APO Summicron 50/2 ASPH: Central veiling flare / fogging

[lct]

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Yes no CVF here. Thanks for sharing.

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[k-hawinkler]

This is the best example I have regarding loss of central contrast.

 

M240+APO50, f16, towards a very bright sky. There are some loss of central contrast, but no central "white-out".

 

I have also scanned through the 2000+ images I have with APO50. Not a single image with the central hot-spot found.

 

 

Thanks and congratulations on your lens indeed.

[helged]

Ideally - none of the APO-50 lenses should show the loss of central contrast demonstrated by some users in this thread. But it is good to know for existing and new users that there are fine copies out there. Hopefully good copies hold for the majority of the produced lenses, although forums like this can make it appear the opposite around.

 

The key message is that those with an ill-behaving lens should contact Leica for adjustment/replacement. In addition - and something that I would assume by now - is that Leica have had a look at their quality checking.

 

---

 

The APO50 is a fascinating lens, indeed. Small, light-weight, high micro-contrast, sharp into the corners and with very little distortion of the focus plane throughout the image, with a very smooth OOF rendering and almost without chromatic aberrations next to highlights. The lens has a tad (but quite pleasant, in my eyes) light fall-off towards the corners at f2, otherwise you get a very evenly lit image. The color rendering is pleasant. Flare can be expected when highlights is 15-20 deg off the axis of the lens. Flare may also creep in from excessively overexposed regions (M240 with live view easily uncovers this). Essentially no flare at f2, though.

 

The APO50-MM combo is the best I have seen considering technical superiority (coming from medium format film; I have no experience with medium format digital or large-scale film, but I guess it is up-there). Of course, the 50-Lux is also a fine lens, as well as other Leica and non-Leica lenses. And no - I am not paid by Leica . Enjoy shooting!

[Rick]

Ideally - none of the APO-50 lenses should show the loss of central contrast demonstrated by some users in this thread. But it is good to know for existing and new users that there are fine copies out there. Hopefully good copies hold for the majority of the produced lenses, although forums like this can make it appear the opposite around.

 

The key message is that those with an ill-behaving lens should contact Leica for adjustment/replacement. In addition - and something that I would assume by now - is that Leica have a look at their quality checking.

 

---

 

The APO50 is a fascinating lens, indeed. Small, light-weight, high micro-contrast, sharp into the corners and with very little distortion of the focus plane throughout the image, with a very smooth OOF rendering and almost without chromatic aberrations next to highlights. The lens has a tad (but quite pleasant, in my eyes) light fall-off towards the corners at f2, otherwise you get a very evenly lit image. The color rendering is pleasant. Flare can be expected when highlights is 15-20 deg off the axis of the lens. Flare may also creep in from excessively overexposed regions (M240 with live view easily uncovers this). Essentially no flare at f2, though.

 

The APO50-MM combo is the best I have seen considering technical superiority (coming from medium format film; I have no experience with medium format digital or large-scale film, but I guess it is up-there). Of course, the 50-Lux is also a fine lens, as well as other Leica and non-Leica lenses. And no - I am not paid by Leica . Enjoy shooting!

 

I agree with all of this. Also, I did reach out to Leica on Thusday, but I don't think they have seen my PM yet and I don't think I'll get a response before I leave Monday.

 

I did try the lens again in hopes that maybe I was just too picky. But, my copy shows the flare immediately when you start pointing it around outside. Nothing as bad as my posts, but it is always there and I'm very sure I could repeat the bad flare I posted.

 

I do want to make clear that the flare is completely eliminated when the front is shaded. I have lenses that exhibit this effect much worse, like my 28 cron which I think is a fantastic lens. But, it needs its big hood!

 

I have been testing all my lenses and they all benefit from good hoods. Sometimes people start threads here that ask, how many shoot without hoods. I was in the group that shoots without hoods. I have now become a huge believer in hoods over the last few days. The LV is an amazing teacher. I had no idea how important it was to get any amount of light off the front element. I guess that is why those cinematographers all use those big bulky shadow boxes. Those guys are beyond expert and I assume they know they can't risk ruining a scene because of flare.

 

I now would be interested in testing the lens with some 3rd party hoods to find something very compact that shades the front of the lens. I think this is where Leica should concentrate.

 

My dealer is going to contact Leica and is arranging for another lens for me. The lens really is amazing in all the ways Helged delineated so well in his post. I'll just have to suck it up and try and live with my crappy old 50/1.4 FLE while on holiday in Europe.

 

Truly blessed and still not a disgruntled Leica customer,

 

Rick

[k-hawinkler]

Hi Rick,

 

Have fun in Europe.

I know you do, judging from your previously posted images.

Be safe.

[lct]

Why would CVF vanish at full aperture and how could the issue be fixed by Leica if the hood were the culprit? In their message to jim.grover, Leica wrote "we want to prevent that this effect occurs at any aperture". I guess they did do it with jim.grover's and helged's samples w/o even touching the hood and they will do the same to pajamies' lens with success hopefully.

[k-hawinkler]

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I agree with helged's copy.

Where is the proof posted for jim.grover's AA lens?

[lct]

I have none, just a guess based on Jim's satisfaction.

[Rick]

Why would CVF vanish at full aperture and how could the issue be fixed by Leica if the hood were the culprit? In their message to jim.grover, Leica wrote "we want to prevent that this effect occurs at any aperture". I guess they did do it with jim.grover's and helged's samples w/o even touching the hood and they will do the same to pajamies' lens with success hopefully.

 

LCT - There are several optical reasons why CVF flare would "vanish" at full aperture. First of all, it does not "vanish." It is still there. I could see it at any aperture. Any.

 

But, several things come into effect at full aperture. The overall contrast of the lens is reduced relative to the CVF. So, the CVF is less noticeable. Secondly, stopping the lens down reduces the effect of light entering the peripheral portions of the optics and reflecting off the optics, the insides of the lens and the inside of the camera box. With less light scattering around, the effect becomes more pronounced at these smaller apertures. And, remember, at smaller apertures the exposure is increased which increases the strength of the CVF which, I postulate is fairly constant, but now increased in intensity with the increase in exposure. The CVF is still the same, it is just the rest of flare that is reduced in comparison to the CVF and the exposure that is changed.

 

You ask, how could the issue be fixed by Leica if the hood were the culprit? In my testing the hood would cause ambient light from falling on the front of the lens which seems to be where this CVF starts. When I produce a condition where the front of the lens has not direct light on it, and I'm not talking about direct sunlight falling on the front of the lens, the CVF immediately vanishes completely. The effect we are seeing, as I said before in this thread, before I even received my copy, is caused by simple lens flare.

 

I'm not sure what they did with helged's lens and I haven't seen examples from those that have not received there lens or have not posted. But, helged's lens still has flare. His example is exactly what I see in mine. I see no difference, other than he hasn't duplicated the same scene.

 

As far as I can tell, this is just the way this lens flares. I am very open to an explanation of what Leica did to "fix" it. But, short of changing the optics in the lens or something else that is causing light to scatter in the lens, I'm not sure what can be fixed. The 28 cron does this and they haven't "fixed" it either. Why. It is just the characteristics of the 28 cron... and many, many Leica lenses. Leica lenses are known to flare.

 

This is simply why we use lens hoods. You know, you don't spit in the wind, and you don't shoot Leica lenses into the sun.

[helged]

Rick: Please report back when you hear from Leica and when you have had the chance to cross-check the adjusted/new copy of the lens! Anything that can be done to reduce the flare would be great - and good to know about.

 

As a side note: My copy hasn't been to Solms for repair; it's an "ordinary" (defualt) production item.

[lct]

...I'm not sure what they did with helged's lens and I haven't seen examples from those that have not received there lens or have not posted. But, helged's lens still has flare. His example is exactly what I see in mine. I see no difference, other than he hasn't duplicated the same scene...

Wishful thinking from my side perhaps... I have so many lenses that i don't count them anymore and the Elmar will probably remain my favorite 50 anyway so i will take my time before ordering the apo, if any, unless Leica explains clearly what happens with this lens but i don't hold my breath. Happy trip to Europe BTW.

[Rick]

Rick: Please report back when you hear from Leica and when you have had the chance to cross-check the adjusted/new copy of the lens! Anything that can be done to reduce the flare would be great - and good to know about.

 

As a side note: My copy hasn't been to Solms for repair; it's an "ordinary" (defualt) production item.

 

Wish you were my neighbor. We could have simply compared and I would really like to see your copy. I still am holding out "wishful thinking" that there exists a lens like yours. I will say that if this is worst flare you can come up with, Ill take your lens! I got to go pack. We are leaving in the morning. (My wife has been packed for over a week)

 

LCT, keep the faith.

[otto.f]

I'm getting more and more the feeling that it all boils down to the discovery of what happens if you do not use the hood, maybe I misread or misjudged some information here but it seems that the moment Leica said: "let there be built-in the hoods on 50mm lenses", there appeared to be flare. And in fact that's plain normal: you have to use effective hoods, always. And especially with lenses that have a more convex front lens. The Summicron 28 has a concave frontlens and is the least flare-prone lens of the whole Leica series, which can be used without the hood with the least risk, relatively speaking.

There may be less difference between APO 50's but more so: difference between the light that falls on the front lens in the different situations in which people have tested and searched for flare.

[Jim.grover]

Hi Karl-Heinz,

Thanks for your thread. Haven't ignored your suggestion...just been travelling! As luck would have it all of my lenses and bodies are currently in Solms as they need a bit of re-calibration (I'd been deferring sending them to Solms for calibration until I had both the 240 and 50 APO...and then getting all of my lenses and bodies done 'in one go' - - most of the lenses are perfectly calibrated, but some are front focusing). But promise to try what you suggest when they return...and will post the thread. But when I tested my new APO, it did seem perfect! So here's hoping! Thanks for your contribution...I continue to be intrigued by this thread. I am a real Leica believer (ditched Canon and haven't looked back!)...but am learning that these amazing lenses do bring with them challenges. Very best, Jim

[k-hawinkler]

Thanks Jim, I am looking forward to your report and hope everything works out just fine with your 50 AA.

I am tempted getting one if I could be pretty sure it works as well as helged's lens.

[Rick]

I'm getting more and more the feeling that it all boils down to the discovery of what happens if you do not use the hood, maybe I misread or misjudged some information here but it seems that the moment Leica said: "let there be built-in the hoods on 50mm lenses", there appeared to be flare. And in fact that's plain normal: you have to use effective hoods, always.

 

Yes this is true except that what I experienced with the 50 APO is always there without a hood unlike my other Leica lenses. The dealer looked at it and just walked back into the store and said, something is wrong with your lens.

 

 

And especially with lenses that have a more convex front lens. The Summicron 28 has a concave frontlens and is the least flare-prone lens of the whole Leica series, which can be used without the hood with the least risk, relatively speaking.

 

This is just flat out wrong. The 28 Summicron is probably my most flare prone lens. Why do you think Leica included the largest hood with it. This lens sucks when it comes to flare from light on the front element. It has nothing to do with the fact that the front element is convex. Please don't start this Leica lore. And, this is still one of my most used lenses.

 

may be less difference between APO 50's but more so: difference between the light that falls on the front lens in the different situations in which people have tested and searched for flare.

 

Maybe. I'm really not sure how much of this is user dependent or lens dependent. But, please don't infer that I went out looking for it. Here is how it went down: I bought the lens and the next day when I had time I went outside our clinic and turned on LV and pointed it around to take a couple quick grab shots and I couldn't find anywhere that it didn't have haze in the center of the LCD. I took it inside to clean the elements, but they where fine. My copy is f*cked up. I don't know about other's. But, you can understand I have my suspicions.

 

I would think most here would be happy that I am reporting my findings. I am certainly not the first. Back to packing. One carry on and one smallish back-pack. No camera bags, of course.

[otto.f]

I did not infer that you searched for flare. But after your report in this thread, people went out testing to try to produce that flare to investigate what could be going on, that's what I meant. And I was not suggesting that I'm not happy with your reports, it is very important for anyone who considers buying this lens!

 

I find out of own experience and from many many people in this forum that the latest Summicron 28 is very flare-resistant. But admitted, I never used it without the hood because I just don't work like that, never.

[Rick]

I did not infer that you searched for flare. But after your report in this thread, people went out testing to try to produce that flare to investigate what could be going on, that's what I meant.

 

I find out of own experience and from many many people in this forum that the latest Summicron 28 is very flare-resistant. But admitted, I never used it without the hood because I just don't work like that, never.

 

I stand corrected. And,thanks for the support on my posts in this thread. Also, you are ahead of me on understanding the importance of hoods. I don't work like that anymore now.

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[algrove]

As Rick knows I have what I think is a perfect copy of the APO 50. I have shot 1678 images with it on the M-240 and MM not counting today's outing. Of that total, I shot just 22 images at f16 and found an un-cropped f16 example to email to Rick. It was a large jpeg file (too big for this forum), but he could at least see how my APO50 lens performed. I also sent him a photo of a model shoot where I was shooting toward the sun which was just a bit off to the left at f2 with a 3 stop ND filter attached. With this last shot exposure was done with a Whibal card where on the M240 I repositioned the crosshairs over more of a dark area of the gray card result and then used a incident light meter to set exposure of course including the ND filter's 3 stops. I am not saying the image is fantastic, but just that camera and lens handled the exposure beautifully since it had a high amount of exposure values.

 

Yes, I have what I believe and Rick believes from what he briefly saw, alibi over the internet, a very good copy of this lens. That said I normally do not shoot it over f8, that's just me, and often f4 to f5.6 is my most common f stop range I use with this lens and most other Leica lenses too.

 

I am posting this to let some of you know that there are good copies out there, but as someone mentioned we seldom hear this on a forum where we are trying to work out problems and often forget maybe there is a silent, I hope, majority.

 

Rick, we all wish you a well deserved fantastic trip and do send us some images.

[MirekE]

I only breezed through the 17 pages of comments and I apologize if I it was already discussed and I missed that - is this flare only visible on M240 and if yes, did you rule out that it is actually caused by the camera? I started to see the same central flare on 90AA with M240 and I haven't seen anything like that with M9.