Based on the threads I've read here the 8.5 dome lamp seems to be much more popular then samller one.
Is that because the 8.5 inch dome will give you a wider light spread then a 5 inch at the same distance?
Yes, when the same amount of light is spread out over a larger area it has to be at a lower intensity, and vice versa.
Excellent post and thread. My only suggestion would be possibly lowering the scaling on the CFL chart. It goes very high, and most people using CFLs are intetested in a PAR range of 10-100 or so ( from what I can gather).
Good suggestion! I changed it.
Great information! What is missing is a graph on LEDs. Thanks for all the time you spent gathering this info and then sharing it with us. I didn't realize that a less than $100 par meter option existed
LED lights can't be treated this way. The variety of configurations is almost endless, so no simple charts can ever show much of value with them. However, it would be possible to put the most popular, most usable on planted tank ones on one chart. Keeping that chart up to date as more and more different LED lights become available would be a major chore. Maybe someone wants to convert the information in LED Lighting Compendium
to this format? It takes a lot of time.