This must be done in 1 playthrough; that goes for the rest of the single player achievements aswell.
Heres a few tips from 'Onsidic' to make this achievement even quicker to get:
Tip 1: Theres a keen observer tonic as your making your way up to Grace that helps your research be worth a lot more.
Tip 2: Theres also a tonic on the Dionysis Park area that increases the length of time the camera will roll. Use that with the keen observer tonic helps alot. extra time should allow you to generally get 1 level per camera roll on some of the enemies that take a few more hits. (Big Daddies)
You will get the Research camera on the Level 'Pauper's Drop',
Here are all 9 subjects you need to fully research for the achievement:Splicers:
Leadhead - These are the normal slicers with firearms; which you met on BioShock 1; there are loads of these enemies running around causing havoc, they were my 2nd subject to fully research, so yeah thier easy enough.
Thuggish - These are the normal slicers with melee weapons; which you met on BioShock 1; there are loads of these enemies running around causing trouble aswell, they were my 1st subject to fully research, so yeah their easy enough.
^Note: 'You should probably complete the Thuggish Splicer research as soon as you get the camera. Mainly because it seems that at some point after the halfway point there aren't anymore in the game, especially near the end.'
(Thanks to ChrisOfTheDead for this tip)
Spider - Yet another BioShock 1 splicer, you first encounter these on the 'Siren Alley' level, a nice place in the level to research them is when you are waiting for the power to come back; in the room where you need a door code in order to go to 'Pump station 5'; this is a good area because there are around 5-7 Spiders to research and also 1 Brute.
Houdini - Yeah... BioShock 1 splicer again, you encounter these shortly after the spiders; on the 'Dionysus park' level, there is a real handy part in the level 'Fontaine futuristics' where you encounter many Houdini in one big room, which is in the 'Fontaine plasmid theatre'.
Brute - And finally the new BioShock 2 splicer, now these guys were my last max research, make sure every time you encounter these stocky beast's that you research them every time, although on the last few level's there are tons of these splicers causing havoc.Security:
Bot - Simply walk straight in front of a security camera for long enough to trigger the bot's; they will be around for 40 seconds i believe, pretty easy to max these.
^ you could also work on 'Look at you, hacker' achievement after you research the bots. :]
Camera - There are tons of Camera's around; search every room in each level, yet another easy one to max.
Turret - There are tons of Turret's around; search every room in each level, yet another easy one to max.
^All above 3 count as 1.Others:
Big Daddy - This includes all Big Daddy types, for example on BioShock you had to Research Rosie's and Bouncer's in seperate subjects; but in BioShock 2, they are all in the same subject together.
Big Sister - You won't encounter many of these in the game if you don't Save/Harvest any Little Sisters; so make sure before going for this that you always deal with every Little Sister in the game; in order to meet enough Big Sisters to fully research.
Alpha Series - You meet up with these enemies on the 'Fontaine futuristics' level, but there are tons of these guy's on the last few levels, so these are fairly easy to fully research.Extra Notes:If you still can't earn this achievement there is an incredibly detailed thread made by Fizzmatix on x360a which with no doubt you will get this achievement with no problems,
here is the link: http://www.xbox360achievements.org/forum/showthread.php?t=20...