Summilux 50/1.4—Glow? Or just plain softness?

[Justin Low]

Hi!

I received my Summilux a few days ago. It had some fungus inside, but I've cleaned that out and the glass looks much better now. This is the first version in chrome, made from 1959–1961.

In my test shots today, on the wide-open shot, I noticed a loss of definition that degraded progressively from the center of the image, to the edges.

Here's a picture (DOWNLOAD FULLSIZE):

At f/4, the frame seems consistently sharp, and the contrast has increased dramatically (DOWNLOAD FULLSIZE):

So my questions;

1. is this the vaunted 'Leica glow' in play, or just plain softness (some would call it poor performance)?

2. Given that my lens is not the best sample to judge, how far has it degraded compared to one in better condition?

Thanks for looking! Please feel free to share your own Summilux pictures too. Oh, and lastly, here's a picture from my M-Hexanon 50/2, wide-open at f/2 (DOWNLOAD FULLSIZE):

 

[squirrel$$$bandit]

Perhaps you could post a photo of a distant scene--that pic merely looks like it's displaying the shallow depth of field at f/1.4.

 

[Gabriel M.A.]

So my questions;

1. is this the vaunted 'Leica glow' in play, or just plain softness (some would call it poor performance)?

No "glow", the first version Summilux is very "soft" wide open, and only stopped down to at least f/2.8 you see it becoming "sharp". There are three things at play here: shallow DOF, low contrast, and haze.

I once, briefly, owned a first version Summilux and it rendered very beautiful shots, but it didn't look this soft. So somewhere in your lens you've got something (perhaps haze, perhaps a very faint smudge of oil film, who knows) in there giving you that "diffusion" wide open.

2. Given that my lens is not the best sample to judge, how far has it degraded compared to one in better condition?

I think it could benefit from a good, thorough CLA. If you said that it had fungus, well, who knows what damage has already been done; have someone tell you exactly what's going on with this lens.

Also, this lens has never been known for its "sharpness", unless you stop it down by a good few or more stops. If it gives you a "glow", as you say (this is not "glow") which is actually more like haze or diffusion, like this, there's something getting in the way of the bright highlights.

My 50mm f/1.5 Sonnar (old Contax mount) developed some haze over time; I cleaned the glass inside (what I could), and the "softness" problem was solved.

I hope that helps.

 

[Mike Richards]

Fungus Residue Ruins Lenses

Fungus Residue Ruins Lenses

Even if you have cleaned the lenses of fungus, there is still a problem with what the fungus has done to the glass. The fungus waste chemically interacts with the glass and leaves spots and streaks. The result is a lens that is prone to flare and provides a very soft image. I ran a quick check of some of my 50's, at roughly the same spot and all at f2.8. You can see the results are about the same as yours. First, My 5 year old Summilux (pre-asph), which I purchased new:


Next, my old, previously fungus infested but cleaned Summicron, purchased used:


BTW, if you had live fungus, beware of contagion. I visited the Leica repair facility in Germany about 4 years ago. Everyone was polite and helpful until I announced I had a fungus infested '50 Elmar that I wondered if they could repair. When they learned of the fungus, two burly bouncers escorted me hastily out the front door with a stern warning not to enter again with that lens.

For comparison, here is the same shot with a used '50 Cron that has no fungus problem, albeit a couple of tiny scratches on the lens:


I suspect the difference between 1 and 3 can be largely explained by improved coatings of recent years.

 

[Mike Richards]

Backlight Glow

Backlight Glow

The formerly fungus infected Summicron (photo 2 above) can be useful in some situations. I rather liked this portrait that I took with the lens. The diffusion effect is especially prominent with backlighting:

 

[Justin Low]

Thanks Mike, that was very helpful. The rear element has some clouding due to the fungus action, but the rest of the lens seems okay.

I have a picture shot at f/2.8, and it is without the 'diffusion' that Gabriel describes. Actually, the 'diffusion' is mostly gone at f/2 also (I reckon 90–95% gone)...

Mike, I guess the coating does play a big part in the contrast, seeing your earlier Summicron compared to the later Summilux. This does bear out in comparing the new Nokton 50/1.5 to the 1959 Summilux 50/1.4, with the Nokton having greater overall contrast.

 

[Mike Richards]

Getting Rid of the Fungus

Getting Rid of the Fungus

I don't remember where I read or heard this, but I understand it's advisable to dry out a fungus infected lens to make sure the fungus is gone and can't infect your other lenses. I set the lens vertically on a black cloth without caps so air could reach the rear element, and opened it up to the widest f stop. Then I arranged a small desk lamp shining closely into the top element and left it on overnight. The combination of heat and dry air circulation theoretically kills any residual fungus. I really don't know if there was any active fungus left in the used lens, but I did the procedure anyway. It seemed like a good idea, it was easy, and did not do any harm.

 

[Highway 61]

There are basically two fungi, both of which I met in some old lenses.

Aerobic fungus (also commonly called "mold") is quite harmless. It grows up as a deep blue/irized deposit on the glass. Isopropylic alcohol removes it for good. Once removed, the glass is as perfect as if no fungus had ever shown up there.

Yet the only issue is that alcohol can remove the coatings as well in vintage lenses with soft, fragile mono-coated glass.

Anaerobic fungus is extremely harmful. It grows up as a white net of "spiderweb" filaments not only on the glass but within the glass surface. Isopropylic alcohol removes it for good too but once the crap removed, the glass looks like it has been cleaned with sandpaper grit, because of the thousands of etchings the fungus has made in the glass. As a result the glass is now hazy/cloudy, and the optical results are of course severely affected.

Basically, yes a lens which have had anaerobic fungus, even carefully cleaned, is then a ruined lens. Yet you can have the sick glass element polished back. This is possible. But this will cost you more than another similar lens in perfect order...

I've seen that kind of terrible fungus in many lenses with dry aperture blades. Oil on the blades is often said to be the first cause of anaerobic fungus to grow, but I disagree. I've be led to think that oil on the blades isn't something prone to have terrible fungus to grow up in a lens.

BTW, if you had live fungus, beware of contagion. I visited the Leica repair facility in Germany about 4 years ago. Everyone was polite and helpful until I announced I had a fungus infested '50 Elmar that I wondered if they could repair. When they learned of the fungus, two burly bouncers escorted me hastily out the front door with a stern warning not to enter again with that lens

"Fungus contagion from one lens to another" is a hoax. Fungus finally develops in lenses in which the spores have been trapped when the lens was built many years earlier. Lens-to-lens contagion is very unlikely to happen. I've seen lenses with terrible fungus stored near other lenses which remained 100% clean.

About what happened at the Leica repair plant, well, that's just funny. Fungus trapped and living in your 50 Elmar was very unlikely to suddenly get out of it and your pocket and go leave its spores where the other lenses were under repair.

Live fungus is everywere around anyway, in our cars, in our flats, in our photo bags, in our beds, in our clothes, etc. Just because that's how life appeared on Earth... 🙂

 

[Mike Richards]

"Fungus contagion from one lens to another" is a hoax. Fungus finally develops in lenses in which the spores have been trapped when the lens was built many years earlier. Lens-to-lens contagion is very unlikely to happen. I've seen lenses with terrible fungus stored near other lenses which remained 100% clean.

About what happened at the Leica repair plant, well, that's just funny. Fungus trapped and living in your 50 Elmar was very unlikely to suddenly get out of it and your pocket and go leave its spores where the other lenses were under repair.

Live fungus is everywere around anyway, in our cars, in our flats, in our photo bags, in our beds, in our clothes, etc. Just because that's how life appeared on Earth... 🙂

Thanks for the pertinent and interesting information on fungus. As for the Leica repair facility incident, it makes more sense now. I gather they go to great lengths to filter the air and maintain a controlled "clean room" repair facility. They don't want fungus or anything else like dust or hair to accidentally get encased in a lens when they re-assemble it. The "bouncers" were wearing white smocks and hairnets, as I recall. This eases my mind a bit as I have a 28mm Elmar in there at the present time for warranty repair.

 

[Listak]

Glow?

Glow?

Is this a glow or a center weighted lens? This is my 50 ASPH in Hong Kong last year

 

[findwolfhard]

Summilux

Summilux

Hello! The early summilux up to 184 **** are basically redesiged Summarits, the Summarit dates back to Taylor and Hobson. Only after that serial number it can be called a Summilux .
This is a shot of an early one, the guys in a shop here let me mount it on my M3 and give a try, Agfa APX 100 and Diafiine with 1.4
The rendition of the shirt comes out quite nicely, also details in upper right corner, belt buckle and belt stitches come out nicely,- but some "glow" or softness ist there, I also blurred some details for privacy lower background .
Best regards Wolfhard
PS. The glass was very clean, no fungus