GAIN, NOISE & SENSITIVITY

The sensitivity of the camera will usually be reference to 4 interlinking element by camera manufacturers.
1.A subject with peak white reflectivity.
2. Scene illumination.
3. F number.
4. Signal-to-noise ratio for a stated signal.

For example: A peak white subject that has 89.9% reflectance lit by 2000 lux quoting the signal or noise ratio will be expressed as the resulting F number when it is exposed. From that example: most of the current digital cameras will be F8 or a better with a signal or noise ratio of 60dB. This does not indicate how much light the camera should use but instead, it allows different camera sensitivity.

NOISE
Greater amplification of weak signals could increase the sensitivity of the camera but it may degrade the picture by adding noise which would be generated by the camera circuits. Contour or gamma correction will not necessarily be needed when measuring the signal or noise ratio. Manufacturers may vary in the way that they will state camera sensitivity, and because of this, comparing the differences between the models will require a conversion of the specification figures. If the camera has the same F number, then the higher the signal or noise ration and the lower the scene illuminance or lux, the more sensitive the camera will be.

GAIN
If there is insufficient light that exposes the picture, then the gain of the head amplifiers may need to be increased and any additional gain will be calibrated in dBs. An example of this would be adding +6dBs which would double the amount of light that is available to the sensors. The amount of switch gain that is available would usually depend on the camera. Some cameras however, will automatically increase gain if the light were to decrease when a specific F number is selected. This could increase noise to an unacceptable level without the cameraman being aware. Cameras may also have a negative gain setting which would reduce noise and control depth of field without the use of filters.

GAIN AND STOP COMPARISON
+3dB will be equivalent to opening up 0.5 stop
+6dB will be equivalent to opening up 1 stop
+9dB will be equivalent to opening up 1.5 stops
+12dB will be equivalent to opening up 2 stops
+18dB will be equivalent to opening up 3 stops
+24dB will be equivalent to opening up 4 stops

Any extra gain in the amplification is a corresponding decrease in the signal to noise ratio and will result in an increase in noise in the picture.

CALCULATING THE ASA EQUIVALENT FOR A VIDEO CAMERA
A video broadcast camera will have a reliable light meter if it has a good auto-exposure system. Most cameras will use a combination of three different exposures: 1. Manual exposure 2. Instant auto-exposure 3. Zebra exposure Some cameramen with a film background sometimes feel more comfortable when a using light meter to check exposure level; they would be able to do this by an equivalent ASA rating which would be logarithmic. There are several methods to determine the rating:
- The sensitivity of the video camera uses a stated light level, signal to noise level, a surface, with a known reflectance value and with the shutter set at 1/50.
- Japanese camera manufacturers use a standard reflectance of 89.9% as peak white while UK television practice is to use a 60% reflectance value as peak white therefore an illuminance level of 3000 lux must be used when transposing a rating of 2000 lux with 89.9% reflectance to 60% peak white working.

Camera sensitivity has increased over the years and in the last few, cameras have begun to include a negative gain setting.

IMAGE INTENSIFIERS To boost sensitivity, image intensifiers are fitted between camera and lens while shooting is occurring in low light levels. The end picture may lack contrast and colour but it will produce recognizable images.

www.candyjarfilms.co.uk

GREEN SCREEN SHOOTING

'Green Screen', also known as 'Chromakey', is a technique used in TV and Film that enables actors and props to be placed within any desired scene without the need for expensive location shoots or set building.

The scene is shot in front of a green-coloured background, which is then replaced with another through the wizardry of modern editing software.

The effect is most commonly used on news and weather programmes, but has recently become a massive component in the latest blockbusters. The likes of 300 and The Matrix Trilogy used this extensively in order to place the characters in stunning and beautiful locations dreamed up by highly talented artists and designers.

300 predominantly used blue screen whilst The Matrix stuck with green

To add the effect in Final Cut Pro, for example, simply add the 'Chromakeyer' video filter to the relevant clip. Place the background of your choice in the video track underneath the clip in the timeline, then adjust the settings by double clicking on the clip and selecting 'settings' from the tab. With a bit of trial and error, your subject will soon be placed into a scene of your choosing – and the great thing is, if you don't like it you can change it at the click of a mouse!

Why green?

Green isn't the only colour used for Chromakey. 'Blue-screen' filming is still in use today, but the principle remains the same. Green is chosen primarily because of the sensitivity in modern video camera equipment, being the easiest colour to pick up by the camera's light sensors. It's also easier to light correctly.

Lighting

One important thing to remember when shooting with green screen is to ensure there are no shadows or significant colour variations.

Software

The big three video editing applications (Final Cut Pro, Premiere Pro and Avid) all have chromakey effects built in as standard. They are, however, fairly basic and for those who often use the effect, it might be worth considering investing in specially-programmed plug-ins that are designed for green screen filming.

To find out more about green screen, check out these links:
http://en.wikipedia.org/wiki/Chroma_key
http://howto.wired.com/wiki/ChromaKeyYourWaytoaGreenScreenDream
http://bigantvideo.co.uk/links-2/what-to-wear-for-a-video-shoot

candyjarfilms.co.uk

SOUND ADVICE

Where filming is concerned, the sound aspect often gets overlooked, which can be unfortunate because most filmmakers agree that audio is just as important, if not more important, than the video side of a production.

Why? Well, audiences typically tolerate watching a film or TV programme with a poor picture as long as the sound is of good quality. Take away the sound, however, or distort it and the experience becomes almost intolerable.

This may have something to do with primal instincts, where a predator was more likely to be heard than seen, for example. Being more 'tuned in' to the aural environment may mean we have a lower threshold when it comes to bad sound.

So, what does the typical filmmaker or video producer have to consider?

       

     1.   Use the right equipment for the right job

Think through what you will be filming and make sure you use microphones that are suitable. It is possible to have all sorts of types of mics, but at the very minimum try and make sure you have access to the following:

- A lapel or radio mic for static interviews or presenting.

- A shotgun condenser for general sound pick up.

- A handheld dynamic mic for 'voxpops' and dynamic presenting.

2.      Position the mic right

Depending on where the sound source is, you will need to make sure the mic is positioned appropriately. In general, you want to get as close as possible, but making sure you don't get undesirable side effects:

- If you are too close to a subject's mouth, for example, you might get 'popping' or unnaturally low frequency (or bass) sound.

- Placing the mic too close can mean it appears in shot – which doesn't look very professional!

- If the source is quite loud, the levels will peak and you will get unpleasant distortion.  

- If you are too close to machinery or people doing a physical activity there is a danger that a collision with the mic will occur (and cause all sorts of problems, including breaking the mic).

3.      Ambient noise

Most of the time, ambient noise is an expected part of any sound recording. Problems occur, however, when this background sound is so loud that it becomes overly distracting. Filming an interview in a canteen, for example, might be impossible during a busy lunch hour because not only will you have the loud drone of people chatting, but all sorts of other noises will pick up on the mics (plates, cutlery, cash registers, shouting, doors banging etc.). You simply won't be able to hear the interviewee clearly.

Filming in certain places can mean you have no control over the location, but if possible, make sure you scout locations in advance and make yourself aware of any potential ambient sounds that could cause problems for your shoot. In addition, liaise with your contact for the location and stress the importance of keeping background noise to a minimum. It may mean having to book a quiet room away from the hustle and bustle – but at least it keeps disruption to a minimum (as well as stress!).

4.      Wind!

If you film outdoors there is always the danger of microphones picking up excess wind noise. Failing to prepare for this can result in ruined audio. Most mics have no or minimal protection against this issue – typically, you will need to make use of an additional windshield or microphone cover. These help to dissipate the air as it blows around the casing, thus preventing any excess wind reaching the sensitive components of the mic.

5.      Listen in

It can be very tempting to just plug in the equipment and leave it at that, but you need to make sure you monitor the sound as well as the visual element of your recording. By listening in on headphones, you can spot those rare occasions of audio drop-out. You also need to use headphones to check sound levels before you start.

During interviews, for example, make sure you get the subject to talk for a minute or two so that you can adjust levels on the camera. You want to ensure no peaking (ie distortion) takes place but that the levels are high enough for when it comes to editing.

Hopefully you'll find this a useful guide to audio when it comes to video production.

If you have any questions, just leave a comment!

www.candy-jar.co.uk

HOW TO BE A YOUTUBE HIT

YouTube is the world's most popular video-sharing website. Over 800 million unique users visit the site each month, with over 72 hours of video watched every minute*.

Whether you've just started using YouTube or have a well-maintained YouTube channel with loads of videos, it's a good chance you want to get as many visitors as possible.

So how do you get more people to view your videos? Well, we've done a bit of research and discovered 15 things you should be doing...

1. Optimise the title - make sure it contains all the relevant keywords people use when searching.

2. Optimise the description - put the website address [http] on the first line. Write the description like a Blog. Use as many keywords as possible - don't be afraid to add a load of content.

3. Optimise your tags on each video - try out the YouTube search bar to find out what keywords people use when searching for videos.

4. Run regular competitions to get people coming back to your channel - see what 'mismag822' does (http://www.youtube.com/user/mismag822

5. Do joint ventures. Collaborate with other people in your niche who have big subscription lists. Ask for an interview - go in to see what you can offer rather than what you can get.

6. Try posting tutorial videos - it's info that people want and will look for.

7. Don't discriminate against people. You're an entertainer so entertain everyone.

8. Subscribe to as many channels as possible.

9. Make friends - post comments about videos and get to know people (just like you would with Facebook). Have conversations and build up a rapport.

10. Create discussions - a positive discussion is good and gets you on the most discussed list. 

11. Don't be afraid of negative comments. It shows people are watching your videos. However, avoid getting into a hate discussion. Be respectful but don't waste your time with trolls.

12. Be consistent. Post a video once a week for example. Don't be overly keen though - posting two videos an hour could become annoying.

13. Be addictive. You want people coming back again and again. For example, make the video in several parts to maintain interest. 

14. Know your audience. When your videos go up, it will only be at the top of the list for a short time (48 hours). Work out the optimum time to post your videos (e.g. 8pm in the evening)

We hope that this helps with your future YouTubing. If we've missed anything or you have any questions, leave us a comment and we'll get back to you. 

*source: http://www.youtube.com/t/press_statistics

Candy Jar is a video production company in Cardiff. For more information please visit www.candyjarfilms.co.uk

TOP FIVE REASONS TO USE VIDEO ON YOUR WEBSITE

These days, you can't run a business without a website. It's a vital communication tool which enables your customers and clients to engage with your products or services – a shop window that's available 24/7, world-wide.

So what do you put on your website? Some text, a few photos maybe ... but is that enough?

It used to be, but not anymore. Video has become an essential component of any self-respecting website. Here's the top five reasons why you need to make use of video – now!

1.      Video makes your website 'sticky'
People are more likely to stick around if they see a video on your site. They'll watch the video and be more inclined to browse a bit longer.

2.      Video encourages customers to buy your product or service
Because visitors are more likely to stick around, they're more likely to buy from you. If you have an online shop, video will help drive them to it and spend some money!

3.      Video helps your Google rating
If you upload your video to YouTube, you'll benefit from the fact that YouTube is owned by Google. Google wields great power when it comes to search engine rankings and having video content from YouTube will do wonders for your site's Search Engine Optimisation.

4.      Video improves your reputation

A well-produced video will show that you're serious about what you do. Making use of real people (ie you!), will demonstrate to customers that you actually are a real person – and people much prefer to buy from human beings.

5.      Video transcends international borders

The beauty of video is that the visuals can be enough to communicate a message. You don't need to pay for expensive translations, just let the video do the talking.

If you're interested in using video production for your website and want to find out more or discuss a project, please get in touch at the Candy Jar website
www.candyjarfilms.co.uk

WELCOME

Hello and welcome to the brand new Candy Jar Films Blog.

This Blog is about all things video. We will be discussing the best filming techniques, looking at the latest gadgets and sharing what's hot in the world of video production. 

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Also, take a look at any of our other Blogs by clicking on the links below:

candyjarlimited.blogspot.co.uk

jellybeansbooks.blogspot.co.uk

onewomanswarbook.blogspot.co.uk

kangazang.blogspot.co.uk