how to light stained glass

[Monique Verbruggen]

This tall and slender structure (‘Toblerone’-shaped) has an “A”-shaped base. The two long sides of the “A” support two panels ̶ 5.5m (h) ̶ covered with mirrors on the inside. The crossbar of the “A” supports a stained-glass leaded window of 5.21m (h) x 1.10m (w). High up, in the enclosed part of the “A”, two showtec Compact Par 7*CW/WW led lights are suspended. The structure is situated in an auditorium with abundant natural daylight. Stained glass needs to be lit predominantly from the back to come out well. During the day the frontal daylight counteracts this effect, in the evening the lighting is tolerable.

 

Without proper lighting this piece of art is simply worthless. Can anyone help me out?

 

 

[lite_lad]

perhaps some flourescent tubes? its not that clear to understand what your really looking for, is it advice or someone to come and do it? pictures would be helpful for advice!

[indyld]

One issue with the piece from a lighting point of view is the mirrors if you need to light the whole thing up from inside. If the stained glass is clear, not frosted, then it would be better if the "backing" was a diffuse reflective material (can as simple as solid matt white) that would take the light. Light from the internal fixtures won't do very much if the backing to the glass element is a mirror and the glass is clear even if coloured.

 

Of course, the mirror element may well be part of the effect of the piece, in which case it's going to be hard to get light to radiate out through the stained glass. If the stained glass was frosted, then lighting the back of the glass would diffuse the light on the surface and cause it to glow.

 

In a church, the thing that makes stained glass work is mainly the bright, diffuse reflecting sky behind it. The light needs to interact with something. With clear coloured glass it just goes straight through and with mirror it bounces straight back off, neither of which produce a "lit from inside" result.

 

A picture of the piece would be helpful.

 

PS. I've seen an attempt at making a church window glow at night time with a large light source from outside. This doesn't really work, what was really needed was a big white backdrop outside that the light was bouncing off. Similarly, when creating the effect in theatre the "glass" (usually gel filters) also needs to be frosted (with a frost filter) for it to have any effect when lit from behind.

 

There is some information on diffuse reflection at http://www.onstagelighting.co.uk/lighting-design/light-reflection-angle-incidence/

[Monique Verbruggen]

 

 

Thanks for yourreactions. The help I am looking for is advice. I make stained glass, so I know it is not a traditional way of lighting stained glass; I am Dutch, don't work in the lightning industry and I am also new in the forum asking business, so forgive me for the mistakes I am going to make.......

 

Yes, the mirrors are apart of the effect as you can see in the pictures. The semitransparent stainedglass is situated halfway the mirrors so the reflections make a hexagonal pillar. I made a smaller model (2.20 high) with only leaded very transparent clearcoloured glass and that one works well with a 40 watt reflector light bulb inthe top. So I really expected it to work with the advised Showtec Compact Parled lights. Is there a led spot that is stronger then the one I used and which could do the job?

 

Pictures http://cms.lofthosting.nl/1.9/files/viewFile/925 http://cms.lofthosting.nl/1.9/files/viewFile/921 http://cms.lofthosting.nl/1.9/files/viewFile/924 http://cms.lofthosting.nl/1.9/files/viewFile/923 http://cms.lofthosting.nl/1.9/files/viewFile/922

 

 

 

 

 

 

[david.elsbury]

Your links are broken, perhaps uploading to Tinypic or Photobucket and then pasting the [ IMG ] tags would work better? :)

David

[Monique Verbruggen]

Thanks for yourreactions. The help I am looking for is advice. I make stained glass, so I know it is not a traditional way of lighting stained glass; I am Dutch, don't work in the lightning industry and I am also new in the forum asking business, so forgive me for the mistakes I am going to make.......

 

Yes, the mirrors are apart of the effect as you can see in the pictures. The semitransparent stainedglass is situated halfway the mirrors so the reflections make a hexagonal pillar. I made a smaller model (2.20 high) with only leaded very transparent clearcoloured glass and that one works well with a 40 watt reflector light bulb inthe top. So I really expected it to work with the advised Showtec Compact Parled lights. Is there a led spot that is stronger then the one I used and which could do the job?

 

Pictures http://cms.lofthosti...es/viewFile/925 http://cms.lofthosti...es/viewFile/921 http://cms.lofthosti...es/viewFile/924 http://cms.lofthosti...es/viewFile/923 http://cms.lofthosti...es/viewFile/922

 

 

 

 

 

 

 

[

 

http://http//s1274.beta.photobucket.com/user/moni331/media/thisistheauditoriumwiththemodel.jpg.html?sort=3&o=5

 

[pritch]

I hope you'll forgive me for saying that you're better at working with stained glass than you are at posting links on the forum! ;)

 

The pictures are here

 

Something I'm wondering is whether a photographic (or even video, as it'll be a constant light) softbox might be useful here? My thinking is along the line of Indyld's post about having a white, lit backdrop outside, and I'm wondering whether using a softbox might be the next best thing?

[mac.calder]

You could look at an LED strip solution - like this mounted either side of the glass facing the mirrors. I would then suggest treating the glass with hair spray which will cause it to diffuse the light.

[Gareth A]

This is a show I once worked on. Sadly the left and right had no depth or width for hiding anything more than a couple of soft light tubes.

 

The middle however was done with the same, but had more depth.

 

The painting is done of frosted perspex and the back was covered with nothing more than tin foil!

 

Worked ok ish!

 

 

http://i1338.photobucket.com/albums/o692/G_Akehurst/IMG_2646.jpg

[Monique Verbruggen]

Very true.http://www.blue-room.org.uk/public/style_emoticons/default/sad.gif I should have stayed working with glass instead of light and computers and photobuckets etc.

But here I am, I have to find a good solution otherwise big trouble.

I"ll try again to send some pictures:

http://i1274.photobucket.com/albums/y439/moni331/thisistheauditoriumwiththemodel.jpg http://i1274.photobucket.com/albums/y439/moni331/thelampshardlyshowonedoorisopen.jpg http://i1274.photobucket.com/albums/y439/moni331/theeffectofthemirrorsmakeahexogonalpillar.jpg http://i1274.photobucket.com/albums/y439/moni331/2compactparlampenrestisweerspiegeling.jpg

http://i1274.photobucket.com/albums/y439/moni331/theinsidewithoutthemirrorsAndthedoorswithoutthestainedglass.jpg

 

I tryed the led strips. Was not enough light during the day, tryed also the regular fluoriscent lamps also not enough light.

Is there a more powerfool ledlamp than the one I used? Which would go all the way down the 5 meter I na slight angle,. get reflected by the mirrors ?

[indyld]

Hi Monique

 

It seems like you would like, in your words, advice but also seems that you are looking for a magic bullet in terms of a particular lighting fixture.

 

The issue with this is unfortunately a design problem, rather than a lighting problem as people here have indicated by their answers. I know you said you tested a smaller piece and that you understand how light and stained glass work. If an artist came to me with this proposal as a lighting consultant, I would have advised a major redesign because the piece and the place are such that it is always going to be hard to make it a success. I'm sure that's not what you want to hear, but there it is and you have made the piece as it stands.

 

Mac's suggestion of hairspray treatment to get the light to diffuse better is worth testing but in the end, 5 metres is a long way for such LED lighting fixtures to get all the way to the bottom. Personally, I'd be looking at something much hotter, less efficient and wholly unfashionable with a decent reflector like some kind of tungsten PAR unit and highest power one I could get away with. However, if the addition of LED strips at both sides of each panel of glass along the full height as Mac mentions doesn't do it (along with a diffuse surface at the glass) then nothing is going to without more diffusion or a diffuse surface behind.

 

It's futile in lighting to ever attempt to beat the Sun at it's own game, which is why the venue for this piece is never going to ideal in the daytime. With that amount of sky and daylight about, it seems odd to oppose it with these beautiful glass artworks and make them fight the skylight, rather than advantage of it.

 

Again, am sure it's not what you came to the Blue Room looking for but at the end of the day, we are lighting designers and understand the physics not just how bright the XYZ 7W LED is. :)

[Monique Verbruggen]

Llap-Goch master; perhaps you are right with your sugestions. IThat a softbox will be the next best thing. But I am still hoping that light from the top will be enough to compete against the daylight. I also wonder whether the softbox will have enough light On tuesday I hope to do some more tests.

[indyld]

Llap-Goch master; perhaps you are right with your sugestions. IThat a softbox will be the next best thing. But I am still hoping that light from the top will be enough to compete against the daylight. I also wonder whether the softbox will have enough light On tuesday I hope to do some more tests.

 

The suggestion for a softbox obviously relies on the box behind the glass, as the sky behind a window, which is similar my first suggestion of a matt white diffuse surface that is lit (from above, below or whatever). This would then take the mirrors out of the game which seems to be a big part of your piece. I've been trying to think of a way to use 1-way glass to harness the available daylight and provide the mirror effect but can't quite resolve it at the moment.

[musht]

Wondered about 2 way mirror as well,replacing the full mirror in current set up, would use the available daylight, something like

 

http://www.mirrorworld.co.uk/TwoWayMirrors/twowaymirrors.asp

 

For night time illumination,mebbe CDM/CMH ceramic discharge lites have a decent spectral output with good efficiency.

[indyld]

CDM/CMH or such could work, anything with a decent spectrum unlike awful CW or WW LEDs which are likely to ruin many bits of the glass original colours for more dull reasons of physics. The short version of this is that Cool White or Warm White LEDs are basically blue LEDS which are then modified by chemistry but the result isn't a great colour spectrum even though they look "white".

 

A key part to fixture design in getting light to travel 5 metres and still be useful is how it's transmitted. Using a fixture/lamp assembly with a parabolic reflector gives one the best chance of still having light at the end of the piece. Although many grown-up LED light engines use all kinds of optical systems to improve travel, still many LED units (cheap PARs or architectural strips etc.) don't really push the light straight forward efficiently and keep it working over any meaningful distance.

 

My other ideas to solve this (which are not likely to be viable on cost / time grounds) include designing the piece to use something similar to a Light Tube / Light Pipe that takes natural light and transports it somewhere else. Of course, this would only really balance the piece with the surrounded daylight and an artificial solution would still be needed at night. This artificial source could "add" light to anything coming from the light pipe and might introduce some contrast in the day time. Lighting is as much about contrast as absolute power, I'm sure the piece already looks great at midnight with all other lights turned off.

 

I'm sure that actually viable solutions are more at the hairspray end of things, but it's a beautiful piece and an interesting problem to consider if you are a lighting designer.