Recieved a 50 1.5C Sonnar ZM today, samples

[Huck Finn]

This seems like a pretty simple situation to me. Since you wanted to get a black lens in the first place send it back for the black one. If the black one doesn't focus properly for you send it to Zeiss telling them your experience and I'm sure they will adjust it for you. Sending lenses to the manufacturer (even new ones) in order for them to be properly adjusted is pretty common for professionals. It is nothing out of the ordinary. It seems as if you like the lens. I would encourage you to go this route.

For the other speculators in this thread the reason for the focus shift, and also the beautiful bokeh, is that the sonnar is not a symmetrical design. It has nothing to do with the quality control of Zeiss.

Adjust it to what, Patrick? When the Noctilux, for example, is adjusted to focus properly at f/1, it doesn't focus correctly again until f/5.6 when the depth of field covers the focusing errors. I imagine that the Sonnar will do the same thing or something similar. Zeiss has said that it is adjusted to focus at f/2.8 as the best compromise. It seems that wherever it is adjusted, it will be off somewhere else among the wide apertures especially when shooting up close with reduced depth of field.

By the way, thanks for your insights. 🙂

 

[awilder]

Steve, the last several shots you posted look fine to me even wide open. The bokeh is really nice and I suspect better than a Nokton. If you can't find a late Summilux in your price range, I would go for the swap at B&H. To confirm it's not a quality control issue, I would set up the camera and chrome Sonnar on a tripod and do some focus tests on newsprint at around 9 ft and 3 ft at f/1.5, f/2.8 and f/5.6 at the carefully focused rf distance and repeat the shots at various bracketed scale focused distances that vary in 0.5 mm (on the focus ring) differences up to say 1.5 mm going in the direction towards infinity. That way you can assess the severity of the focus shift and compare it to the black one from B&H.

 

[SteveRD1]

Sent it back today, but here are 3 more

Sent it back today, but here are 3 more

Sent off the Sonnar back to BH today for a refund. I was going to buy the used summilux they had - it was the version before the ASPH at a 9+ condition for $1399 - I went to buy it a few minutes ago and it was gone! Its been there for 3 days, and now its gone. Arg! Anyway....

3 more pics, same subject, same light

1st is the Noctilux at F1 (I will miss this lens!)

2nd is the sonnar at 1.5

3rd is the summicron at f2

I almost caved and bought a new ASPH lux (have 6 months no interest through my bill me later acct at BH) but they are just about ALL sold out as well! Only have one LHSA black laquer left at $2850! I may wait a bit for another used lux. The sonnar is nice, but the performance at 1.5 bugs me. I took a portrait of my son at 1.5 and it was vey very soft. Much softer than the Noct at F1.

At F2 and up its terrific.

 

[SteveRD1]

ooops,

ooops,

sorry the photos above...the 1st Noct shot was at 1.4 not F1

 

[SteveRD1]

One more!

One more!

Just scanned these in...

First is with the Sonnar at F2

2nd one is the Summicron at F2

Bigger difference than I thought, and you can also see the warmer color portrayed by the sonnar

Next message will show 100% crops of each

 

[SteveRD1]

100% crops

100% crops

1st is the sonnar 100% crop

2nd is the cron

I still do like the sonnar. I realize the softness is the signature of the lens, and in some situations it would work well.

 

[shg005]

seems like cron has better microcontrast, but this is well known fact.
I think that cron has to be compared with 50/2 planar, but not with sonnar. Very big difference in their optical schemas. More closely - sonnar vs summilux, planar vs cron

 

[awilder]

Steve, the Sonnar shot of the flower appears to be focused in about the same plane as the Noctilux at f/1.4 but less saturated than the Noct. I'm not too surprised because it may have something to do with softening effect wide open from the inherent spherical aberration (SA). With the Sonnar, focus calibration set for reduced SA levels at f/2.8 (according to Zeiss) where sharpness becomes really bitting. Focus from reduced SA at f/2.8 is slightly behind the subject compared to focus wide open where SA is greatest. Focus calibration with the Noctilux takes the opposite approach. As a previous owner of the 50/1, I did critical focus testing at different stops and found it was calibrated to favor focus at the widest apertures where SA had it's biggest effect. This preserves decent sharpness at the larger apertures at the expense of bitting sharpness from f/2.8 through f/5.6.

Attached in the next 2 posts are some tightly cropped central images at f/1 and f/4 correctly focused by the rangefinder and the same slightly defocused 0.05 mm by inducing a shift in the scale focus setting. The defocused image greatly improves f/4 centrally but at f/1 induces a veiling haze resulting from the outer SA rays now being defocused. The defocused resolution at f/1 is about the same at the core but the peripheral SA rays now softens the appearance of sharpness and overall contrast especially evident in the edge spread for the large black box. The first two shown here are just at f/1, the left correctly focused and the right defocused in the minus direction by 0.05 mm (approx. 1.5 mm of focus ring movement).

 

[awilder]

Next at f/4 correctly focused and then defocused (in the minus direction) by 0.05 mm. Hope this helps.

 

[Sonnar2]

It seems that wherever it is adjusted, it will be off somewhere else among the wide apertures especially when shooting up close with reduced depth of field.

True. That's what focus shift is about.

 

[Trius]

What the heck is "SA"?

 

[Huck Finn]

What the heck is "SA"?

"Spherical aberration" I would assume.

 

[ferider]

Spherical Aberration, Earl.

Sad that we have now created an internet rumour that the Zeiss C-Sonnar is "soft focus wide open" due to focusing shift, when

- this effect is certainly not visible in 600x400 web postings
- it is shared by many other lenses
- it is easily obscured by user errors and possibly sample variations (that also exist with other manufacturers).

It is almost impossibe to consistently focus an RF 50/1.5 wide open, close up, even with an M3, unless you use a tripod. It is also typical for many lenses to achieve higher resolution when stopped down 1 or 2 stops. Check with Puts, many Leitz lenses behave like this as well. Many classic Sonnar variants behave similarly.

Kudos to Zeiss for building a 50 Sonnar, a design that used to be labeled
as "too expensive to use for the manufacturing of modern lenses".

Roland.

 

[Nachkebia]

I am still thinking of getting this special lens, it is really special I have to admit, it is soft but all the lens from past are soft, I think i have to get it until they stop producing it 😀

 

[awilder]

Here are some interesting numbers as reported in the May 1976 issue of Popular Photography by Norman Goldberg when bench testing 32 normal lenses. Measured spherical aberration (SA) from wide open to 4 stops down in the pre-asph. 50/1.4 Summilux had 0.02 mm, the 50/1.2 Noctilux had none(!), the 50/2 Summicron had 0.05 mm, and the 50/2.8 Elmar had 0.12 mm. Keep in mind for super critical sharpness with a circle of confusion (CC) of 0.01 mm, the depth of focus (DOF) at the film plane is +/- the maximum aperture in mm x 0.01. Thus, total DOF "envelope" for a CC of 0.01 mm is 0.02 mm for f/1, 0.028 mm for f/1.4, 0.04 mm for f/2, 0.056 mm for f/2.8 etc. Incidently, a standard CC of 0.03 mm is typical for normal viewing, so triple the previous figures. Given their maximum apertures, those SA test figures were low enough as to not affect critical sharpness from any focus shift effects unlike the 50/1.5 Sonnar or 50/1 Noctilux. BTW, Erwin Puts reports the SA of the 50/1 to be 0.12 mm from f/1 to f/5.6. My results with the 50/1 through f/4 was about 0.09 mm so this is roughly consistant with his results.

 

[SteveRD1]

Spherical Aberration, Earl.

Sad that we have now created an internet rumour that the Zeiss C-Sonnar is "soft focus wide open" due to focusing shift, when

- this effect is certainly not visible in 600x400 web postings
- it is shared by many other lenses
- it is easily obscured by user errors and possibly sample variations (that also exist with other manufacturers).

It is almost impossibe to consistently focus an RF 50/1.5 wide open, close up, even with an M3, unless you use a tripod. It is also typical for many lenses to achieve higher resolution when stopped down 1 or 2 stops. Check with Puts, many Leitz lenses behave like this as well. Many classic Sonnar variants behave similarly.

Kudos to Zeiss for building a 50 Sonnar, a design that used to be labeled
as "too expensive to use for the manufacturing of modern lenses".

Roland.

I disagree. I can focus the Noctilux at F1 every time, spot on, handheld, even at 1/15. I have never been able to focus the Sonnar, close at 1.5, which again seems to be a "feature" of the lens. It IS soft wide open when compared to my old 50 Lux ASPH, and Noctilux at F1. Also, Im using a .72 MP. I have NEVER had an out of focus shot using any of my lenses with the MP or M7.

One more 100% crop comparison.

1st one Noct at F1
2nd Sonnar at F1.5

These are 100% crops, scanned with a Nikon coolscan 5000 using the same settings. Straight from the scan file. No problem focusing the Noct at F1. The ZM does have a front focus problem up close wide open. BTW, both shots I focused on my eye.

Still, after all of this, I am still considering buying it again (bit the black one this time) becuase my options at that price range are pretty limited for fast lenses. Not interested in the Nokton (size) and the Leica ASPH is $2900 new, which is 3X the amount of the ZM. Plus, shots that are not so close and not wide open are great on the ZM. I do have a few shots that are very nice looking at F2-F4 It's a charming lens with nice warm color.

 

[Trius]

Steve: I can see the front focus in these last two shots, better demonstrated (at least for me) than some of the others. The fingernail on your "trigger finger" is sharper in the Sonnar shot than with the Noct. However, there's a difference in aperture/DOF, as well, but I'm pretty sure that's what I'm seeing.

BTW, the colour balance difference wouldn't influence me for digital reproduction or C41 use, but for slides, yeah, it's a point to consider.

This has been a great thread. When I see Joe's photos with the Sonnar as well, I'm with Vladimir ... want one.

 

[furcafe]

I have to agree w/Steve. With some practice, it's not that difficult to consistently focus @ f/1.5, f/1.4, or f/1, as long as your subject isn't moving.

Per the posts from Huck & others, I think the problem here is that there are 2 separate issues: (1) Focus shift: Zeiss explicitly states that they decided to optimize the Sonnar for close-focusing @ f/2.8 & not f/1.5, as I presume would have been done in the old days (& which accords w/my experience w/the old CZJ, Z-O, & CZ 50/1.5 Sonnars); (2) Quality control/sample variation: There may be an issue w/Zeiss's QC, as posts from back alley, et al. seem to show that not every Sonnar-C front focuses as much as Steve's example.

I disagree. I can focus the Noctilux at F1 every time, spot on, handheld, even at 1/15. I have never been able to focus the Sonnar, close at 1.5, which again seems to be a "feature" of the lens. It IS soft wide open when compared to my old 50 Lux ASPH, and Noctilux at F1. Also, Im using a .72 MP. I have NEVER had an out of focus shot using any of my lenses with the MP or M7.

One more 100% crop comparison.

1st one Noct at F1
2nd Sonnar at F1.5

These are 100% crops, scanned with a Nikon coolscan 5000 using the same settings. Straight from the scan file. No problem focusing the Noct at F1. The ZM does have a front focus problem up close wide open. BTW, both shots I focused on my eye.

Still, after all of this, I am still considering buying it again (bit the black one this time) becuase my options at that price range are pretty limited for fast lenses. Not interested in the Nokton (size) and the Leica ASPH is $2900 new, which is 3X the amount of the ZM. Plus, shots that are not so close and not wide open are great on the ZM. I do have a few shots that are very nice looking at F2-F4 It's a charming lens with nice warm color.

 

[ferider]

I have never been able to focus the Sonnar, close at 1.5, which again seems to be a "feature" of the lens. It IS soft wide open when compared to my old 50 Lux ASPH, and Noctilux at F1.

Steve, I believe there is a specific problem to your lens and that the problems that you are observing are not related to the Sonnar focus shift.
I am OK blaming ZI quality control, etc, even though sample variations are common with other manufacturers as well. All I am opposing is that what
you are observing is typical for this lens.

As a side annecdote, a friend of mine, who shoots Nikon digital, _always_ orders two copies of a new lens from B+H and sends back the
one he likes least.

I can focus the Noctilux at F1 every time, spot on, handheld, even at 1/15 ... I have NEVER had an out of focus shot using any of my lenses with the MP or M7.

Good for you. I cann't, and my fastest lens is 1.2. But then I drink a lot of coffee, I smoke and people that I shoot move.

BTW, shooting at 1/15 moves you off any MTF charts anyways, which is OK with me, I am an advocate of acceptable sharpness.

Per the posts from Huck & others, I think the problem here is that there are 2 separate issues: (1) Focus shift: Zeiss explicitly states that they decided to optimize the Sonnar for close-focusing @ f/2.8 & not f/1.5, as I presume would have been done in the old days (& which accords w/my experience w/the old CZJ, Z-O, & CZ 50/1.5 Sonnars); (2) Quality control/sample variation: There may be an issue w/Zeiss's QC, as posts from back alley, et al. seem to show that not every Sonnar-C front focuses as much as Steve's example.

Exactly. From my experience, the Canon 50/1.5 was optimized for around f5.6 (similar to the original Sonnar), and the Nikkor 50/1.4 per Dante Stella for f2 (although my sample seems to be better at f2.8 or so).

Roland.

 

[Krosya]

I just got an RMA from BH for the sonnar (they sent me the wrong color anyway) and I am still deciding if i should buy this again in black (color i ordered) and deal with its flaws or buy a used Summilux pre-ASPH or bite the bullet andgo for a Summilux ASPH (doesnt it focus closer than the pre-ASPH?)

The sonnar can be used stopped down and at F2 + it rivals the summicron (see garbage can pic) but at 1.5 it can only be used with certainty at a distance. So F2 up close is fine. 1.5 is not.

The way I look at this - why would you want to have and pay for a 1.5 lens if you can't really use it fully at 1.5? I'd go with Leica. It seems that since some people here (like Joe) have a Sonnar that works (read - focuses) just fine at 1.5 - it's a QC issue, otherwise it would be the same for all. It seems that you have a much better bet with fast Leica and than get a Planar or Cron for 2.0 if you want. If it was me - I would not risk it. Funny, I have an old beat-up russian J-3 lens that focuses perfect wide open at close distance and is very sharp. Sonnar design yet doesn't have any front focus issues. Go figure.