Catalyzes the conversion of divinyl chlorophyllide to monovinyl chlorophyllide. Reduces the 8-vinyl group of the tetrapyrrole to an ethyl group using NADPH as the reductant. The best substrate is (3,8-divinyl)-chlorophyllide a (DV-Chlidea). Very low activity with (3,8-divinyl)-protochlorophyllide a (DV-Pchlidea) and (3,8-divinyl)-magnesium-protoporphyrin IX monomethyl ester (DV-MPE). No activity with (3,8-divinyl)-magnesium-protoporphyrin IX (DV-Mg-Proto) and (3,8-divinyl)-chlorophyll a (DV-Chla). NADP(+) + protochlorophyllide a = 3,8-divinyl protochlorophyllide a + H(+) + NADPH Optimum pH is 7.0 with DV-Chlidea or DV-Pchlidea as substrate, optimum pH is 6.5 with DV-MPE as substrate. Optimum temperature is 25 degrees Celsius with DV-Chlidea as substrate, Optimum temperature is 20 degrees Celsius with DV-Pchlidea or DV-MPE as substrate. Porphyrin-containing compound metabolism; chlorophyll biosynthesis.