35mm Summicron v4 almost useless wide open

[davorb]

Advertisement (gone after registration)

Is it just mine that's a lemon, or is this thing so unsharp wide open that it's bordering on unusable? As soon as I get to f2.8, it looks amazing and has great character.

I've attached an example where I shoot it wide open. And no, it's not me missing focus (at least I think it's not).

.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[davorb]

I just noticed I have a skylight filter on in this. But it can't affect it that much, can it?

[davorb]

In the back of the lens I can see some of this on the sides. Is this fungus or separation? Is that's what's causing my issue?

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Ba Erv]

It looks like one or the other…hard to tell from the picture.

Edited August 15, 2022 by Ba Erv

[farnz]

It looks to me like the buckle on the strap on his right shoulder is a little bit crisper than his face so that suggests a focussing issue to me.  (By the way, I'm not insulting your technique so please don't take this personally.)

Since the man's face is presumably what you wanted to be in the sharpest focus but it's not at the centre of the picture then you must have recomposed after you had focussed on his face and this is a common mis-focussing issue with rangefinder cameras when shot wide open because the 'zone of focus' is a disc with its centre on the lens's axis and at right angles to the axis and its depth determined by the aperture used.  You can think of it like a 'wheel' on an axle extending from the centre of the lens.  If you now recompose so that the man's chest is at the centre of the picture then you will tilt the 'wheel' so that his face is not in the plane of sharpest focus and can appear soft unless you have used a small aperture that provides plenty of depth of field, which might hide the mis-focus. 

A trick for compensating for mis-focus from recomposing is to move slightly back from the subject so that the point of interest moves into the zone of focus.  The amount to move back is normally only a centimeter or so but will depend on the aperture, the distance between camera and subject, and the amount the 'wheel' has been slanted.

This might not be the reason for the softness in your picture.

Other possibilities might be: 1) subject movement, 2) camera movement (slow shutter speed), 3) a de-centered lens element, 4) part of the lens being off-axis.  Some 35 Summicron Mk 4's were manufactured in the Midland plant and the two sides of the lens (and the two sides of the Double Gauss design) are held together with a plastic ring, which can fail or dislodge, which would de-centre one half of the Double Gauss light path from the other so that they're on different axes and need collimating.  I doubt that that's the problem here but it might possibly be.

Perhaps the final thing to consider is whether the rangefinder in your camera is accurately aligned with your lens.

From the second picture it looks like your lens is suffering from Balsam separation (but not fungus) although I would not expect the separation to be the problem.

Pete.

[Jared]

I think you need somewhat more controlled circumstances to determine the source of the issue:

1. Many Leica lenses have enough field curvature that focusing and recomposing when shooting wide open can present a problem for off center subjects. You need to try center subjects--just to narrow down possible causes
2. A skylight filter shouldn't cause any issues (except, perhaps, with unwanted reflections and flare), but you never know. Try testing without.
3. It is possible you are just not focusing accurately. If you have a camera with LiveView, then try testing that way. If you don't have LiveView, try shooting a ruler that runs diagonal from front to back in your frame to see if your camera/lens are front or back focusing
4. You need to eliminate motion blur as the cause as well, so shoot some samples on a tripod
5. On other possibility--and I'm not sure how much of an issue it was with the 35mm Summicron IV--is focus shift. A lot of older Leica lenses had slightly different focus points wide open and stopped down, and what is right for f/2.8 isn't what's right for wider apertures. Honestly, though, this is mostly an issue with f/1.4 Summilux lenses, and much less so for Summicron's, and your sample is a lot more severe than I would normally suggest for focus shift. At most, this could be a part of the issue, but isn't the explanation all by itself.

If you find your camera/lens are front or back focusing (likely), it could be an issue with the camera rangefinder calibration or with the lens. Honestly, Leica didn't tighten up their tolerances until the release of the M8.2 around 2008 or so. Your lens was made before that. Assuming you have a more modern camera, I would suspect the lens is out of calibration. If that's the only issue--that the lens is either front or back focusing--that can generally be fixed by shimming the internals of the lens. Leica can do this, and if I recall they don't charge too much, though the turn around time can be veeerrrry slow. 

The pre-asph Summicrons at f/2 were definitely a bit softer than their successors, but not to the level you have shown, so your results definitely show a problem. Eliminate the possible causes one by one with a more controlled environment. Take off the filter, shoot a flat subject, evaluate the center of the frame, and use a tripod. Throw in the ruler/tape measure to evaluate front/back focus. Shouldn't take you more than an hour or so to narrow down the cause.

As to the fungus/separation... Does it look like it's on the rear most element? The rear element on the 35 v4 was a singlet, not a doublet, so that would rule out separation. So, assuming it's on the rear-most element, it's either a coating issue or fungus. Or, I suppose, it could be--and I'm going to use a technical term here--gunk. If it is in the second-to-rear-most element, then separation is a definite possibility. None of those issues would cause loss of sharpness. They would, at most, result in loss of contrast.

[rtai]

Advertisement (gone after registration)

What camera did you use? If it’s a rangefinder then maybe focus is out of alignment. When I test a new lens I check focus with the RF and then live view to see if both are correspondingly in focus.

[Erato]

8 hours ago, davorb said:

Is this fungus or separation?

Could be.

Perhaps you should inspect your lens carefully, especially look into inner elements(from 2 to 6) against strong light(Jewelry Appraisal Flashlight, UV LED).

 

Wide open could be razor sharp, indeed. FYR.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

11311 Summicron-M 35mm f/2, V4, M10-P

 

11311 Summicron-M 35mm f/2, V4, M10M

Edited August 15, 2022 by Erato

[lct]

Misfocus at first glance but your pic is too small to be sure. I would check if the shoulder strap is actually sharper than it should be. What is sure is the 35/2 v4 is not the sharpest 35 but it can do much better at f/2 when it is properly focused (link). 

[stray cat]

Is it really necessary to launch your query with such a subjective, negative headline? Before even garnering the opinion of the knowledgeable and helpful people here you’ve denigrated a fine lens as being “almost useless wide open”. Anyone who has this lens knows this is far from the truth - as is inherent in the design of all Leica lenses, wide open is where they shine. So by all means ask a question but please do so without feeling the need to add your subjective conclusion before you get the guidance you need, such as that most generously given above.

[pgh]

1 hour ago, stray cat said:

Is it really necessary to launch your query with such a subjective, negative headline? Before even garnering the opinion of the knowledgeable and helpful people here you’ve denigrated a fine lens as being “almost useless wide open”. Anyone who has this lens knows this is far from the truth - as is inherent in the design of all Leica lenses, wide open is where they shine. So by all means ask a question but please do so without feeling the need to add your subjective conclusion before you get the guidance you need, such as that most generously given above.

Oh gosh, is it really necessary to go into a sanctimonious response like this? Yes, I am sure this fine lens and all of its V4 siblings have their feelings crushed over being called out online by someone who surely just does not properly appreciate their, um, character and personality.

I mean, I get what you're saying, but the amount of irony of responding like this instead of just saying something productive is enough to fill my growler.  

[farnz]

10 minutes ago, pgh said:

Oh gosh, is it really necessary to go into a sanctimonious response like this? Yes, I am sure this fine lens and all of its V4 siblings have their feelings crushed over being called out online by someone who surely just does not properly appreciate their, um, character and personality.

I mean, I get what you're saying, but the amount of irony of responding like this instead of just saying something productive is enough to fill my growler.  

In the same manner that your response includes something productive?  Perhaps you might like to follow your own advice.

(And, yes, I had already posted a helpful response further up the page.)

Pete

[pgh]

15 minutes ago, farnz said:

In the same manner that your response includes something productive?  Perhaps you might like to follow your own advice.

(And, yes, I had already posted a helpful response further up the page.)

Pete

I'm not giving advice. I didn't comment to be productive. 

[Anbaric]

Whatever the cause, any relatively modern 35mm f/2 lens from any major manufacturer ought to be better than that, even wide open. So it's either technique or an issue with the equipment (perhaps a problem with the lens or maybe a rangefinder than needs calibrating).

[Ba Erv]

I wonder if anyone has even considered that the OP might not have even had on the correct colored socks that day.

[charlesphoto99]

Lens needs a focus calibration, and CLA that's all, esp. if your other lenses focus well on your body. It happens, it's all part and parcel to owning a Leica. If in the US, then send to DAG. I have a 135 APO there now for just that reason (and the lens hood etc was coming loose - from lots of use). If one does have a misfocusing lens, and are a good enough at rf focusing, then one can retrain oneself to compensate with the patch (i.e know where to land it, front or back depending on the shift), esp if just using the one lens. It's a pain, but I was doing it on my 135 shooting crows in the neighborhood until I couldn't anymore, and have done so with with other lenses with known focus shift (i.e. 35 1.4). It's a way to get by until biting the bullet and getting it fixed. 

Otherwise the 'look' is exactly that of a 35 'cron V4 wide open. Like it or leave it (not my cup of tea on color, but otherwise a fine lens for b&w, imo). The inner smudge shouldn't effect too much, doesn't seem like fungus, more like separation of some sort, but I could be very wrong. Send pics to DAG or repair person of your choice, with a succinct, to the point letter, and get a quote.  

[otto.f]

16 hours ago, davorb said:

Is it just mine

Not just yours, mine had this too, until it had a CLA at Wetzlar for something else and the 2.0 was amazingly usefull after that. 

[adan]

20 hours ago, davorb said:

Is it just mine that's a lemon, or is this thing so unsharp wide open that it's bordering on unusable? As soon as I get to f2.8, it looks amazing and has great character.

Image quality looks fairly normal to me.

The 35 v.4 was designed 1) 42 years ago, 2) to be as compact and light-weight as possible, 3) for photojournalists to shoot fast (put subject in middle of picture, focus, shoot - in less time than it takes to write).

For compactness, it uses a double-gauss design, with a seventh element to improve curvature of field. But with a 35mm field of view, that still stresses the limits of the DG formula wide-open (as it does in the same-era 35 f/1.4 Summilux pre-ASPH). There remain significant amounts of coma and astigmatism, which rapidly degrade resolution and MTF in parts of the picture outside 3-6mm from the center of the picture.

(But it was the best Leica could do, in that size, until they developed the molded-ASPH element process, and replaced the v.4 with the Summicron-M ASPH in 1997.)

See MTF chart below for f/2.0 (the numbers across the bottom of the graph (Y') are mm out from the center of the frame - 12mm to the sides of a vertical picture, 18mm to the top and bottom of a vertical picture, and 21mm to the extreme corners. Anything below 30% contrast (the numbers on the left side) is getting pretty weak- note the bottom-most dashed ---- line (tangential structures at 40 lpmm) drops below 30% quickly.

Which in your composition means it is possibly sharp in the black T-shirt area, but once you get farther from the center than that, it will get progressively fuzzy. It is not a great lens for "rule of thirds" compositions or other off-center compositions until, as you note, it is stopped down to f/2.8 or more - and even at f/8 the corners will still be quite weak.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Now, there may also be a focus error (focus-recompose, or misadjustment).

As to the air bubbles, that does look to me like incipient separation of the cemented elements 5/6. At the stage it appears to have reached, I wouldn't expect that to affect resolution much (yet), just produce a hazy low-contrast patch. It could stay like that for years - or a shock could precipitate complete separation suddenly.

Edited August 16, 2022 by adan

[Advertisement]

Hallo,

Look here: Leica M

[davorb]

Thanks for the feedback everyone. I've decided to take a few test shots later today with live view to rule out any focusing errors on my part.

[davorb]

I apologise for wasting everyone's time. It appears to have just been operating error on my part. Idk how I managed to fail with multiple images, so that I started thinking it was the lens.

I just took another test shot, and the lens is tack sharp. Thanks for your help.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!