[toni-a]

We are reading a lot about vintage lenses and exotic lenses, sometimes the prices are outrageous, obviously many are a total waste of money while others might be interesting for some features.
Adapting such lenses and manual focusing has its drawbacks however some of them might be interesting for some features.
For instance Helios M42-2 58mm f2.0, has acceptable sharpness , it has a special swirly bokeh that can be interesting in some shots , I didn't mind getting one for 20$ yesterday (I already have m42 adapter)
Had fot free with it Jupiter 135mmf4.0, it has nothing special, not worth it... discarded it even for free.
Do you have any list of lenses having special characteristics that make them worth getting ?

[stoppingdown]

My first answer would have been the Helios 58mm f/2, but you already got it. Another legacy lens that I own is the Trioplan, but it's a much more controversial lens - we discussed about it in the past, and some love it, some hate it. Furthermore, it's among those that are expensive, which makes things more complicated. A third lens that I really enjoy is a Nikon 50mm f/1.8 AF-D.

Most times I use all these three lenses with adapters embedding focusing helicoids, for macro (flowers and critters). The three lenses have very different characteristics: the Nikon, in particular, is the one with a "normal" behaviour (smooth bokeh, but without exotic effects) and it's the sharpest (even wide open: for instance, the Helios, wide open, is sharp only in the centre).

Sorry for the self-citations, but some images are needed to clarify my points. Here you find a comparison of the three lenses for macro:

http://stoppingdown.net/blog/three-different-bokeh/

Here some more info for what concerns aberrations:

http://stoppingdown.net/blog/bokeh-and-other-optical-qualities-with-extension-tubes/

These are by far the shots that gave me the best results with the Nikon:

http://stoppingdown.net/blog/zygaena-filipendulae/

Note that the Nikon should be relatively inexpensive, in any case I have an auto-focus version. Of course auto-focus in this context is useless, but it's a lens I inherited from my previous Nikon life. Should I buy it from scratch, I'd evaluate a cheaper, manual focus version. But even though 50mm are usually easy to produce and have good performance, I'm not sure the manual, older versions have the same quality (it could be worse, but it could be also better, I really don't know).

Note that manual focusing with macro (and flowers, which easily move, not to talk about critters) requires loooots of patience and tons of shots, to pick keepers from. I sometimes wonder to have myself the patience for that job. But it's rewarding.

Of course I've talked about macro, but legacy lenses might be good also for other stuff, such as portraiture, but it's not a field I'm interested to.

Phillip Reeve (https://phillipreeve.net/blog/) publishes a rich and ample review of manual lenses to be used with adapters, you could start and have a look there.

[toni-a]

Meyer optic trioplan isn't worth all that money IMHO, you can get the original trioplan for much less.
Knowing it is a three elements rudimentary disign without any aspherical or special elements it is quite easy to manufacture such a lens some even made one themselves ...
So trioplan by meyer optics (or any meyer optics overpriced product) is a waste of money, the original trioplan for a good price why not ?

[stoppingdown]

The new Trioplan is out of question, but also the legacy one is expensive: I'm seeing prices in the range 350€ - 500€ on eBay...

[toni-a]

Well it wasn't that expensive a while ago...

[davidmanze]

The new Trioplan is out of question, but also the legacy one is expensive: I'm seeing prices in the range 350€ - 500€ on eBay...

  That's the price I was seeing......with several examples even higher.

    They have to be found in places where "nobody knows they what they are"...junk shops, brick a brack..........directly they hit ebay the game is up!

   No doubt there are hundreds rattling around in cardboard boxes full of miscellaneous junk.

[obican]

   No doubt there are hundreds rattling around in cardboard boxes full of miscellaneous junk.

Right where they belong?

[stoppingdown]

   No doubt there are hundreds rattling around in cardboard boxes full of miscellaneous junk.

Right where they belong?

Bad boy...

The problem is that those in cardboard boxes aren't probably in good conditions. On eBay, at least, you can have more chances that they're selling you a good one. When I bought the Helios I preferred to spend a little more (60€, it was also offered at cheaper prices) to pick a seller who takes them, cleans up and lubes before selling (ok, we're talking of a different magnitudo of prices...).

PS Klaus, the "quote" button, when pressed, reads "QOUTED".

[Rover]

I consider my Sigma 14mm and "exotic and vintage" lens, since it's a film design from the late 90s anyway (and it's a miracle that they chose to add their freshly developed HSM to a frikkin' ultrawide, seeing as how many people are still saying that there's no need for AF in an UWA at all). Other than that... I really want to find that Industar I've seen kicking around in my parents' cabinet years ago. Adapt it for the heck of it if I ever feel the urge to go lo-fi.

[davidmanze]

I consider my Sigma 14mm and "exotic and vintage" lens, since it's a film design from the late 90s anyway (and it's a miracle that they chose to add their freshly developed HSM to a frikkin' ultrawide, seeing as how many people are still saying that there's no need for AF in an UWA at all). Other than that... I really want to find that Industar I've seen kicking around in my parents' cabinet years ago. Adapt it for the heck of it if I ever feel the urge to go lo-fi.

  I think we have the basis of an extremely powerful business relationship here Rover...
  
   You buy me all the super cheap exotic lenses you find in cardboard boxes  ......... and I'll send you links to all the overpriced exotic ancient lenses that I find on ebay!  
     
 The famous Industar...
          Yep, lo Fi indeed!............................ the Russian Trabant of the optical world.

    It's most annoying feature was the aperture ring.......it was "cleverly" fitted to the focus ring and was stiff to turn..........so after focusing the camera through it's dim viewfinder wide open to see anything.....you then had to prevent turning the focusing ring in order to turn the aperture ring which wanted to turn the lot!
      It was remarked by many Zenith shooters using the Industar and used to these inconveniences....

        .........that the Trabant was an extremely advanced car indeed!

Optically it wasn't bad at all, I used it as an enlarger lens (Leica thread 39mm) where it served me very well!