29 Jun 2011

Exercise: Shiny surfaces

The challenge here is to make an image of a highly reflective object without the distractions of the photographer, the camera or the lights becoming a major problem.  The images below demonstrate the problem:

The requirements of the exercise were to organise the set-up with the camera beside the light giving unwanted blown highlights and reflections.  The studio flash obviously left some bright reflections but because this was being shot with a single artificial light source there weren't many other problems.  In order to get to see my own reflection, eg in the last image, I had to move in front of the lamp so that I got enough illumination to be seen.  Quite honestly, this was a poor way to demonstrate the problems. 

A much better way to show the difficulties of unwanted reflections was to shoot the objects again out of the studio under natural light, as can be seen here:

Having successfully produced some distracting and unwanted reflections, the next part of the exercise would best be described as something that Heath Robinson or a Blue Peter presenter might produce.  We were required to create a cone out of tracing paper and staples that fitted to the end of the camera lens and widened out to encompass the object we were photographing.  This was going to be difficult and hardly the best solution.  I did, however, manage to get something that approximated the description!

To give me flexibility in movement I split my cone into two parts that allowed me to shift my viewing angle around. In the past I have got over this problem by using a large white muslin or thin cotton sheet with a hole for the lens but the idea was the same. From inside the white 'tent' there are few, if any, reflections and the lighting can be directed onto the subject from outside through the material. Commercial versions can be purchased for only £10 or so for small ones.
Large <em>Photo</em> Light <em>Tent</em> Cube 120cm (48 inches) and 4 colour backdrops
Once I had sorted out my temporary 'tent' I rephotographed my shiny objects.  The tracing paper cone was far from practical and it took all my patience to get the floppy paper out of the shot and focus let alone attend to the details.

So the principle of shooting from within a white translucent volume with the lighting on the outside shining through the walls certainly works... I just wouldn't suggest a tracing paper cone for the job!

Exercise: Concentrating Light

This exercise suggested we fashion a cone of light to highlight a subject by using a tube of card or something similar.  Luckily I have a snoot that I use with my studio lights that is a purpose built version of the same thing.With the snoot in place it forms a pool of light that looks like this:

Here the intense light of the flash has correctly exposed the table but the amount of light has been restricted to a narrow beam by the snoot placed over the light.  The area around the bright-up appears to be in dark shadow when, in reality, it is quite visible to the naked eye.  Being set at around 1/100, f18, ISO50, the camera only sees the area of intense light produced by the flash.  In order to narrow the beam of flash further, I placed a honeycomb filter over the end of the snoot.  This attachment looks like a handful of hexagonal straws which only let light through the hollow centres and further ensure that unwanted light doesn't spill out from the snoot.  The honeycomb can give a slight grid effect to the light as can be seen here:

When photographed in this highly directional light the subject appears in high contrast and in a pool of light surrounded by shadow.  It has a rather dramatic effect with the vase being outlined by light and dark with just enough detail showing to give substance.

The same set-up from the side shows more detail of the vase.  A little bright up at the bottom right corner comes from a slight reflection and could easily be removed post production.