There is a light kit available for the Chrony which over comes this problem, it should also be possible to make your own set up.
The advantage of the Chrony (I have the F1) is that it can be used whilst shooting targets. I can set mine up on my homemade bench so that It records the velocity whilst I am accuracy testing.
Each pellet weighed then shot. Thus you know the MV and FPE for each shot of a group and can use this info for pellet testing/selection. It helps determine whether a light/heavy pellet does fly faster/slower and whether or not this affects the POI.