50 lux vs 50 apo

[Soden]

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I think you proved that different colors of the spectrum have different focal points by that. Has nothing to do with the lens.

BTW an APO has been found out to reduce that phenomenon

If APO has any effect at all then it absolutely has everything to with the lens. All focal points are mitigated by the lens design. Why do some lenses have a warmer cast and some are cooler, if the lens has nothing to do with it?

[otto.f]

And that’s the point of a APO lens! All colors focus on the same point.

 

 

 

Which does not mean that if you use a filter that the shift stays away

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[Soden]

Which does not mean that if you use a filter that the shift stays away

Well there are other causes of focus shift, but the fact that the 50 APO is also a FLE lens helps in that regard.

[onasj]

I struggled with this same decision, before choosing the 50 APO.  In part my decision was based on my love (and ownership) of the 35 lux FLE.  Every now and then I'm shooting at 50 mm wishing I had a lux, but for the most part, I love the fact that when I'm using the 50 APO, I simply don't have to worry about any lens-derived potential problems with a shot.  No sharpness issues, no CA, no focus shift, no field curvature, no excessive vignetting, no astigmatism, no coma-- it's pretty much perfect, except you can't open it wider than f/2.

 

Another upside to the 50 APO is the size-- about as small as one could hope for in a world-class, highly versatile lens capable of shooting outstanding portraits, buildings, landscapes, and decent low-light photography.

 

An upside to the 50 lux of course, besides the aperture, is that the 50 lux is only very expensive, not absurdly expensive

Edited October 7, 2017 by onasj

[Soden]

Since this question has been opened. I wonder what the T value of the 50 f/1.4 ASPH and the 50 APO is? I’m often surprised as to just how dark I can shoot with my 50 APO.

[frame-it]

https://blog.mingthein.com/2012/05/25/leica-50-2-apo-asph/

 

http://farm8.staticflickr.com/7072/7248243680_3015ae51d5_o.jpg

 

"The 50 AA meters the same as the older 50 Summicron, which is to say the Zeiss is 1/2 to 2/3 stop faster still. What this means in reality is that you can use the same aperture, get the same exposure histogram, but use a shutter speed that’s 50% to 75% faster on the Zeiss. It matters because you’re effectively getting more light into the camera, which can be critical especially in marginal situations."

Edited October 7, 2017 by frame-it

[jaapv]

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As you know, the ASPH was designed during the time when Leica said a digital M was impossible. I bought one back in 2005 and I think it had been available for at least a year prior to that.

As we all know, Leica was working on the M8 quite a while before it came out (and quite a while before they admitted the possibility;) ) I would say the two were developed in tandem.

[Jeff S]

Once again, this interview with Peter Karbe (see both pages) provides a very interesting background to the development of the 50 Summilux ASPH...

 

https://www.shutterbug.com/content/leica-lens-saga-interview-peter-karbe

 

Jeff

[frame-it]

+

 

 

 

Once again, this interview with Peter Karbe (see both pages) provides a very interesting background to the development of the 50 Summilux ASPH...

https://www.shutterbug.com/content/leica-lens-saga-interview-peter-karbe

Jeff

[Soden]

Maybe using a filter is a different phenomenon than focus shift? An orange filter for instance is a filter which places the optimal sharpness point a bit behind the focal point. Focus shift is caused by changing aperture

Maybe you, but not Focus shift. MJH gave a very complete discourse on the subject. Focus shift is masked by changing aperture not created by changing aperture. I have tested this phenomenon (as said earlier) with a f/1 noctilux at f/1, by simply changing the filter.

[wattsy]

I would say the two were developed in tandem.

I wouldn't. I think you are just making stuff up.

 

 

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[01af]

The floating elements are a method to correct focus shift and do not require a change in aperture.

That's a common misconception.

 

Floating elements reduce spherical aberrations at distances shorter than infinity. They have nothing to do with aperture-related focus shift. Of course, anything that reduces spherical aberration helps to reduce focus shift ... but only indirectly so.

 

 

Focus shift is a change in focus point, which can be caused by many things.

We are talking about aperture-related focus shift (in German: Blendendifferenz) which is caused by exactly one thing—spherical aberration.

 

 

And that's the point of a apo lens! All colors focus on the same point.

That's another common misconception. In the original, narrower sense, apo (short for: apochromatic, as opposed to achromatic) means, three colours (as opposed to two) will focus on the same point. But a good achromatic lens (corrected for two colours) still may have less chromatic aberrations than a poor apochromatic lens (corrected for three colours). It all depends on what happens to those colours the lens is not corrected for.

 

So, in a wider sense, apo may possibly not actually mean, 'corrected for three colours' but instead, 'extra-low chromatic aberration.' That's not the same thing. And the maker usually won't tell which meaning he was having in mind.

 

Years ago, the designer of both the Summilux-M 50 mm Asph and the Apo-Summicron-M 50 mm Asph, Peter Karbe, said in an interview, the Summilux-M 50 mm Asph actually meets the criteria which would make it an apo lens (by whichever criterion). But back then, they felt it was ridiculous to put the 'Apo' designation on a 50 mm standard lens so they just dropped it. This means the Summilux actually is an apo lens even though the writing on the front ring doesn't say so.

 

Anyway—while the Summilux-M 50 mm Asph's chromatic aberrations are pretty low indeed, the Apo-Summicron-M 50 mm Asph's are even lower by a considerable margin. So from today's point of view, it seems like a good idea to leave the 'Apo' designation out of the Summilux. The Summilux definitely is an excellent lens but the Apo-Summicron is even better.

 

As a bottom line, I would say:

 

If you want to carry one 50 mm lens then get the Summilux-M 50 mm Asph—the new black-chrome (as opposed to black-anodized) version with scalloped focusing grip, 43 mm filter size, and separate ventilated hood is particulaly appealing. If you're ready to carry two (money's no object; brain-damaged freaks only) then get the Apo-Summicron-M 50 mm Asph plus the Noctilux-M 50 mm Asph.

 

[jaapv]

I wouldn't. I think you are just making stuff up.

 

 

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I can read dates. The lens was introduced less than a year before the M8. Do you really think people at Leica are not aware of the developments within the company? Maybe they walk around the building with gags on their mouths.

Anyway, a lens "developed for film" and a lens "developed for digital" is a fairytale. The only difference is that lenses need more narrow tolerances in this digital age.

[wattsy]

I can read dates. The lens was introduced less than a year before the M8. Do you really think people at Leica are not aware of the developments within the company? Maybe they walk around the building with gags on their mouths.

Anyway, a lens "developed for film" and a lens "developed for digital" is a fairytale. The only difference is that lenses need more narrow tolerances in this digital age.

Like I say, you are just making stuff up. The 50 Summilux was introduced in June 2004 (more than 2 years before the rather rushed M8 hit the market) and, if you read the article that Jeff S likes to cite, the lens was in development for many years. As for your last point, I can’t agree, especially where M lenses are concerned which, as you know, have particular problems with digital compatibility.

[jaapv]

They don't; the issue is with the rangefinder-focusing tolerances and has nothing to do with the optical design.

If you are refferring to the incidence angle of wideangle lenses, this has relevance only for lenses shorter than 35 mm, and we are discussing 50 mm lenses here.

[NB23]

Hype and only hype.

 

If I post images and specify that they were taken with a 50 APO ASPH, whoah, you bet they are going to be receiving extra looks. They would be taken at least 20% more seriously.

 

20% Hype-o-rama.

[01af]

Hype and only hype.

[FeralCoton]

I struggled with this same decision, before choosing the 50 APO. In part my decision was based on my love (and ownership) of the 35 lux FLE. Every now and then I'm shooting at 50 mm wishing I had a lux, but for the most part, I love the fact that when I'm using the 50 APO, I simply don't have to worry about any lens-derived potential problems with a shot. No sharpness issues, no CA, no focus shift, no field curvature, no excessive vignetting, no astigmatism, no coma-- it's pretty much perfect, except you can't open it wider than f/2.

 

Another upside to the 50 APO is the size-- about as small as one could hope for in a world-class, highly versatile lens capable of shooting outstanding portraits, buildings, landscapes, and decent low-light photography.

 

An upside to the 50 lux of course, besides the aperture, is that the 50 lux is only very expensive, not absurdly expensive

Good points. I do love the lux. One always has to wonder if grass can be even greener and better rendered. I have tried the nocti and it is wonderful but too large to take around. The size of the APO is great and I’ve read how wonderfully it renders, but I lose 1.4 and a load of cash. Still....

 

 

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[otto.f]

I know the apo is supposed to be edge to edge sharp and eliminate CA. But how much different is it than the 50 lux, which is quite sharp itself (at least I thought sharper than 50 cron). But what makes the apo worth twice the price? (Worth in Leica world, of course).

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BTW, are you sure you are a 50 photographer? If not, try the Elmar50 for a while. This is an astounding lens for its price and sometimes I think: where is that wonderful 5000$ difference with the APO? I swapped my 50lux asph for this Elmar50 years ago and with no regrets. I’m happy that I got rid of this tumbling forward of the body when put on the table with the 50lux on it, hated that.

Do you need edge to edge sharpness on a 50, or would that be more important for 28 or 35?

Edited October 8, 2017 by otto.f

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Hallo,

Look here: Leica M

[wattsy]

They don't; the issue is with the rangefinder-focusing tolerances and has nothing to do with the optical design.

If you are refferring to the incidence angle of wideangle lenses, this has relevance only for lenses shorter than 35 mm, and we are discussing 50 mm lenses here.

 

You wrote that the 50 ASPH "was designed with a sensor in mind". I still rather doubt that and nothing you have written authoritatively supports your case. My experience (and I think your's too?) is that Leica initially had a lot of trouble calibrating this lens for digital. Leica tried more than once to correct mine for back focus in the close focus range and couldn't sort it. I even bought another one in 2011 and this was not much better. It wasn't until about fours years ago that I tried a 50 Summilux (the black chrome one) that seemed to be perfect. Far from being designed with a digital sensor in mind, I get the distinct impression that the 50 ASPH is a lens that Leica had to work quite hard to get it within the necessary tolerances.

 

As for only discussing 50mm lenses here, you were the one who appeared to be referring to lenses for film and lenses for digital in generic terms. I was just responding to that.

 

Anyway, a lens "developed for film" and a lens "developed for digital" is a fairytale. The only difference is that lenses need more narrow tolerances in this digital age.

Edited October 8, 2017 by wattsy