Portrait shots indoors with backdrop - advice please

[andya700]

I have a choice of backdrops which I can use - white, black and chromatic green. I have a good source of natural light through one large window (never direct sunlight on the subject though), but I can add fill in light from a flash with tilt head.
I have a couple of questions regarding colour of backdrop and aperture.
I am guessing that with a solo portrait shot in colour, I use white or black backdrop with whatever aperture I choose depeneding on the effect I wish to achieve - relatively sharp all over or a degree of softness to the shot, keeping the eyes pin sharp.
I would like advice on group shots, because it obviously takes a smaller aperture to achieve a perception of sharpness across the whole image.
I haven't had a chance to practice this, and I will be using a 24 - 105 f4 lens between 8 to 12 feet away from the subject. I am thinking f8 or f11 for the average group shot. I was also thinking of using the black backdrop for colour and the green one for monochrome.
I would like to know what the portrait experts use, because this is fairly new territory for me.

Cheers.

 

[Phil V]

If you want a crisp white background, it needs its own lighting, it should be exposed more than your subject, so even with window light it'll be further from the light source than your subject (straightforward ISL) and will therefore be darker than you'd like.

As for aperture and groups, remember that your plane of focus is a straight line, so all eyes at exactly the same distance from you will be in focus even at f1.4, I use f8 on groups that are 20 people deep, you can get away with lots less for small groups (depending on your distance from them).

But back to backgrounds and lighting. As a rule I'd advise people learn about lighting before moving to backgrounds, people think it's the use of backgrounds that make images look like they were shot in a professional studio, this couldn't be more wrong, or indeed the wrong aim. You don't want images that look like they were 'shot in a studio' what you want is 'good images'. Enough light isn't the same as good light, and what raises your work above snaps is the right light.

 

[Blank_Canvas]

Just to add to the above, to a get crisp white background you need to use two lights pointing at the backdrop to remove all shadows and create even lighting. This is where a four-light set up comes into its own. Two on the background and a key/main light and fill-in light on the subject in front.

 

[andya700]

Thanks guys,that has explained quite a lot to me.

Phil - "Enough light isn't the same as good light, and what raises your work above snaps is the right light." - I couldn't agree more with that.

Nick - thanks for the tips on where to light the background, and what to use on the subject.

 

[Sir SR]

Some excellent advice as ever from Phil.

I rarely use a backdrop but like using reflectors/natural light or a couple of studio lights with appropriate modifiers to get "good" light. Have started using a bit more bounced on camera flash recently.

As Phil says, it's about understanding light and having the right sort of light rather than having enough light!

 

[juggler]

Top advice from Nick, Phil & Shaheed there.

Studio backgrounds really show up lighting flaws in a way that an outdoor location or environmental portrait won't.
Aiming for pure black or pure white can be tricky, both in the lighting and post processing. I'd stay away from the green sceen, though, as it commits you to monochrome or photoshoppery.
If you can get hold of a mid or dark grey paper roll then it will be a lot more forgiving.

That said, if you're determined to use plain backgrounds, using only window light and an on-camera flashgun, for the solo portraits I'd suggest using the white background but aim to have it go mid or dark grey by virtue of being further from your light(s) than the subject. Achieving an acceptable graduated mid grey is fairly straightforward and to my mind more interesting. Bounce the flash from a white wall behind you or the ceiling if there's no white wall.

A reflector - e.g. a big piece of white card taped to a chair - may be invaluable.

If I was using just natural light on a group shot then I'd go outside unless I was completely stuck. Unless your windows are a bit special.

The only way I can think of to get a pure white background with the kit you have is to put a few layers of voile in the window and stand your subjects against it, then bounce your flash to illuminate the subject. Or use a large reflector. A meter would be helpful here, or use the blinkies when chimping the image. Note that the backlighting may need you to boost the contrast in post.