Bokeh comparison: fast primes vs. average speed primes

[caspert79]

In this topic
http://forum.mflenses.com/smc-m-pentax-50-1-4-is-fast-as-1-2-lens-wide-open-t34792.html AhamB included the following link http://www.fredmiranda.com/forum/topic/924270/16#9034350 which shows a comparison of bokeh between fast primes and not-so-fast primes. Based on the pictures in the link, I agree that the bokeh of the faster lenses looks better then the bokeh of the not-so-fast lenses (at the same aperture). If it appears that this difference in bokeh applies to fast vs not-so-fast lenses in general, this could be a strong argument in favor of choosing fast lenses. I decided to put a few of my own lenses to the test. Unfortunately, I couldn't include any F/1.2 lens, for I don't have one at the moment.
All pictures were taken at F/2. The lenses included are:
SMC Pentax K 50/1.4
Auto-Revuenon 55/1.4
SMC Takumar 55/1.8
Super-Takumar 55/2.0
Rikenon XR 50/2.0

Here are the results:


One thing that struck me is the colors generated by the Super Tak 55/2.0 which are very cool compared to the other lenses. The Revuenon, which is also single coated, produces much warmer colors (under these lighting conditions).

Looking at the bokeh, I think the two fast lenses produced the most pleasing bokeh indeed. I think the winner of this contest is the Revuenon 55/1.4 while the Rikenon XR 50/2.0's bokeh is the least satisfying.

Feel free to comment!

[LucisPictor]

I agree. In these shots the Revuenon wins.

[dimitrygo]

[Seele]

I totally agree with your observations. To my eyes, I never find over-corrected spherical aberrations at out-of-focus distances appealing, especially behind the focussed distance. With a gun to my back I would rather have under-correction behind, and over-correction in front; this would cut down the dreaded nisen-bokeh a lot.

[kawasakiguy37]

overcorrection does result in a sharper image though (for the part that is in focus). So really you just have to choose what fits the bill best.....sharp and ugly bokeh or a little less sharp and amazing bokeh

[jjphoto]

I'm not convinced that a slower lens would necessarily have better bokeh.

[IAZA]

I agree with jjphoto,
Bokeh opinion is subjective.
For those pictures above, I would like to sompare color instead of bokeh
The pentax looks more green while rikenon and revuenon more yellow. I prefer Pentax.

jjphoto's test... i like zuiko one

[djmike]

[caspert79]

@jjphoto
I think the difference in Bokeh shows more clearly at F/2 than at F/2.8 (and higher). I did a bokeh test before with several 50/55mm lenses @ F/2.8 and the difference in bokeh-quality was hard to tell:
http://forum.mflenses.com/several-50-55-mm-primes-compared-in-the-field-t34237.html

[jjphoto]

By the way, I don't think it's a good idea to shoot trees, plants or anything that might sway in a breeze as this can create softness that has nothing to do with the lens itself.

[caspert79]

[dimitrygo]

[Orio]

My opinion is that a test like this only shows how similar the 50mm lenses of modern era are, since they are all built on the same double gauss scheme.
There are only slight differences in colouring which is due on the type of coating that is chosen.

[Keysersoze27]

Second test that I have seen that clearly shows that the C/Y 1.4/50 has smoother bokeh than the Summicron 2/50.

I'm remarking this because in 98% of all opinions I have seen on various forums is that the Summicron has smoother bokeh than the Planar.

[jjphoto]

I'm not sure that a single set of images is enough to properly describe a lens and the way it behaves at different distances and with different subjects either.