The fast fifties comparisons – batch I, part 4.

Pekka Buttler, February 2021 – June 2022

Welcome to part 4 of the JAPB comparison of nine fast fifties. This is a big article, that has been subdivided into several parts for convenience and the sake of humane loading times.

This is Batch I of JAPB’s comparison of fast fifties. Have a look also at the ‘cover page’ of the entire fifties -comparisons here.

Table of contents

• Part 1: Introduction, the lenses: pedigree and handling
• Part 2: IQ-comparison I – The Brick wall test
• Part 3: IQ comparison II – Urban vitas
• Part 4: IQ-comparison III – Bokeh and blur (you are here)
That fuzzy stuff
Bokeh (and blur)
Feel (tonal range, micro-contrast, depth perception)
• Part 5: IQ-comparison IV – Night-time vistas
• Part 6: Summary and conclusions

That fuzzy stuff…

This part of the comparison covers two quite diverse aspects. The first aspect is bokeh and the other is the general feel or rendering of the lenses. While disparate, these two aspects have one central commonality – both are very much subjective and hard to quantify.

Bokeh (and blur)

Thus far, this comparison review has focused on sharpness, but one of the things you expect from a large-aperture lens is to enable selective sharpness, in other words: subject separation. Therefore, we will next have a look at what type of blurriness one can expect from these lenses. But before we go on, two paragraphs of theory and another one of meta:

What is ‘Bokeh’ and what is it not?

The sheer amount of out-of-focus-ness of a background (or foreground) is defined by only four things: The actual focal length, the used aperture, the distance the lens is focused at and the distance to the background/foreground.
• Longer focal length => more blur potential;
• Wider aperture => more blur potential;
• Shorter focusing distance =>more blur potential;
• Longer distance to background (or foreground) => more blur potential.
Hence, any two lenses used on the same camera on the same tripod produce the same amount of background blur as long as their focal length and aperture are the same. But that is not what is commonly referred to as ‘bokeh’

Instead, ‘bokeh’ is typically used to indicate the characteristics or qualities of blur. This is by no means an insignificant topic, because as the primary function of a blurred background (and, sometimes, foreground) is to direct the viewer’s eye away from that background (and onto the subject), a background which – while out of focus – is nervous or jagged, runs counter to the purpose of blurring the background in the first place. That much basically everyone agrees on.

From that point onward, ‘bokeh’ is a notoriously difficult topic to discuss, because what is considered ‘good bokeh’ seems to be subject to taste. One need only have a look at discussions about ‘swirly’ bokeh or ‘soap bubble’ bokeh to see that opinions both run the gamut and those reasonings put forward in defence of one or another type of bokeh are more personal than universal. Therefore – instead of me passing judgment on the bokeh evident in a series of perfectly boring test shots, I’ll let you judge for yourselves.

The Rose garden

The summer of 2020 was (weather-wise, in Helsinki) somewhat unstable. Otherwise warm and sunny days would often be interrupted by short squalls. While certainly annoying (in case you wanted to stay outdoors for the entire day), it did make for vibrant foliage and the potential for a lot of raindrop-reflections. In this situation, the seemingly perfect (extremely challenging) situation for a series of test shots for bokeh and blur showed itself in the ‘rose garden’ – a portion of a city park characterised by rose bushes and sculpted topiaries (the topiaries are, however, not featured in the imagery).

Note, please: In this test, the results of the Minolta 58 mm lens are again valid for comparison as the focusing distance is comfortably within the lens’ abilities.