre helps to even that out and make the zone where exposure is optimum a bit larger. Moving the lights back helps with this too (inverse square law). It takes a bit of setting up work.

Edit: check out a Lastolite Hilite background. They're a couple of hundred quid, but make life easier, especially if space is tight.
 
Last edited:
Sara Anderson said:
Thanks Hoppy will check it out.. Again great tips, appreciated!
Click to expand...

Yup some great advice thanks from me too.

Hope you don't mind Sara OT but can anyone suggest a setup for shooting against a white wall?
 
Phil V said:
The tip I've just remembered is to cross the flashes so the l/h one lights the r/h side and vice versa. Creates a more even light because of the more even fall off. I can't remember who suggested it (Garry?).
Click to expand...

right!! i'm stealing that one! :thumbs:
 
DizMatt said:
right!! i'm stealing that one! :thumbs:
Click to expand...

:thumbs:

Just to explain the inverse square law I mentioned above, ie if you double the distance from the light to the subject, the brightness is reduced to one quarter. That's a two stops drop, which is a lot!

So if your background lights are close, using round numbers they might be only only 1m from the near side, and 4m from the far side. Ratio 1:4 and massive fall-off. But if you can move the lights back one more metre, you then have 2m to 5m, ratio 1:2.5, much more manageable. The further the better, though that also brings other potential problems with spill and possibly with power.

It's not easy, and with studio work, plenty of space is a big advantage in lots of ways. Hard to come by in most domestic environments, hence the popularity of Lastolite's HiLite background http://www.lastolite.com/hilite-backgrounds.php Dramatically reduces the width needed, and getting even brightness is a relative doddle, too.
 
You must log in or register to reply here.
Back
Top