Your thoughts for the ideal on-camera LED

Norman99

Norman99

Well-known member
After reading and seeing a million or more ( so it seems) camera top led lights from domestic and overseas makers and reading specs and such, what would the ideal LED camera top light be ?
Mainly for social events, interviews, weddings or where an off-camera light would not be practical.
Would a model like these specs be considered ideal or there is some improvements to be done ?
Just a survey I always wanted to hear from users like you.

All aluminum construction
Water resistant for rainy days
Weighs about 12 oz.
Accepts 6 to 18VDC from P-tap, D-tap eng AB plugs, or 4 pin XLR etc.
Dimmer of course
3 position Color switchable 3000K, 4200K and 5400K
High CRI 80-85
Wide even beam of 65 degrees H no hot spots
Consumes LESS than 10W from source
1600 lux @ 3 ft. on any color setting
Metal shoe
Dimensions less than 3X2X3 inches

Anything to add/improve upon ?

Thanks.
 
I guess there is no improvement/nothing to add then...Good, that's exactly what I wanted to see.
 
Various battery mount options to include batteries that so many people have piles of: SONY, Canon, Panasonic, JVC, etc.
 
Great. The light shall have a DC input connector 2.1 X 5.5mm , lockable collar (round power DC in male) so that a battery sled (optional) can be used. Detachable DC wire going from sled to light Something like this http://www.varizoom.com/products/lights/s7200.html

Also the fact that the newer tapeless cameras will be drawing much less power from the camera batteries ( no motors to transport tape and video head spinning), these led lights can tap the power DIRECTLY from the camera batts that are designed for that purpose. Swit US has them for Sony and Panasonic with a DC tap on the batteries themselves. Here : http://www.swit.us/dv-batteries.html Both camera and the led light may draw LESS than 15 watts from one battery. Finally done away with the heavy battery belt.
Problem with some LED video lights is that they require 9 or 12 volt minimum to operate ( the seemingly good ones) and are way expensive for what they are, so those 7.2 volters cannot be used. Nice thing about the light design is that the color temperature is always at the setting selected on, either 3000K, 4200K or 5400K. Some variable temperature leds can allow a sweep control of either the amber or blue leds, but it is hard to precisely dial them back to a previous setting say when all of a sudden you have to balance for the outdoor and after get back in again for tungsten. This light will eliminate that dialing in thing and avoiding re-white balancing. I really am designing one based on videographer's preferred wish list. The more feedbacks I get, the better. Thanks for the suggestion
 
Not a bad wish list, but for me, a CRI of 85 is a bit sketchy. If you could get up in the 90 - 95 range it would make me more comfortable.

I am trying to standardize on all daylight sources now, so an honest 5600K (as long as there's no green spike) would be better than paying extra for warmer LEDs and switch gear I would rarely use.

- Greg
 
I´m glad to hear your LED project is well and alive, since it is a while since I heard from you.
How is it coming along?

Frank
 
Hi Frank, everything's going just fine. Just a few minor changes/enhancements. Sourcing available hi cri's isn't easy. There are many but the output is low or very few with a decent output and practically none with 95 CRI/high lumen. Sure it is easy for them to be 90 cri BUT the color temp is in the 2700 to 3000K range, but as soon as the leds go above the 3200, then the cri drops to 85 and eventually 70 at the high 6500K range. It is really a juggling act to find a balance of high efficiency/CRI/color temp. So far I have narrowed it down pretty much to be in the mid to upper 80's in the 3200 to 3500K range. In the meantime leds for video use in the mid 80's would be available in the neutral range ( 4000-4200K or thereabouts) . Also the constant current driver that cannot cause the dreaded pwm flicker so the newer breed of video cameras shooting at a wide range of shutter speeds won't have any banding issues. Reflectors or optics to channel the wide led spill from 125 degrees native to a more manageable 70 with minimal loss. Truly a daunting task. Also considering to use as few leds as possible in the design to avoid the multi shadow effect of multi led design. The design calls for only 2 lighting class leds with a lumen out of 750 each and the reflector to raise the ante by a factor of 2.2 or better. Maintaining a constant CRI throughout the temp range will be impossible but it will surely be 90 at around the 3000K and around 75 at the blue end. A little bit more work and time needed.
 
Just an update to the sample model as mentioned.
Specs measured under controlled conditions ( totally dark room, 70 degrees F, lab dc PS, Gossen Luna pro digital, light set to neutral 4000K setting :

60 degree H beam or approx. 75 degree diagonal, with not more than 140 lux difference from center to the corners.
1435 lux reading at 3 ft. (taken with incident reading sphere at beam center having sensor 3 ft. from the front surface of unit)
1295 lux reading taken at the 4 corners of the beam.
Power draw from 7.2 volt dc power supply is 1,305 ma (1.305A) = 9.4 watts ( measured at rated output, no dimming)

And there you have it. That is the most efficient use of input power to output light I can muster with the most efficient leds out there.
9.4 watts usage for an equivalent 75 watt halogen filament. ( almost a 1 to 8 ratio )
 
Adjustable arm (on camera light stand if you will) so light can be moved to 2 or 10 o'clock position on subject. Yeah probably easy to make but would be great if someone else made a led and gave me that. Also I want cheap battery power option.
 
All units will be supplied with similar to this, swivel into any direction.
http://www.bhphotovideo.com/c/search?Ntt=bescor+sa-1&N=0&InitialSearch=yes

As a pro light for pro use, AA's are out of the picture. The suggested option is the pro tap connector called D-tap or P-tap 14.4 volts DC or ANY DC source from 6 to 18 V. A very affordable battery option is Radio Shack 7.2v nimh battery for RC that goes for around $40 with the charger. 3000ma rated or higher.
 
Suggestion for power: Take a lesson from A few of the monitor manufacturers and offer mounts for the typical batteries used on handycams. SmallHD is a great example, I can use my existing Panny batteries and chargers.

Grant
 
An other powering idea.

1. I like something pro with a spiral cable and locking plug, that I can use with my V-mount batteries, that I have on the camera anyway.

2. As an option, different piggyback adapters (backplates) for camera batteries and one with a AA battery housing would be great.
Those adapters use the same cable as the v-mount battery, so you have the best on both and don´t need a second power inlet.

my ct2, Frank
 
Hi Grant and Frank, have yiou seen post #4 on this thread ? the sled adapter will allow Sony, Panny, and Canon batts. to be used. A spiral cable with a locking plug will be ideal, just sourcing one ( Switchcraft,Tensility, DigiKey etc.) is difficult especially the spiral part. V-mount batteries are really the way to go for ultra extended run times, especially if they have the built in P-tap on them. I am in the process of negotiating with an overseas supplier for a spiral cable that extends to 24" with a locking 2.1X5.5 mm barrel dc connector. Thing is, they need a minimum order of 5000 units for that to happen and a 60 day wait to production. There are spiral cables readily available but no locking collar. ZYCZ90 B&H part # is an example of a lockable plug with a power tap on the other end. Ideally I prefer the unit to be powered by the camera's battery as it draws less than 10W or by the mentioned sled. AA's have not been tested with the unit and cannot recommend them at this time. I did, however, put a Sony NP-F 960 L ( 7.2V 6000 ma) series on it and got well over 3 hours and at another test got over 5 hours by slightly dimming the unit to achieve 1000 lux. Thing with leds is that they are not linear in output to power ratio. You can dim them down a wee bit and have huge gains in run time. That is the reason my designs do not allow the leds to reach their highest rated output but to be driven to the sweet spot for maximum efficiency for light output.
 
Ha! Looks like you have already read my mind.

I see the AAs as a - nice to have - emergency option module, if everything else fails, one could still go to the next supermarket and get some batteries.

Frank
 
Hi Frank, yes you can hook up 4 AA alkaline in series to get 6V BUT the amp draw will be around 1.5 amp at that voltage and would leave little or no minimum DC V headroom for the driver to operate within regulation, so the dimming part will not have it's full swing range. Not only that, but I did not do any testing at all with AA's for any relevant heat/leakage/safety issues, so I cannot recommend them as a viable alternative at this time.If you must use AA's, then 8 in series will not only give better run times but most importantly reduce the amperage to 750 milliamps as the V in to the lamp would be 12V and the driver would have plenty of headroom to spare.No testing done with that config. but suffice it to say that the unit is well protected against reverse polarity mishaps. Even though I rate the unit to accept from 6 V to 18 volts, the 6 volt figure is the bare minimum for the driver to operate to feed the leds
but not with AA alkalines as the voltage droop on alkalines would be reduced to 5.5 volts or less, below the driver's minimum range. At that point, the dimming function is severely restricted. Most intended users will either drive it with 7.2 V Li Ions or the 14.4 Pro bricks. I will try to include a universal (110-220) 12 or 16 volt DC adapter with the units as soon as I can source a reliable supplier at a low cost.Which brings me to the topic as to what would be the attractive market price for it. I will try to keep the unit as affordable as possible and at the same time not to sacrifice on build and component quality. Again a juggling act.
 
Hi Patryk, samples of the 3 color light should be available for initial field evaluation by the end of May or sooner if possible. Delays were due to :Minute changes in regards to controls placement to be the optimal positioning of power / dimmer/ and 3 way color selector switch. I have decided to go for a 3 position color temperature selector switch for repeatability accuracy at 3 most used color temperature values as opposed to the stepless potentiometer variety that introduces the possibility of wear and tear on the control over the life of the lamp. There are units that have electronic mode settings along with memory functions and digital status display, but then again, bells and whistles are not what a reliable rugged light warrants. Simple, practical, rugged and reliable is what is needed. And affordable.
I'll put you on my list Patryk. Thanks
 
Just need a little feedback as far as color temperature choices on this one. The color temperature selector switch is a 3 mode choice setting. I can do it either 3000K-4200K-5400K ( my personal preference) or any of these combinations:

2800-4000-5200K (A)
2800-4500-5700K (B)
3000-4000-5000K (C)
3200-4300-5500K (D)
3000-4500-5800K (E)
3300-4500-5700K (F)

Any replies would be greatly appreciated as the final decision as to color choices will be based on this survey.
 
Since it's set, and not a dial-in adjustment, I'd want something closest to what is considered "standard" - 3200K and 5600K. That would put me in D or E territory.
 
You must log in or register to reply here.
Back
Top