Oh great purveyors of Leica knowledge:

What is the respective weights of the various issues of Leica 90 Summicron lenses. The early Chrome (1965), early Black (1970), late Black (1995) and the latest APO? How do the various versions compare optically wide open, knowing that the APO is the best, how do the others stack up?

Thank-you.

Mark J.

-- Mark A. Johnson (logic@gci.net), November 10, 2001

Answers

Weights:

Early (1957 design) per Lager's book: black 680g

Early chrome: Lager doesn't list a separate weight for the chrome barrel

late (1980 design) black 410g (Lager) 475g (Leica brochure)

late (1980 design) chrome 690g (Leica)

APO, 500g (Leica)

Just to make things complicated, there were actually at least three variants of the first version: with separate lens hood (very early only), with built-in two-part hood and heavy knurling, and then a version just before the 1980 redesign with lighter knurling like today's lenses.

There were also two variants of the small non-APO: very early where the one-piece telescoping hood covered the aperture ring when collapsed, and then the rest of the run, where the hood was shorter and didn't cover the aperture ring when collapsed.

I've shot all three of the designs recently trying to choose a 'cron to go with my 2.8. IMHO the 3 optical designs stack up like this wide open:

1.APO design: Lots of contrast wide open, and the sharpest.

2.1957 design: Actually a tad sharper than the 1980 design at f/2, and not too far from the APO, but with much lower contrast than either. Stopping down the contrast increases, but the sharpness improves more slowly, so that it falls behind the 1980 design by f/3.5.

3. 1980 design: not quite as sharp as the 1957 at f/2, but with more contrast (not up to APO). Picks up resolution and contrast fairly fast when stopped down.

Both the 1957 and 1980 designs have a fair amount of chromatic aberration that doesn't get much better stopping down - slight purple/ green fringes around the edges of objects. This is the main limitng factor on the sharpness, especially for the 1980 design. It's more obvious near the corners, and stronger in the 1980 design than in the early version, possibly due to the 'telephoto' optical layout in the small lens (??). The 'APO', as its name suggests, eliminates this completely at all apertures.

To explain why I haven't made up my mind which way to go yet: The 1980 design is relatively cheap, and good stopped down, but IMHO the worst at f/2. The APO has too much macro-contrast for my taste, but the best sharpness everywhere - pricey. The 1957 design has good resolution but weak contrast at f/2, and doesn't hold up as well at smaller apertures - plus it's bulky. My ideal would have the APO's resolution and chromatic correction but the 1980 design's contrast signature. Others, no doubt, will disagree. 8^).

-- Andy Piper (apidens@denver.infi.net), November 10, 2001.

HI,

did anyone also compare the 90'con to 90 2.8 tele-elmarit-M?

-- joseph (jose_phla@hotmail.com), November 11, 2001.

Here is a photo of photographer Claire Lerner shot with the latest (non-ASPH) 90mm Summicron-M @ f/2. The inset is a magnification of the eye. It's only a poor JPEG, of course, but even so you can see that there is no chromatic aberration and that it is more than acceptably sharp, especially given the slow shutter speed (ca. 1/8 sec. on tripod). You will also note the extremely lifelike character of the image, the superb 'bokeh', the natural color rendition—without the slightest hint of crossover—and the soft and pleasing highlights, all aspects in which Leica lenses excel.

I suggest that if you plan on actually shooting with the 90mm Summicron-M, you will find that it is a portrait lens without peer in the 35mm format, despite the supposed "flaws" in its performance, none of which has ever bothered me in the slightest.

Peter Hughes Photography

-- Peter Hughes (ravenart@pacbell.net), November 11, 2001.

Peter:

One of the characteristics of this board; If you want to correct a dropped tag it usually takes three attempts. I usually use 4 just to be safe.

Art

-- Art (AKarr90975@aol.com), November 11, 2001.

As usual, Peter Hughes shows the way - pictures are worth a thousand words.

Top row: Blowup showing faint magenta/green color fringes in shot with the 1980 (v.2) 90 Summicron. f/4 or thereabouts. Note that despite the color fringe, the seam in the workman's jeans is resolved, even in a blowup equal to about a 60" x 40" print.

It takes a sharp dark/light edge contrast like this for the fringing to show up, and it is only visible near the corners - I meant to say that in the previous answer.

Bottom row: Blowup showing f/2 image quality of the large 1957-1979 90 'cron.

Peter's example shows the astounding 'fadeaway' backgrounds formed by the late non-APO lens at f/2 - something neither the APO nor the early version do as well, IMHO.

.

.

I'm still trying to make a decision, but I'm leaning towards Peter's version at the moment.

-- Andy Piper (apidens@denver.infi.net), November 12, 2001.

Andy -- You're right about chromatic aberration showing up worst with dark against light colors. Now, if that's the worst c.a. you can show from a 90mm Summicron, well, that's not so bad. You should see the c.a. I used to get from Canon USM wides: 20mm f/2.8, 28mm f/1.8 and even a 14mm f/2.8L. Much worse than that!

As for the beautiful 'bokeh', that's why I own the lens and that's one of the main reasons I shoot Leica (and Hassy).

Frankly, I'm leary of aspherical elements in lenses. Perhaps they do correct for some aberrations, but at what cost? This is just a gut feeling, not backed up by any empirical evidence, but I think the best lenses, as far as character and 'bokeh' are concerned, are no faster than f/2 and w/o ashperical elements. Also, micro-contrast is very important! And the late non-ASPH Leitz optics seem to have that in spades.

-- Peter Hughes (ravenart@pacbell.net), November 12, 2001.

Mark:

Correction: I quoted various weights above as from "Lager". Doooh! They were actually from Dennis Laney's book LEICA COLLECTORS GUIDE.

I just purchased and weighed a very early "late" non-APO 90 Summicron. It is just a tad short of 16 oz. (484g) or in other words 475g, just like the later "late" ones. There is NO Summicron 90 that weighs 410g - that is the weight of the current Elmarit 90 in black mount. I assume that's how it got into Laney's book.

My new 90 'cron performs marginally better than the one I had before - or at least focuses more consistently. Since the optics are the same, it must just be production variance.

-- Andy Piper (apidens@denver.infi.net), November 14, 2001.

for the, ahem, unintiated - what is chromatic abberation?

-- sparkie (sparkie@mailcity.com), November 14, 2001.

Joseph: As of Monday I have both the 90 Tele-Elmarit-M and the 1980- 1997 design Summicron - of course I did a preminary comparison. They are very close in sharpness, IMHO. The 'cron is a little better in the corners at f/2.8, and has more contrast at all apertures - the contrast difference is visible even looking at negatives without a magnifier. Still waiting for slide processing to look at bokeh/color stuff. I will probably post some samples separately once/if I get anything worth showing.

Sparkie: Look at my example of the workman dressed in black above. See how his black clothes are rimmed with purple at the top and green- yellow underneath? It is caused by the lens elements acting like prisms and starting to break up the light into a rainbow. The lens is focusing the blue-purple light slightly differently than the green or red light. The effect is usually minimal at the center and grows stronger as you move towards the corners of the frame. Within a piece of glass the effect is called 'dispersion', and in the final image the effect is called 'chromatic aberration'.

It is the same effect that causes infrared light to focus differently than visible light, and why you need to refocus most lenses to a little red 'infrared index' mark if shooting IR film.

It is most obvious in long focal length lenses because the aberration gets magnified along with the rest of the image. It also increases with large apertures, which is why the first ED/APO/L lenses were all f/2.8 telephotos (well, the APO-Telyt-R is a 3.4) - they needed the fix the most. You will notice that nobody bothers to make "ED" or "APO" normals/wide-angles (yet).

The fix for this aberration is primarily to use Extra-low Dispersion (ED) glass(es) in the lens design - glass which bends the light to form an image more equally at all wavelengths. In the 60s/70s Canon tried using lens elements made from quartz and flourite crystals, which have low dispersion but were very fragile and expensive.

In the '80s ED glass became available and is now relatively common, even in 'consumer' zooms, and is used in Nikon ED lenses, Canon 'L' telephotos, and, of course, Leica APO lenses. All these lenses do a better job of focusing all colors at the same place than a lens made from 'ordinary' glass.

CA is most visible in color pictures, but also affects B&W because some of the light rays just aren't going where they should. In B&W a strong yellow, red or orange filter will cut off some of the errant rays and improve sharpness, which is partly why a lot of 'Nam-era photographers kept a yellow filter on their Nikkor 200s permanently.

-- Andy Piper (apidens@denver.infi.net), November 14, 2001.

Awesome Andy. Thanks. I have an B+W orange filter which I bought 3 months ago to go onto my 35' cron ASPH, but havent used it yet until i find a 'bright'/low contrast situation in order to use it. as i thought by using it on a normal situation may give it too much contrast, ie. that the new cron ASPH is pretty contrasty anyway. Or should i use it all the time when shooting B&W regardless? i know should just try it with and without and see for myself -but always like hearing from people more experience. cheers

-- sparkie (sparkie@mailcity.com), November 15, 2001.