Igor, Thanks for the references. I should be able to access the full text of the DOI through my university account. Maybe I need to refresh my physics and optics courses from 40 years ago :)
It's difficult to reproduce the 3d pop. I think foreground and background should be blurred. Toine > > > On Oct 5, 2020, at 1:10 PM, Igor PDML-StR <[email protected]> wrote: > > > > > > Toine, > > > > First, let me say that you've got a very nice image! > > > > Paul has given a very simple explanation for the visual effect you (we) > > observe. The further difference is (as Paul and a few others pointed out) > > comes from the quality of the bokeh for the particular lens. > > > > As you probably know, the lead (actually, lead oxide!) in the lens glass > > raises its refractive index. This allows for thinner lenses for a given > > focal length. However, glass with a higher refraction index has higher > > dispersion that needs to be corrected to make the lens achromatic (i.e. to > > minimize chromatic [and spherical] abberations). > > So, the combination of these factors *can* affect the bokeh. > > > > I've found this informative write-up on B&H website: > > https://www.bhphotovideo.com/explora/photography/tips-and-solutions/understanding-bokeh > > It gives a nice overview of what and how plays a role in the bokeh - with > > some nice illustrations. > > In particular, I didn't know that there are lenses with adjustable bokeh. > > > > Now, I was curious about how much is known scientifically about bokeh. > > It is clear that at least some lens manufacturers pay attention to it. > > > > While I didn't do a deep comprehensive search in the scientific literature, > > it seems, - not much seems to be published on that topic. > > I've been able to find a few research articles adressing the theory and > > theoretical calculation of the bokeh, but there are literally handful of > > those. (And there was some research on how to fake bokeh, - I assume aimed > > at creating "creative filters" for the phone-shooters.) > > > > Of those, one paper I looked at was Viktor P. Sivokon, Michael D. Thorpe > > Optical Engineering, 53(6), 065103 (2014). > > https://doi.org/10.1117/1.OE.53.6.065103 > > (Sorry, it requires paid access. Feel free to contact me directly for > > detail.) > > They were able to model bokeh mathematically (analytically) and compare > > to the actual bokeh produced by lenses with a reasonable accuracy. > > Here is one of their results: > > http://42graphy.org/misc/BokehCalculated-SivokonThorpe.jpg > > > > Cheers, > > > > Igor > > > > > > Toine Sun, 27 Sep 2020 10:56:03 -0700 wrote: > > > > Yes I agree thats the main effect. However this guy even includes lead in > > glass as a pop factor. The rendering of bokeh also adds to the effect. > > Zooms have a busy bokeh. > > > > > > https://photographylife.com/the-death-of-beautiful-rendition-and-3d-pop-on-modern-lenses > > > > I can hardly see the difference in his before after shot with the slider > > > >> On Sun, 27 Sep 2020, 18:46 Paul Stenquist, <[email protected]> wrote: > >> > >> What is seen as 3D “pop” is just limited depth of field. And because > >> primes generally have a larger app wide open than zooms, they give you > > more > >> control over DOF. > >> > >> Paul > >> > >> > On Sep 27, 2020, at 10:44 AM, Daniel J. Matyola <[email protected]> > >> wrote: > >> > > >> > That certainly does "pop"! > >> > > >> > Dan Matyola > >> > *https://tinyurl.com/DJM-Pentax-Gallery > >> > <https://tinyurl.com/DJM-Pentax-Gallery>* > >> > > >> > > >> > > >> >> On Sat, Sep 26, 2020 at 2:54 PM Toine <[email protected]> wrote: > >> >> > >> >> I read a lot about primes vs zooms and old designs of primes. That > >> >> should result in something like 3D pop. Never noticed it until today: > >> >> > >> >> > > https://www.repiuk.nl/albums/new/#&gid=1&pid=005-899-20200926-imgp3095-edit > >> >> > >> >> I find myself lugging the DA*300 around on a daily basis. Maybe > > because > >> it > >> >> pops. > >> >> > >> >> Do I need new glasses? > >> >> > >> >> Toine > > > > -- > > PDML Pentax-Discuss Mail List > > [email protected] > > http://pdml.net/mailman/listinfo/pdml_pdml.net > > to UNSUBSCRIBE from the PDML, please visit the link directly above and > > follow the directions. > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
