Inside this issue
Large Format Camera Accessories
The Supporting Cast
Amateur Photographer who plays with big cameras and film when in between digital photographs.
Once you’ve bought your large format camera, it’s time to look at the ‘extras’ that you’ll need in order to take pictures. We’ll be covering lenses and lens panels in the next chapter so for now here is a run down of what else you’ll need for your bag. It’s worth remembering that most of what you know about choosing equipment is not the same for large format. Even a poor camera with a cheap lens can make stunning images and so what you tend to pay for with large format is to do with ease of use, flexibility of control and enhanced pleasure in operation.
First of all, we’ll look at the ground glass, loupe and dark cloth. These are the components that give you your view of the world and the better quality you get, the better your experience of using the camera will be.
Ground Glass & Fresnel
The ground glass is your window to the world, your live view and your auto focus. Having a ‘bad’ ground glass can make using the camera considerably less enjoyable. However, the good news is that a good quality, basic ground glass can be had very cheaply and most modern cameras come with a good quality example as standard.
The ground glass is just what the name implies, a piece of plain float glass which has been ground on one side until it becomes diffuse. The amount of grind is a personal taste and why some people like to grind their own (a long process, only for the patient). Less grind and you will have a brighter screen but potentially have double images and a ‘hotspot’. A coarse grind can be brighter but the texture will be visible. A very fine grind will be darker but will be clear and easy to focus. People have done the research before you though so I would trust a decent commercial screen.
For most lenses, a standard ground glass will do the job nicely but you need to know that the light coming from a wide angle lens will hit the corners of the ground glass at an acute angle. Most of the light hitting a ground glass carries on in the same direction and so in order to see the corners, you have to move your head in line with the light rays. In practice, this means that on a wide angle lens it looks like you get a ‘hot spot’ in the centre of the ground glass and dark in the corners. As you move your head around, this hot spot moves around the screen of the ground glass. This can make focusing hard in the corners and also makes composing quite difficult. To solve this problem you can introduce a fresnel lens behind the ground glass (some manufacturers say in front but that can cause focus registration issues). The fresnel is effectively a flat lens which redirects these acute light rays hitting the corner of the ground glass back towards your eye. This means that the hot spot is a lot less.
Just like lenses, fresnels can range in quality. At the very top end, the Maxwell fresnel is particularly good but also particularly expensive. Just like a normal lens, the fresnel can have different focal lengths and Maxwell screens are available in focal lengths to accommodate ultra wide angle lenses. The Maxwell screen (and some others) combine the ground glass and the fresnel into a single moulded unit. Being in control of the ground glass as well means that you can buy brighter versions. Have a chat with Mr Maxwell on the phone (but don’t expect the phone call to last less than an hour!).