The ML840H is an 84 LED panel with daylight corrected light, a variable brightness control and a flash mode. It mounts on a hot shoe and has a tilt bracket that can be used mounted on the camera horizontally or vertically.
Manfrotto ML840H LED Light Features
The panel has a built in lithium rechargeable battery and comes with a charger plus adaptors for power sockets in different countries. It also has a short flash sync lead, a removable tilt cold shoe bracket with tripod thread and a set of three filters.
30 Hour use from fully charged battery
Universal power supply
84 LED lights
Bounce angle bracket
Dimmer control from 100% to 0%
Warm, diffuser and daylight to interior correction filter
Manfrotto ML840H LED Light Handling
Attaching the LED panel to a camera is just a case of sliding it onto the camera's accessory shoe. If the camera doesn't have an accessory shoe you could buy a flash bracket and mount the panel to the side. Then you adjust the angle using the supplied tilt bracket. This can be removed from the panel to reduce size if you are just hand holding the light or it can be placed on the horizontal or vertical edge to change the orientation of the panel.
The bracket locks solidly and provides the all-important down angle for macro and close work.
The only control is a brightness setting on the left that rotates. This is also the click stop on / off switch. It acts like a dimmer switch, offering variable control of brightness.
A button on the back switches the flash on. It's a low power option for stills photography and uses the supplied PC sync cable to connect to a camera. The cable is just long enough to reach the camera's sync socket and is dependent on the camera having a PC socket. A slightly longer cable would allow more flexibility, but you can at least buy a flash extension cable if necessary.
The ML840H comes with three plastic filters that slide into the front behind the perspex protective panel. They fit in really easily and lock so they can't fall out. They also take up little space, so easy to carry around with the light. What would be even better is if it came with a small pouch to carry the light panel with a pocket for the filters.
Manfrotto ML840H LED Light Performance
One of the main benefits of an LED panel is its continuous light source for video. There's a brief flash of light as the unit is turned on making it impractical to add light mid way through a video recording unless you have it ready, switched on at minimum power. Other than that the illumination is fine for video, apart from vignetting with wider angle lenses that you'll see below.
Here's how it looks for a video recording. The camera used was the Pentax K-5 with the 16-45mm zoom lens.
You need to avoid using the ML840H with lenses wider than around 40mm as the circular illumination begins to show with quite heavy fall off at the edges. With longer lenses in the 80-100mm region, the illumination is even across the frame.
The photos below show the vignetting. They're taken one meter away from a light coloured wall and the lens is at 24mm to show the circular light pattern. The ISO was increased to show the output. The ISO1600 version is about the correct tone of the wall, so that also shows the light isn't that powerful.
A light meter reading measured f/2.8 and 2/10ths at roughly 1m. To put that in perspective the built in camera flash of most DSLR cameras usually has a guide number of between 8 and 12 (ISO100/M) meaning you couldn't shoot at f/8 or f/11 at 1m.
LED - 1/125 sec | f/5.6 | 24mm | ISO100
LED - 1/125 sec | f/5.6 | 24mm | ISO400
LED - 1/125 sec | f/5.6 | 24mm | ISO1600
Flash - 1/20 sec | f/5.6 | 24mm | ISO100
In the sequence below, taken with a 100mm lens at f/2.8 and ISO100, I started with the mannequin illuminated by the room light, then switched on the ML840H and gradually raised the power. The final shot is with the ML840H set to flash. The camera was two meters away and while the LED is bright enough to illuminate the mannequin (at a slow 1/10sec shutter speed) the flash at the higher sync speed of 1/125sec has underexposed.
Daylight - 2.5 sec
ML840H on Low Setting - 2.5 sec
ML840H at 1/3rd power - 1.3 sec
ML840H at 2/3 power - 0.3 sec
ML840H at full power - 1/10 sec
ML840H using Flash - 1/125 sec
Using the ML840H for outdoor nature:
I've been using a ring light, torch or reflectors to illuminate fungi, but found the Manfrotto ML840H LED provides a really useful light for close up work like this. The vignette is less important as it's used to emphasise a smaller part of the scene. In the example of the Fly Agaric above I was able to add some light to the stalk and under side gills without having much affect on any of the surrounding detail.
Above left is without the LED and right is with it on full power.
Below is one of my favourite fungi photos I've taken to date. The ML840H has given just enough light to pick up detail in the spider's web and add what looks like a shaft of sunlight due to the daylight corrected LEDs. Exposure was 1/160 sec at ISO 200.
For this kind of photography the ML840H is ideal as you can concentrate on getting the exposure correct for shadow areas and bring a subtle amount of light in to the highlights. And unlike flash you can see what you're doing as you adjust settings.
Using the ML840H for indoor still lifes:
The exposure for this ornament was 1/125 sec at f/3.5 and ISO400. The left hand photo is without the LED panel (window light to right), middle is with the panel switched on at full power and right is using flash. The camera was about 70cm from the sculpture. The flash is brighter, but being able to control the intensity of the continuous light gives far more scope.
Value For Money
With an RRP of around £250 this is a very expensive panel light. It's discounted to £160 by many retailers but still way above the price of 120 LED panels you can pick up on eBay for about £35. The positive side is it's a Manfrotto product and it feels really well built with no doubt good quality control and it certainly was highly reliable during the test. The cheap versions don't always have dimmers, or a flash feature, and they usually take AA batteries. There's often no vertical position either.
Manfrotto ML840H LED Light Verdict
I certainly had fun using the Manfrotto ML840H, especially for the close range fungi shots. It would be good if the spread of light was more rectangular to increase the number of uses and a more realistic price would be helpful for many who could currently use the money to buy a more powerful flash unit with diffuser or video light. The variable output control and daylight correction comes in really hand when balancing the flash with daylight and for close up nature subjects it's great fun to use.