Should i get my CZ Sonnar 50 optimised at 1.5 ?

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nasdak

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Hello folks,

Just another CZ 50 Sonnar thread...
I just bought one second hand, ran some tests on my M8 body and found it is optimised for 2.8 (tack sharp at 2.8 and beyond ; noticably front focus at 1.4 and not so much at 2)

It is still under waranty and i wonder if i should have it set to focus at 1.4 by Zeiss.
It's my only 50mm so i will use it at 1.4 in low light when necessary, at 2 for portrait and 4 or 5.6 for landscape... So i don't know what's best

i've seen test charts, but in real life, If optimised at 1.5, will it be usable at 2 for portrait and at smaller aperture for daylight work ?

I now there's no evident answer to that question, i'd just like to hear your thoughts!

Thanks
 
If you optimize for f1.5, it will be usable from wide open to f2.0 and from f8.0 to f16. In my experience (on film) this lens renders at its best at f 2.8-4.0 for portraiture. For general shooting I would recommend a Planar 50/2. I ended up keeping 2 versions of C Sonnar, but the one that gets the most use, is optimized for f 2.8.
 
Yup. I'd get it optimised for wide open and close up, as that is when you will be most aware of the transition in focus and sharpness. And as Kroysa said, what is the point in having a top drawer fast lens if you can't use it wide open?
 
Thanks for your quick replies !

I think I need to check if i can easly compensate the front focus at 1.5 by leaning forward after focussing, before i make a decision.
 
mfogiel said:
If you optimize for f1.5, it will be usable from wide open to f2.0 and from f8.0 to f16. In my experience (on film) this lens renders at its best at f 2.8-4.0 for portraiture. For general shooting I would recommend a Planar 50/2. I ended up keeping 2 versions of C Sonnar, but the one that gets the most use, is optimized for f 2.8.
Click to expand...

That is precisely why I thought so hard about this lens and in the end gave up the notion of adding it to the gear stash. It's a shame that there is no proper literature from Zeiss on this (other than some 'artistic' hogwash) and film users will be having a hard time with the results they get till they find out why and they may never do till they check the internet. Digital users still have the opportunity to investigate and experiment with the different settings to come to the above conclusion.

That being said, if I have the lens and I'm shooting wide open most of the time, I would optimize it for f/1.5.

Cheers,
 
I've only shot my Sonnar (optimized for f1.5) at f1.5 or f2 and found it a bit of a hand full ... but I'm getting used to it and my results are improving at short distances with each roll of film. The signature at f1.5 when you get it right is worth the effort IMO.

Life wasn't meant to be easy! :p
 
1.5 which is why you bought a 1.5 "old school" lens. Use your Planar, Elmar, Summicron, or Heliar for the rest of the time.

If you have no other 50 and do not wish to aquire one, then learn how much to change the focus manually when you use it at 2.8. Run some tests and reference the debth of field scale, ie focus infinity to 4.0 on scale like you do for IR work. Another possibility is to learn how much to put the RF out of alignment and in which direction.

If you can not get infinity into focus, because front focus is the issue, I would get a different lens for that work.
 
I have one and it's optimised for f2.8 and I can see no reason to change it. This makes sense to me -- it's a f2.8 lens that has 'emergency' f1.5 & f2 and I don't have to think about focus shift if I'm shooting at f2.8 or smaller. Having one optimised for f1.5 would be too complicated for me.
 
Strange that Roger has not yet posted his own link:

http://www.rogerandfrances.com/photoschool/ps firstlook sonnar 50.html

Scroll down a little bit and there will be an explanation on how to use the 1.5 optimized lens. I will have the opportunity to try that technique soon and see if it works. this little article made me change it to 1.5...I guess I could always have it changed back...
 
morback said:
Strange that Roger has not yet posted his own link:

http://www.rogerandfrances.com/photoschool/ps%20firstlook%20sonnar%2050.html

Scroll down a little bit and there will be an explanation on how to use the 1.5 optimized lens. I will have the opportunity to try that technique soon and see if it works. this little article made me change it to 1.5...I guess I could always have it changed back...
Click to expand...

Interesting article but the writing style creeps me out a little. If Roger and Frances are continuously referred to in the third person, who is actually writing the article...:confused:

edit: seems that "we" wrote the article :)
 
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nasdak said:
Hello folks,

Just another CZ 50 Sonnar thread...
I just bought one second hand, ran some tests on my M8 body and found it is optimised for 2.8 (tack sharp at 2.8 and beyond ; noticably front focus at 1.4 and not so much at 2)

It is still under waranty and i wonder if i should have it set to focus at 1.4 by Zeiss.
It's my only 50mm so i will use it at 1.4 in low light when necessary, at 2 for portrait and 4 or 5.6 for landscape... So i don't know what's best

i've seen test charts, but in real life, If optimised at 1.5, will it be usable at 2 for portrait and at smaller aperture for daylight work ?

I now there's no evident answer to that question, i'd just like to hear your thoughts!

Thanks
Click to expand...

I had the same sort of dilemma when I bought my Leica 50 mm 1,0 Noctilux. I was 'strongly' adviced by Leica to accept the slight front focus at 1,0 as a 'natural thing' and not to tamper with either lens or camera adjustments. But you have to be aware of it when using the lens at largest aperture. After all; it is this slight front focus that is 'normal'. My Noctilux ssems to be spot on somewhere between 1,4 and 2,0. (well, at 2,0 any DOF slight shift is covered by a much larger DOF anyway) So, 2,8 would be normal for a 1,5 lens.

No, I would not tamper with that.
 
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jonmanjiro said:
Interesting article but the writing style creeps me out a little. If Roger and Frances are continuously referred to in the third person, who is actually writing the article...:confused:

edit: seems that "we" wrote the article :)
Click to expand...

Always a problem, and yes, it does look awkward sometimes. I could do it as 'I', but as we both use the kit and provide the input and pictures (I do the writing on the site, though for magazines it varies -- sometimes it's one of us, sometimes the other, sometimes both) that seems unfair. If enough people dislike the approach, I can change it in future. We don't get many complaints about it, but I'd be grateful for others' views.

@ Morback: thanks for posting the link.

Cheers,

R.
 
I would have it optimized for F1.5.

When you use the lens at F2.8, just "overshoot" the focus a little bit. Intentionally misalign the image by a small amount to correct for the shift. It might take a little practice.

On my own Sonnar, an uncoated 1937 5cm F1.5 CZJ lens converted to Leica mount, I optimized for F2. Turned out that F1.5 was still sharp, F2.8 was good, and F4 was usable.
 
nasdak said:
Thanks for your quick replies !

I think I need to check if i can easly compensate the front focus at 1.5 by leaning forward after focussing, before i make a decision.
Click to expand...

Mine is optimized at f2.8 because I shoot frequently with the sonnar from f2.8 to f8. When wider than f2.8 I nod very slightly to the subject if I'm close, just as you describe.
 
i played with it yesterday and that focus shift IS indeed annoying... it can't have proper focus at 1.4 and 2.0 because depending on distance, i don't know how much to lean.
I think i will have it recalibrated for 1.4
 
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