How to back light - WarmGlass.com

How to back light

This is the main board for discussing general techniques, tools, and processes for fusing, slumping, and related kiln-forming activities.

Moderators: Tony Smith, Brad Walker

Post Reply
Andrea R
Posts: 61
Joined: Fri Sep 30, 2005 10:52 am
Location: Canada

How to back light

Postby Andrea R » Sat Oct 18, 2014 3:16 pm

Im working on a piece that needs to have light behind it to show it off best. Its all about colour from light to dark and it will be a wall hanging. Whats the best way to go about this all thoughts welcome!!
Thanks,
Andrea
Image
"C'est Moi (Its Me)"

Bert Weiss
Posts: 2337
Joined: Tue Mar 11, 2003 12:06 am
Location: Chatham NH
Contact:

Re: How to back light

Postby Bert Weiss » Sat Oct 18, 2014 7:50 pm

The more space you have behind you, the easier it is to back light. Look to the sign industry for white light panels. I have used perimeter LED's facing backwards and bouncing off of roscolux crinkled aluminum vinyl back sheets. I had 8" and it works. This is stuff used in the theatre lighting industry, that is essentially like wallpaper only made with crinkled aluminum foil.
Bert

Bert Weiss Art Glass*
http://www.customartglass.com
Furniture Lighting Sculpture Tableware
Architectural Commissions

tbach
Posts: 33
Joined: Tue Jan 04, 2011 11:35 pm
Location: Hillsboro, Oregon

Re: How to back light

Postby tbach » Sun Oct 19, 2014 1:24 am

I have been working on this problem for several months. Many of my newer projects involve screenprinting, tracing and matting - the finished piece needs to be either in a window (not always possible) or backlighted. My solution goes as follows:

I use a Nielson#35 frame (Americanframe.com) to construct my lightbox. Glass art is backed by a piece of 40%white acrylic sheet cut to size - this evenly distributes the light. LED light strips, dimmer, power adapter and 12VDC connector came from Hitlights.com. A piece of Masonite whiteboard is used for the back of the lightbox, with the white facing inside to provide a good reflective surface. I glued strips of white foamcore around the inside of the frame, and attached LED light strips all the way around to provide illumination (had to use superglue - self-adhesive tape did not work at all!). Frame was assembled (with included hanging loops) and then glass, acrylic and backing were inserted. Dimmer was plugged into 24W power adapter ... and there was light.

Being my proactive self, I have created an instruction sheet in MSWord - it has more details than the "Reader's Digest" version above. The finished lightbox is not that difficult to put together, and I would estimate the total cost of a 10" by 12" somewhere between $80 and $90. If anyone is interested in detailed instructions, PM me and I will email the file.
Attachments
NobleWoodsIlluminated-smallweb.jpg
PopGirl2Illuminated-smallwe.jpg

Bert Weiss
Posts: 2337
Joined: Tue Mar 11, 2003 12:06 am
Location: Chatham NH
Contact:

Re: How to back light

Postby Bert Weiss » Sun Oct 19, 2014 10:25 am

Nice job. One key to that setup is the dimmer. You want to be able to control the light level. Particularly with kiln fired glass, too much light is a killer. The texture throws the light around and makes the image difficult to discern. Moderate light looks best.

white polystyrene sheet is also a good inexpensive diffuser.
Bert



Bert Weiss Art Glass*

http://www.customartglass.com

Furniture Lighting Sculpture Tableware

Architectural Commissions

Buttercup
Posts: 555
Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: How to back light

Postby Buttercup » Sun Oct 19, 2014 6:52 pm

Great results. Thank you. I've PM'd you to take you up on your kind offer as 3 of my art glass panels are about to be mounted in a large wall-mounted lightbox. I've recommended they hire a lighting consultant and given as much info as I can, however I'm not up on all the latest technology but it sounds as though your solution will take out the trial and error component. Thank you, Jen

Morganica
Posts: 1079
Joined: Mon May 19, 2003 6:19 pm
Location: Portland, OR
Contact:

Re: How to back light

Postby Morganica » Mon Oct 20, 2014 3:29 am

I've had a couple of pieces mounted on flat LED panels with programmable color/intensity and thought they looked pretty good.

Lightboxes are great if you've got a way to conceal the power source (or you don't mind telling the client to plug in the art). In my house I've had picture lights built in so that I can control them from a bank of switches...but that pretty much ties the art to a fixed location.

When I need the work to be portable, I use mirrors or silver leaf behind the glass. I'll cut a mirror slightly smaller than the work, attach it to the inside back of a shadow box (I usually have to replace the cardboard backing with hardboard), and then mount the work on standoffs with plenty of space around the edges. The light comes through the piece and is reflected back out by the mirror--if you light the work properly you get a surprising amount of transmission.

I sometimes use palladium leaf in the concealed parts of transparent castings, especially if they're against a wall or on a pedestal. The leaf will reflect just enough light to make the piece glow.
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

Jangilany
Posts: 1
Joined: Tue Jun 21, 2005 1:33 pm
Location: Gilbert, Arizona

Re: How to back light

Postby Jangilany » Mon Oct 20, 2014 7:29 pm

I am following this thread because I have the same idea - small fused panels that are in a standard Ikea-type frame/shadowbox. I was thinking that there might be some small acrylic "bits" around that would disappear behind the glass but am not finding anything quite like what I am envisioning.
edited: my actual question is about the stand-offs themselves :-) What do you use?

tbach
Posts: 33
Joined: Tue Jan 04, 2011 11:35 pm
Location: Hillsboro, Oregon

Re: How to back light

Postby tbach » Mon Oct 20, 2014 9:17 pm

Just completed an instruction pamphlet describing the process I have been using - would be happy to send a copy to you ... either pdf or word format. I have already discovered that I can't download pdf file at warmglass, and that the word file is too large, so I will have to email it directly to you.

Just let me know your email address - either through the forum or through PM

Ted Bach
http://www.tedbachglass.com
tbach.tbach@comcast.net
Hillsboro, Oregon

Peter Angel
Posts: 186
Joined: Fri Oct 31, 2008 9:26 am
Location: Newtown, Sydney, Australia.

Re: How to back light

Postby Peter Angel » Thu Oct 23, 2014 7:45 pm

Morganica wrote:
I sometimes use palladium leaf in the concealed parts of transparent castings, especially if they're against a wall or on a pedestal. The leaf will reflect just enough light to make the piece glow.


Cynthia, how do you attach the palladium foil to the glass?

Pete
Peter Angel
http://peterangelart.blogspot.com/

A bigger kiln, A bigger kiln, my kingdom for a bigger kiln.

Sashaziv
Posts: 15
Joined: Tue May 06, 2014 8:48 am

Re: How to back light

Postby Sashaziv » Thu Oct 30, 2014 1:55 pm

Hi, interesting thread! I'm wondering, have any of you used edge-lit LED panels in your lightboxes? If so, how far away from the dispersal glass/ acrylic did you put it? Do the dimmers have a wide range?

I'm currently trying to design custom lightboxes for some roundels painted with regular opaque paint fired on float glass. The dispersion would be float glass fired with transparent white. I'd like even, bright lighting. So I thought a led panel, or led strips mounted on the backing board would be the way to go? or could i consider any other options?

Many thanks in advance, Sasha

Buttercup
Posts: 555
Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: How to back light

Postby Buttercup » Thu Oct 30, 2014 7:04 pm

Sasha, my own experience with edge lighting has been on 10 mil (3/8”) or thicker, carved glass, not painted and fired, and the lighting has to be ‘trapped’ right up against one edge of the glass with none spilling onto the back or front of the glass.

I don’t understand how your glass painted with opaque paints will transmit any light. Can you clarify? That might help us make suggestions. Jen

Sashaziv
Posts: 15
Joined: Tue May 06, 2014 8:48 am

Re: How to back light

Postby Sashaziv » Fri Oct 31, 2014 7:38 am

Hi Jen, thanks for the reply! Sorry, by opaque, I actually just meant standard glass paint (i.e. not enamels/ transparent) I'm using the Reusche weather resistant colors range on clear float glass.

To make the idea clearer, here is a photomontage prototype I made. The roundel would mounted with four edge pieces, and framed in a leaded square. As shown in the image, this square would be then fitted into a larger aluminum frame. Not sure how I’d do that yet - probably need to take it to a framers when done!

So my thoughts initally were that led strips on the back mounting, or and LED panel behind, might be the way to go, as I dont want a larger box using flourescent tubes. What do you think?

Many thanks! Sasha
Attachments
lightbox prototype.jpg

Buttercup
Posts: 555
Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: How to back light

Postby Buttercup » Fri Oct 31, 2014 8:04 pm

Sacha, did you take up Ted Bach's kind offer? He's investigated this problem in depth. See also Bert's post. From personal experience with backlit painted and fired glass the light must be either diffused or reflected; no visible light source that will be viewed through the front of the image. It would be a shame to put acrylic sheet up behind it as I think from your previous posting of the image, that the background is silver stained (?) and it would just looked like soft-boiled egg yolk.

A self-lit panel with evenly distributed light or a suitable surface at the back of the frame off which reflected light can be bounced back through the glass would be the softest. Unless the light source is just perfect you'll need a dimmer, as Bert suggests. Consider the colour, too. The depth from the glass to the lit surface is important, too, and will vary according to the artwork. Also think about the power source for the lighting. You don't want a power cord dangling out of the bottom of the frame; not very mediaeval. Jen

Sashaziv
Posts: 15
Joined: Tue May 06, 2014 8:48 am

Re: How to back light

Postby Sashaziv » Mon Nov 03, 2014 6:43 pm

Dear Jen, thanks very much for that! Sorry for late reply. Actually the photo is just an example, but the other pieces will be the same - black/brown paint on transparent glass, but less medieval! (: (No silver stain) The piece in the photo is mounted with a glass pane directly behind, painted thinly with matt white. (This gives it an extra bit of texture compared to a milky plexi).

Thanks for all the ideas. I’ll check out the side/ reflected light idea, and have messaged Ted. Actually, I want a relatively bright light effect, it doesnt have to be too soft, but I guess its all about testing. I’d probably try the brighter LED strips, if I went that way, and maybe put them around the inner leaded square in my frame, to get them a bit closer to the roundel. Cheers, Sasha

Morganica
Posts: 1079
Joined: Mon May 19, 2003 6:19 pm
Location: Portland, OR
Contact:

Re: How to back light

Postby Morganica » Mon Nov 03, 2014 10:07 pm

Peter Angel wrote:
Morganica wrote:
I sometimes use palladium leaf in the concealed parts of transparent castings, especially if they're against a wall or on a pedestal. The leaf will reflect just enough light to make the piece glow.


Cynthia, how do you attach the palladium foil to the glass?

Pete

Usually I'm doing it as part of other lamination/epoxy processes, so as I'm mixing up the epoxy for something else, I wipe it across the area to be gilded, just enough to evenly dampen. Then I drift the leaf down onto the surface and tamp with the gilder's brush. Sticks like, er, glue, and it's very durable.

Practically speaking, though, I'd imagine that just about any gilding size or glue that didn't discolor the leaf would work. The gilded area is protected, since it's behind the glass and inside some kind of frame or mount, so it's not likely to be touched.
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

Buttercup
Posts: 555
Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: How to back light

Postby Buttercup » Mon Nov 03, 2014 10:38 pm

Pete, the traditional glue is made from rabbit skin. (In outback Oz one should be able to walk out into the back paddock and get the raw material). It comes in crystals, a bit like coffee crystals, and you boil it up with water. It really stinks. Just put 'Rabbit skin glue' into Google, lots of hits. I would expect liquid gum arabic would work, too, possibly hair spray if you can drop the leaf on quickly before it dries. Jen

KaCe
Posts: 126
Joined: Sun May 15, 2005 2:25 pm
Location: Old Town, Tacoma, WA
Contact:

Re: How to back light

Postby KaCe » Sat Nov 08, 2014 4:00 am

I don't have answers to 'how', but I do have some small kernel of info that people here may/may not already know. I have been interested in lighting of glass for over 8 years, but have not been able to get my s&%t together. When I began researching one very interesting thing I found was that lights, including LEDs, come with differing degrees of beam spread and that overlapping the beams slightly can give a smoother lighting effect. Another way to say it is that the lights can be focused tight like a spot light or be broad like a flood light. If one wants an even look then more of a flood light type beam set a little further apart will make an even light along an edge or frame. If the beams are too focused the lighting can look splotchy (hot where the light is and cool between the lights). As I said, this was just a nugget to think on when planning lighting. I plan to mine this thread and others like it in the near future. Best of luck to all on their lighting projects.

I am also interested in Arduino, small computer boards that can be programmed to run lights. I want one of my designs to light when there is noise and another only when it is quiet. You can program timers and other criteria into the boards. Has anyone here used them? Just curious as to which one and for what purpose.

Great discussion.

suds
Posts: 34
Joined: Fri May 09, 2014 10:44 pm
Location: Sonoma County, CA

Re: How to back light

Postby suds » Sat Nov 08, 2014 1:41 pm

KaCe wrote:\ When I began researching one very interesting thing I found was that lights, including LEDs, come with differing degrees of beam spread and that overlapping the beams slightly can give a smoother lighting effect. Another way to say it is that the lights can be focused tight like a spot light or be broad like a flood light.

I am also interested in Arduino, small computer boards that can be programmed to run lights. I want one of my designs to light when there is noise and another only when it is quiet. You can program timers and other criteria into the boards. Has anyone here used them?


Yes, when you go LED shopping it's important to look at the "Viewing Angle" specs. For back lighting in a shallow box I'd probably go with the widest angle I could get which is typically around 120° - 140°.

I've never played with Arduino but I've built plenty of projects using Microchip PIC's and I currently have a lighting related project on the bench that's based around a PIC 16F690.
Steve


Post Reply

Return to “Techniques and Tools”

Who is online

Users browsing this forum: No registered users and 33 guests

Warm Glass

2575 Old Glory Road, Suite 700
Suite 700
Clemmons, NC 27012
Phone: (336) 712 8003
Email: wg@warmglass.com