Tag Archives: family of angles

Exercise: Shiny surfaces

The brief:

Find an object that is so shiny that you can see your face in it. Choose an object that you can lay flat on the floor and photograph from above. Choose a simple background. Set up the object, camera and a light positioned close to the camera. Through the viewfinder, you should be able to see how unsatisfactory the effect is. Take a photo for reference.

Take some tracing paper and roll it into the shape of a long cone so that the wide end will set around the object (but out of view), and so that it tapers upwards to the small end, which should just surround the lens. Ideally, the length of this cone should be exactly the distance from the camera to your subject. Tape, and trim as necessary.

Take a second photograph. Experiment with a light in different positions and at different distances. Also try changing the angle of the object slightly.

For the life of me I could not get the exercise with the tracing paper done. I did not have enough tracing paper it would seem, although I went through about half a roll and not matter what I did, I still got an image in the surface of my object. The shiniest object that I could find in my house that gave a reflection were some cutlery pieces. I’m more a fan of brushed steel than stainless. The cutlery is not new or straight out of the box, so some wear and tear and nicks will be visible on the metal’s surface. Unfortunately my wireless triggers render the Nikon’s CLS system null and void, so my flash details don’t record on my EXIF data and I did not make a note on each photograph as to what the flash settings were. I mainly experimented with full power, 1/2 power, 1/4 power and 1/8 power, occasionally using +.03 and +.07 exposure compensation. My speedlight was used with a diffusion dome throughout.

Here is my reference image (fig 01). The spoon was placed on the floor on top of a black velour garment. The tripod was placed over the spoon and the light was off to one side. Terrible image – there I am with the tripod and half my kitchen is also reflected in the spoon.

Fig 01 reference image

Fig 01 reference image
f5.6, 1/200, 55mm, ISO 100

Fig 02 – one of the many attempts to manhandle the tracing paper into shape. Still no better than before.

Fig 02 with tracing paper

Fig 02 with tracing paper
f5.6, 1/200, 55mm, ISO 100

Fig 03 – I gave up on the tracing paper effort and put the spoon on a table on top of the black velour jacket and started to experiment finding the correct placement of the light. I found with the light on camera left I was getting a little too much of a hot spot on the metal.

Fig 03 light camera left

Fig 03 light camera left
f8, 1/200, 46mm, ISO 100

My jacket had picked up a bit too much dust to photograph well, so I switched to black card (fig 04), which unfortunately doesn’t photograph as well as the black material.

Fig 04 light camera right to side

Fig 04 light camera right to side
f8, 1/160, 46mm, ISO 100

I then switched to a white card and tried to soften the shadows and exposed to brighten the metal (fig 05).

Fig 05 light camera right to side - on white - light

Fig 05 light camera right to side – on white – light
f8, 1/160, 46mm, ISO 100

I then dialed down the flash power so that I could darken the metal (fig 06). I think this is possibly my favourite image as the deeper colour gives a bit more form to the slight octagonal shape of the cutlery’s handles.

Fig 06 light camera right to side - on white - dark

Fig 06 light camera right to side – on white – dark
f8, 1/160, 46mm, ISO 100

I would have preferred to soften the shadows of the two spoons a bit more, but I’m not quite sure how that should be done as the last three images were done with a big diffusion panel in front of the speedlight. I’m thinking I probably need one or two gobos positioned over the spoons to cut the shadows. Unfortunately all the voice activated light stands have retired for the night so I will have to make do with this result for now.

Fig 07 light camera left - light tent

Fig 07 light camera left – light tent
f8, 1/4, 55mm, ISO 100

The following day I decided to have one more go at this using my light tent (fig 07). The light was positioned 45 degrees to the cutlery on camera left and a diffuser was held in front of the light. The shadows are definitely more acceptable in this image.

I don’t think I will ever look at spoons in the same way again without thinking of how the light is striking them and what reflections are bouncing back. I have learned that one has to consider so much more than just the family of angles and positioning of the light and camera. All possible distracting elements that might possibly show up in a reflection have to be identified and removed or camouflaged wherever possible.

Reference List

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


Light terminology

It’s now November and I’m beginning the section on Light – so much more to learn. I started a Vocabulary section back in early March and added to it in April I believe, so there are a few more terminologies that I should add now. These are all related to light. As I work through the light section of this module, I will come back and add to this posting.

  • transmission – light that has passed through a subject, e.g. clear glass
  • refraction – the bending of light rays as the light passes through a subject from one material to another
  • diffuse transmission – the scattering of light waves in random directions, e.g. when light hits thin paper. An object that aids diffuse transmission would be a diffuser cap for a flashgun. Light is absorbed, reflected and transmitted.
  • absorption – light that is never seen again (absorbed by the subject and emitted as a heat source). An example of a light absorbing material would be black velvet.
  • reflection – light that strikes a subject and bounces off
  • diffuse reflection – same brightness regardless of the angle of view. Light is reflected equally in all directions. White things produce diffuse reflection.
  • inverse square law – intensity of light is inversely proportional to the square of the distance. For a visual (and better) explanation check out this video by Mark Wallace.

  • direct reflections – a reflection of the original light source
  • the angle of incidence = the angle of reflectance – light rays bounce off smooth surfaces at the same angle that they hit it.
  • family of angles – direct reflection are only visible to the eye within a limited range of angles – basically the angles that produce direction reflection. Important because it determines where we should place our light source.
  • polarized direct reflection – a reflection that is half as dim as a direct reflection due to the absorption by the polarizer.
  • perspective distortion – when viewing a three dimensional subject where the part further away appears smaller than the part that is closer to the viewer, which in turn appears larger.
  • tonal variation – the light and dark areas in the subject. Ideal tonal variation should include a partly shadowed side, a shadowed side and a highlighted side.

Reference List

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

Wallace, Mark (2011) Digital Photography 1 on 1: Episode 59: Inverse Square Law: Adorama Photography TV [online, webcast]. Adorama TV. Available from: https://www.youtube.com/watch?v=f5BIvSBjvLg. 12 mins 15 secs. (accessed 12 November, 2014)

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