Oncidiums are generally hard to generalize due to the fact that they are found all over the world with so many different conditions that there is no one general rule to fit all of them in a way. For the most part they take a good amount of light, almost a full sun light with a bit of shade making them best in a south or west facing light source at 2000-5000 foot candles. Some can take a sole morning light but there are many that require a stronger source. Temperature is also split, dividing itself to intermediate temperatures to warm temperatures. Intermediate oncidiums love having night temp. from 50-60F and 70-80F during the day. Warm oncidiums can take temp. from 60-90F depending on circulation and humidity. Oncidiums tend to continuously grow bulbs, resulting in a need of a good phosphorous and nitrogen fertilizer.