What is a PAR map?

Photosynthetically Active Radiation (PAR) is the term given to light that drvies photosynthesis. PAR is nominally defined as being in the visible spectrum from 400-700nm, but in reality it goes beyond these ranges – especially into the Far Red and UV spectra.

While PAR drives photosynthesis, other wavelengths affect growth that determines structure and yield characteristics.

UV light around 400nm causes mild stress responses in plants that increase secondary metabolites including terpenoids and flavonoids. Far Red light above 700nm has a synergistic effect with Red light (600-700nm) that acelerates photosynthesis (known as the Emerson Effect). Far Red also accelerates flowering.

Typical LED grow lights have no UV, no near-UV and no Far Red, yet are still described as “full spectrum”.

High Light 420 boards are among the only “true” full PAR spectrum boards on the market, with UV and high levels of Far Red (9.5%).

Measuring Light Intensity

Spectrum is an important element in growing. But light intensity is more important. Too much light can be just as detrimental as too little.

To ensure your plants get the correct amount of light, you need to work out how many photons a given fixture emits over a given area, and how intensity drops off near the edges. The more even the light spread, the better.

Grow Lights Australia products are tested in-house by LED Teknik using the latest Viso Systems LabSpion Goniometer – the industry standard in measuring light intensity, 3D pattern and spectrum.

Viso systems create IES files that when loaded into software such as DIALux can create simulated PAR maps for predicting the best LED configurations, mounting heights and driver settings for any given area.

The unit of measurement for these PAR maps is PPFD (Photosynthetic Photon Flux Density).

High Light 420 PAR maps

Each of the following PAR maps is based on the recommended plug-and-play kit for common grow areas.

The ideal PPFD measurement will vary depending on plant species and stage of growth, but 800-1,000 PPFD is generally considered ideal for many common species of flowering and fruiting plants. Lower levels of 400-600 PPFD are suggested for leafy greens.

To read the maps, note the red outlined areas that are High Light 420 panels mounted to heatsinks. The isolines represent PPFD readings. All calculations are based on an enclosed area with 80% reflective walls.

Typical grow tents have 90% or better reflective walls. Flat white painted walls typically reflect 80% of light that hits them. Actual PPFD readings may be higher or lower depending on reflective wall surface, but we’ve found that 80% provides a very accurate estimate for most indoor grow areas with a 5% margin of error.

Click on each image to expand.


The above PAR map is for our 220W Single Plug & Play Kit 50cm (20″) above canopy height in a 0.75m x 0.6m area (2.5′ x 2′). This is a max effort configuration with an average 990 PPFD over the entire area.


This is the same 220W Single Plug & Play Kit over a 0.8m x 0.8m area (2.7′ x 2.7′) with a nice light pattern and average 800 PPFD. These kits can light up to 0.9 x 0.9m (3′ x 3′) with an average 700 PPFD


This PAR map is for our 340W Long Configuration Plug & Play Kit at just under full power 50cm (20″) over a 1.2m x 0.6m area (4′ x 2′).


This PAR map is for our 340W Square Configuration Plug & Play Kit over a 0.9m x 0.9m area (3′ x 3′).


Same as above, but over a 1m x 1m area (3.3′ x 3.3′) with an average 812 PPFD.


This PAR map is for our 470W Square Configuration Plug & Play Kit at full power hung 60cm (24″) over a 1.2m x 1.2m area (4′ x 4′). This configuration is well-suited to single-plant grows.


This is the same 1.2m x 1.2m area lit up by two 340W Long Configuration Plug & Play Kits hanging 60cm (24″) above the canopy. This configuration provides very even canopy coverage at over 1100 PPFD and is ideal for SCROG grows that fill the entire area.


This is a 1.5m x 1.5m area (5′ x 5′) area lit up by the same two 340W Long Configuration Plug & Play Kits also hanging 60cm (24″) above the canopy. This is the recommended configuration for all areas from 1.2 x 1.2m (4′ x 4′) to 1.5 x 1.5m (5′ x 5′).


For 1.5m x 1.5m (5′ x 5′) and larger areas, two of our 470W Long Configuration Plug & Play Kits deliver maximum light intensity at 60cm (24″) hang height. This is the recommended configuration for larger areas with supplemental CO2. If high intensity is not required for the first few cycles – but may be desired down the track – the drivers can be dimmed to suit, then turned to full power once CO2 is in place.

The beauty of the new High Light 420 boards is that they are as flexible as your imagination. If you don’t see your configuration here, and are still unsure which kit you need, we can create a custom configuration and PAR map like the ones above to help you decide. Simply Contact Us with your query.