F1 Vision Mixing

[IanG]

Firstly, I'll say that James is much better informed than I on the comments you make and I'm sure he'll clarify, but I'd just like to respond to a couple of your points.

 

The BBC no longer have many big OB trucks, they don't have the money, but more importantly have the sense to know that the industry is changing so fast it is not worth buying new trucks at the moment.

 

Not quite true. I believe Unit 12 is currently being replaced and Unit 2 has 1080i HD capability.

 

most of the HD trucks can take lots more stuff than the BBC one that is referred to earlier in the post, things like the sound is taken in to a 56 ch digital mixer, compressed into dolby and recorded, then for re-mixing decoded mixed and sent out, as dolby compression is really good and takes up very little tape space.

 

Actually, many of the large format BBC vehicles can take far more than 56 channels. I understand the Calrec desk in the CMCCR has 224 inputs.

 

And I'm not sure what you're referring to when you say "Dolby Compression" in this context.

 

As far as layout and vision goes it is much better than the BBC truck, more kit, due to new things like plasmas and TFT screens.

 

People seem to be under the impression that just because plasmas and TFT's are the current great thing they're ideal for all situations. Yeah - you can vision mix from them, but I'm yet to find a engineer, lighting director or vision operator who would even consider using them for picture monitoring.

 

Matrix's are another big thing, you can have loads of inputs and say a 32ch vision mixer, then on the matrix's you chose the extra cameras you want to switch into a vision mixer channel, say maybe a camera on the lead car, so you don't look at all the cameras at the same time, you follow the race and look at cameras that fit that bit of the coverage as and when you need to.

 

They are, but that's nothing new - broadcasters have been doing that for years. Many presentation mixers are <10 channel units fed a small number of feeds from main and reserve matricies.

[johnb]

As someone who works alongside James, and has some connections with BBC OBs, I tend to agree with what Ian has said.

 

Yes OBs have sayed away from having their own HD truck up until now. This mainly because of the wide range of standards available, and waiting to see what the demand is and for what. In the mean time they have been hiring in HD trucks (hence the events to show the other people's vehicles) so they have been providing the facility. Having said that, they are in the process of refitting Unit 2 (one of the type 8's) with HD facilities capable of up to 1080i resolutions.

 

As for large trucks - OBs still has a lot of their own. DCMMR and CMCCR are the two large truck capable of handling events like golf where you have 2 or 3 cameras for each of 18 holes, studio camera, VTs, radio cameras (to name a few), so have to be capable of serious numbers of inputs, both on the video and the audio inputs. Also Units 10 & 11 (and now 12) can handle large sporting events. As such matrix and digital desks with multiple layers have been common features for a number of years.

 

The different trucks are built for different purposes. For something such as sport where everything is happening all at once the biggest problem they face is easy access to each of the sources. You need to be able to get at the pictures/sound as fast as possible, hence the use of large vision mixers and monitor banks, trying to route the souces into the vision mixer on the fly while trying to cut fast paced action is very difficult. I know when looking at choosing elements such as the digital sound desks one of the features given a priority had to be the number of faders they could fit in the space.

 

If you have a look at the BBC Resouces Website it has a good overview of the different types of trucks. However at the moment it is not reflecting the HD truck, the new Unit 12 (same size as unit 10/11) or the new links truck capable of unlinking something like 8 links at the same time.

 

I have to agree with Ian on the comments about TFT monitors - they are fine for seeing that there is a picture there, but as quality monitoring thay are just not up to scratch. Unfortunately as decent grade one monitor to seeing all the defects in a picture still needs to be a CRT which means space and weight.

[marc]

Just to add to what I said, and I do agree with you,

 

I have to agree with Ian on the comments about TFT monitors - they are fine for seeing that there is a picture there, but as quality monitoring thay are just not up to scratch. Unfortunately as decent grade one monitor to seeing all the defects in a picture still needs to be a CRT which means space and weight.

 

I do not like the idea of plasmas or TFT's in ob trucks or studios, where I have work done building new bbc studios we are still fitting CRT, which is great, and I hope they never get replaced by plasmas at the moment,

 

My point is that when you look at lots of the ob facilities that show at things like the Broadcast Production Show and the like they seem very keen on using plasmas, I still don't really want to buy them due to the limited life :D .

 

Yes OBs have sayed away from having their own HD truck up until now. This mainly because of the wide range of standards available, and waiting to see what the demand is and for what. In the mean time they have been hiring in HD trucks (hence the events to show the other people's vehicles) so they have been providing the facility. Having said that, they are in the process of refitting Unit 2 (one of the type 8's) with HD facilities capable of up to 1080i resolutions.

 

I know that the BBC are now building there own trucks again, but as you say uuntil now they have sub hired. which is the way the BBC is now, I only know of one LD still employed full time by the BBC, and the rest of their buildings are staffing is much the same, sub it in as you need it, then you don't have a truck rotting in a car park that cost you x number of million.

 

Actually, many of the large format BBC vehicles can take far more than 56 channels. I understand the Calrec desk in the CMCCR has 224 inputs.

 

And I'm not sure what you're referring to when you say "Dolby Compression" in this context.

 

It was not a BBC truck that I saw this in, and yes some trucks can take more inputs in one hit, but it is all about space and size, as there is the need for CRT monitors the sound kit is fitted into the smallest space possible in most cases and as sound can be made "smaller" with the aid of technology unlike a CRT, so it is.

 

mk

[James]

To follow on from the comments John and Ian have made, I would like to add something regarding the use of TFT's and similar displays on OB vehicles.

 

Unit 25 is a brand new unit, It uses a very small floor plan to great effect ofering the facilities of a larger unit through the use of flat screens for the pres stack.

 

Remember not everyone wants a huge vehicle. Not all programme bugdets can afford them and not all programmes require them. OK If you are doing athletics then 22 cameras is sensible but if you are recording a theatre production to tape? would you even need six cameras? Some places like theatres in central london don't have enough space to park a huge articulated lorry!

 

http://www.bbcresources.co.uk/images/obs/prod_units/unit25_3d.jpg

 

As you can see from the floor plan

 

http://www.bbcresources.co.uk/images/obs/prod_units/unit25plan.jpg

 

The pres / sound area is very large as the flat screens add a lot to useable floor space, and as they draw less current and therefore dissapate less heat they mean the unit has smaller power and aricon requirements.

 

However as John said earlier it's impossible to colour grade properly on a TFT. Therefore in Unit 25 there is a full CRT stack for engineering and VT. This compramise benifits everyone alowing the unit to be small in size, beneficial for access and transportation, but big in capacity, keeping the clients happy and producing the best programmes.

 

 

James

[Ellis]

As a non TV person who has seen broadcast quality monitors (> 10 years ago), the picture quality (resolution, colour reproduction linearity and sharpness) of the monitors used by broadcasters is far in exess of the best domestic or commercial CRT.

 

A Plasma or TFT screen can give a comparable output to a domestic or commercial CRT. I suspect that a TFT capable of broadcast quality could be made, but the market is small and the cost would probably be high (Would a broadcaster accept even one fauty pixel - most domestic TFTs have several!).