Cunha
Member
While reading on zeisscamera.com..Henry Scherer's website, I found this photo illustrating the newly available CZ Sonnar's.
Henry describes the older Sonnars as having "zero depth of field" at certain settings. Does someone have a photo illustrating what exactly he is talking about? Thanks a lot. I will have some good things to show you folks soon. First post here. Dont beat me up 
uhligfd
Well-known
If Henry has an active website, I see nothing out of the ordinary that you contact him re his "zero DOF" and let us know what that terms is for him.
Why ask us about what you can readily get yourself, I cannot understand, Cunha. Good luck! And courage.
Why ask us about what you can readily get yourself, I cannot understand, Cunha. Good luck! And courage.
ferider
Veteran
Welcome, Cunha.
Wide open, at minimum distance, the 50/1.5 Sonnar has about 3cm DOF (on 35mm film), much like other 50mm lenses. All lenses always have a single focus plane, and DOF is a measure denoting how quickly objects in front or behind that plane render out of focus. The example photo you show is probably shot at f4 or f5.6 or so. You can calculate DOF using http://www.dofmaster.com/dofjs.html.
I think Henry is just writing "marketing speak". He sells C-Sonnars and re-furbished older Sonnars.
All the best,
Roland.
Wide open, at minimum distance, the 50/1.5 Sonnar has about 3cm DOF (on 35mm film), much like other 50mm lenses. All lenses always have a single focus plane, and DOF is a measure denoting how quickly objects in front or behind that plane render out of focus. The example photo you show is probably shot at f4 or f5.6 or so. You can calculate DOF using http://www.dofmaster.com/dofjs.html.
I think Henry is just writing "marketing speak". He sells C-Sonnars and re-furbished older Sonnars
.All the best,
Roland.
Cunha
Member
The article seems to be demonstrating the advantages of a more modern lense design and seems to make sense. I talked to Henry about the new CZ lenses and I came to the conclusion that I'd like to keep my old camera, old. He supports my conclusion but I have very little doubt that the newer CZ lenses that usually cost well over 1000 dollars are in fact better lenses. But for me, half the value of my IIIa cd is that it is a very old camera that takes very good photos. To upgrade it with modern optics would lessen that value. However, if I was a photographer with greater skill and wanted to continue to take the best possible photos with my IIIa I would no doubt purchase one of the limited edition lenses. I have seen a lot of unwarranted negativity towards Henry Scherer and zeisscamera.com and it is sort of discusting. He sells his services, like any place does. He sells the products he has available, like any business does. He also provides useful information and gives contax owners fair warning about the dangers of a "common" CLA of which I have been witness of the dismal quality. The wealth of good information on his website incites a lot of interest in his services and because of that, he is extremely successful at his camera business. But to blow off everything he says as "marketing speak" is just silly. In the nikon forum they discuss those new japanese carl zeiss lenses and several of the first comments essentially blow off Henry and his write up on them. No one presents a single fact, or even appears to have read his article or the support for statements he made regarding the lense. Either way. Keep taking good photos. Thanks guys. Thanks for the link ferider.
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ferider
Veteran
Hi again, Cunha,
1) there is absolutely no way the above picture was taken at f1.5.
2) in his article, Henry only talks about infinity collimation. He disregards (a) focus shift and (b) RF calibration wrt normal focal length.
I have owned and used a C-Sonnar.
Best,
Roland.
1) there is absolutely no way the above picture was taken at f1.5.
2) in his article, Henry only talks about infinity collimation. He disregards (a) focus shift and (b) RF calibration wrt normal focal length.
I have owned and used a C-Sonnar.
Best,
Roland.
uhligfd
Well-known
So, what ifs "zero DOF"? Did you find out? Can any lens at any setting have THAT?
Or is it just a catch phrase?
Or is it just a catch phrase?
ernesto
Well-known
I think It may mean (in practical terms) "almost zero" DOF.
Under that circumstances you could have a subject half out of focus and half in focus, which would need special focusing skills of the photographer.
Ernesto
Under that circumstances you could have a subject half out of focus and half in focus, which would need special focusing skills of the photographer.
Ernesto
ZeissFan
Veteran
I've located my old lens tables booklet that was published by Zeiss Ikon for the Carl Zeiss lenses.
Here's what it has:
When focused to 4 feet, at f/1.5, the depth of focus for the 50mm Sonnar is is 3'11" to 4'1-1/4" -- roughly 2-1/4 inches.
With the 85mm Sonnar focused to 4 feet, depth of focus is 3'11-1/2" to 4'0-1/2". That's just one inch, and that's not much room for error.
Possibly, you could expect similar results with the modern-day lenses, but that's just a guess and I'm not an engineer, so I could be way off.
If the actual focal length of the new C-Sonnar is longer than the actual focal length of the old Sonnar, it's possible that depth of focus would be shallower.
Still, I don't think it would reach zero, and perhaps Mr. Scherer is simply taking some editorial license in his argument that depth of focus is extremely shallow.
In the end, the choice is between old and new. Old Sonnars have a certain look. The new C-Sonnar has its own look as well. It's not "which is better?" but "which do you prefer?"
That's how I see it.
Here's what it has:
When focused to 4 feet, at f/1.5, the depth of focus for the 50mm Sonnar is is 3'11" to 4'1-1/4" -- roughly 2-1/4 inches.
With the 85mm Sonnar focused to 4 feet, depth of focus is 3'11-1/2" to 4'0-1/2". That's just one inch, and that's not much room for error.
Possibly, you could expect similar results with the modern-day lenses, but that's just a guess and I'm not an engineer, so I could be way off.
If the actual focal length of the new C-Sonnar is longer than the actual focal length of the old Sonnar, it's possible that depth of focus would be shallower.
Still, I don't think it would reach zero, and perhaps Mr. Scherer is simply taking some editorial license in his argument that depth of focus is extremely shallow.
In the end, the choice is between old and new. Old Sonnars have a certain look. The new C-Sonnar has its own look as well. It's not "which is better?" but "which do you prefer?"
That's how I see it.
uhligfd
Well-known
There is actually one technical way to give a subject zero depth of field, if it is the closest to the lens: focus just as much in front of the subject as the (non-zero) DOF at the given aperture is: you will just get the first hair sharp and everything behind that is fuzzy: "zero DOF" achieved, literally.
micromontenegro
Well-known
The fact that everything behind your subject is out of focus does not eliminate the depth of field that continues to exist in front of it. You still have DOF, you're just not using it.