LED Light Boxes / Panels

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Nomad Z

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Been looking at the cheapie LED light boxes / panels on eBay and the price seems very low - anything from 30-odd quid for an A3.

They mostly seem to be aimed at artists for tracing. Are they any good for viewing negs and slides? Is the lighting even and strong enough? How about colour temperature?

Are they too good to be true, or am I right in thinking that the price is about right given where LED computer screens are at these days? (I assume it's basically the illumination part of an LED monitor.)
 
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I made one for just that porpose. I got pleasure with
it only after a white plexiglass was fit to it, as diffuser.
 
I ordered one. It seems there are two types - a thicker one that uses a mains adapter and has adjustable brightness but no statement of colour temperature, and a thinner one powered via USB and has a stated "10000 - 13000" colour temp (presumably Kelvin) but no indication of being dimmable. The dimmable ones have three fixed brightness settings and it think it's a case of pressing the power button sequentially (and I gather it's a touch control, so maybe3 a risk of changing the brightness inadvertently).

I went with the USB one with a stated/claimed colour temperature, for 32 quid.
 
Post back how you get on with it, I'd be interested in one if it was decent enough quality
 
Yes, I will do. If it illuminates negs well enough, I'll see about trying one of those phone apps that invert the image. I'd like a way of previewing 135 and 120 colour negs in particular so that I can select which to scan (because scanning whole roll films is tedious, especially 135).
 
I bought one of these from Home Bargains and use it to display my slides as well as a light box for photographing negatives to digitise them.

http://www.homebargains.co.uk/products/12357-cinema-led-lightbox.aspx

Looks like they're sold out online but the Works still have them for £10

https://www.theworks.co.uk/p/new-gi...1&cadevice=m&gclid=CPjTpMCBrtMCFWEq0wod5ZkLeg

They can be powered by AA batteries but also have a barrel connector input so I've soldered a male USB connector to one and power it using a standard mains USB phone charger.

As it stands up on its' side and has three supports built in, it works well as a permanent display.
 
Saw that on eBay, but it's a bit small (I got an A3), and it looks like the horizontal retainer bits would get in the way. Aside from previewing roll film strips, I want room to view several 5x4s, and possibly 10x8. Looks like it would be fine for roll film, though.
 
Nomad Z said:
Saw that on eBay, but it's a bit small (I got an A3), and it looks like the horizontal retainer bits would get in the way. Aside from previewing roll film strips, I want room to view several 5x4s, and possibly 10x8. Looks like it would be fine for roll film, though.
Click to expand...

Yeah, it's definitely limited to 135/120 but for the price the temp and brightness output are very good. There's also good coverage across the face so no obvious dull spots. I'm sure the dedicated A3 panel will be more consistent though.
 
stevelmx5 said:
... As it stands up on its' side and has three supports built in, it works well as a permanent display.
Click to expand...

Whatever happened to your "almost finished" 120 transparency display unit, Steve?
 
ChrisR said:
Whatever happened to your "almost finished" 120 transparency display unit, Steve?
Click to expand...

Just for you Chris, I've just spent an hour re-designing the LightBlock so it can be built up using easily cut layers rather than being routed out of a solid block. The benefit of this is that it's much quicker to machine and can be done entirely on a laser cutter from 6mm/3mm MDF or plywood and 2mm opaque acrylic.

LightBlock-Front by Steve Lloyd, on Flickr

It's still running the same internal LiPo battery that's charged externally via standard micro USB input, and outputs a 5v USB connection for charging other devices.

LightBlock-Rear by Steve Lloyd, on Flickr
 
That looks really tasty, Steve. And reversal b&w as well, yum yum!!!
 
Arrived. Works. Well worth the money.

It turns out that the 5mm thick one also has three levels of brightness - no switch, just an area at the edge that detects the presence of a finger. I wouldn't say it's hugely bright, but it's bright enough. Dense negs will still look dense. The lower brightness settings seem too dull to be worth using for photography stuff. The supplied USB cable is nice and flexible, and has some sort of mini/micro/small connector at the lightbox end that I don't recognise (could be the latest standard for all I know).

Illumination is pretty even - the light meter app in my phone reckons about 0.5EV variation. Its colour temperature readout varied from 6600K to 6650K.

The top is one surface - the black border is under the layer of acrylic. This means that you can slide a neg over to the side rather than try to get a fingernail under it - nothing at the edge for it to catch on. Haven't tried any of those neg inverter apps yet, but I think it will be fine for viewing at least. In lieu of that, I just tried it using the phone camera and Photoshop...

Straight from the phone, rotated, resized, and a bit of unsharp mask.
LED Lightbox Contacts 01.jpg

A tad blue in the phone camera. The negs are in a Secol archive sheet.

After a quick PP in Photoshop.
LED Lightbox Contacts 02.jpg

Blimey, it's a set of contacts!

Steps were (from the original): Rotate, resize, convert to greyscale, adjust levels left and right to maximise dynamic range, invert, levels middle control to the right to bring the somewhat low contrast images up a bit, a touch of unsharp mask.

I think this thing will work very well as the hybrid photographer's contact frame. The above was way less hassle than using the V700 scanner - a no-brainer, in fact. So, what I think I'll be doing is develop the negs and get them into the sleeve, do the contact sheet thing, and then select which images to scan properly. Since the phone is quite high res (the above 6x9cm shots were 1100 pixels wide before resizing), it'll be fine for an index image as well. I guess I'd still need to look into an app for inverting colour negs, though.

For the hassle saving factor alone, a definite thumbs-up.
 
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Just been messing with some colour negs, and I have a quick & dirty method. The basic idea is take a set of negs, build a series of adjustment layers to do the conversion, and save that as a .PSD reference file. Then, to convert a new set of negs, I load both the new image and the reference file, get both images visible on the screen, and drag-copy each layer onto the new image. Here's an image that was corrected by dragging layers onto it, with a couple of small tweaks afterwards...

Colour Negs Adjusted Using Copied Layers.jpg

A bit magenta in the outdoor shots (most were under glass at the botanical garden in Edinburgh), but a lot easier to see what's going than by looking at the original negs. Certainly usable enough for something that takes a minute or two.
 
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