Tutorials
Taking Just One Lens
We went for a drive to Llanrwst in North Wales, recently. It’s a small town near to Betws-y-Coed, on the edges of the Snowdonia National Park. The River Clywd runs through the town, which was our main destination. It was a hot and sunny afternoon, so we thought that a bit of relaxing by the river would be a welcome way to spend some time.
I took the camera along with me but, since it was hot (and I didn’t intend to spend the time looking for pictures) I decided to just take my Canon EF 50mm f/1.4 lens, since it is the smallest and lightest of the lenses I own. It can be an interesting challenge to restrict yourself to a single, fixed focus lens, when out and about with the camera.
Looking along the river from my position on the bank
Using Flash Gels
A rainbow of flash gels
I suppose the first question to answer is, “What are flash gels?”.
A gel is basically a coloured sheet of heat resistant acetate that is used to change the colour of a light source. They work by absorbing the frequencies of some colours of light and letting others pass through. Fortunately, because the light from strobes and portable flashes is a similar colour to daylight, you will get the colour change you expect - such as a blue gel making the light blue. Because the gels absorb light, you will lose some of the intensity of the light. The number of stops of light that a particular gel absorbs is available from the vendor or the manufacturer of the gel.
Gels normally come in square shaped sheets, for use with studio strobes or theatre lights, but you can cut these down to size for use with portable flashes. Some companies sell pre-cut gels that are the right size for the front of a speedlite. Gel manufacturers, like Roscoe or Lee, do sample books of the different colours of gel that they make. These contain strips of each gel that are about the right size for the front of your flash. The sample books can be difficult to get hold of though, due to the obvious popularity of ‘free’ flash gels. I usually buy the pre-cut gels from www.flashgels.co.uk.
Gels come in a multitude of different colours but, from a photography point of view, they can be classed into two types. Colour correcting gels will change the colour of the light your flash to match the colour of another source of light, such as incandescent bulbs or fluorescent strip lights. Theatrical gels change the colour of your light to give you a particular creative effect, such as using red gels to make something appear hotter or blue gels to make something appear more sterile or technical. You can also use the colour correcting gels to get certain effects but I will go into that in more detail later.
