Requesting a photo-metric gives you accurate information on how your LED light will perform in the environment you request. These results allow you to see LED fixture locations, foot candles at ground level, shading or shadowing due to light pattern coverage.
This is all very helpful in deciding how many lights you need, beam angle of the lights you need and wattage for the lights you need in order to meet your expectations. This all helps in establishing your out of pocket costs for your new LED light fixtures.
Photo-metric reports are very simple to obtain and very accurate when looking for a finished product. IBA LED supplies photo-metric reports free of charge. LED lighting is new to this country and by going on line you will see all kinds of conflicting information when it comes to performance.
The bottom line is that photo-metric reports simply determine very useful facts.