Camera Types, Digital vs Film and Sensor Size

Before I knew much about photography I thought digital was bound to be an improvement on the types of cameras I used as a kid, and the way we relied upon the likes of high-street processors to get our film processed. However, after studying photography for at least two and a half years, I now know the differences between film and digital couldn't be more different in terms of the way they record light and create images. Film is raw and random, in the way it relies on actual chemicals and film emulsion in the creation of grain. Digital, on the other hand, is based on a more linear process of ones and zeroes (binary) resulting in pixels. 

A bit about digital sensors

The size of the sensor is what determines the resolution and image quality. A lot has been made of high mega pixel counts over the years, but this is mainly a marketing strategy to shift more cameras. Manufacturers basically rely on the consumer's lack of knowledge of sensor size, prone as they are to assuming the higher the mega pixel count, the better the camera. Not the case. A mobile phone (like mine) that boasts a 8mp camera means very little, for the sensor is very small. This means the sensor is not picking up as much light in its photo-sites than that of a larger sensor of the same mega pixel count.   

Most of the students on this course use dSLR cameras with an APS-C sensor. This is a Digital version of the traditional Single Lens Reflex camera that I will be looking at shortly. APS-C stands for Advanced Photo System (type C), which is basically a cropped version of a a full frame sensor: the size of a traditional 35mm negative. Digital SLRs with full frame sensors are generally a lot more expensive because of this. 

The scaled-down size of the APS-C sensor also effects how we think of the focal length of the lenses we buy for them. For example, a 50mm lens on a APS-C is the equivalent of 75mm on a full frame. Why? Because you need to mulitply the size by 1.5 (for Nikon; 1.6 for Canon) to arrive at the full frame equivalent.

SLR:

As I've mentioned that the full frame dSLR is basically a digital version of the traditional film SLR, I might as well start this section by discussing what exactly this is.
SLR stands for Single Lens Reflex, which refers to the fact that what we see when looking through the viewfinder represents how the resulting image will look.

We see the scene through the viewfinder because the mirror is held out of the way, until the shutter is pressed, when it raises to allow the light to pass through the pentaprism and eventually onto the focal plane (film negative).

Digital SLR

As I mentioned above, most people interesting in photography nowadays will have one of these. This is because they are easier to work with, and there are less scope for mistakes. I read an article on Adobe's website over two years ago about Gamma Curves and the difference in how information is recorded between digital and film. I do not plan to regale you with the details of this very mathematical article, but I will reference the famous Ken Rockwell, in saying that digital has issues recording highlights because- once they reach White- the highlights start to clip/go off the scale. Film- on the other hand- "overloads gracefully when things get too white and wash out" (2). 

Medium Format

This is the Mamiya 645 Medium Format camera. We used a version of this when shooting our Serrano-type portraits in the studio, along with when we shot out still life flowers.

Medium Format can be said to refer to any camera that uses a negative bigger than 35mm, but smaller than a 5x4", which is the smallest Large Format cameras come in, which I will discuss below. Medium Format can also be separated into a few sub-types, such as folding cameras, Twin Lens Reflex (these are what we deem as the real "oldies") and SLR (similar to what most of us have, but the viewfinder is at the top, so we look down into it- above). Replaceable viewfinders can also be bought for the SLR-type.

Medium Format cameras generally use a 120mm roll of film, but the size of each negative ranges from 6x4.5 (in the case of the Mamiya above), to 6x6 square, to 6x7, right through the rarer models of 6x24 panoramic. The film is basically ripped-off at different points according the size of the camera's focal plane. 

When I used the above Mamiya, I had great difficultly focussing the thing (especially when trying to focus on the eyes for my portraits), but I guess this is where the fun is, for it brings us closer to more traditional photography.

This is a comparison of 35mm film (right) and regular medium format film (left) (1)

Digital Medium Format

There are two main types of digital medium format camera: those that are fully digital, and the analogue versions that can be fitted with digital backs (like we used whilst shooting our portraits and still lives).

Hasselblad H4D-50, 50 megapixel Medium Format camera.
These are more often than not used for advertising and fashion shoots due to their large sensors and huge resolution.

This the Leaf Aptus II digital back on a traditional medium format camera. We used a leaf digital back when we shot our images in class, but our's didn't have an LCD on the back, so we had to tether it to the computer, where the image would appear seconds after the shutter is pressed. In short: the digital back allows an analogue camera to take a digital image (usually in the TIFF file format). The digital back helped with the above difficulty in focussing to some degree, for at least we could view our images on the computer screens a few seconds after they were shot.

Large Format

Arca Swiss Monorail 5x4.
This is similar to the model we experimented with in class.

Large Format is a term applied to any camera with a focal plane larger than 5x4 inches. They normally consist of two standards (plates) connected by a set of bellows, used for perspective control, in the middle. The front standard houses the lens, and this can rise to eliminate the converging verticals we see when we photograph buildings. The rear standard can also be moved into the position of either landscape or portrait orientation. The monorail model above allows for the most movement of all the Large Format types, which is what makes it perfect for studio work. 

The first thing I noticed about this format was how we do not need to second guess what is going on within the workings of the thing like we do with digital bodies. A lot of the time we are made to understand how a digital camera works without actually witnessing it for ourselves. With Large Format, when we are told that a lens of 150mm, we know that the glass is exactly 150mm away from the focal plane where the film is loaded. 

Most students of digital are familiar with the likes of 'tilt shift' techniques afforded to us by specialist tilt-shift lenses, products such as the Lensbaby, and various effects in Photoshop, but Large Format offers us the original tilt shift with the use of the bellows. By moving the front standard left and right, we can choose our own perspective and sweet spot of focus: basically by shifting the lens and altering what is recorded by the film. 

Other Camera Types

Compact

Basically, everyone, has had one of these at one point in their lives. They are generally point-and-shoot cameras, but these days manufacturers have started adding more features to them, such as bigger LCDs and higher zoom capabilities; basically, edging in more high-end features for lower prices. Low-end compacts are suitable for your average night out or just taking pictures of friends, but for those wanting better image quality and more features, people generally opt for something a little more high-end.

Compact System Cameras 

   

Sony NEX-5N

                                                                

These seem to be all the rage these days, due to their interchangeable lenses and compact size. They often use the same CMOS sensors- and have many of the same features- of dSLRs, but their compact size is perfect for the man/woman who refuses to walk around public places with a something as big as a dSLR. I have met many a photographer/camera obsessive who also own one of these for ease of picture-taking, and so they don't have to take their large bodies everywhere they go. However, the disadvantages of these types of camera is that a lot of them don't have viewfinders (rather you view the image on the LCD), and they are a lot slower to start up (3).

Bridge Cameras

When I started taking a real interest in photography in September 2010, this is what I started off with. These are meant to "bridge" the gap between compact and dSLR cameras. They have many of the same features (inc. a viewfinder), but they generally don't allow for the changing of lenses. Rather, the focal length is controlled by a digital zoom, like that of of compact, but a lot more powerful. For me, use of my friend's Sony Cyber Shot HX1 was a good way to introduce me to the aperture and shutter speed, whilst letting the camera doing half the work. 

Rangefinders

Leica M3

Rangefinders show two images in the viewfinder, and when these two are the same, the photographer knows the image is in focus. There are many advantages of the Rangefinder over that of the SLR. For one, they don't have a mirror, which means there is no sound of it moving out of the way to allow the light to hit the negative/sensor. No mirror also means the camera takes a picture a lot quicker. This is perhaps the key advantage for me. With the SLR there will always be a delay between pressing the shutter and the sensor receiving the light needed. So if we are taking a picture of someone who blinks at the last second, we risk having their eyes closed, whereas with a rangefinder, what we see is more likely to be what we get. Leica are probably the most coveted example of this type of camera, known for the use by the roving reporter or street photographer because of the quietness of the shutter.

1) http://en.wikipedia.org/wiki/Medium_format_(film)#120_and_220
2)  http://www.kenrockwell.com/tech/filmdig.htm
3)  http://www.which.co.uk/technology/photography/guides/compact-system-cameras-explained/