Question about white backgrounds

Hey everyone. I just made a little studio with some worklights, bedsheets, and butcher paper. I am going to buy some real photographic background paper next week.

My question is, how do i get the background PURE white? I will be shooting an all black drum set (i'm talking ALL black, like every stand, clamp, drumhead, cymbal, and stick) and my friend wants it on a pure white background.

Do I need a few lights on the background itself?

Yes, you need the light on the background to be two stops brighter than that on the drum set. It is easier with two lights on the background. One on each side to get an even amount of light all the way across the background.

Great, I'll use my 2 mini floodlights for the background. Does it matter where I take the picture of my gray card for my custom white balance? Should I take a picture of it where the set will be, or where the background is?

I am only replying to this to make it easier to find.. I would like to know as well..

You probably want to do the white balance where your subject is because you want the colours of your subject to be correct. The problem you will run into is that if you are lighting your subject with strobes and your white background with tungsten floodlights, the background will come out looking orange. But if it is 2 stops brighter than your subject it will probably blow out to white, and if not a tweak of levels in post processing will sort that out quickly and easily (Done it many times with my dodgy lighting set up).

If you do your white balance on the background, the background will come out white with no post processing, but your subject will come out with a blue cast.

I wasn't planning on using a strobe. Just tripod, camera, and whatever shutter speed I need.

ItsMike wrote in post #6421593
I am only replying to this to make it easier to find.. I would like to know as well..

fyi, on the top bar, you can just subscribe to the thread.


check out zackarias.com
he has a great tutorial on white backgrounds

The California Kid wrote in post #6423184
I wasn't planning on using a strobe. Just tripod, camera, and whatever shutter speed I need.

Still, the floodlights will come out with an orange colour cast. So the same idea applies. Anything that is overexposed will come out white, or white enough that tweaking levels can make it white without affecting the correctly exposed subject.

Just make sure that you shoot in manual after getting a correct exposure reading with the lights turned off. Otherwise the bright background will screw with your auto exposure, coming out grey and the subject underexposed. Also, if you do end up using a flash to supplement your lighting, run that on manual, not auto or TTL, for the same reasons.

White balance should be taken where the subject will be with the lights to be used on the subject. In this case your BG will be yellow but you can fix that with a cto gel on the flash.

Zack Arias has a great site and some very good information but do not rely on his tutorials as a reference. He admittedly, does not do things by the book and has a method that works. It's great that he puts the info out there but be careful and do not use his methods as universal 'how-to's'.

You also have to be careful when following tutorials for white backgrounds because if you're not using the exact same background or color/tint as in the tutorial then what one person recommends is meaningless.

First of all, have you ever noticed that depending on who you listen to or which tutorial you follow you see different readings to make it white. I've seen anything from 1/2 stop to 2 stops over the subject exposure for pure white, so can they all be right?

Yes, and No. I say this because some of them are right but some are just pouring more light than necessary on to a background to make sure it blows out and becomes pure white. In and of itself that is fine (although technically incorrect) but it becomes problematic when so much light is then reflecting off that background and comes back to the subject area creating flare, wrap or halos. Not good.

Another thing to consider is that it's going to take a different amount of light to render white seamless pure white than it will an off white or gray background. So if you're using someone's method that says to meter 2 stops over the subject exposure that's only going to apply to the material and color used for the tutorial and will not be correct for anything other than that material.

An alternative method, and the one I use, is to meter the background in reflective mode rather than incident. Why? Simple. Now you have a constant. It doesn't matter what color the background is as long as it reflects the correct amount of light.

The same applies to rendering a background black. The amount of light reflected will be a constant compared to the subject taking aperture. Part of what throws people off in the process is that they don't create even lighting across the background so although you may have a central spot behind your subject that is white, there is a gradation as you move outward and eventually begins to appear gray. This usually makes you increase the power to get everything white but that's the wrong approach. You're better off moving the light further away or if you don't have the room to do that you can try wide angle reflectors that some manufacturers make, or you can of course add a second light. No matter which method you use you want even light with no more than 1/10 or 2/10 stop variance across the background.

Here's something you can do to determine for yourself how much light you need to render a white background, and it eliminates the problem of wondering whether the information you're given in a tutorial or web site is correct.

All you have to do is set up for a white background, get the light as even as possible across the background and take a test shot with the exposure correct for your subject area. Now open that file in your RAW editor without any default settings that may change exposure, brightness, contrast, levels or curves. Use your eyedropper or sampler and see what values you're getting from that background. White is technically about 245 and pure white that is essentially blown out is 255. All three channels (RGB) should be giving you the same values. Regardless of what you read in a tutorial, if you're not getting a value of 255 then you have not achieved pure white with no detail. If you're getting 255 then you have achieved pure white but you have to be careful that you're not just clipping the hell out of it so the next thing to do is to begin dropping the power until it comes just under 255 and then you know where you go from pure white to highlight clipping and then to highlight clipping that is out of control.

If you do this while metering incident values then this value will constantly change for every background you use. If you take reflective readings then you can take that value and apply it all the time, no matter what background you're using.

This is a great experiment and an important one because there is a lot of misinformation and generalizations made on the internet and in forums. By doing this you'll have an accurate way to create white backgrounds any time you want and you'll know it's going to be white.

So Robert what you sayings is that I set my camera f-stop to my shooting aperture. take the shot of the bg and make sure it is just under 255. Adjust power of the bg lights to make it so.

That's usually I do it shooting for 250.

Hi Bobby,

Yes, that's what I am saying. So for instance, if you're shooting against white seamless and you're subject taking aperture is f/8 then you would take a reflective reading from your background, making sure you're about 3 1/3 to 3 1/2 stops over your taking aperture and you should be right in the ballpark for pure white, showing values between 250 and 255.

Regardless of what anyone tells you, if you're not seeing those numbers then it doesn't matter what you're told or read. Some will push that to 4 stops to be perfectly safe but if you do the experiment you'll find you don't need to go as far as 4 stops if the background is lit evenly.

Once you establish that value you can then shoot on a gray background with your taking aperture at f/8 and as long as you are getting a reflective reading of 3 1/3 to 3 1/2 stops over that you're going to render that background as pure white. That would not be the case if you were taking incident readings. The number will always be different.

That was an awesome post TMR, very informative.

TMR Design wrote in post #6423552
Part of what throws people off in the process is that they don't create even lighting across the background so although you may have a central spot behind your subject that is white, there is a gradation as you move outward and eventually begins to appear gray. This usually makes you increase the power to get everything white but that's the wrong approach.

Hrmm....I think you're on to a good way of explaining this because you turned the concept of "even coverage" into something that is to be measured instead of just being seen. Very cool....l.because most people don't have a visual reference for "even coverage" and that makes it very hard to explain. However, if they can be taught to measure even coverage to a value then they'll also be able to visualize the results once they get the values correct. Very cool.

Gentleman Villain wrote in post #6425636
Hrmm....I think you're on to a good way of explaining this because you turned the concept of "even coverage" into something that is to be measured instead of just being seen. Very cool....l.because most people don't have a visual reference for "even coverage" and that makes it very hard to explain. However, if they can be taught to measure even coverage to a value then they'll also be able to visualize the results once they get the values correct. Very cool.

Thanks Mike,

This goes back to the the way I was taught by Scott Smith. Not only did he teach me to use reflective readings for my backgrounds but he instilled in me the idea of doing my own experiments to confirm information. Even when he showed me something he never just asked me to believe him or trust blindly. I was always encouraged to test theories and concepts to make sure they worked and were repeatable.

I always encourage others to do the same.