Zeiss Biotar 58mm f2 vs Helios 44-2 58mm f2

Yup, I'd agree #2 has the smoother bokeh... it's the Helios

back-story: my go-to lens in the 50s is a voigtländer 50 1.5 which renders a buttery smooth bokeh transition (plus is disturbingly sharp and quite quick to hit focus - keeper rate from the voigtländer is really good).

I was hoping for a bit of the 'biotar craziness' out of these two lenses in order to offer something new over the voigtländer. As far as I can discern, the biotar actually does 'being a biotar' better than the Helios does. And the Helios does better at being a 'generally good lens' than the biotar does... which i found a bit surprising. I was expecting the helios to be a bit softer and more vignette-y than it is.

from my 2 lenses... the biotar swirls more and has a more distracting bokeh (what I was looking for). It's very sharp in the middle wide open, vignettes and goes soft to the edges quite markedly (which doesn't bother me). The contrast and colour are stronger than the Helios ootc, but it's a small Lightroom nudge to equal them out. The Helios has much nicer softer bokeh which still induces a swirl with the right background elements, but isn't quite so busy and distracting as the biotar. It's quite sharp in the middle wide open, but (probably due to the contrast differnce) doesn't seem as sharp as the biotar.

Issue for me with both: the focus turn is enormous... 270deg from stop to stop. That's a lot of finger-work with two kids tearing around.

im keeping both lenses as they're both terrific examples, but for the time being, the biotar is the one mounted to the camera. Makes a slightly crazy image, and also oozes a bit of old-school cool in polished Aluminium.

another shot from the biotar (tldr; lens #1). No risk of a papercut from the sharpness in this particular pic, but I think is a great example of the look I was hoping to get from this Lens Duo.

with slight pp adjustments for contrast and colour to make the comparison in rendering a little clearer. the difference in contrast captured by the biotar remains evident though:

Biotar (lens #1)

Helios (lens #2)

just thought id update this with some random images from both lenses. not so much a 1:1 copmparison, but a commentary on things worth mentioning

firstly - helios, shot straight into the sun, and kept it together. flare to the left of frame and through the bottom has dulled contrast and actually helps the subject in the middle to pop a little more. certainly not bad performance in really bad conditions. a bit of a push in pp, but nothing particularly hard nor selective. the helios is proving to be quite a 'reliable' lens... sharp, creative bokeh but not crazy nor dominating, and seems to land me decent keeper rates.

and today (and actually the reason for this post)... the biotar...

Im having a real love hate relationship with this lens. i want to love it. i want the shiny aluminium finish and beautiful machining to actually make pictures as good as it itself looks, its letting me down most of the time though

the bokeh is picky, sometimes it works, some time it doesnt. sometimes theres a massive amount of glow in in-focus highlights, sometimes not and its suddenly sharp as nails. i cant pick it yet, and im not sure when i want to use it. i took it out today, and have maybe a 5-10% keeper rate. its definitely not a 'shoot what ya got' style of lens.

that said, for todays pile of crap images, it comes along and pulls this hat out of the bag! i suddenly forgive all its misdemeanors, and it can stay! what amazing separation, and for f2?! just wow, freaken wow...

(not a whole lot of pp in this one either! a little bit of levels and contrast, but really nothing much... thats more or less how it looked ootc!)

original without processing

i pushed the blacks as you rightly observe, but as you can see it doesnt change the character of the shot dramatically - hence 'little' as i dont think it really 'altered' the nature of the shot as captured that much. that background washout is 100% lens. (i batch processed it as one of a series from todays outing - i didnt really do anything specific to this particular image per se)

edit - or are you talking about the pics from the first post? yeah, theyve been pp'd too with a similar curve. wasnt an exercise in colour though, more in render, bokeh, sharpness and feel. i took two lenses, went shooting with the kids, played with the images as i saw fit, then simply stood back and asked myself which lens i liked more.