I had originally posted a thread in "Optics and Lenses", but that got deleted since I neglected to read the forum rules before posting ...
Anyway, I was debating whether or not to exchange my 50 Planar ZM with a 40 Nokton. Reasons: more speed, more compact, more like a 50mm on the M8, the 67mm-equivalent field-of-view being somewhat quirky. Downsides: nowhere as nice in rendering as the Zeiss.
Here I am now, still debating whether or not to keep my 50 Planar or to sell it in favor of a more 50mm-ish lens for my M8. Here are my options:
1) 40/1.4 Nokton
2) 40/2 M-Rokkor or C-Summicron
3) 40/2.8 Sonnar
In the long term, I would like to own one of each (for the fact that I love 40mm lenses and that each has its unique character), but for the moment, I'll have to make do with one.
I am also debating whether to extend my focal reach to 75 or 90mm (100 / 120 equivalent on M8) with either a 75/2.5 Heliar or a 90/4 Elmar/M-Rokkor. Judging from the going prices of second-hand Planars, this is what I could get if I manage to find one or more good deals:
Option 1: 40/1.4 + 40/2
When I give up my 50 Planar, I give up its nice colour rendering and gentle bokeh. The 40 Nokton does not render either as nicely. The 40/2 'cron and Rokkors though have a good reputation. Any intel on how they compare to both the Planar and Nokton?
Option 2: 40/1.4 + 90/4
This would effectively give me a low light + a tele option, which would be nice. The 90/4 should also work well for portaiture, albeit only in good light.
Option 3: 40/2 + 90/4
Like Option 2, only with the 40 'cron/Rokkor instead of the Nokton. Less preferred.
Option 4: Either Option 2 or 3 but with 75 Heliar instead of 90 Elmar/Rokkor. Slightly shorter, so not as much of a stretch from 40mm as a 90, and also slightly faster. But also slightly more on the used market. Has a very good rep, but so does the 90/4.
Option 5: Skip all of the ahead and go directly for the 40 Sonnar, which I know I would love for its rendering. MAJOR downside: I'd have even less speed than with my 50 Planar. And I do want one lens that I can use in low light without having to go to 2500 ISO.
Option 6: Sell a kidney. Joking of course
I cannot think of parting with either my 28 Biogon or my 15 Heliar, as I just love both lenses too much. The 50 Planar, however nice its rendering, is a lens that I like but that also doesn't excite me overly much. Yes, it has the typical Zeiss look going on, but with its equivalent focal length on the M8 it is kind of an oddball. Also, its rendering is sometimes too gentle, although I must say I have taken some wonderful pictures with it in the past.
Alright. What do I do? Sell the Planar? I WILL regret it. On the other hand, I WILL appreciate a lens with better low-light capabilities. This is really difficult for me, so I hope a little input from your side can help me come to a decision.
Btw, the decision is not to be made instantly. For my upcoming trip to NYC (on which I will embark this Friday), I'll take my current kit consisting of a 15 Heliar, 28 Biogon and 50 Planar. It is a nice kit, and the spread is also quite balanced. We'll see, maybe when I come back I will have come to a conclusion on my own ...