Something happened yesterday

[Guest lightnix]

I went to see a product demo yesterday, that PRG Distribution were holding up at the Royal Opera House. The main aim was to run a shoot out, with the VLX and Nemo Seachanger up for comparison with a VL3500, VL2500 and 2k tungsten source.

 

Half way through, it hit me... There's something about tungsten now, which looks distictly dated, like gaslight - at least to my eyes - and I find myself becoming increasingly irritated, by the way it changes colour the moment you start to dim it.

 

I am now pretty well convinced, that the writing really is on the wall for tungsten. Sure - it's unlikely to disappear completely for the moment, but the time will come - probably sooner rather than later and definitely within the next 20 years - when tungsten will no longer be the entertainment industry's No.1 light source.

 

Am I alone in thinking this? :P

[mark_s]

I'm the opposite - I like the way the colour temperature changes when dimming. It opens up a lot of creative opportunities - for example O/W can be anywhere from full on white glare, to dim yellow. Certain colours are also very versatile when combined with this effect, dimming to a warmer or much less intense colour. L052 is a good example, as it L793. Of course if you had all the resources in the world you'd never need to draw on this, but if you're limited to few lanterns, this can be used to great effect.

 

I'd much rather have the ability to do this at the expense of having to think more carefully about how I use the light than not having it at all and not needing to think so much. I sincerely hope that the industry doesn't move away from tungsten any time soon - I believe it will remove an important tool from the lighting designer's toolbox.

[Guest lightnix]

Tungsten's colour temp change has caused me a few headaches on corporate shows; where adjusting the levels downwards, has resulted in complaints from the client that the lighting is now the "wrong colour" - leading to regelling - usually during a meal break.

 

With energy costs spiralling (you ain't seen nothing yet), it will become increasingly difficult for LDs to justify the use of a light source, which is barely 10% energy efficient; especially as more economic alternatives, which are almost as good in terms of output, become more widely available.

 

It's not just the energy efficiency, though. The "full on, RGB+W" white from the VLX made colours look more vibrant IMO - probably (and ironically) due to the poor CRI of the RGB component. It kind of reminded me of what happens in photography, when you start shooting through a polarising filter. The bunch of flowers in the demo, which was lit by the tungsten, looked dull and muddy, compared to those being lit by the VLX - the same went for skin tones. This may not always be a desirable effect, but I think it could become a standard for musicals, concerts and other events, where a "hyper-real, larger-than-life" look is required.

[Tom Baldwin]

I think this is a very interesting question, and I suspect the succinct response runs along the lines: "once our ability to control LED sources, and their ability to deliver better (controllable) CRI and colour temperature improves, then we will see incandescent sources fade away."

 

 

We have numerical properties to describe light sources - colour temperature, gamut, CRI etc, but I always feel that these only provide an incomplete description of their capabilities. There seems to be something else, something emotional, about our response to them that should be captured as well.

 

Speaking purely from a theatrical perspective, I like the colour shift of dimming tungsten and the smoothing effect of thermal inertia - so many non-incandescent sources seem to have rather brutal dimming curves. There is something soft and cosseting about the way the shift to a lower

colour temperature loses the strident character of bright white light. I'd hate to lose that in the search for better efficiency.

Of course, there are also plenty of times when I'd like tungsten to have an "instant off" capability too!

 

 

As the capabilities of LED fixtures increase as measured by the numerical properties, so their ability to simulate existing lamp technologies will improve. The question then is how do we control them? Today, using the Selador fixtures and some custom control software it would be possible to set a colour using an HSI model, and on a separate control channel specify the CRI. As the value of this channel decreased, so the custom software would prefer the R, G and B emitters only, instead of using the full set of seven colours to achieve the requested colour. In practice, this would allow real-time control of the "hyperreality" Lightnix mentions. we need additional control capabilities for the other aesthetic parameters - whatever they might be. As a simple example, I'd love a control property which allows me to specify incandescent simulation - decay time and colour temperature shifts. Obviously, I can program that today on a per-cue basis, but it's a lot of extra work which falls into the category of "something a computer could do better than a human".

 

 

Would anybody care to speculate on what they other aesthetic parameters might be? For example, does the eye subconsciously perceive flicker which is too fast for conscious perception? Do DC arcs look different to AC arcs (with the same electrodes and gases)?

 

 

Tom

[indyld]

As a simple example, I'd love a control property which allows me to specify incandescent simulation - decay time and colour temperature shifts. Obviously, I can program that today on a per-cue basis, but it's a lot of extra work which falls into the category of "something a computer could do better than a human".

 

Rock and Roll LD's who are using a lot of LED kit are already defining custom intensity curves on the desk to compensate for the more instant snaps when bumping the LEDs compared to the same action with tungsten PARs. When you've spent your career bumping tungsten ever so slightly early, your natural timing seems out of what doing the same with ML shutters and LEDs even more so. And taking it one step further in the controlability stakes can't be beyond the wit of man ;-)

 

I personally love the way that bumped ACL fans seem to almost "roll" out (and back) their beams like a cluster of chameleons tongues.

 

Whether tungsten will cease to be the No. 1 light source for shows depends on the advancement of other technologies, something that is probably inevitable. Technology simply is what we use at the moment, preceeded by what we historically used to use and superseded by what we will use in the future.

 

Light is light.

[Nick512]

I think I have to disagree.. My all time personal favourite light is the VL5 Tungsten. I love the way that the lamp color temp and the colour fins interact. The way it fades in and out is also a wonderful thing, Yes you can come close to replicating this fade with custom curves ect.. but show me an LED fixture where the first 5% of the fade is smooth I have always found that you get a jump as the LED gets its first 1%. also trying to fade out in white almost always shifts colour as you get to the last few percent. Deep saturated Blues and UV's are also a problem with LED. I find them very clinical lights.. there is still something a little special about the light you get from a tungsten source.. maybe its just me but I have yet to be taken by any LED fixture just yet..

 

However I was asked to take the first 40 VLX's on Kylie's USA tour earlier this year and they were great. They were actually a lot better that I had anticipated with the colours and they are really bright. VL are working on some changes to the software that I requested to help with the dimmer curves and working on a way to get the beam angle down a little as this was my major concern. (I love tight beams on washlights). I had them paired with 2500 spots and to be honest the VLX was much brighter. They were more comparable to the VL3000 Spots in the Rig!! Which was quite a shock and actually cut through the VL3500 Washes too..!! For that particular show they were actually quite perfect BUT... I would still spec a VL5 or VL500T over the VLX's on my next project.. In fact I have..!

 

Quick Pics Here for all interested.. The VLX's are on the vertical Drop Ladders.. The US wash behind the center DS Screen are VL3500's!

 

http://img.photobucket.com/albums/v640/nickvislight/11.jpg

 

http://img.photobucket.com/albums/v640/nickvislight/12.jpg

 

http://img.photobucket.com/albums/v640/nickvislight/13.jpg

[adam2]

I suspect that tungsten theatre lanterns will be around for many years yet, but will gradually become less popular, especialy for new instals.

I have no doubt that tungsten will eventualy go the way of limelight, gaslight, and carbon arc lamps, though not just yet.

 

LED and discharge sources are much more efficient and also longer lasting, though not yet suitable for all applications.

 

On a new install, LED and discharge lamps will probably be cheaper in capital cost, as well as saving electricity and replacement lamps.

A large conventional lighting rig can require 1MW (1,000KW). Providing this much power entails considerable capital cost, perhaps requiring a dedicated substation.

Switchgear and cabling for such loads is expensive and occupies substantial space, dimmers are also expensive and take up valuable space.

Each dimmer channel will require its own circuit to the lighting grid, again at substantial cost.

Removing the heat from 1MW of lighting is likely to require substantial ventilating plant, and probably air conditioning.

This entails considerable capital and running costs, and the plant takes up valuable space.

 

If instead LED and discharge sources were installed, the load could be reduced to perhaps 150 or 200KW, with very substantial savings in switchgear and cabling.

Numerous lanterns could be connected to each circuit, and no space would be required for dimmers.

A/C plant, if required at all, would be much smaller and cheaper.

 

At the other end of the scale, consider a very small install in a Church hall or similar.

Conventional lighting would probably require at least 10KW, which would require perhaps two circuits each of 32 amps, and a couple of 6 channel dimmers.

Installing this will require an electrician, probably at a cost of several hundred pounds, and may require an upgraded service, as this is often only 60 amps in small premises.

 

If instead LED lanterns were used, the load would be much less than 3KW and could therefore be plugged into a single 13 amp socket, with no installation costs whatsoever.

The saving in installation work would pay for quite a few LED lanterns.

[deranged-angel]

I'm a big fan of LEDs and had a few fixtures on the spectroradiometer. The main problem usually comes down to the control. 8 bit isn't really enough for accurate dimming because as you get lower levels, one of your colours is bound to jump steps and even a tiny amount is obvious. If you are trying to create a particular colour and lux level then LEDs are definitely the way forward as tungsten is too erratic. I believe Selador have now come up with a 7 colour LED unit. Has anyone tried it? what is it like?

In a few hundred years time when we only use LEDs, someone will do a project where they try to recreate the way a stage was lit with tungsten but using LEDS :(

 

Emma.