Chain adjustment and slack measurement

[Robik]

Hi all, 

Just wanted to gather thoughts from other on this. I find chain adjustment a little subjective and find I can influence the slack of the chain depending on if first pull down the chain to start measurement or start from the droop position, as well as how much force I apply. I know the manual might tell you basically how to do it but mine (cbr600f) doesn't specify how much force to apply when meauring the chain slack (also who actually uses a force meter to do this?) 

I just try to aim for the middle and hope that right. 

Thanks all