Not Your Everyday Banana

by Bart Arondson

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

I am a natural light photographer that is venturing into studio/backdrop portraits at the request of some of my clients.

I have a portable studio for my needs with a white muslin backdrop.

I am using one (maybe two) Speedlite 580 EX flashes with shoot through umbrellas as lighting.

In my practice shots, I cannot seem to get a nice "blown out" white background without dulling my subjects (decreased contrast/lighter exposure on their face and clothes).

I am not a fan of seeing the muslin draped or crinkled in the background... although I know that's definitely a style... I will probably iron it but I can never get it perfectly flat and plus I need to transport it so it will get some wrinkles.

Also, what can I do to avoid any shadows against the backdrop itself (shadows created by the subject). I do have them placed slightly away from the backdrop but kids sometimes move around. Also if I am doing little children, I don't think having a small backlight would be practical (not that I have one... )

share|improve this question
    
Are you willing to increase the equipment you use? It's hard to achieve what you're looking for with only a couple of lights. –  John Cavan Oct 29 '12 at 13:35
    
Are you lighting the backdrop with one of your speed lights? –  ElendilTheTall Oct 29 '12 at 13:35
    
possible duplicate of How can I create an inexpensive white backdrop? –  Matt Grum Oct 29 '12 at 13:51
    
Yes, I am willing to increase my equipment (although since this isn't my primary type of photography and I have limited storage space, I was hoping to keep it to a minimum). Definitely would love suggestions! Thanks. –  cm49 Oct 29 '12 at 13:56
    
Hmmm; suggested duplicate question is about backdrop for product photography, but Matt's answer covers studio portraits, which is this question. –  mattdm Oct 29 '12 at 14:38
show 1 more comment

4 Answers 4

up vote 10 down vote accepted

To get the "blown out" white background you have to overexpose the background.

You have no choice, in order to over expose the background you need a very powerful light aimed at the background.

If you have two flashes place one of them behind or to the side of the subject aimed directly at the background behind the subject (unmodified, without an umbrella), you want to set the power to the minimum that will overexpose the area around the subject (any area not touching the subject can be easily made white in post).

Placing you subject as far as possible from the background helps because it minimizes the reflection from the background on the subject.

You then use the second flash as the key light and ambient light as fill (obviously that means you start by metering for the ambient and set your flashes power based on it).

share|improve this answer
    
Thank you, this was very helpful. If I have to stick to two flashes (one to illuminate the backdrop and one to illuminate the subject), does it matter if they are both on the same side or should they be on the left, one on the right? Thanks for the tip about not using the umbrella to illuminate the backdrop too. –  cm49 Oct 29 '12 at 20:34
    
@cm49 - in theory the location of the background light is not important because it's just creating a bright spot of the background and the light shouldn't hit the subject at all - the only thing that matter is the distance to the background - if you put the flash very close to the background you can reduce power and get less light on the subject but the closer the flash the smaller the blown out spot. –  Nir Oct 29 '12 at 20:54
add comment

Just to add to what Nlr was written:

You have no choice, in order to over expose the background you need a very powerful light aimed at the background.

Instead of "very powerful", what should actually be said: two stops brighter than the exposure of your subject.

So for a given ISO and shutter speed, and (say) f/5.6 for the subject of your photo, you need to have your background at f/11. If your subject is at f/4, then your background has to be at f/8 to be blown out. (On the opposite end, if you want your background black, you need it to be exposed four stops below your subject.)

Most dSLRs (assuming you're using one, and not medium format or film), have about a six stop range. The middle (18%) grey that the camera meters for is most of the way up in that range on all dSLRs that I'm aware of.

So saying "very powerful" is a bit meaningless, and depends entirely on what you are exposing the subject at.

If your subject is at f/2.8, then reaching f/5.6 should be unreasonable for many flashes. If your subject is at f/11, then you'll definitely need a lot of photons to hit f/22.

This introduction by Joey Quintero for B&H is pretty good intro on studio lighting and light ratios:

http://www.youtube.com/watch?v=-ibFanS5GC4

share|improve this answer
    
Thank you... this was great additional info... Thanks for the link! –  cm49 Nov 4 '12 at 19:55
    
That posted link for the youtube video is set to private. –  ziggy Mar 31 '13 at 19:44
add comment

@cm49, know that this is hard to do and that you may find touching it up a bit in post is easier than getting the perfect white background. @dan's reply is spot-on. You need your background 1 to 1.5 stops brighter than your subject.

And of course, depending on the distance between subject and background, you may see some bleed from the background being a light source (as @dan mentioned). That's one reason it's hard. So get the happiest medium you can and handle the rest in post.

Good luck!

share|improve this answer
add comment

The right way to do this is to light your subject and your background separately.

Ideally you would use two (or more) flashes to light the white background, with one on each side. However, with enough separation and a tight enough shot, one flash for the background can be enough to make this work. Set the exposure for this with a few test shots and refer to your histogram. You should try shooting as metered, refer to the histogram, add some "+" exposure compensation, then try shooting again. You want to get the white to just into the highlights. You do not want to blast them with all of the power in the flashes and then consider yourself successful. Blasting it with so much light will cause the background to reflect light and become a light source itself, causing the light to spill from the back onto your subject.

Once you've got the background set, move on to getting the subject exposed correctly.

share|improve this answer
    
Thank you... this was also a very helpful answer. I will consider getting a third flash and stand! –  cm49 Oct 29 '12 at 20:35
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.