Build your own teleprompter

November 28, 2010

Now then, let’s clarify some straight away.  Autocue is a brand name.

Ok, that said, what is a teleprompter?  Well, it’s an autocue :)

Basically, if you want your presenters/students to be able to read their script directly into camera without having to memorise it (and trust me, they never will memorise it) then you need a teleprompter.

The problem is that a professional version costs in the region of £3000.   They work really well at that price but there is a cheaper option.   I’ve gone through a number of home-made iterations.

Firstly, placing a monitor just below the camera, connecting a laptop to it and running MS Word is actually quite effective, although the presenter’s view can start to drop down.

Using a piece of perspex in front of the camera can work too.  You need to cover the camera with a dark material so that the reflection is maximised for the presenter.  The problem with this method is that the words are reversed in the reflection.  We spent quite a while with a periscope arrangement, bouncing the image of the monitor off a mirror before reflecting it again in the perspex.

This arrangement was very heavy and a little bit scary when using it with the taller teachers.   It becomes much safer to actually mount the monitor on top of the tripod.   Our CDT technician knocked this up for me:

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And I sat down and wrote my software, ASprompt

ASprompt Pro

I’m incredibly proud of this software, having built it from scratch to meet my needs.  Programmed in Flash, you can type directly into the white box or paste from any text editor (well, better say most).  It has speed controls, countdowns, headings and mirror options.

At one point, I almost got a version working that automatically played videos on another PC, but I really need to learn how to use Adobe Air to make that work.

Because of the amount of work I put into it, I initially asked for £10 per copy, however, I know how schools and budgets are, so contact me here and I’ll sort something out.


Camcorders – the return

November 14, 2010

This post is both a tip and a “how to build your TV studio”.  Navigating the world of camcorders and their uses in school has been something I’ve commented on before

For those of you who’d prefer not to reread my rants a quick up-to-date:

  1. Ideally in a school we’d use a professional video camera, but they cost upwards of £4000
  2. The next best choice is a 3-CCD camcorder, but the industry has more or less stopped making them
  3. New camcorders record to hard drive, which cannot be easily edited in Adobe Premiere Pro

As a result of the above, I bought up 4 Panasonic NV-GS500 camcorders and have protected them with stark warnings and a nervous disposition whenever they are loaned out.Panasonic HS700

Finally, and fortunately, a new breed of camcorder has come to the rescue of us poor, beleaguered IT specialists.  And it’s Panasonic, once again, that’s leading the cavalry charge. 

Their new range of 3MOS camera sensors not only offers photographic quality video (perfect for greenscreen) but it also records in an open-source codec.

That may not sound like something to get excited about, but that’s MASSIVE! 

What that means is that any editing program which chooses to can edit of the recorded video.  Including Adobe Premiere!

I’ve spent the designers’ acquisitions budget for this year :( so cannot take advantage personally of the cool piece of kit,but please don’t wait for me.  Snap them up before they disappear.


Lights

October 6, 2010

When painting a window-less room dark, matte green, its surprising how dark it is.    Lighting becomes and interesting issue.    You need to provide the camera with even light on your green wall to give it as close as possible, one single shade of green for the computer to be able to remove the colour.

You also need to light your subject, otherwise they’ll will look too dark for the replacement background. 

And you need to make sure the subject does not cast a shadow onto the green, otherwise you’re back to different shades.Lighting set up for a school TV Studio

The Solution

Get your presenters to stand around 4-6 feet from the wall.   Place two lights above them  in a line parallel to the wall about the same distance from the wall as your subject.   Then place another light (with a filter) about the same distance from the wall as the camera is, but off to one side.

That’s all very well“, I hear you saying, “but if you put lights up near the ceiling, they’ll burn the tiles and set off the smoke detectors“.

And you’re quite right, imaginary, if slightly gruff teacher.

That’s where these babies come in:

A Hi-light

A Hi-light 

These Hi-lights are low temperature Halogen lights.   Even when they’ve been running for an hour, you can put your hand on the casing and they don’t feel hot.

We got them from Newland Media, a company specialising in school video production.  Newland also make/sell the brackets which easily clip onto ceiling tiles, which means you don’t need expensive lighting bars either.

A Tri-light

The third light in our setup is a Tri-light.  This does get hot!  Very hot, so keep students away from it.

The enormous umbrella on the front is the diffuser (which comes with the light).

The whole setup costs near £1000 and is the most expensive area I’ll talk about, but the level of control you gain by lighting properly makes the investment worth it.


Tripods!

September 20, 2010

No the War of the Worlds invaders, but the things to keep your camera steady.

Tripods are really awkward things to get your head around.  The big problem is so many places sell cheap photography tripods as something you can use with a camcorder.    And you can, if you never want to move the camera while recording.

We struggled for a long time with cheap tripods.  The prevailing wind of course is that you need a Fluid-Head Tripod.   Which moves the camera on a bed of oil preventing all friction.   This is great if you have a few thousand pounds free.

There is a third option, inbetween cheap & useless and ultra professional.   And that’s the Manfrotto 501 range.

Manfrotto 501 tripod head

For some reason, semi-professional tripods are sold as heads and legs separately.   I’m not sure why, it’s not as if you can use the head without legs and a set of legson their own is no good if you ever plan to attach a camera to them.

You need the Manfrotto 501 head ~ £75 and a set of legs for them, also around £75.

That jumps the price up a bit from a £20 tripod you can buy off Amazon, but you’ll just have to trust me when I say that the level of control and flexbility you get is worth it.  

Not to mention the robustness.

An additional feature that has already saved me a couple of times is you can’t accidently drop the camera off the tripod once it’s attached!  That little red safety button on the side stops the camera shoe slipping.  Phew!


Dublin Bay green

August 31, 2010

In my last post on this topic I talked about digital cameras and how green works best.  But then, what green should you use.

The technology has improved greatly from a couple of years ago and exact colour doesn’t matter as much as it once did.   You can certainly avoid the specialist paints for chromakey which sell at nearly £60 a litre!

Dulux's Dublin Bay greenI went to the local B&Q and looked through colour charts until I found that closest I could to Primary Green.   Dulux’s Dublin Bay 3 is a really strong, quite dark green which when lit by a couple of cold ceiling lights produces a very good result.

The most important thing with painting a room is making sure the surface is evenly painted so that the wall is the same colour all over.  That’s the important bit, uniformity. 

Oh and do make sure you buy the Matte finish, not the Satin or Gloss, the whole point of painting the wall one colour is defeated if the camera sees a great white splodge of reflected light.


What camera? (and a bit of expo)

August 18, 2010

Building the TV studio 2 years ago, it was relatively easy to choose the cameras.   At the time, Standard Definition was still the prevalent form, although High Definition was quickly taking over.

Panasonic spotted a gap in the market and released a series of 3-CCD camcorders capable of shooting in much better quality than normal 1-CCD home camcorders.

CCD?????

A CCD

A CCD chip from a regular camcorder

In basic terms, (mainly because this is a far as I understand it) a traditional camcorder contains 1 microchip that records the image from the lens and turns it into a digital signal. 

A three chip (3-CCD) camcorder has three microchips, one for each primary colour.  This means that the 3-CCD camcorder gives effectively three times the quality of a regular camcorder.

This quality isn’t broadcast standard but it very useful for greenscreen.

Greenscreen

Greenscreen, chromakey or (in 1970s Doctor Who) Colour Separation Overlay works by having a computer recognise a single colour and removing it from an image or video.   Then any other image can be used to fill in the removed bits.   For this you need to provide a solid primary colour background to your presenter but problem with regular 1-CCD camcorders is that they provide a very poor signal, full of noise or rather not a single colour.

3-CCD camcorders have a chip for each primary colour so the colours are much less noisy and therefore much more solid.

Why a green backgroud?

Red is the main colour in human skin tones (certainly more than blue or green) so we don’t pick red. 

Blue works best with Film so on Making-Of DVD extras you’ll often see blue as the background, but for digital video, the colour processing works best with green. 

Green contains more information in the digital video signal than blue.  It’s as simple as that really.

Back to cameras

Just because something says HD doesn’t mean better quality than SD.   HD on camcorders refers to the output size of video not the quality of the image.  Plus, lets face it HD video is bigger, so processing requires a more powerful computer and more storage space.   In school we try to stick to 640×480 video compressed into WMV, so at that size there’s no point shooting anything in HD.Panasonic's NV-GS500

Unfortunately, the Panasonic 3-CCD range of camcorders we bought has now disappeared in the HD/SD battle.   They were the NV-GS500 and cost around £500.

I’ve been in a bit of a minor panic about what to do when they need replacing.   The market is still in flux so it’s hard to tell what the next best option will be.  Right now, it seems like there is nothing near the GS500s for quality and price.

Panasonic has released a series of 3-CMOS camcorders.   CMOS is the chip normally used inside digital stills cameras and is generally considered better than CCD.  A camcorder called a 3MOS has three of these chips just like the 3-CCD.

In future posts, I’ll talk about how we connect the cameras to the video switcher, which also affected the decision over which camera to buy. 

Ultimately, the cameras are the most important part of the studio as once a camera is chosen, everything falls into place.  Video standards, vision mixing and even which tripods are all governed by that choice.


Edirol LVS-400 Video Switcher

August 6, 2010

The hardest part about designing a TV studio was finding the right mix of technology to ease-of-use.   Before I ordered anything, I spent a lot of time visiting other schools and looking at their solutions.   The problem I frequently saw was that a school would go to a professional company who would provide the exact right kit any small, professional TV studio would need.

The trouble with this is that schools don’t need the same kit as a professional TV studio.  We don’t need £4500 cameras, or high-end editing systems.  We don’t need High Defintion video.  Not when we’re going to compress it to 640 pixels wide in order to share it on a VLE or stream it into every classroom.  

Professional studio companies will happily supply this level of equipment because it gives the students access to the same kit they would use if they get jobs in the media.  That’s the excuse…sorry reason.  But this stuff is sooooo complex you have to train the students how to use it, and let’s face it, it’s also really, really expensive.

The Newtek Tricaster is a fabulous video switcher and can produce incredibly clever greenscreens, but it’s cheapest educational price is nearly £8,000!   That’s £1,000 more than the entire studio I fitted!

Fortunately, during my research…umm…”quest”*…I visited Sunderland’s City Learning Centre and was introduced to the Edirol LVS-400

Edirol LVS-400

This Video Switcher is a hardware “box” that allows you to change between 4 different video inputs and greenscreen/bluescreen one video source (such as your camera) over the top of another (such as a computer running powerpoint) .  And it does it for the amazingly cheap price of £786.  Yeah, I know it doesn’t sound that cheap but it is one tenth the cost of the Tricaster!

The real benefit of the Edirol though is training time is two minutes – 60 seconds of which involve telling the children not to idly flick the lever up and down.  I’ve given up on trying to stop the teaching staff.

Rather than spending your time training students in equipment you yourself will barely know how to use, the Edirol provides an easy greenscreen solution allowing you to spend your time encouraging the shy kids, getting others to spend more time on the presentations and generally just enjoying the experience.

* Which wasn’t just an excuse to spend sometime out of school – just like you reading this blog isn’t just a bit of distraction during work :) )


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