2. Cameras - what to use?
Table of contents
Types of cameras
There are many types of cameras available. With the pace of technology, it can be very hard to keep pace with developments and what is right for you to use for your digitisation project. The most used type of camera used in digitisation workflows are SLR cameras, (Single Lens Reflex), modern versions of which are sometimes referred to as DSLR (Digital Single Lens Reflex). SLR cameras have been around for nearly 90 years and widely used by professional photographers for the last 60, with many of the defining images of the latter half of the last century being taken on 35mm film using an SLR. Some examples, showing the evolution of such cameras are shown below:
Figure 1: the evolution of SLR cameras. Top row, left to right: Exakta (1936) Wikimedia Commons; the Nikon F (1959) Wikimedia Commons; Minolta Maxxum 7000 (1985) Wikimedia Commons. Bottom row: Nikon QV-1000C (1988) DIGICAMMUSEUM.COM; Nikon D5500 (2010) Wikimedia Commons; Panasonic Lumuix S1R (2019) ePHOTOzine 2022 (mirrorless camera - next step beyond SLR).
Advantages of SLRs include:
- Full control of all settings during taking of the photograph (we will discuss why this is important later)
- Convenient size for professional use - not too large or too small
- Interchangeable lenses for different situations (close-up, wide-angle etc)
- Can be connected to other accessories - e.g. studio flash units
- Optics are good enough to allow reasonably high resolution of detail
During the decade from 2000-2010 digital image sensors began to become available which had potential to replace traditional silver based film emulsions in regular cameras. Initially these were expensive, somewhat clunky factory modifications of existing film based cameras, and they came with numerous limitations, but very soon these problems were resolved, and prices began to drop to affordable levels which further hastened adoption levels. Today, digital has replaced film in all but a few very limited, niche applications.
Digital SLRs retain all of the features listed above, but by eliminating the use of film being in several extra attributes, such as:
- Live video feed from the sensor, which makes complex focusing and exposure scenarios much easier
- Instant preview of results via the LCD screen (now higher resolution than some TVs)
- Results automatically available in a form that can be stored electronically and shared via the internet
- Very low cost per photograph if the camera is used intensively (you might expect a lifetime from a quality camera body to be around 100,000 frames or more)
Arguably it is the last two points on this list which have been transformative in allowing off-the-shelf DSLR’s to be used in museum mass digitisation projects. It would be impossible to do the kind of things we are discussing here if using a film SLR.
While the SLR cameras are the most widely used for digitisation, any camera shooting in a raw format, with >12 megapixels and a video out jack, could feasibly be used. Recently, DSLRs are being superseded by mirrorless cameras such as the Panasonic SR1. However, these are very similar to DSLR cameras being almost indistinguishable for the average user, and simply represent the latest evolution of SLR type cameras. Mirrorless cameras are even frequently referred to colloquially as SLRs.
What camera to choose?
The cameras used for digitisation do not need to be overly fancy and off the shelf SLRs costing around £2,000-3,500 new will produce images of high quality and are used in many specimen workflows. While other cameras with higher resolution and other features are available, such differences also come at a high price cost while not providing many substantial benefits for most digitisation projects.
For example, let’s compare the two cameras shown below.
Figure 2: Two cameras - two very differnet prices. Image sources Hasselblad 2022 (left), ePHOTOzine 2022 (Right).
The left-hand image is of the H-system camera from Hasselblad, and is one of the most advanced DLSR cameras easily orderable online and is capable of taking 100 to 400 megapixels images. However, at a cost of $32,995 (not including lenses) this is far too expensive for most digitisation projects. Additionally, images of such high quality are generally unnecessary for specimen analysis and are difficult to store. Much cheaper options are often better, such as the Panasonic Lumix S1R shown on the right and used in our . This camera cost in the region of £3,000 and takes single image shots of 47 megapixels or stacked shots up to 187 megapixles. In summary, while these two cameras have a roughly 10-fold difference in cost, this does not translate into a ten-fold difference in image quality.
When choosing a camera for digitisation, it is recommended to stick to one brand of SLR camera for your workflows. While camera design is quite conservative, there are differences between makes in their button layout, cable positioning, batteries, tethering programs etc. Sticking with one make means that cameras and their parts can be interchanged with minimal fuss. New versions of the cameras are frequently released, but often don’t result in large scale changes. Even if the model you are using is dis-continued you are still likely to get good replacement parts or hire specific pieces of equipment if you’re using one of the major brands. Sticking to one brand of camera within your institution also makes training new digitisers easier. The main SLR cameras are produced by Canon, Nikon, and Panasonic, but other brands exist too and are all fairly similar in appearance and in operating.
Figure 3: camera deign is quite conservative. These three cameras are made by three different companies and are a mixture of DSLRs and mirrorless cameras. Despite this, the three are very similar and without brand names would be difficult for the acergae person to tell them apart. Even the buttons are often in the smae places. From left to right: Nikon D5500 (2010) Wikimedia Commons; Canon EOS 5D Mark IV Wikimedia commons; Panasonic Lumix S1R ePHOTOzine 2022
Finally, remember that the best camera body in the world will not produce decent results if the attached lens is not up to the same standards, so you should budget for the lenses you will need in your calculations. Some cameras will be sold bundled with inexpensive “kit” lenses which are suitable for general photography, but you may also want to look at professional specialist lenses as well. In some cases, second-hand cameras or lenses could provide a more cost effective way to acquire the necessary equipment.
Next page: 3. Camera settings and specifications