A different kind of LED project...

I take a lot of pictures. I photograph and review watches for fun and for publication. So I spend a lot of time with lights that are hot and expensive, not to mention unwieldy, illuminating very small targets.

I've been wondering if anyone here has seen or can imagine a system of white LEDs that would be bright enough to light a small stage for photographing watches? Is it something I could run off 110? And are there any kit solutions (or out of the box) solutions or would I have to try my hand at breadboarding something from scratch (something, by the way, not likely to happen).

Any thoughts? Any ideas?

And just to give you an idea, here is my latest, for the web, review...

Click here for the watch review

THANKS very much for any help or insight you care to provide. It is most appreciated.

Iceweasel,

I think this will be the start of a very informative thread! I will leave it to the photographically-unchallenged to do justice to your question.

Larry

Leds would not be any cooler than incandescents.

For tons of discussion about photographing watches, see the "Time Exposure" section of www.timezone.com . Click on the "Community" tab from the front page, then select the "Time Exposure" menu item.

Paul,

You really think LEDs wouldn't be less hot than incandescents? It seems hard to believe especially given the excessive heat many high temp photo lights generate. Well, maybe I just have to settle for something that uses less energy and, perhaps more importantly, is smaller.

And thanks for the TZ, I've been a visitor, reader and contributor there, on and off, since not long after it was started. There's a lot of great discussion there to be sure but it's not really the angle from which I was hoping to approach this.

Thanks.

You might experiment with Lumileds' "warm white" Luxeons - they have substantially better color rendition than regular luxeons.

You might be able to buy a Lumileds ring, line, or flood kit preloaded with the luxeons, which would eliminate most of the fabrication on your part. You'd have to make some sort of suitable housing and find some way to drive the thing (there are strightforward 110V AC drivers out there).

It might be more of a project than you're looking for.

Alternatively, you could look into Nichia's 5mm warm white product, but you'd going to have to breadboard a decent array of those to get signifigant output.

I find that for close up work, I get good results using a 1 watt luxeon driven at it's normal current as a side light.

I use a 1 watt lux as a work light for my lathe. It's heat sink does get hot, but the light it produces has almost no heat. I'd not want my halogen light as close because of the heat it generates.

As idleprocess mentioned, you might get a ring that you can use for a close up light (around the lens style) and simply under drive it for less heat. There's a guy who makes LED conversions of those little halogen lights that you see in recessed spots. You know, the ones with bayonet style prongs and a faceted reflector. Those might work as direct replacements for some of your current lamps.

Keep in mind that I have a very poor eye for color and composition, and that what looks good to me may make a professional gag.

Daniel

Maybe consider Lamina Ceramics series of high output diffuse LED sources. The BL2000 should put out more that a 3W luxeon into a totally even and wide wall of light..... I mean very wide and very even. I don't know how they do for colour balance, but mine looks a very clean white colour on brief tests. If you contact them , they ought to be able to suggest mains voltage drivers for them, you will need some heat sinking though, but nothing more than other LEDs.
Hope this helps

PEterW

PeterW, thanks for mentioning the Lamina engines. I have been looking at them for awhile but have yet to see a consumer product that uses them so I've been hesitant. From the web site they seem like the ideal thing. Price-wise, they're not even all that bad. Color I can deal with digitally if I have to, so while it's important, it's not the prime consideration. The issue is really, a strong yet diffuse source. Usually you end up getting the brightest thing possible then bouncing it around or diffusing it behind panels.

I have to buy a few of the Lamina panels to see what happens.

What about switching to daylight compact fluorescent bulbs?

Get one of the BL2000 series and see how it goes, report your experiences back to CPF and maybe we will see a whole lot more flood mods based on these things.

PEterW

Why stick with just white LEDs why not mix to get the right color "white"? There's a desklamp I saw that does just that. http://www.eco-lights.com/docs/led_tcp_galaxyled.shtml

Off topic: iceweasel, do the second hands on watches ever land exactly on the second marks all the way around the dial? I've been going round with a maker here and they say that none do.

How about something like this? I'm pretty sure you can get whatever color you want from it, but I'm not sure how diffused nor how bright it will be. There is one on CPF Auctions for $100, but you will need to buy a power supply for it..

Thanks. Some great responses.

I responded to the watch question via email. If you didn't get it John, let me know. I'll send it via PM or something.

I actually had considered creating something that was "full spectrum" and not just a collection of white LEDs. In fact, my thought was, if it could be controlled reasonably, to have some of the banks contain colored LEDs and use them not only to enhance the "whiteness" of the light but to also offer some lighting effects by dimming the white and strengthening, for instance, the blue, for a very cold look.

It would be a great idea if I could afford it, build it and then actually control and use it. But I can't. So it just remains an idea.

Thanks everyone for all the suggestions.

Hi iceweasel,

Haven't gotten an email. My profile has my email listed without using symbols to try and avoid spiders. If you just clicked on it I don't think it would work. I really would like to hear what you have to say. So if you don't mind please try again.

TIA,
LT

Rather than try again...

here is the text of the email...

First, we have two basic issues here. Are the watches in question mechanical or quartz? I get the vibe that you might be asking about quartz. And that's really no deep insight on my part as quartz watches are the vast majority of what's out there and what most people wear.

So we'll deal with the less likely circumstance first.

In a mechanical watch the movement of the second hand is determined by the "beat" of the watch and the gearing involved. In most cases this involves about five discrete movements per second. Hence the reason people tend to refer to mechanical watches as having "sweep" seconds hands. The hands individual movements are quite small and quick giving the hand the appearance of "sweeping" around the dial. If you take a one second exposure photograph of a mechanical watch you can usually clearly see the five movements, slightly blurred in the image.

In most quartz watches the second hand is driven by a stepper motor that moves the hand once per second. There are some exceptions found in fairly expensive quartz pieces but even they tend to suffer from the same foibles as their less expensive and much more common brethren.

The problem is, given the the extremely low cost of most quartz watches and the fact that most people really don't care whether or not the seconds hand is aligned with the actual indices on the chapter ring, most companies don't even try to make it "hit the mark" each second. Add to that the relative difficulty of always getting the stepper motor to move the hand precisely, well, you have a case where the overwhelming majority of analog quartz watches with seconds hands don't really line up with the marks most of the time.

I think it all comes down to the fact that most people just don't care.

Now, to refute your watchmaker friend you might look at the Mecha-Quartz models from IWC (International Watch Company). They tend to be extremely accurate and do, in the main, align with the indices (as they should). There are also much more humble examples of quartz watches with properly aligned seconds hands from companies such as Seiko. But it is the exception, not the rule.

I hope that ramble helps. You're right if your point was that some hands do align. Your watchmaker friend is wrong if it was their contention that such was impossible or that no one tried. But in general, your friend is correct in describing the vast majority of watches out there.

Thanks for the post on the CPF.

Best regards,
russell (ice weasel)

Re: Rather than try again...

Iceweasel,

Can you give me some dimensions for your ideal light source and its shape, or at least how many directions you might want the light coming from?

The beauty of LED illumination, for the product you desire, is that you can control the color balance fairly easily. If that were combined with fiber optic delivery, then you could have not only color control, but cool light near your subject, i.e., the watch, and consequently, the camera also.

I am presuming that since you are in a studio, there is no need for a portable solution, right?

Re: Rather than try again...

Russell,

Thanks for the info. The company is Citizen and I went to their home office here in Japan to hash it out with them. The watch is an Eco-Drive Skyhawk JR3090-58L http://www.citizenwatch.com/us/frame_noflash.html

The second hand wouldn't hit 12 straight up for zeroing so I sent it in. Long story short they say it's within spec. It only hits the second marks part of the way around the face and it's irritating. On cheaper watches it's not a factor but I was expecting better. Besides they were turkeys about it.

Thanks again,
John

Tell me more about these diffuse lamina lights. Are they in the same class as the Luxeons (size, efficiancy, light output) or are they more similer to the 5 mm LEDs? If they are more eficiant than a Nichia white array I will change my design.
Thanks, Eli

oeo2oo,

Well, the "stage" I currently use to shoot things is fairly small. No more than 12" in any dimension. I could increase the size of that slightly but I wouldn't want to get any smaller. So my thought was to design three, maybe four independent but identical light sources that I could move around to illuminate this area. The trick is, of course, getting a fairly white balanced light and a very diffuse but bright light. Certainly the last part of that is self-contradictory. Diffusion is more important that absolute brightness. But since my "subjects" don't move, exposure times aren't overly important (though for various reasons it would be nice to have some flexibility there).

The work is far too close for strobe illumination so the one of the main concerns becomes heat projecting from the front the light source. There's no sense in zapping a $100,000 watch with a ton of UV and heating it up to 140 degrees. It's just not right.

I think the Lamina light engines might be a good source but I can see that they're still so new I'm going to have to dive in an blow some money to see if they'll work for what I want.

Thanks again everyone for the help and suggestions.

You might want to look at Kassoy. They just started selling a line of led lights for jewelers to use with diamond showcasing. They aren't cheap, but maybe it will give you some ideas, or you can find the same thing cheaper elsewhere. The web site is the same name.