Lighting 102 Unit 1.2

This was a very interesting excercise and caused my brain to give a couple of pops with an aha here and an aha there.

For the shots I wanted to be sure that the fall off in light was due to the inverse square law and not by the flash pointing in the wrong direction, so I included the shadow in the shots.

I also wanted to see if different length lenses made any difference to the light.

The top row were taken with a Pentax 50mm f/1.4 lens.

The bottom with a Sigma 70 - 200mm f/2.8 lens.

Set up details are:

Flash was a Sunpak 383.

Subject to background 1.6m (always the same).

From left to right, for both top and bottom:

1. Flash to Subject 6.2m

Flash on 1/2 Power

Camera 1/125 @ f/8

2. Flash to Subject 3.1m

Flash on 1/4 Power

Camera 1/125 @ f/11

3. Flash to Subject 1.5m

Flash on 1/8 Power

Camera 1/125 @ f/11

4. Flash to Subject .8m

Flash on 1/16 Power

Camera 1/125 @ f/16

 

That was at the limit of my 50mm lens and flash capabilities so I stopped there. I could have used tissue paper to dull the flash even more, but I would have had to guess at the settings.

Interesting points to note:

Each image is 2 stops less than the previous one (One on flash and one on camera) which confirms the inverse square law exactly as I halved the flash distance each shot.

The length of the lens makes no difference to the lighting of the subject.

The length of the lens does make a difference to the apparent shadow size.

The longer lens also softens the shadow, presumably due to depth of field.

It's amazing what you can get up to on a day off work.

 

 

 

Done