Hamish Gill
Tech Support (and Marketing)
I thought it might be useful to create a few articles on some of the basics of camera's. I've seen quite a few articles like this online but they are often over complicated so my approach is going to be a very simplistic one!
The first of these articles is answering a question I was asked almost every day I worked selling cameras - "What is an SLR?"
An SLR is a Single Lens Reflex Camera.
Single lens because it has a single lens on the front - This might seem an odd thing to call a camera, obviously it has a single lens, but back in the days when everything was black and white (or sepia) and SLR's were invented a common type of camera was the TLR or Twin lens reflex camera - more on that another time.
The reflex bit comes from the fact that there is a mirror and prism inside the camera that reflects the light through an eyepiece to the user of the cameras eye.
If you have a look at this image you can see the path of the light (in green) as it travels through the lens, reflects off the mirror, up in to the prism and is bounced around the eyepiece to the users eye. The diagram is a side on view of the camera.
You will notice that there is a mirror and shutter between the lens and film or sensor. Quite simply, when you press the button to take the photo the shutter moves out of the way and the mirror flicks up. This allows the light to hit the surface of the light sensitive surface (film or sensor) behind.
So what is the advantage of this system and why are they so popular?
The biggest advantage is the fact that when you look through the viewfinder you see through the lens (as described).
These days we can of course get the same effect from looking at a digital screen but for many this doesn't quite cut the mustard in the same way as looking at an image through some glass does.
Something that is perhaps less obvious is that when looking through the viewfinder of an slr the image you see is the right way round and the right way up!
If you were to view the image as it hits the sensor it would be upside down and side to side inverted, the clever combination of mirror and prism corrects this issue for you making framing the photo a much easier prospect than many of the other types of camera around when SLR's were first invented.
There are also some disadvantages of this system, the main being the size! SLR's can be small, but there is no getting around the fact that to make the system work there is a requirement for a mirror, the space for the mirror to move and a prism.
Because of this disadvantage there has in recent years been an increase in popularity of "mirrorless" Cameras like the Panasonic g series and Fuji X-pro1. These cameras are now popularly known as "CSC's" or "Compact system cameras" but in their early days were often refereed to as "MILC's" or "Mirrorless Interchangeable Lens Cameras". More on this type of camera to come soon!
One last thing to remember about an SLR, be it digital or film, the mechanical part is much the same so my rudimentary diagrams apply regardless of the medium you are shooting!
(This might be the second time you have spotted this, and if you are Lesley you will notice there is a comment missing, im sorry, we had a few issues)
The first of these articles is answering a question I was asked almost every day I worked selling cameras - "What is an SLR?"
An SLR is a Single Lens Reflex Camera.
Single lens because it has a single lens on the front - This might seem an odd thing to call a camera, obviously it has a single lens, but back in the days when everything was black and white (or sepia) and SLR's were invented a common type of camera was the TLR or Twin lens reflex camera - more on that another time.
The reflex bit comes from the fact that there is a mirror and prism inside the camera that reflects the light through an eyepiece to the user of the cameras eye.
If you have a look at this image you can see the path of the light (in green) as it travels through the lens, reflects off the mirror, up in to the prism and is bounced around the eyepiece to the users eye. The diagram is a side on view of the camera.
You will notice that there is a mirror and shutter between the lens and film or sensor. Quite simply, when you press the button to take the photo the shutter moves out of the way and the mirror flicks up. This allows the light to hit the surface of the light sensitive surface (film or sensor) behind.
So what is the advantage of this system and why are they so popular?
The biggest advantage is the fact that when you look through the viewfinder you see through the lens (as described).
These days we can of course get the same effect from looking at a digital screen but for many this doesn't quite cut the mustard in the same way as looking at an image through some glass does.
Something that is perhaps less obvious is that when looking through the viewfinder of an slr the image you see is the right way round and the right way up!
If you were to view the image as it hits the sensor it would be upside down and side to side inverted, the clever combination of mirror and prism corrects this issue for you making framing the photo a much easier prospect than many of the other types of camera around when SLR's were first invented.
There are also some disadvantages of this system, the main being the size! SLR's can be small, but there is no getting around the fact that to make the system work there is a requirement for a mirror, the space for the mirror to move and a prism.
Because of this disadvantage there has in recent years been an increase in popularity of "mirrorless" Cameras like the Panasonic g series and Fuji X-pro1. These cameras are now popularly known as "CSC's" or "Compact system cameras" but in their early days were often refereed to as "MILC's" or "Mirrorless Interchangeable Lens Cameras". More on this type of camera to come soon!
One last thing to remember about an SLR, be it digital or film, the mechanical part is much the same so my rudimentary diagrams apply regardless of the medium you are shooting!
(This might be the second time you have spotted this, and if you are Lesley you will notice there is a comment missing, im sorry, we had a few issues)
