Fade to black portraits??

[Seastudent]

Hello TPF, I'm new to the site and wanted to jump in with a question for all of you knowledgeable photogs.

I've always been fascinated with black and white portrait photography where there's a soft light hitting a small area of the model and then the rest of the model fades to black with the background. No visible traces of a backdrop, just crushed black. I did some searching on the web to try and find a photo that resembles what I'm talking about and I'll post the link below. I understand light positioning, and I have an exterior speedlite which I just started playing with. But I haven't quite thrown the concept together.

Sam Fowler | Photography : Photo Keywords : portrait. 

Thanks

 

[Kerbouchard]

Some of it is post processing to take care of any missed details, but the main thing is that you have a large diffused light source(possibly gridded) as close to the subject as possible. The closer the light is to the subject, the greater the light fall off will be. It is also important that your background be as far from your subject as you can get it and that there are no stray lights hitting it.

Heck, you can use a white background and make it look black with the way you position your lights, but obviously, a black or grey background is easier.

If you are interested in lighting, you might want to pick up a copy of Light, Science, and Magic. It's a very well put together book on how to light just about anything and what the different options are.

 

[KmH]

Light Science and Magic, An Introduction To Photographic Lighting, Fourth Edition

Light falls off as a square function of distance, according to the Inverse Square Law. Light falls off more the further away the light source is. If the distance to the light source is doubled, the light fall off at the subject is 4 times less light 2x2 = 4. Double the distance again, and the light fall off at the subject is now 16 times less 2x2x2x2 = 16. Inverse-square law - Wikipedia, the free encyclopedia

The key points Kerbouchard made is to keep light from spilling on the background. That is easier to do if the subject is well away from the background, the light is close to the subject and not angled towards the backdrop.

The closer the light is to the subject, the larger it's apparent size relative to the subject and the softer any shadow edges will be. However, if a light source is small even when close to the subject (like a light bulb or hot shoe flash unit) the shadow edges will still be pretty sharp.

When doing strobed light (flash) photography, shutter speed is used to control the ambient light, and the lens aperture is used to control the strobed light exposure. To get a solid black background you want a small lens aperture and a fast shutter speed. How small an aperutre you can use then depends on how powerful your strobe light is.

If you look at tutorials for shooting smoke, the setups would be very similar.

The background in this image is a medium gray seamless paper and the smoke (I colored the smoke with Photoshop) is lit by 2 speedlights I had flagged so light couldn't spill onto the gray background paper:

Here you can see the same brand and color gray seamless paper background in a more conventionally lit shot;

 

[Kerbouchard]

Light Science and Magic, An Introduction To Photographic Lighting, Fourth Edition

Light falls off as a square function of distance, according to the Inverse Square Law. Light falls off more the further away the light source is. If the distance to the light source is doubled, the light fall off at the subject is 4 times less light 2x2 = 4. Double the distance again, and the light fall off at the subject is now 16 times less 2x2x2x2 = 16. Inverse-square law - Wikipedia, the free encyclopedia

Just one quick point because I had to read this part of your post a couple of times to make sure we were on the same page, so to speak. I think you actually misspoke or I am reading too much into what you said...in any case, light actually falls off less, or at least at a less rapid rate, the further away the light source is from the subject.

Yes, as you double the distance from the light source, the light at the subject has 4 times less light. It is referred to as the inverse square law. The part that I don't think either, me or Keith explained well, is why having the light source close to the subject is important for this type of shot. Perhaps using a real world example would explain it the clearest.

See, if your light is 1 ft from the subject, than at 2 ft, there will be 4 times less light. Simple. Well, if the light is 8 ft from the subject, than it won't be until you get to 16 feet that you have 4 times less light. The closer the light source is to your subject, the more rapidly the light will fall off. It helps if you think of your background as a separate subject. You want to light your main subject properly, but you want your secondary subject, i.e. the background, to have almost no light on it. In order to do that, you want to make sure you have as many 'doubling' spaces in between your main subject and background as possible. By having your light source close to your main subject, it is relatively easy to make that happen.

Hope that makes it a bit more clear in case our previous explanations were a little confusing.

P.S. On a side note, if you are doing portrait photography with several rows of people, you want to have your light relatively far away so that there is not a noticeable fall off between the first row and the last row. The inverse square law has many nuances and can make your photography a lot easier when you get to know them.

 

[gsgary]

Something like this

1 light high, with high intensity reflector

 

[Big Mike]

Yes, the key is to understand the properties of light and use that to your advantage. As Keith points out above, you can make just about anything look black in a photo (grey paper in this case)...you just have to make sure that it isn't getting much light. Or more specifically, that it's getting less light than your subject, and that you set your exposure for the light that is on your subject.

As for the fade to black, that has everything to do with the position of the lights and the model. If your light is on the camera's angle...there is very little (or no) fade. But as you move the light away from the camera's position, you see less lit area and more shadow area (provided that your model is 3 dimensional).
Also, there is the hard & soft properties of the light. A soft light will give you soft edges to the shadows, where the subject gradually transitions from light to shadow (assuming a round surface). A soft light comes from a light source that is large, relative to the subject. A hard light will give you hard edges to the shadows, and is produced with a relatively smaller light source.