Tag Archives: contrast

Exercise: Contrast and shadow fill

The brief:

Set up a simple still-life shot. Leave room for access at the sides of the set, and make sure that neither side is close to a wall. Shoot from the same level as the subject, with camera on tripod. Fix the light about three feet to one side of the object and at its level, so that it is aimed at right angles to the camera’s view. Take the first photograph without a diffuser in front of the lamp, and the second with the diffuser.

Then take a white card and position it about one metre away from the subject on the opposite side of the light and facing it. Take a photograph. Then move the white card in about half a metre and take another photograph.

Take a piece of aluminium foil that will cover the area of the white card and place against the white card, dull side facing the object. Take a photograph. Flip the foil over and with the shiny side facing the object take another photograph. Then crumple the foil and smooth it out again. Place it against the card with the shiny side facing out and take another photo. Compare the results and arrange in order of contrast.

I again used my Nikon speedlight for this exercise, power was set to 1/2 throughout the sequence. My camera settings were f8, 1/160, 45mm, ISO 100. I was very frustrated when setting up my background for this exercise. My background cloth which had been ironed so that there were no creases was intent on showing “bubbles” when lit by the flash. Try as I did, I could not get rid of this. I tried putting extra cloth and black card under the cloth, but nothing really worked. I even taped the edges down after stretching the fabric taut. So please forgive my bubbles. To get the full learning experience from this exercise I have not done any post-processing.

Fig 01 Bare flash

Fig 01 Bare flash

The image with the bare flash has hot spots all the way down the left side of the figurine with the result that the highlights have blown out and the background is washed out (Fig 01).

Fig 02 Flash with diffuser

Fig 02 Flash with diffuser

With the diffuser fitted to the flash the result if much better. There are details in highlighted sections, the background is properly saturated even though the image is a little dark on the right (Fig 02).

Fig 03 White card 3 feet away from subject

Fig 03 White card 3 feet away from subject

With a white card held 3 feet from the subject right side of the image is a tiny bit lighter – mostly noticeable on the cheek area (Fig 03).

Fig 04 White card 1.5 feet away from subject

Fig 04 White card 1.5 feet away from subject

With the white card 1.5 feet from the subject the difference is more pronounced. The right side of the image has lightened up quite considerably and the folds on the skirt are now discernible (Fig 04).

Fig 05 Foil dull side

Fig 05 Foil dull side

It is quite difficult to see the difference between the white card at 1.5 feet and the foil dull side, but I think some subtle highlights have been added back into the cheek area, but it looks as if the skirt has picked up more contrast (Fig 05).

Fig 06 Foil shiny side

Fig 06 Foil shiny side

The foil shiny side has produced more contrast somehow, but I think I must have angled the card incorrect. I did shots with labels to identify which scenario the images were supposed to represent and then removed the label to shoot the photograph again and my labeled image and unlabeled image look a little different, so I’m thinking I must have moved the card slightly after I removed the label. Unfortunately I only discovered this after uploading the images. In Fig 06 there is more contrast down the right side of the subject.

Fig 07 Foil crumpled

Fig 07 Foil crumpled

The crumpled foil lightens the shadow in the underarm crease on the right hand side, casts more of a shadow on the right side of the face, and deepens the contrast of the skirt area.

I have arranged the images in order of contrast going from lightest to darkest in the gallery below.

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Light—Science & Magic

So I have begun to read Light—Science & Magic An Introduction to Photographic Lighting by Fil Hunter, Steven Biver and Paul Fuqua. At first, when I picked up the book and flipped through it, I thought that it would be very dry. Was I ever wrong! I never thought physics could be so interesting. My high school physics teacher (a few decades ago) would have been much more engaging if she had used a book like this, bless her.

One often hears photographers saying that they want to learn how to see the light. Well, this book teaches exactly that. This is the first time I have read (or heard) such a comprehensive explanation. The authors begin by explaining what light is – electromagnetic radiation, how the electromagnetic fields work, the colour of light, brightness, contrast, hard light and soft light. They then move on to explain the basics of lighting: shadows, highlights, transmission of light, absorption and reflection.

Chapter three delves more into reflection, specifically how light is reflected off different subjects or surfaces. It covers the different types of reflection, namely diffuse reflection and direct reflection. Then the maths kick in (though thankfully no calculations are needed) and concepts such as the Inverse Square Law and the Angle of Incidence and the Angle of Reflectance and the Family of Angles are covered. What was extremely helpful were the exercises or experiments I could perform to demonstrate these concepts. There were a few “Aha!” moments for me! The difference between unpolarized direct reflection and polarized direct reflection was also dealt with and now I know how my polarizer is supposed to work so I will definitely be making better use of it than I have in the past. The illustrations on page 45 of the children using the skipping rope were quite helpful, but I wasn’t totally connecting with the concept until I went online and viewed a video on Youtube: Doc Physics – Intro to Polarization Filters! or…why are those sunglasses so expensive? – Doc Shuster, published February 20, 2013 [accessed April 4, 2014].

The magic of the science is coming alive for me and the light has been switched on.

Reference List

Hunter, Fil et al, (2012). Light—Science & Magic An Introduction to Photographic Lighting. 4th ed. Oxford: Focal Press