Draft letter to the British Board of Film Classification - P5

I've asked BBFC to certificate my film opening in order to have a proof that it belongs with a 12 classification. This will allow me to target my audience and small children will be not allowed to watch it. I've sent a message to BBFC email address where I have explained why I think a 12 classification is the most appropriate and that I need it for my ICT project. Certificate from BBFC will also prove if I've given the right classification to my project.

Film Poster

Video Files' Formats

There are many different video formats such as:

- MOV;
- MP4 (MPE4);
- AVI;
- MPG;
- M4V;
- M2T;
- WMD;
- VOB;
- GIF;
- M2T
- and a lot of others.

Lossless and lossy video compression.

Lossy compression gets gradually worse the more you encode it. If you have a source video from your camcorder, and you encode it to a lossy intermediate codec that your video editor understand, then encode it again to a final product that you upload to YouTube, you've essentially reduced the quality of the video twice. Even if you match or exceed the bit rate each time, the compressor will work to copy the source file in a new way, essentially making a copy of copy.

Commonly used lossless video compression methods include:

- FFV1
- ProRes (Depending)
- Huffyuv
- Dirac (Can be lossless)

Lossless creation is an exact pixel-by-pixel copy of the original file. Each pixel is taken from the source and placed in the new file exactly where it existed in the source file. A lossless compression may significantly increase file size.

Commonly used lossy video compression methods include:

- H.264
- MPEG-2
- MPEG-4
- MPEG-1
- VC-1

Lossy compression methods don't make pixel-by-pixel copies of the source at all.

Compressed and uncompressed video files.

Video files may be compressed or uncompressed. Uncompressed video files consist of raw video in the form that it was originally recorded. File sizes for uncompressed video files are typically very large. Compressed video files may either be compressed using a lossless or lossy technique. Video files compressed using a lossy technique typically take up significantly less disk space when comparable to lossless video files.

Aperture, Shutter Speed & ISO research

ISO

ISO is the level of sensitivity of your camera to available light. The lower the ISO number, the less sensitive it is to the light, while a higher ISO number increases the sensitivity of your camera. The component within your camera that can change sensitivity is called “image sensor” or simply “sensor”. It is the most important (and most expensive) part of a camera and it is responsible for gathering light and transforming it into an image. With increased sensitivity, your camera sensor can capture images in low-light environments without having to use a flash. But higher sensitivity comes at an expense – it adds grain or “noise” to the pictures.

The difference is clear – the image on the right hand side at ISO 3200 has a lot more noise in it, than the one on the left at ISO 200.

Shutter Speed

Aperture

Aperture refers to an adjustable opening in your camera lens that is able to limit the amount of light passing through the lens and hitting the camera sensor. 

To control your camera’s aperture, switch your camera mode to aperture priority. In this mode, you are able to manually control your camera’s aperture. The camera will change the shutter speed automatically to match the aperture that you had selected to create a picture that is properly exposed when the shutter release button is clicked.

Aperture is measured in F-stops. The lower the F-stop (e.g. f/2.8), the wider the opening of the aperture. While the higher the F-stop (e.g. f/22), the smaller the opening of the aperture. When the aperture is wide open (e.g. f/2.8), more light will enter through the camera’s lens, therefore, less time is required for proper exposure which meant faster shutter speeds. Wide aperture will also cause a shallow depth of field in your picture, where the foreground and background of your picture is blurred except for the subject which you are focusing on. However, the opposite applies when the aperture is small. When the aperture is small (e.g. f/22), less light will enter through the camera’s lens, therefore, more time is required for proper exposure which meant slower shutter speeds. Small aperture will also cause a deep depth of field in your picture, where everything in the picture is in focus.

Wide aperture (e.g. f/2.8) is useful for taking pictures in low light conditions as more light gets to enter and hit the camera’s sensor. It allows you to use faster shutter speeds as well that can be used to freeze action on moving subjects such as a running dog. It is also suitable to use when you want to take portraits or macros where you want a shallow depth of field so that the subject will be sharp and stand out in your picture.

Small aperture (e.g. f/22) is useful for taking pictures in good light conditions as there is more than enough light that will enter and hit the camera’s sensor. It allows you to use slower shutter speeds which can be used to give your subjects a motion effect in your picture. Remember the running dog example? We can use slower shutter speed to create a motion effect of the dog, running in your picture, bringing your picture to live. A small aperture is also suitable to use when you want to take landscapes or group shots so that everything in the scene is considerably sharp.