The 30X and 100X lighted magnifier are tools everyone serious about harvest timing should have. They make it easy to monitor the resin development process. After seeing 400X images of resin glands, I decided to also buy the 100X magnifier. It supplies a superior view, providing an enhanced perspective of resin gland condition and development.
I recommend buying the 30X model first and if you would like to expand your analytical capabilities, buy the 100X model. They both allow for a much closer inspection of the clarity, color and condition of the resin glands, which should be swollen and unbroken while remaining transparent and slightly amber, if at all, at the peak of ripeness. Some prefer harvesting earlier, as THC degrades to more sedative cannabinoids as the glands ripen.
Harvest timing is a matter of personal preference. When the glandular trichomes are clear with very little, if any coloration, THC levels are at their peak with CBD and CBN both at levels that will not overly influence the THC with their sedative effects. Some prefer more overwhelming narcotic type effects, allowing the resin glands to cloud and begin to amber or darken to increase overall cannabinoid content. The resin glands appear and therefore will mature at different times. A compromise is made when determining the desired overall maturity level to harvest. It depends on the growers preference in effect and palate.