This was shot at the same time as my medium telephoto comparisons (see post below), but since I don't have comparable shots with other lenses I'm posting it separately. It shows the worst bokeh I've ever seen, personally. And with a Leitz lens, no less! (The APO-Telyt 180 f/3.4 - wide-open.)

A cautionary example for those who want to know what 'bad' bokeh looks like. Some of the tree branches show quadruple images at full resolution. And at bottom center some OOF branches actually come back INTO focus due to the interference of the multiple images. Plus those bright-ring 'locomotive headlight' circular highlights. Wowsers!

In fairness - this was shot on Velvia, a contrasty film that will reinforce any squirelliness in the original image quality. And if you look at the inset that shows the full frame, you will see, at the very top, the foothills of the Rockies. This part of the image - 15 miles away, is relatively smooth. So bokeh does vary depending on how distant and how OOF the background is.

But still...!

-- Andy Piper (apidens@denver.infi.net), December 05, 2001

Answers

Thanks, Andy. The bokeh depends also on the lens type design: the Gauss-double (symmetrical), the Doppel anastigmat, the Triplet- complex, Triplet-simple, the Achromat/Apochromat and so on. The Apo Telyt 180 is the Apochromat–type lens. Compare it to the Elmarit 180/2.8 (Triplet-complex) you will see a difference! The best bokeh give the lenses of symmetrical type (‘cron, ‘lux… Planar, Xenon/’tar, Dagor, Nicola Perscheid….), then a bit worse but very good do the complex triplets (Elmarit’s, Sonnar’s, Heliar’s …), the worst one do the plain Triplet’s and Achromat’s (IMO, as bokeh is very subjective issue).

-- Victor Randin (ved@enran.com.ua), December 05, 2001.

So Bokeh is for real...That is the ugliest out-of-focus background I've ever seen!

Thanks Andy, the picture is very illustrative.

-- Mani Sitaraman (bindumani@pacific.net.sg), December 05, 2001.

Thanks, Andy. By the way, the bokeh can be different in out of focus area before the focus plant and after it.

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), December 05, 2001.

..focus planE..

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), December 05, 2001.

Andy,

I'm feeling with you. It really doesn't look good, but I've seen worse shots. There is a nice article about bokeh here, including some good and bad examples. To me it is interesting that you always seem to encounter bad bokeh when you have an irregularly illuminated background.

Kai

-- Kai Blanke (kai.blanke@iname.com), December 05, 2001.

Hello Andy,

please consider, that the APO 3.4/ 180 mm lens was designed for military use in the first place. It was ment primarily for surveillance purposes and such things and it had the best correction at infinity as far as I´am informed. You find more on this in the J. Lager books.

Don´t know if this could have something to do with your boukeh problem.

Best wishes

-- K. G. Wolf (k.g.wolf@web.de), December 05, 2001.

I sure agree the the bokeh looks bad in this shot. I think the lighting and the geometry of the subject exacerbate the illusion. The vertical and diagonal lines combined with the specular highlights caused by harsh side lighting in the background make this the poster-child for bad bokeh in an image. I've got some shots with a 50mm Summicron that have remarkably bad bokeh too. I'd be interested in seeing any images you have taken with the APO Telyt that you feel have good bokeh. Also, whether you have used of 135mm Leica lenses you felt had better bokeh?

-- Dan Brown (brpatent@swbell.net), December 05, 2001.

Well it certainly is not butter smooth but it is still much better than what any mirror lens would have done. Pictures fron mirror lenses make me sea sick.

-- John Collier (jbcollier@powersurfr.com), December 05, 2001.

I tested a 135mm Elmarit-R last year that had bokeh almost just like your shot. Really nasty and harsh, so I returned the lens. I was thinking about maybe getting the 180mm f/3.4, but not any more! Thanks for posting the shot.

-- Bob Kramer (bobkramer@coopercarry.com), December 05, 2001.

Very distracting background, all right. Apparently when lenses are more highly corrected, they become higher in bad bokeh as well. BTW, where were you; in Golden?

-- Bob Fleischman (RFXMAIL@prodigy.net), December 05, 2001.

As per my earlier post, I do not think any Leica APO designs are particularly known for their good bokeh, but the real point is - what other 180mm lens can you use that gives as good performance wide open and when stopped down that has significantly better bokeh? I have had a few (but only a few cases!) of similar shots from my Telyt. The particular lighting in your shot exacerbates the issue. I don't think you should let this really put you off the lens. If you want the lens for nice smooth portraits then you might want to think again anyway. The 90mm APO M lens is considered by many to be too sharp for flattering portraits too. As a long time user of the Telyt for all uses: landscape, architecture and candid portrait shots, I do not find the bokeh difficult - but there is always the odd shot that does something nasty. I really do not think it should put you off! The lens usually has perfectly adequate (but not spectacular) bokeh characteristics.

-- Robin Smith (smith_robin@hotmail.com), December 05, 2001.

I hadn't noticed the poor bokeh characteristics of the 180 APO-Telyt before; here are a couple examples of how I've used it. I'd say the bad bokeh doesn't show up because I've got evenly-illuminated backgrounds, although in the Emily photo a 'bright ring' circle of confusion, a sure sign of 'bad' bokeh, can be seen in the lower right corner:

http://www.wildlightphoto.com/mammals/pete.html
http://home.earthlink.net/~telyt/EMILY.HTM

My experience with the 135mm Elmarit-R is all 'good' bokeh but then I'm using a first-version lens, not the later Canadian version:

http://home.earthlink.net/~telyt/ED.HTM


-- Douglas Herr (telyt@earthlink.net), December 05, 2001.

Shapness isn't everything. Personally, since Bokeh is very important to me, I would stay away from APO & ASPH lenses.

My 50mm f/2.8 F Distagon is a bit Bokeh-challenged for a Zeiss optic--amorphous areas are good but I have to watch out for straight lines--but what do you want from a high-speed retrofocus wide-angle lens for a medium format camera!

-- Peter Hughes (ravenart@pacbell.net), December 05, 2001.

I agree about asph and apo lenses not having such great bokeh (as a rule - the 35 1.4 asph seems good to me) - kind of ironic that just as minolta, canon and nikon are improving theirs (9 blade aperture diaphragms etc etc) leica are ruining their's by over correction. Still, if people are going to get all obsessed with max. aperture performance what can we expect! Give me tones and smooth bokeh everytime (now where can I get a 75 1.4 that doesn't get in the way of my viewfinder...)

-- steve jones (stephenjjones@btopenworld.com), December 05, 2001.

Steve

(now where can I get a 75 1.4 that doesn't get in the way of my viewfinder...)

I suggest an 80mm Summilux for the R!

-- Robin Smith (smith_robin@hotmail.com), December 05, 2001.

All good points.

Lighting, contrast, relative distance between subject and foreground/ background, lens corrections, even film choice all have an affect on bokeh, as with any part of photography. And this shot certainly - what do I want to say? - incorporates the worst-case scenarios for each of these influences. Even a 'good bokeh' tele might have been challenged in this setting. As someone said, a "poster child' situation.

I wasn't trying to 'dis' the APO-Telyt per se. In my comparison between the APO and some other medium teles the bokeh is nowhere near this - ummh - intense? - although the potential is hinted at. And the Telyt nails sharpness.

I think this is just one of those trade-offs we have to live with in photography: shutter speed vs. depth-of-field, grain vs. film speed, etc. For maximum resolution across the image plane, and esp. corners wide open, you have to correct spherical aberration, and that extra correction tends to spill over into the OOF areas, making them less smooth. You pays your money (esp. with Leica) and you takes your choice.

Doug sure knows how to handle the Telyt - somehow I just KNEW "Pete" was going to be the white horse 8^) - by keeping good separation between the subject and background.

-- Andy Piper (apidens@denver.infi.net), December 05, 2001.

Bob: Golden is back there by the foothills (where the bokeh gets smoother). See thumbnail of picture.

This was shot from Englewood (or Littleton? the Denver 'burbs blend some) - anyway 5100 S. Broadway, more or less.

-- Andy Piper (apidens@denver.infi.net), December 05, 2001.