LED Light Table?

[LFLarry]

Can anyone recommend a color-corrected LED light table that you know is good? I don't need anything larger than 8x10.

I plan to lay some of my 4x5 transparencies and also some of my color negatives on a light table and then use the digital camera on a copy stand as a scanner in order to digitize the film and then bring the RAW files into Photoshop for editing, etc.

Thanks

[Alan Klein]

I just bought a Kaiser Slimlight LED light box. Very thin. rechargeable through a USB that it's furnished with and AC charger. They come in different sizes - I have the smallest version. Thjey have larger version that would work for you. 5000 Kelvin light. Although I just tried it today, it seems very well made in Germany.
http://www.kaiser-fototechnik.de/en/produkte/2_1_produktanzeige.asp?nr=2454
https://www.bhphotovideo.com/c/product/1417564-REG/kaiser_202455_slimlite_plano_5000k_battery_ac.html

They also have a version that is used for photo copying with a stand. I know nothing about it but it might work for you. Good luck.
http://www.kaiser-fototechnik.de/en/

[Drew Wiley]

Why do you specifically want LED? Right off the bat I detect a potential discrepancy in the ad. If the LED's are allegedly 5000K, it means the light box is not, because you still have a color bias in the diffuser, backing, and quite possibly a quality control issue. Kaiser is certainly a reputable brand, but squeezing this all into such a slim package introduces some real issues which their older tried-and-true, deeper tube technology is known to have ironed out. I mention this because duplicating work is a more demanding application than just slide viewing. If it were me I'd want to at the very least have the right of return if my color temp meter detected something significantly out of whack which can not be easily corrected with filters. Some of these LED lighting devices are more than a thousand degrees K off from the rated specs. Merely light balancing your camera might not correct for certain imbalances. I went to the trouble of making my own duping copystand lightbox using very high quality CRI 98 German color-matching tubes and an optical glass top. I can't think of anything LED that color accurate. Quite a bit goes into this kind of project, including special interior paint. The thinner the box, the more some kind of compromise comes into play.

[LFLarry]

That is very interesting Drew. Whether it is LED or not, are there any commercial color-balanced lightboxes that you can recommend for digitizing film?



Why do you specifically want LED? Right off the bat I detect a potential discrepancy in the ad. If the LED's are allegedly 5000K, it means the light box is not, because you still have a color bias in the diffuser, backing, and quite possibly a quality control issue. Kaiser is certainly a reputable brand, but squeezing this all into such a slim package introduces some real issues which their older tried-and-true, deeper tube technology is known to have ironed out. I mention this because duplicating work is a more demanding application than just slide viewing. If it were me I'd want to at the very least have the right of return if my color temp meter detected something significantly out of whack which can not be easily corrected with filters. Some of these LED lighting devices are more than a thousand degrees K off from the rated specs. Merely light balancing your camera might not correct for certain imbalances. I went to the trouble of making my own duping copystand lightbox using very high quality German tubes and an optical glass top. Quite a bit goes into this kind of project, including special interior paint. The thinner the box, the more some kind of compromise comes into play.

[Drew Wiley]

You could look at either traditional fluorescent tube Kaiser boxes (not cheap) or Just Normlicht, which B&H still also offers, I believe. They have relatively compact versions ideal for your needs. These don't flicker like fluorescent room lighting sometimes can, which is an important feature when copying. These high quality brands also use a specific interior white paint which offsets most of the diffuser color bias. One technicality with color matching tubes is that some of them are designed to pass a certain amount of UV comparable to sunlight, even if they're 5000K balanced. This has a slight effect on most digital receptors which a simple 1B skylight filter can easily handle right from the start better than post-correction. Singh-Ray has a special filter for this purpose, but it's quite expensive, and an ordinary coated Hoya 1B is nearly as good.

[Pere Casals]

Can anyone recommend a color-corrected LED light table that you know is good? I don't need anything larger than 8x10.


This may be perfect: https://www.amazon.com/Neewer-Camcorder-3200K-5600K-Ultra-Thin-Portraits/dp/B07WD6QXMJ/ref=sr_1_3?keywords=panel%2Bled%2Bcri&qid=1573814432&sr=8-3&th=1

197435

At +95 CRI color accuracy has to be perfect. You may need to place a white plastic diffuser on it for perfect even intensity.


On any doubt, and recommended, place an IT8 transparent calibration target on it, shot it, and make a calibration. From that all colors in the IT8 patches will be nailed to standard RGB values. It is true that different targets made of different films may deliver different calibrations, but result will be close enough in practice. Use that profile in PS, etc.

[Alan Klein]

I have an old light table in the attic that I haven;lt used in years. I ought to pull it out and sell it.

I wonder if I used my NEC Spectraview II program and puck used to calibrate my NEC monitor, whether it would give me accurate readings of it and the new Kaiser Slimlight LED light box I just bought as to Kelvin etc.??? Any thoughts on that?

[Greg]

Personally prefer to use a graphiclite D5000 STANDARD VIEWER. Think I acquired it around 1990, and it has served me exceptionally well since then. The evenness of its illumination is amazing. Have used it to digitally copy well over 2,000 glass plates (up to 8x10) over the years for museums. Yes it is big and bulky compared to a LED panel.

[Jeroen]

These are reportedly the best, and also very expensive: https://heilandelectronic.de/led_kaltlicht. There's a link to an Ilford test report om that page.

[Drew Wiley]

No Pere, that cheap toy you post would be inappropriate for copying applications for reasons I already mentioned. Not only will the color temp be way off from the advertised rating, but the illuminated surface will be quite uneven in a dimply-looking sense. All it takes it one look at these things actually turned on to detect that flaw. And reading them with a color temp meter will give them the final blow. CRI 95 is far from ideal, especially when you need to factor in about a 15% BS Coefficient in how cheap gear is advertised. An ideal light source would be a modern upside-down 8x10 colorhead, except that it would be hot and probably blind you too. Since the colorhead option is generally unrealistic, there are indeed high quality light boxes made for this kind of purpose. Three brands have already come up - Kaiser, Just Normlicht, and Graphiclite. You could also obtain something from the MacBeth Prooflite series (now owned by XRite, I believe). Lots of authentic options; but you don't get something for nothing. I should add that truly calibrating any such system requires a good color eye and goes beyond shortcut instrumentation. But always start with a precise control like a LF chrome of a MacBeth Color Checker Chart shot under ideal exposure and color temp conditions. I've been through all this rightside-up, upside down, sideways, backwards, you name it. And at the present time I cannot fully recommend any affordable LED option. Remember, this is for sake of color sheet film being copied when laying right atop a diffuser. There won't be intervening space to allow that further diffusion like an LED head intended for enlargement, or a flat panel intended for general portrait lighting from a distance, etc. The IMMEDIATE SURFACE has to be completely evenly illuminated.

[Pere Casals]

reasons I already mentioned.

Drew, today EPSON V850 uses a LED illuminator, with no problem. As I mentioned an additional diffuser may be required on the panel...

Spectrum will be continuous enough to make an IT8 calibration nail color accuracy.

[interneg]

A TLCI-2012 score of at least 85 is what you want - and the results have a tendency to suggest that price of the luminaire doesn't necessarily indicate the quality of its performance. It's a far tougher test than CRI.

[Drew Wiley]

Sigh ... I don't have time today to discuss all the "what if" factors. So I'll simply default to the position that a well-made lightbox will be reliable far longer than most scanners, be less complicated to operate, and cost less too. And if the OP ever wants to copy color film onto real film rather than digital capture and jumping through hoops post-processing, it has to be pegged very close right from the start.

[Pere Casals]

A TLCI-2012... It's a far tougher test than CRI.

Well... for low rating there is a difference, for high ratings usually TLCI and CRI give similar ratings:

197455

This is for the Aputure Amaran AL-M9 DSLR illuminator



Sigh ... I don't have time today to discuss all the "what if" factors. So I'll simply default to the position that a well-made lightbox will be reliable far longer than most scanners, be less complicated to operate, and cost less too. And if the OP ever wants to copy color film onto real film rather than digital capture and jumping through hoops post-processing, it has to be pegged very close right from the start.

Yes... nothing like tungsten to throw the tungsten spectrum, but it converts 95% of the power into heat...

Best LEDs (violet source) are even better than a ceramic discharge metal-halide (CDM) lamp, and second rate leds (blue source) are almost as good as a CDM. Of course there are also very bad LEDs, but a LED sporting CRI Ra 98 deserves some respect.

[choiliefan]

Artograph LX series have adjustable color temperature: https://www.artograph.com/light-boxes/

[Drew Wiley]

I'm getting close to one of those "read my lips" moments. You don't get something for nothing. Of course, you can use all kinds of these devices. But doing accurate film copy backlighting is something much more demanding than a mere tracing tablet provides, especially if one opts to do it using film itself. Reminds me back when people would pay about fifteen bucks for a Spiratone slide copy device that looked like a black spray painted toilet paper roller; and that's exactly the kind of results you could expect - flushable.

[Pere Casals]

Drew, OP is not to expose/copy film on the table, he asks for a illumination source to scan with a DSLR.

[Alan Klein]

I tested Kelvin in five locations on my Kaiser Slimlite Plano 2453 in both battery mode and 120 power charge mode. Display portion is 6.3" by 8.7" for this model. See first image. I used my NEC Spectraview II puck and software to take the readings. The bottom image is a typical reading shown on my monitor. Of course, the intent was to take reading of the monitor but I put the puck on the Kaiser lightpad.

Beside the Kelvin reading, you get other readings. But I don;t know if those are of additional value. Does anyone know what they mean?


197558

197559

[Drew Wiley]

Color temp meters have integrating spheres, but can still be fooled off-axis. But IF those readings in your sketch are indeed accurate, it means the light pad is hopelessly uneven in terms of color temp, and would be useless for anything like duplicating. Doesn't surprise me.

[Drew Wiley]

Pere - if it's not suitable for film, it's going to be less than ideal even with a digital device. The whole point is accurately balanced RGB spectral peaks. Yes, one can jump through flaming hoops in digital post-correction; but there's always the risk of coming out the other side smelling like smoke.

[Alan Klein]

I'm not using it for copying rather for looking at chromes. Curious about the different readings. I imagine that's probably because there are dozens of LED's that make up the whole panel. So you can get various light outputs making up for the differences across the pad. A copying light probably had one or two lights thru a diffuser that evens out the light so it's spread better over the whole pad. Has anyone actually measure it like I just did to see whether or not the color and Kelvin is consistent?

[Drew Wiley]

You could try reading the same spots multiple times, but by turning the color temp meter somewhat different directions in relation to that, to see if you still get anomalous readings. But all this goes back to the fact that, even IF the little light sources were themselves consistent, there are other factors involved. No big deal if just sorting out chromes. I have something similar for portable casual viewing use.

[Alan Klein]

In looking at the Kelvin numbers, there's about 2% total difference from all the readings from the "worse" to the "best". What that means to someone using it as a light source for copying, I don;t know. But the 2453 unit I measured is recommended by the manufacturer for that purpose.
http://www.kaiser-fototechnik.de/en/produkte/2_1_produktanzeige.asp?nr=2457

[Alan Klein]

I just noticed that the film holder sits an inch or two above the surface of the LED light table. So the light will be diffused. When I measured the Kelvins, the NEC measuring puck was on the surface of the LED light table so it was more effected by the variables of the numerous LED's.

[Drew Wiley]

It's obviously something being marketing for amateur MF and 35mm slide work, and not for serious LF use. What I'd do is take a shot of a very even gray surface with larger film and a long enough lens to be devoid of falloff, then see how that copies over that light source in terms of illumination evenness. Color accuracy would requires separate tests. Just depends on how nitpicky your intended application is.

[Alan Klein]

I use an Epson scanner. I bought the Kaiser unit to view slides and chromes, that's all. I figured since I had a NEC Spectraview II puck, I'd measure what the light table puts out as that info might be useful to others in making a selection either for viewing or for copy slides with a digital camera. I hope my research helped someone.