06.07.2022

Ring lights vs. LED lights. They are actually not two different genres of lighting but two different approaches to lighting depending on the kind of photography that you do. Incidentally, both ring lights and LED lights are basically the same thing – they are both LED lights. The only thing that is different is the shape. Photography as a term encompasses several different genres and sub-genres. Portrait photography, e.g., is an extremely popular genre and is one of the key areas where both these types of lights are used.
The most obvious thing about ring lights is that they are shaped like a, well, a ring. They are the best when it comes to shooting beauty shots. The ideal kind of light that would produce flattering facial portraits of models wearing cosmetics or jewellery. Photographers love them, and so do models.

But what is so special about them? The shape. Ring lights are shaped like a ring and that shape allows the light to uniformly light a face, usually from a straight-on angle. The top-of-the-line ring lights such as the Spectrum Aurora 19” Gold Luxe II Ring light come with a colour temperature adjustment knob. A brilliant feature that allows you to match the colour of the light with the others in the studio. This is useful when you are working in a multi-light setup and or when you need to adjust the colour of your key-light with that of the ambient light in the room.

Most professional units, such as the Spectrum Aurora 18” Diamond Luxe III Ring light are battery operated. And this is a huge advantage when shooting outdoors. You can adjust the colour temperature to mimic the sun’s light and or use it to compliment the sun to produce an image that appears shot entirely with natural light.

The term LED panel lights denote an array of LED lights setup on a panel type base. This base could be rectangular or square and depending on the specific purpose or utility of that panel lighting systems. Additionally, the number of LEDs on any LED panel lighting system can vary. Usually, the higher number of LEDs, the higher price of the unit.

Just like the ring lights we read about above, LED panel lights also come with the option to change the colour temperature. Allowing you to seamlessly mix the light with natural sunlight or allowing you to adjust it with the ambient light colour temperature inside a room.

RRing lights are best utilised for the purpose of shooting portraits. They are primarily used for capturing those beautiful catchlights on the eyes of a model. But beyond that ring lights are useful for product photography and macro photography as well. In both product and macro photography you work with a macro lens and get in close to the subject in order to produce an image that fills the frame. When working with a small focal length lens you must move in closer to the subject in order to fill the frame. That may and often blocks the ambient light. A small ring light is the best solution for ensuring a proper exposure. A speedlight or strobe is out of the question in such a situation. Additionally, if you use focus stacking technique you will need to have a constant source of colour balanced light. A ring-light is a good solution.

Ring lights are best utilised for the purpose of shooting portraits. They are primarily used for capturing those beautiful catchlights on the eyes of a model. But beyond that ring lights are useful for product photography and macro photography as well. In both product and macro photography you work with a macro lens and get in close to the subject in order to produce an image that fills the frame. When working with a small focal length lens you must move in closer to the subject in order to fill the frame. That may and often blocks the ambient light. A small ring light is the best solution for ensuring a proper exposure. A speedlight or strobe is out of the question in such a situation. Additionally, if you use focus stacking technique you will need to have a constant source of colour balanced light. A ring-light is a good solution.

What happens if you supply too much voltage to an LED?
In the most simple terms: it will kill the LED. However things are really not that simple.

First off, an LED is a current driven device, not a voltage driven device. That is, it doesn't really care what the voltage is, but it does care what the current is. Of course, too much voltage will kill it - but too much current, regardless of the voltage, will kill it.

It's important to understand that an LED is what is known as a non-linear component. Things like resistors are called linear because they have a linear relationship between voltage and current. Increase the voltage, and the current increases by the same proportion. Increase the resistance and the current decreases by the same proportion.

Once the voltage reaches the "forward voltage" of the LED the current flowing through it rapidly increases. As you can see it very quickly gets towards infinity. Above a certain point and an increase in voltage has no real difference in the current. In that example the difference between 3V and 5V would be both infinite and zero. In other words, it's pretty meaningless.

But we're still over-simplifying, and that's because we've assumed an ideal power supply. That is, one that can supply a fixed voltage, but infinite current. In other words, a power supply with zero impedance.

No such thing exists, though.

Every fixed-voltage power supply can be seen as an ideal voltage source with an in-line (series) resistor. That resistor limits the amount of current that the supply can provide before the voltage drops too low.

f the voltage of the source is above the forward voltage of the LED it will try and draw an infinite amount of current from the source. That current will lead to a voltage drop across the resistance RZ, which results in the output voltage of the source being reduced.

It will reduce to be the same as the forward voltage of the LED.

We can, of course, calculate the current that would come out of the supply if we know the impedance of the source, but that's not something that is often known. So you assume it's low and take precautions.

What is the difference between edge-lit and back-lit LED panels?
An edge-lit LED panel is made of a row of LEDs attached to the frame (or circumference) of the panel, shining horizontally into a light-guide plate (LGP). The LGP directs the light downwards, through a diffuser into the space below. Edge-lit panels are sometimes also known as side-lit panels.

A back-lit LED panel is made of an array of LEDs fitted on a horizontal plate shining vertically down through a diffuser into the space to be illuminated. Back-lit panels are sometimes also known as direct-lit panels.

Both designs have advantages and drawbacks. Edge-lit panels were the first to be mass-produced.

The edge-lit design was used first for several reasons:

A light-guide plate (LGP) is an effective and simple way to diffuse the light very evenly, avoiding the risk of bright spots. The best LGPs are made of acrylic (PMMA) which has a very high light transmission % and does not yellow with age.

The presence of the LGP means that the diffuser is not solely responsible for spreading the light evenly so low-cost materials can be used in the diffuser, provided they don’t yellow with age.

No lenses are required and the edge-lit design functions well with a variety of different LED beam angles.

Heat from the LED chips is dissipated via the frame, so the rear can be light-weight and it won’t get hot, so the driver can be placed here if required.

In an effort to reduce the cost of edge-lit panels some manufacturers introduced cheaper materials and assembly processes that impacted on their quality. Principally, this involved the LGP. Polystyrene (PS) LGPs are now used by some manufacturers, but if UV stabilisers are not added these will yellow with age and the panel will become dull in the centre while the periphery remains bright. Also, PS has a lower light transmission % than PMMA.

Technical advances have allowed back-lit LED panels to be introduced.

LEDs have become more efficient, so the thermal advantage inherent in the side-lit design is now reduced, though not eliminated.

Lenses have become cheaper to produce and modern adhesives mean that they can be securely fixed to each LED to create an even light distribution without the risk that they will fall off – a failing with some earlier and cheaper back-lit panels.

Micro-prismatic diffusers have become more common, less expensive and more effective, so the double action of the LGP/diffuser combination is no longer required.

Because cheaper edge-lit panels used LGPs with a low light transmission, eliminating the LGP altogether, as with a back-lit panel, has meant that back-lit panels have a reputation for being more efficient.

The lighting market now accepts back-lit panels as readily as edge-lit panels. Here at NVC we have had both designs in our product range, but we have decided that edge-lit is marginally better. This is because the rear of the panel is the most convenient position for the driver and, because we offer 5 and 7 years warranties, we are keen that the driver should remain as cool as possible.

A Guide to Dimmable LED panel lights
Considerations when dimming LED Panels

Dimming LEDs is not as simple as dimming incandescent bulbs. But by following our guidance, dimming LEDs can work for you and become a great way to make even bigger energy savings and control your lighting environment.

When it comes to introducing dimming to your lighting setup, make sure that the LED panel, or more specifically the driver, is dimmable. Most LED panels are sold with a non-dimmable driver, as a dimmable driver must include more electronics which adds cost.

Once that’s all sorted, it’s simply a case of taking a look through our dimmer range choosing your dimming method.

Dimming methods

Mains Dimming:

This will be familiar to many people, as it’s the method generally used in homes. Mains dimmers tend to be rotary and are what you would find on a wall in place of a light switch. They have a knob you can twist anticlockwise or clockwise to decrease or increase the light output and push in to switch the light on and off.

Mains dimming works by chopping up the electrical signal from the mains. It does this by switching the electric current on and off several times a second. The result of this rapid switching is that less power is available to the light as the power is off for part of each second.

The light is on and off at full power, but less light is delivered in total compared to if it was on the whole time. Since our eyes cannot process the rapid switching, our brain interprets this as a steady, dimmed light source.

The power from the mains in the UK comes in a wave with a frequency of 50Hz. That means this wave is repeated 50 times a second. As the current from the mains is alternating, switching from positive to negative every cycle, there are 100 cycles of current per second: 50 positive and 50 negative.

Mains dimming is achieved by switching off the power for a period twice in every wave, one for each cycle of current.

Mains dimming can be split into two types – Leading Edge and Trailing Edge. But it’s not necessary to worry about this as the Varilight V-PRO dimmers we recommend for all our LED Panel TRIAC dimmable drivers are compatible with both Leading Edge and Trailing Edge drivers.

Choice of dimmer power

When LED drivers are first switched on, they draw a large amount of current for a very short time, until the capacitors inside them have charged. This is known as ‘in-rush”. This does not change the overall power consumption at all, so LEDs are still big energy-savers, but it does mean that a dimmer will ‘see’ them as having a higher wattage.

LED light dimmers therefore are de-rated for use with LED products. This means that while the dimmer may show a rating of 400W, the LED dimming rating could be 100W. Please therefore always check and adhere to the manufacturer’s rating for LED dimming.

What is the difference between pendant mount, surface mount, ceiling mount, and wall mount?
When shopping for lighting and fixtures, it is important to understand the different types of mounts that are available for specific types of lighting. The type of mount needed is dependent upon the need and the placement of the light fixture. While pendant, wall and ceiling mounts all follow the same mounting technique and can be loosely defined as surface mounted, they each have their own specifications and applications.

A surface mounted light sits on top of a flat surface like the flat part of a ceiling and protrudes away from the surface. Surface mounts that are specifically mounted to the ceiling are also called ceiling mounts. Some surface mount lights in industrial lighting can be attached to the ceiling by either a static fixture or a chain. This type of lighting comes in all shapes and sizes, and is ideal for settings where there is little space between the structural ceiling and the dropdown ceiling, or when the ceiling is exposed. In these situations, recessed lighting is difficult or nearly impossible to install. These types of light mounts can also be installed with little alteration to the surface it is mounted on.

Ceiling mounts can be split into two categories: flush mounted and semi-flush mounted. A flush mounted light fixture does not have a gap or space between the fixture itself and the ceiling. A semi-flush mounted light fixture, however, has a small gap between the light fixture and ceiling. Semi-flush mounted light fixtures are comparable to pendant light fixtures, but they do not hang as low as pendant lights. These two types of ceiling mounts are ideal for places with low ceilings as they take up little space.

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