Base Perception range is 500
Glacial Armor +300
Focused Accuracy +300
Tactics for a lvl 50 tank +242
Making a total of 1342 but at level 50 your perception cap is 1153.
At that level you would see a Stalker running Hide (-500) and Stealth (-390) at a distance of 263.
A Stalker running Hide (-500) and Invisibilty (-611) would be visible at a range of 42.
A pair of stalkers running Hide, Invisibility and using Grant Invis on each other would be almost impossible to see. You would have to be within 10 feet/yards (or whatever measurement the game uses, can't remember atm)
Both SR and DA scrappers are capable of pulling this off too.
Octavian Vanguard
@ohmsEU and @ohms 2
Badging character: Bimble on the Union server, Badgehunter.com and City Info Tracker.
thx for that
just wat i wanted to know 
Actually, Ice Tanks just need Glacial Armor + Chilling Embrace to be able to see ANY stalker within melee range.
Chilling Embrace's debuff will disable all Stealth/Cloaking powers except for Hide within the area of effect (10 foot PBAoE), and Glacial Armor lets you see through Hide.
In that scenario, the perception cap doesn't matter since you've reduced the stalkers effective -perception to 500, regardless of what it was at previously. More stacked +perception is still good for seeing stalkers at longer distances providing that they're not already at the stealth cap.
A toon at the perception cap can only see a stalker at the stealth cap within a 10 foot range, so if you're not actively hunting stalkers and have fairly quick reflexes there's no real benefit to getting tactics.
The only toon that can see a stalker at the stealth cap at a distance of more than 10 foot is an Ice controller running Arctic Air. With just that power they can make any stalker visible within 25 feet... (NERF!! NERF!!) 
Good point although CE only helps if the stalker is coming for you rather than going after the squishies, which is often the case.
I should also point out that there are easier ways to get +perception rather take the powers yourself. Clear Mind and Clarity from a friendly defender or controller spring to mind.
Octavian Vanguard
@ohmsEU and @ohms 2
Badging character: Bimble on the Union server, Badgehunter.com and City Info Tracker.
good point OV, personally i usually PVP as a stalker and wanted to go to the other side and since ice tanks really gave me probs in PVP i thought, might as well..
also, i know this depends every nite, except on planned events, how often do defenders with CM etc.. actually PVP?
personally i cant imagine just buffing my team mates and not doing much after but then again my stalker usually does go for any squishy first
i was looking at glacia armor and noticed it had +perception
so i thought that
glacia armor+focused accuracy+ tactics = you should see any stalker?
i just wanted to no if anyone has tried this combo and found it useful for stalker hunting. and plz tell me if im way off in someway
also i was wondering, can any other build pull this triple threat off on its own (without buffs from another toon) would be nice if it was only possible by ice tanks but i doubt that is the case
P.S. YAY!!! i8 is here