Recommendations for a fast 50.

[Sonnar Brian]

Too bad Zeiss did not hook the Aperture ring up to a small helical or to an indexed RF cam. Change the F-Stop, compensate for the focus shift.

When I buy one, it will be optimized for F1.5.

 

[back alley]

in use the 50/1.5 zm lens is a joy.
the focus 'issues' are only issues in rare occurances.
i rarely shoot at min. distance and have NEVER had focussing problems.

if you are looking for a close focus portrait lens i recommend an 85 or 90 lens anyway.

 

[ampguy]

lenses with severe focus shift should only be sold for SLRs.

 

[back alley]

there is no severe focus shift.

 

[Sonnar Brian]

Focus Shift is a worse problem on an SLR these days. Very few cameras have DOF preview. When you focus wide-open, and the lens stops down for the exposure- the focus shift gets you. At least with RF's, you can learn to offset the split image a little, as Roland suggested.

 

[raid]

I guess, people mean the "new" Zeiss Sonnar 50mm 1.5 and not the original CZJ 5cm 1.5 Sonnar when they refer to focus shift ... etc. Right?

I am sticking with my original 1930's CZJ 5cm 1.5, as optimized by Brian in LTM.

 

[Roger Hicks]

Keith- if you are buying this lens for the speed, get it optimized for F1.5. From what I've read on the forum, the shift on this lens is several inches at minimum focus. If you are looking for existing light portraits, etc, this shift would be difficult to work around.

The older Sonnars are not as sharp as this new lens. Maybe the shift is not as evident as the lens are softer, or not has big in magnitude- but by F4 any shift is taken care of by the DOF. I use my lenses at F1.5, F2 and then skip over to F4 when stopping down. With the C-Sonnar optimized for wide-open, it sounds like yo go from F1.5 to F8.

Dear Brian,

Check here for a real test: scroll down until you come to the (otherwse extremely boring) pictures of the Encyclopedia Britannica. http://www.rogerandfrances.com/photoschool/ps firstlook sonnar 50.html. Once you're used to the lens you can rock back or forward a few inches for absolute maximum compensation.

Cheers,

R.

 

[TWoK]

Focus Shift is a worse problem on an SLR these days. Very few cameras have DOF preview. When you focus wide-open, and the lens stops down for the exposure- the focus shift gets you. At least with RF's, you can learn to offset the split image a little, as Roland suggested.

What DSLR doesn't have a DoF preview button? I do agree with Brian that when using auto-diaphragm lenses it is no easier to deal with a focus shift than with a RF. It can be worse since SLRs can actually focus closer than a coupled RF.

 

[Sonnar Brian]

So as long as you use the DOF preview on your SLR to focus and do not use Auto-Focus (and I'm sure NO ONE ever uses that feature on modern cameras), Focus Shift in lenses should not be a problem. I never use my F3AF on autofocus.

Roger, very nice write-up on the lens. I'm sold. But I still want it optimized for F1.5. Like all my other Sonnars, used a lot wide-open. I can compensate for F2.8 and F4 using the techniques mentioned.

 

[TWoK]

Brian, which DLSRs don't have a DoF Preview?

 

[Sonnar Brian]

Many of the consumer grade DSLR's and SLR's do not have DOF preview. Many of the newer (post 1980) SLR's also dropped it. I do not keep up with new DSLR's, the D90 lists it as a feature, the D60 does not My D1x has DOF preview. That is my newest DSLR. I spent $6500 on it. Still works well for technical documentation.

Most DSLR's when used on Autofocus cannot compensate for focus shift in a lens. I suspect most people use AF focus rather than manual focus and DOF preview when using a lens at other than wide-open. I'm simply stating that focus shift on an SLR is probably worse of a problem for most users than it would be on a rangefinder which is focussed manually.

 

[Keith]

A member who is Oz based has PM'd me to let me know he has a lens (Sonnar C) for sale ... unfortunately it's been optimized for f2.8!

Do the lenses have to be sent back to Zeiss Germany for this service?

 

[Keith]

By the way I meant add ... this thread has turned into a mine of advice and information and I thank Brian, Roland and other contributors! 🙂

 

[ampguy]

Hi Brian

Hi Brian

Not sure what setups you're talking about, but all my Pentax and Nikon gear lets you stop down.

The lens I own with the most focus shift is a 43-86 1st gen Nikkor zoom. To even meter with it (it is non/pre AI), you have to stop it down (with Nikon F3 - about a bazillion of these were made, btw - it went to the moon ...)

Anyways, to do anything that involves viewing through it, you will absolutely see the focus shift at the aperture that is set on the lens.

Check out an older Pentax or Nikon SLR system.

Many of the consumer grade DSLR's and SLR's do not have DOF preview. Many of the newer (post 1980) SLR's also dropped it. I do not keep up with new DSLR's, the D90 lists it as a feature, the D60 does not My D1x has DOF preview. That is my newest DSLR. I spent $6500 on it. Still works well for technical documentation.

Most DSLR's when used on Autofocus cannot compensate for focus shift in a lens. I suspect most people use AF focus rather than manual focus and DOF preview when using a lens at other than wide-open. I'm simply stating that focus shift on an SLR is probably worse of a problem for most users than it would be on a rangefinder which is focussed manually.

 

[Sonnar Brian]

> Check out an older Pentax or Nikon SLR system.

I have some of those older Nikon systems. The compact SLR's such as the Nikon FG and EM did away with the DOF preview. The Pentax K-1000 and ME did not have it, either. It's not uncommon to pick up an SLR made after 1976 or so without DOF preview. On the Nikon DSLR line-up, it appears that models "below" the D70 do not have it. I am not aware of any Autofocus system that is smart enough to compensate for focus-shift when stopped down. You could make one that does it: but no one would like it as the image would appear to be out of focus through the finder, or there would be an extra lag when you press the shutter release as the body/lens refocus to take the shot.

Back to the C-Sonnar: This lens uses a 46mm filter, and the front element is larger in diameter than the older F1.5 Zeiss Sonnars of the 1930s and 1950s. Those lenses use 40.5mm filters. The larger front element means less vignetting at the edges. As focus-shift is related to the aperture of the lens, and the front element of the C-Sonnar is bigger than the older lenses, I'm guessing that could contribute to a larger focus-shift.

 

[ferider]

Makes sense. Also wondering about the effect of the additional element in the back.

 

[Roger Hicks]

Isn't one of the three groups split (air-spaced), making it a 4-group lens, not a straight Cooke Triplet with cemented groups?

Could be wrong, and am too busy/lazy to check.

Cheers,

R.

 

[ferider]

Correct.

 

[kermaier]

What, like the Canon EF 50mm f/1.2L USM?

Another lens that's given the wrong end of the stick online. Does it shift? Sure, it CAN, under certain circumstances. Maybe I'm just lucky or my shooting style is "outside the zone" but I have no problems with mine. In fact, it's one of the nicest L lenses going and by far the best Canon 50mm.

I'm just sayin' 🙂

My all-time favorite lens so far is the Canon FD 50/1.2L. I never noticed any focus shift, but I don't know if it's different from the EF version.

::Ari

 

[kermaier]

Also a good one! I have that version as well. It has floating elements, whereas the EF does not - therefore no shifting. The 85mm f/1.2L also has floating elements. It's weird that Canon chose to omit them with the 50mm f/1.2L, but the bokeh is very sweet as a result, I guess.

Hmm, interesting -- I wonder why they messed with such good lens designs when they changed mounts.

Yes, I had the 85mm f/1.2L as well, but I sold it (sort of regretting that) -- also an amazing lens. Even though it's been about 2 years since my F-1 has tasted film, I can't bring myself to sell the 50/1.2L.

Just for fun (apologies for the OT hijack):

Canon F-1, FD 85mm f/1.2L, Fuji NPS 160

::Ari