If i said you can get an awesome portrait Len’s for £30 you would tell me i am joking.
Step up the awesome Helios 44-2 58MM F2.8 8 Blade version, Made in the USSR Avail for £30 on eBay.
Also we have the Carl Zeiss Jena DDR 50MM F1.8 6 Blade. (Between £60-£90).
I have had both on these lenses for over a year or two now and never got around to buying an adapter to use them on my Nikon gear, I used them both on my 7D before i switched back to Nikon though.
These Lenses are both M42 mount (Old Pentax) But can be fitted to Canon and Nikon with adapters from Ebay (Around a £1)
On Canon they both focus to infinity, On Nikon the fall just short, There are other adapters available to make them focus to infinity but i will be using them for portraits so do not need one.
Of course the only draw back with these is that they are manual focus. Once you get the hang of using them though it comes naturally.
The shot examples below are shot on my Nikon D810.
I fell in love with the Helios Bokeh, It has a lovely swirly effect and is nice and sharp wide open. The Helios focuses down to 0.5m. I have to say that out of all of the lenses i have ever owned, This is one of the sharpest and most quirky of them all.
As always with any old Len’s beware of fungus and dust inside the lenses.
I will leave you with a portrait i took this morning of Toby with the Helios so you can see the awesome swirly Bokeh.