Spectrometer Comaparisons
Howdy!
I’ve gotten a lot of pings to share some photos comparing the quality, spectrum, and strength of different grow lights. Below are photos from my $2,000 spectrometer used to take full spectrum readings so you can see not only PAR (photons), but also what wavelength the photos are emitted in.
Please note that Lux/Lumen/Foot Candle meters only measure visible light and not specifically the amount of photons being emitted. They can give you a relative sense of light, which is great for general applications, but are not completely accurate for plants and photons.
Attached are also photos from different Sun situations— through a window indirect and direct, in a greenhouse, direct sun, etc. so that you can compare them to a light you’re using and see how many hours of light (called a Daily Light Integral) you would need to provide your plant to match conditions of a greenhouse.
You don’t HAVE to match a greenhouse’s amount of photons, but your plants will be growing below their potential mass. Keep in mind an increase in light means an increase in photosynthesis, which requires more water and nutrients.
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Keep in mind, these photos were only quickly taken for my own reference over the past year. I did not intend to share these, so they’re not the best quality. They should still be a great resource for anyone curious though!
Sansi, Barrina, Monios
Sansi 36 Watt Bulb at about 2’ Distance
Sansi 36 Watt Bulb at about 1’ Distance
TWO Barrina T8 Yellow at about 6” Distance
ONE Barrina T5 Yellow at 1’ Distance
TWO Barrina T5 Yellow at 1’ Distance
ONE Barrina T8 at 1’ Distance. Sorry numbers are blurry, but basically 2x a T5— and you can see significantly higher blue spectrum photons.
Monios T8 Yellow at 6” distance
Expensive, Overkill Lights
Large Cannabis-level Grow Lights (unsure of brand) at less than 6” Distance
Smaller canabis grow light measured at 1’ distance
Sun Conditions
Indirect Sun through a Window WITH Screen
Indirect Sun through a Window WITHOUT Screen
Direct Morning Sun through Single-Pane Window WITH Screen
Direct Morning Sun through a 30% Shadecloth
Direct Morning Sun through Single-Pane Window without Screen
Direct Morning Sun NO SHADECLOTH.
In a shaded Greenhouse will full sun - Pointing AWAY from Sun
In a shaded Greenhouse will full sun - Pointing DIRECTLY AT Sun
Sunlight coming through the Canvas roof of our Budget Rental Truck’s cargo hold.
NOTE: PAR is in uW/cm here and NOT mW/cm. 1 uW = .001 mW. This means the truck was receiving a much lower amount of light than previous readings.
If you want a more budget-friendly Quantum PAR meter (NOT lumens/lux/FC), I tested this one against my Spectrometer and it’s dead-on.
