You can obtain this achievement with just one other person who has a vision camera, you yourself do not need one. ( presuming the other player does not need this achievement. )
As stated in the other guide you can only get 20 snapshots from each of the 4 categories.
1) Freeburn - Take down someone in freeburn
2) Event - Take down someone in a race
3) Rulebreaker - Someone needs to best your freeburn road rule
4) Photo Finish - Win races.
Now you can combine this with:
First start a freeburn session online and invite your boosting partner. Make it invite only to stop randoms joining. Proceed to take them down 20 times here. Then make the shortest race possible and save it. Start this up and take down your buddy another 20 times. ( you can do it all in one race or do say 2 a race to split it up ). Finally win that race 10 times and you'll unlock both the 50 snapshot and win 10 race achievement.
The easiest way to take them down is to boost into their side and T-Bone takedown them.