More bokeh? 200mm @ f/2.8 or 100mm @ f/2.0?

[Daniel Browning]

Thanks for the kind response, Jon.

Yes, I was using the word in the way I thought Mr. Powers Brent intended, even though it isn't how I would have used the word.

When in Rome. []

Okay, that makes perfect sense. Of course, if you really want to quantify blur with a single number (and thus answer which lens has more) you have to specify which given distance you care about .

You're quite right.

In addition, I guessed that by "bokeh" the OP wanted to also take into account another feature of long lenses: they magnify background details more.

I think so too.

I *thought* this contributed to our perception of a blurred background

Agreed.

(quite separate from how big the OOF disk of a background point will be)

I think one of the ways in which the increased magnification of the background affects our perception of background blur is by increasing the size of the OOF disk on the sensor (though in a very different way from which f/number affects the OOF disk.) One other way that someone else mentioned in this thread is by having less background to begin with.

According to Bob Atkins, bokek is a combination of quality and quantity of OOF blur.

That's not the impression I get. Bob says:
<p style="padding-left: 30px;"] "While the quality of blur - bokeh - is in itself a "fuzzy" concept and
something that's quite difficult to predict or control, the quantity of blur can be
calculated quite easily and it's something over which the photographer has control through
choice of focal length and aperture."


To me it seems like he treats bokeh as quality only.


Thanks again, Jon.