Acid test for a 50mm Summilux

[tom_bryant]

<P>There has been much speculation as to how good or bad the old Summilux 50

was. Pop Phot flunked its wide open performance around 15 years ago, although

I've always been pleased with my results.</P>

<P/>

Just how good is it wide open?

<P/>

The night sky is an excellent test. Stars are essentially point sources of light,

and any shape they show is due to abberations in the lens, and the dark

background around most of the stars allows all those abberations to be viewed in

garish detail.

<P/>

Here's a 7 minute shot on Agfa 100 scanned at 3000 dpi, and made into a "Highest

resolution" jpg. You can pretty much see the grain.

<P/>

Note how sharp the center is, and even in the corners, the fainter stars are still

tiny. The lens seems to have more coma than curved field, IMHO, despite the

ravings of Pop Phot many moons ago. BTW at f/5.6, it's of course exquisitely

sharp, but then, so is just about everything else.

<P/>

Be warned that this is a 7.9MB file you'll be pulling over a DSL connection, so

be patient. On the off chance that the URL below just pulls up my main page,

click on the "The Center of the Galaxy" tag in the top right.

<P/>

<A HREF="http://mainsequence.org/top/shMW_Center.html">Click here to have a look</A>

<P/>

Just in case you're astronomically inclined, the center of the picture is at

Right Ascension 17h 25m, Declination -26 degrees. The streak running through

the center is a satellite. The light that exposed the film was between decades

old to over 30,000 years old, with the exception of the satellite, which was

milliseconds old reflected sunlight.

[lee hamiel]

Great shot Tom

 

Downloaded fairly quick for me

 

Thanks for posting & sorry I don't have any expertise in this zone for offering questions/observations

[35mmdelux]

"Just how good is it wide open?" isn'this a relative question? Can it capture light? Certainly. Jaxtaposed to other lenses it begins to fall behind according to many sources.

 

I don't know that its all speculation. In 30+ yrs of prod, most have preferred the 50 Cron. maybe that is changing w/ the intro of the 50mm asph?

[piotr_panne]

I did \'Sunspot\' a couple of days ago with cheap hamburger.

[paul hart]

Tom: absolutely marvellous. I really like the streak caused by the satellite.

[jeff h.]

Great photo (and great lens); makes me want to drag my 8" SCT outside and clamp a

camera on the back!

[canfred]

Interesting Tom , I think you (Peter) should get out of the sun immediately its a little too hot on your brain.

[ulrich_messmer]

I'm sure the Asph version is better, but the old Summilux is nowhere near as bad as some people make it out to be. Looks like the parroting of the "soft in the corners" phrase that started with the first version has stuck with it right up to the last version with modern coatings etc.

 

On the other hand, the Summicron can do no wrong, even though the version IV is far too sensitive to flare when shooting into the sun (at least mine, a tabbicron... I finally replaced it with a Summilux and am much happier now). I guess it's the price/performance ratio of the Summicron that's made it so popular. And the older versions don't flare as much, at least my old collapsible doesn't. A while ago somebody even posted an interesting trick here on how to cure the tabbicron flaring with a cardboard baffle.

[richard_ilomaki]

Tom

 

Thanks for all the great stuff on the site. The lens has more than a little COMA and Spherical aberation, but not so much as a $15,000, 2000 mm refracting telescope I used a few years ago at a University of Toronto observatory.

 

Another example of a good lens, hobbled by the "Nacisisim of Minor Differences".

 

Cheers

[nickr]

Tom,<br>

Do you have to actually focus a lens when photographing point sources? If not, since the

stars are point sources, could you have focused at 1 meter (I assume you focused on infinity)

and tested the lens? I think infinity focus is more the exception for shots taken with this type

of lens.

[john_graham3]

Those stars are point lights but not very bright ones (7 minute exposure??!!) Try a line of street lights at night, which is closer to what most people would probably shoot with that kind of lens. IM--and it's just an--O, for $500-700 it's a heckuva lens, but I only see the 43-filter model going for that, the 46-filter seems to be $1300-1500 and I wouldn't pay that much for one when minty asphericals have been going for $1800-1900 lately on the 'bay.

[nickr]

Like the lights in this shot, John:<div></div>

[john_graham3]

No, in that shot the lights are way OOF, unlike the subjects which are only a little OOF :*) What I meant was a night street scene where the streetlights are in focus, so that any coma halos are clearly portrayed. Though the 50 Summilux has always been considered very good in terms of handling point sources without overall flare (better than the Summicron AFAIK), it does have a tendency to a little coma in the corners wide open at night with point lights. Nothing even remotely as bad as the 35 Summilux (non aspherical). Considering when the 50 Summi was designed it's really remarkable how well it does and how many other 50 1.4's fell at its feet up until just recently.

[ronald_moravec1]

Who cares if doesn`t flare when it is not sharp until 5.6 or 8. Just look at the couple portrait linked above. The ones I looked at all made images like that shown, soft, and the most barrel distortion by a large margin of any 50 mm lens ever made by Leica.

 

I would take the first one made in 1959 over any of the later 40 year span ones. But I won`t get that either because I have yet to find one that is better than my Summarit. The second version made for 40 years has a more uniform definition across the frame whereas the first ones were sharp in the center and getting softer towards the edges.

 

If you want Leica and 1.4, get a new 1.4 or a Noctilux and use it at 1.4.

[tom_bryant]

Comments on the comments:

 

The picture was a piggyback on a Celestron C-8 Ultima, with PEC on and the polar axis within a few arc minutes of the actual pole.

 

The lens *was* focused at infinity.

 

My Noctilux stayed home. It's just too big and it's hood does not reverse.

 

The Summilux has been dropped on the concrete at least twice, and bumped innumerable times. The mount looks like a beaver once chewed on it. Of all 11 of my lenses, it's my favorite.

 

As to the stars not being bright, Antares (the red star in the lower right) is way over exposed. Note how M4, a globular cluster barely visible to the naked eye (just a bit right of Antares) looks almost as bright. Antares is over 100 times brighter than M4.

 

After a bit of overexposure, the film iteslf starts to show its defects, like halation. Antares shows quite a bit of halation. Note the star directly above Antares. It's much less overexposed, and the abberations are a bit less as well.

 

I suspect that the new Summilux would have produced a sharper image in the corners, but, as someone else has already noted, these lenses were rarely used for this purpose.

[john_graham3]

"Who cares if doesn`t flare when it is not sharp until 5.6 or 8. Just look at the couple portrait linked above. The ones I looked at all made images like that shown, soft"

 

I don't know why your shots weren't sharp but that one is OOF, obviously. No one (except you) has ever said the Summi wasn't sharp until 5.6 or 8, just that it wasn't sharp out to the corners until then (actually in my experience, it's more like f/11 for perfect corner sharpness).

[a._j._valys]

So back to the satellite. You guys must have better eysight or imagination than I, because I do not see anything streaking across the sky!

[alan_wilder1]

I saw it with no problem. It looks like a scratch on the emulsion.

[jerry_pfile3]

Tom,

 

Curious as to whether you have the v1 or v2 Summilux (serial above 1,845,000 or so). I know my v2 surpasses my limitations as a photographer. I'm certain the current ASPH version is a 'better' lens though, whatever that means to most individuals.

 

The experiment kinda makes me want to duct tape mine to my Questar though.

 

Best,

 

Jerry