Nifty Fifty wrote:
Because we recently discussed the varying degrees of bokeh at the same aperture. This video also points out this phenomenon in relation to Lux vs. Cron (from 16:40 onwards). I find the difference there even more striking.
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How interesting, the cron at 2.8 looks exactly as the lux at 4!
I really don't know how to interpret that. It would be interesting though to mention the speed of the shots: is the shutter speed for the cron at 2.8 the same as for the lux at f4... which would suggest that the cron F2 is not a really f2, but more a 2.5 or so...
hesb wrote:
How interesting, the cron at 2.8 looks exactly as the lux at 4!
I really don't know how to interpret that. It would be interesting though to mention the speed of the shots: is the shutter speed for the cron at 2.8 the same as for the lux at f4... which would suggest that the cron F2 is not a really f2, but more a 2.5 or so...
This differing behavior is apparently not that uncommon. The Viltrox 50 at aperture 2 looks like the 50 GM at aperture 2.8. That's how this discussion even started. The exposure times behaved plausibly, meaning they were the same at the same aperture setting.
In Ted Forbes 50mm GM f/1.4 review, he compares the f/1.4 GM lens with the f/1.2 GM lens and the f/1.2 GM lens has bigger bokeh balls @ f/1.4 than the f/1.4 GM @ f/1.4.
At 5:04 mark, as the forum will not allow me to deep link in the video:
milend wrote:
After reading Dustin Abbot's review, I purchased the 50mm F2 Air. ... Otherwise, it's the perfect lightweight 50mm for me.
After having used the lens for a few months, it's absolutely cracking value - sharp, light and great rendering (to me, as an amateur). The other lenses I own don't come close relative to how much they cost me and how much they weigh (35GM, 40mmF2.5, 35mm F1.8, 24-50mm F2.8).
Clearly a superb lens across the aperture range. People seem to use it at either end - at f2 or (say) f5.6-f8. After seeing a lot of reviews, I noticed the bokeh settles very nicely at f2.8, in case you need/prefer that effect.
'the f/1.2 GM lens has bigger bokeh balls @ f/1.4 than the f/1.4 GM @ f/1.4.'
Besides lens configuration, designers have a fair degree of control over this physical effect, by the placement and physical diameter of the entrance pupil. A larger entrance pupil diameter produces larger, more prominent bokeh balls.
And the location of the entrance pupil (how deep inside the lens) influences the shape and behaviour of the lens. Which may help explain why some lenses with low blade counts still manage (slightly stopped down) bokeh that appears smooth much of the time. This one has nine blades.
