M2/35.18 result

Roman · Mar 3, 2005

taffer · Mar 3, 2005

Roman... LOL, you've indeed taken this seriously

That said, I REMEMBER a shot in PN (not sure if Leica or Classic forum) where a Sonnar 50/1.5 rendered a lot of oof rings in a picture taken close up and wide open.

Roman · Mar 3, 2005

Well, if my favorite lens gets slandered....
No experience w/ the 50/1.5, though!

Roman

Doug · Mar 3, 2005

Well, maybe we could call it something else!

This certainly is not the same horrible "ring bokeh" produced by a mirror lens (maybe that's donut bokeh!). The disks created by specular highlights in the out-of-focus background have sharp outer edges that are brighter than the centers. Also, those edges are brighter on the side of the disk nearest the axis of the lens, pointing toward the center. A discussion I've seen on bokeh (http://www.luminous-landscape.com/essays/bokeh.shtml) claims this configuration is due to overcorrection of spherical aberation. The newest aspheric lens designs seem to produce these OOF highlights with pretty even brightness across the disks. This doesn't necessarily produce the smoothest looking bokeh, but I guess it does say their spherical aberations are well corrected!

merciful · Mar 3, 2005

taffer said:
Bokeh or not bokeh, Merciful's portraits inside bars are simply great, I still remember the first one from him I saw, taken with a Canonet.

Thanks again.

I did a roll today at ISO 12,800 with the Nikkor 135/3.5: I should have results in a day or two.

Roman · Mar 3, 2005

Doug,

but that's precisely where I have to disagree - the Sonnar does not have bokeh with bright outer edges (a result of overcorrected spherical aberrations, as the article in your link points out), but bright center type OOF highlights in the background (I'm always talking about background bokeh here - that is, OOF highlights behind the plane of sharp focus - foreground OOF highlights are usually the opposite type of the background OOF highlights); Sonnars produce background OOF highlights like in Fig. 3 in this link: http://www.kenrockwell.com/tech/bokeh.htm
This article explains the relationship between bokeh and correction for spherical aberrations:
http://www.vanwalree.com/optics/spherical.html
And a less technical one:
http://homepages.ihug.com.au/~parsog/Guy/bokeh.html

As you correctly pointed out, bright-edge background bokeh is typical of overcorrection of spherical aberration - and the Sonnar is a lens that is undercorrected for spherical aberration!
Another hint for undercorrected spherical aberration is low contrast at large apertures - somewhere in here: http://www.imx.nl/photosite/leica/technics/optics01/lensdesign01.html - and low contrast, esp. wide open, is very typical of Sonnars!
And here is a lens test page that also assumes from the results that the Sonnar is an undercorrected lens:
http://www.rickdenney.com/lens_testing5.htm
and the conclusion:
http://www.rickdenney.com/lens_testing6.htm

Roman

aizan · Mar 3, 2005

maybe there's a difference between russian sonnars and german and japanese sonnars? 50mm, at least. i don't think it's a problem with longer lenses.

Roman · Mar 3, 2005

Merci,
BTW, sorry for hijacking your thread...
Roman

Sonnar Brian · Mar 4, 2005

Nice Bar Shot! Sharp lens. $91!!!

The Bokeh is much like the Nikkor 5cm F1.4 "Sonnar" derived lens.
http://www.rangefinderforum.com/photopost/showphoto.php/photo/3971/sort/1/cat/575/page/1

The Nikkor is much "harsher" than the Zeiss Sonnar that it "copied"; a by-product of the optical trade-offs that went into the particular formula. The Nikkor was optimized for use close-up and wide-open, and probably gained its fame for its day.

And my LTM Nikkor 5cm f1.4 even cost $4 more than your Canon!

jdos2 · Mar 4, 2005

! ! !
Lol!

wilt · Mar 13, 2005

Two examples of the bokeh of the Jupiter 8: here and
here.

back alley · Mar 13, 2005

nice shots wilt!

joe

wilt · Mar 13, 2005

backalley photo said:
nice shots wilt!

joe

Thanks!

I really like the J-8, particularly the out of focus areas. My lens, made in 1976, is good mechanically. Have another one, in silver, made in the late fifties, but focusing is stiff.

In the long run I hope to get hold of another body than the Fed 3 it lives on at the moment. It is too ..., well, loud and obvious, and the viewfinder could be brighter.

Wayne R. Scott · Mar 17, 2005

Here is a Sonnar 50mm f1.5 example of bokeh.

Wayne

M2/35.18 result

Roman

Guest

taffer

void

Roman

Guest

Doug

Moderator

merciful

Guest

Roman

Guest

aizan

Veteran

Roman

Guest

Sonnar Brian

Product of the Fifties

jdos2

Well-known

wilt

Well-known

back alley

IMAGES

wilt

Well-known

Wayne R. Scott

Half fast Leica User