From the looks of what I did, I misread the charts, I'm going to redo some math once I get home...
But the decline starts at 100mf I think.
I'll keep you updated...

Okey guys let's get to the point. With my hdin im farming meph nm, how much mf do I need to find viper, strng of ears and magefist? tell me pls

With 200mf:
Mephisto (Q) - mephisto (NM) Durance of Hate Level 3 1:285
Mephisto - mephisto (NM) Durance of Hate Level 3 1:445

i have like 170 mf ^^

That would make 100 mf the best choice, since uniq amount decreases after that. It's not true. Check any dropcalc or extensive run logs

Quest bugged Andy is a better choice for string and viper at least... only like 1:300.

I mean in all reality, the decline starts as soon as you get 1 magic find...
Because the chances of finding magics/rares/sets is always higher
But you only notice the differene when you get 300+ mf

Harlequin Crest drop chance from Embalmed Unique (mummy) in Ancient Tunnels with /players 8:

100 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:26491
200 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:21467
300 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:19194
400 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:17904
500 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:17030
600 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:16413
700 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:15950
800 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:15622
900 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:15355
1000 mf: Embalmed - mummy3 (H) Ancient Tunnels 1:15101

diminishing returns? yes. declining uniqs after a certain point of mf? no.

for bosses it's different.

This post was edited by sebhehe on Feb 26 2014 04:55pm

Can you explain a little about bosses? I mean, will it help me to get better itamz from mephi? hjahah

is there any TL;DR version of this argument between Seb and Jomblified?