Lenses – A not very brief history – L02

What to sayabout them. Well, lots really.

The have changed a great deal over the last 180 years, and yet they haven’t. Confused? I’ll try to explain.

The concept of lenses is ancient, possibly going back a thousand years. That lens’ is thought to be a sphere which changed the appearance of an object when viewed through it. Not exactly what we would call a lens today. However, it did spark experimentation, albeit with slow progress. The rudiments of the camera came with the camera obscura (latin for ‘dark room’) sometime in the 1500’s. This consisted of a large room with a lens mounted either on a wall or the roof, projecting onto a wall or a table. As light entered the lens, so it projects an image.

Photography was invented by a Frenchman, Louise Jaques Mandé Daguerre in 1839. He used single-element convex lenses, but these created optical abberations, where light is split into its respective elements.

Chromatic aberration.

It is recognised that another Frenchman, Charles Chevalier, son of an optician, created the first true camera lens. It was an achromatic lens, that does not split light into it’s respective colours, .. This was done using two lenses. The downside was that with two apertures, and the silver medium used to fix the image, exposures would be lengthy, sometimes hours or more, as a very small aperture was required to prevent spherical aberration. This is where the different elements of light fail to meet at a fixed focal point.

Spherical AberrationA number of developments then occurred, with larger apertures, thus shortening exposure times. Initially the were used for portrait photography, but as new lenses were created so new photographic techniques were available, such as panorama etc.

Bear in mind the cameras being used were what are known as Bellow Cameras with the lens mounted on a wooden plate attached to a runner that had a bellows between it and the main body of the camera that housed the camera. A frosted glass plate was inserted into the back to view the image. Moving the lens adjusted the focus. Once the image was satisfactory, a cap was placed on the lens to prevent light entering, the glass removed and a photographic plate inserted. The lens cap was removed and the plate exposed for the length of time the photographer felt was right. It did mean the image had to be stationary, as modern photographers know today with long exposures. For portraits at this time the sitter would often have their neck and head held in a brace to prevent movement!

The first ‘adjustable’ lens was developed by John Waterhouse in the 1850’s. This was not a single lens as we have today, but interchangeable lenses with different sized holes in them. Understanding ‘Aperture’ had still not been worked out! That took a further 20 years! The realisation that aperture affected depth of field was a major breakthrough. His system became incorporated into modern lenses, although it was not standardised until 1949, with three recognised formats being used, American (as advocated by Eastman), German and British. The latter was accepted, giving us the f-numbers or f-stops we know today.

Progress became rapid, with the first telephoto lens appearing in 1905. It was the 1930s that saw the acceleration of photography, especially as an art form, as cameras became more affordable, common and ‘portable’. George Eastman’s invention of celluloid film greatly assisted in this growth. It was the Second World War that really saw camera and lens development take off, especially in Japan. This may be due to many factories were destroyed and Japan focused on technology, and their development of camera and lens technology is still very much in evidence today

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s