Does knowing the V-C-F values of the lamps output eliminate the need for the lamp manufacturers Spectral Distribution Graphs?
The V-C-F values represent the total watts being consumed within these 3 regions. It does not replace a Spectral Distribution Graph which enables the grower to determine precise spectrums within these regions where the majority of the energy is being consumed.
Does knowing the V-C-F value eliminate the need for field measurements of lighting intensities?
The grower would be advised to continue using a quantum PAR meter for initial lamp intensity output at set determined distances from the lamp to meet proper crop Photosynthetic Photon Flux Densities (PPFD) and enable the grower to monitor intensity depreciation at the beginning of each crop cycle.
Can you explain how V-C-F values are achieved?
This process relies on knowing the spectral distribution of the lamp and how much energy it consumes at each individual wavelength and adding that together to show the watts consumed within that region. The manufacturer must have the equipment to take spectral distribution measurements from within that limited V-C-F bandwidth and then publish it in a watts/region format.
If I only have a standard light meter that measures Lux, Lumens and Foot Candles can I use that meter to test intensities between my crop cycles?
While we still recommend a quantum meter a typical photographic type of meter (photometer) will measure intensities loses in the Visible/Carotenoid (C) region of the 520-610 regions spectrum. The relative intensity losses within the (V) and (F) regions would be fairly proportional to the losses in the (C) region.
I’ve not seen other manufactures adopt this approach to publishing their lamps output. Are there other methods that would give the grower enough information to compare lamp outputs?
Part of the problem is that lighting manufactures do not have a generally accepted industry standard plant absorbance sensitivity curve that manufacturers can point their lamps output data relative to that curve. The problem has been identifying a meaningful curve that is broad enough to cover a majority of plant species net absorption regions. Many manufacturers will refer to the German DIN Standard 5031-10 but this has not been accepted as, nor should it be, a hard and fast standard for all plant species.
If two manufacturers have posted identical V-C-F values can a gardener presume the results will be the same?
The short answer is no. But this answer also depends on the previous answer where specific plant sensitivity curves would ultimately tell which lamp is emitting within the peak absorption ranges that are ideal for that particular plants photosynthetic processes. Watts/Region is a way to determine how much energy the lamp is emitting within that region. Since each region is broad enough that specific wavelengths within those regions may be drawing most of the energy plant response can vary with identical V-C-F values as a result of spectral differences within the regions. It is entirely possible that when comparing two lamps with identical V-C-F values that one lamp will outperform the other.
Think of it this way; you can go into two separate restaurants and order lasagna. Both chefs will have the same or similar ingredients to get to the final dish. Both dishes have the same calories but one dish may be substantially better tasting and better for you. Plants will react the same way when ‘fed’ light where wavelengths within the watts/region are different between the two lamps.
Do reflector or fixture designs enter into the Watts/Region values?
They do not. As in the previous two answers when comparing identical or even higher values, other considerations would be actual spectral distribution within the three regions. Beyond that other factors to consider would be:
- How much heat a lamp/ballast combination contribute to the grow room
- Light being emitted outside of 400-700nm
- Intensities at the canopy (PPFD)
- Spectral distribution within each region
- Fixture design as thermal management
- Reflector design and quality
- Lamp size and shape
- Consistency of spectral mix from the lamp(s) to the canopy
If I know the lamps V-C-F values what should be considered when interpreting a lamps output based on its spectral distribution?
When you have the V-C-F value you are interpreting the amount of energy under the height and width of the data points shown within these graphs. For example a graph showing a high peak thin sliver intensity at a specific wavelength may not contribute as much to a plants development as a lower peak wider spectrum. To illustrate this point we would refer you to the DIN 5031-10 where you can see the radiant power differences between HID and LED relative to the plants sensitivity curve.
Ideally one should consider lamps spectral output characteristics in terms of its ability to show:
- Some baseline broad spectrum coverage between 400-700nm
- Lamp to Plant efficiencies: Higher intensities in the known high PAR absorption regions
- Broad enough spectrums within the plants PAR absorption regions
Armed with this information one should also consider the importance of lamp lifespan, i.e. replacement costs and spectral stability as the lamp ages to maintain repeatable crop production.
Do LED Grow Light put off heat?
Yes, every light produces heat. It does not matter if the light comes from a bulb, diode, or a star like our sun; they all produce heat. LEDs provide a more efficient means for converting energy to light than other methods and therefore produce less heat, but they can not break the laws of physics. Physics dictates that anything that consumes electrical power will emit heat; claims that LED lights don’t produce heat are entirely false– just ask any physics teacher
What are differences between LED and tradtional lightings?
- HID lights (metal halide, high pressure sodium and ceramic metal halide) require heat to produce light by arcing electricity through selected gasses, making them extremely hot, to the point the gasses glow. This means HID bulbs themselves are extremely hot– hot enough to start a fire, and many gardens have gone up in flames because of this danger. LEDs’ electroluminescence technology is entirely different and does not require heat to produce light; LEDs themselves will not get hot enough to start a fire.
- Much of the energy used by HID lights is emitted as infrared light (above 800 nanometers). This “light” is not usable by plants and only works as a “heater”, warming up the plants — and everything else under the light. This is why HID light feels warm on your skin, while LED light does not. Our LED grow lights don’t waste energy creating unusable and detrimental infrared light; all the energy goes toward growing your plants.
- Because LEDs aren’t wasting energy producing light plants can’t use, we can use less energy overall to get the same (or better!) growth from plants. Less energy consumed means less heat; for a given growing area, LED lights will put off less heat than any equivalent artificial light
What is the beam angle and why is it important?
It’s easy to be confused by the idea of beam angle and how it can affect plant growth. Each individual diode (LED stands for Light-Emitting Diode) has a cone-shaped lens that can be designed to focus the light coming from the emitter anywhere from 30° to 180°. In LEDs, beam angle refers to this angle of the light cone the primary lens creates. It is important because it determines the intensity of light reaching the plant as well as the total effective footprint of the light.
HID (MH / HPS) bulbs have a 360° beam angle- half the light produced is aimed up and away from your plants, which is why a reflector is needed to try and reflect as much of this light as possible back down to your garden. LEDs in general are more efficient at growing plants than HIDs because LEDs only produce light aiming toward your plants. Properly-designed LED lights that use an optimal beam angle in the primary lens have no need for a reflector.
Each diode in every Easy LED grow light uses a 120° lens, which is the best angle to achieve a large footprint with intense light covering all of the growing area. Many other companies sacrifice the footprint in order to achieve better canopy penetration by using a 60° or 90° lens, or even use secondary lenses to further focus the light into a narrow cone; this is often the only option with weaker LEDs. Easy LED’s Universal Series of lights use only the most powerful 5-watt chips, so we can use a more oblique angle to create a generous, evenly-covered footprint while still maintaining superior canopy penetration.
Watt-for-watt, our lights have the largest, brightest, most evenly-covered footprint of any LED grow light on the market so you can grow healthier, high-quality plants everywhere in the footprint. We maximize your yield rather than just the reading from your PAR meter directly under the light!
What are lumens and are they useful for evaluating grow light?
Lumens are a measure of luminous flux, or the total amount of visible light radiating from a source, weighted by the human eye’s sensitivity to the particular wavelength of the light. Lumens are the best measurement to use when evaluating how well a light will illuminate an area for human eyes. The human eye is most sensitive to light in the yellow range of the spectrum, so 100 photons of yellow light have a higher lumen rating than 100 photons of blue light or 100 photons of red light.
Plants preferentially absorb red and blue light. Lumens preferentially weight yellow light and de-weight red and blue light, making lumens just about the worst light intensity measurement possible for evaluating how well a light will grow plants.
Lumens’ measurement of human-visible luminous flux differs from PAR, which measures radiant flux — the total number of photons in the visible spectrum without weighting for human visibility. Yield Photon Flux (YPF) is like lumens in that photons are weighted based on their wavelength, but YPF weights them based on their usefulness to a plant rather than to the human eye, and YPF considers photons outside of the human visual range. For this reason, YPF is the best measSaveurement of light intensity for growing plants, although it still has significant drawbacks as we explain here.
Why do plants need horticultural LED light?
mostly use red light and blue light for proper vegetative growth and flowering. And humans who need to see the plants appreciate a little light in the green part of the spectrum, which is where we see best. So the best LED grow lights are those that combine, in the proper proportions, light from these three parts of the spectrum. With LEDs, we are able o provide only the usable spectra and wavelengths without wasting energy on those that are not beneficial to plants.