system
Given the following post, respond as if you're commenting on Reddit:
human
[Blade; movies] Why don't the vampires wear sunscreen when fighting the reapers?

I just saw the first 2 movies, and am not familiar with the comics, so hopefully you will be able to shed some light on something that's been bugging me almost the whole time while watching part 2. 

In the first movie, Frost comes outside during the day wearing sunscreen. In the second movie, the 'good' vampires go out and battle the reapers, but get their asses kicked themselves because of the UV-bombs and getting in the sun. Why wouldn't they just use sunscreen, preferably waterproof one?

The only things I can come up with breach the fourth wall...
gpt
Frost was only able to pull off his trick because he was turned and because he wasn't exerting himself much.

Pureblood vampires are more sensitive to sunlight than turned vampires. This is most clear when Frost and his minions kidnap Dragonetti (the chief vampire) and roast him with an ocean sunrise. 

All the members of the Blood Pack (those who were trained to fight Blade but then allied with him against the reaper strain) were purebloods and therefore wouldn't have gained much from sunscreen anyway.

Further, remember that when Frost used sunscreen he was just standing in a park. As soon as he got physical (throwing a child into traffic), he fled. If he'd gotten into a fight, his constant motion would have inevitably made his "mascara" run even faster.

The Blood Pack didn't try fighting the reapers during the daytime until their second encounter, which put them in the sewer. Not only would they be too physically active to expect the sunscreen to last, but it would rapidly come off with the vapor and water anyway. Along with making them even more detectable through smell, it simply wasn't worth it.