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Zeiss Contax G Lens DOF Chart

G

Guest

I just bought a G2 with the 28, 45 and 90 lenses and and the TLA 280 last week. Sold my F100 and glass. It was just to much to schlep around. I love it.

One thing bothers me, though - no depth of field on the lenses. How hard could this have been for Zeiss/Kyocera to do? Anyway, while the DOF chart in the manual is OK, like most Americans (and more than a few Brits), I think in feet, not meters. So, I've converted the chart in the book to feet. For me, at least, it's much easier to visualize.

I'd be glad to send it to anyone who wants a copy. It's in Microsoft Excel format. Just email me at dzimme6725@aol.com. Do what I did; print it once at full size and then again at 50-60% depending on how good your eyes are. Then take them to Kinko's to get laminated. That way you'll always have one with you, either in your bag or in your pocket.

DZ
 
G

Guest

I uploaded the DOF sheet of Dan Zimmermann now into the download section. The pdf file shows DOF in feet and in meter.

You can access it either via the navigation bar/downloads/G-system or via the Forum/G-system/downloads.

Thanks again to Dan Zimmermann for his contribution! Since the maintainance of this forum is a lot of work and I can not update everything as fast as I would like to, I appreciate that help a lot!

dirk
 
G

Guest

Dirk wrote: "You can access it either via the navigation bar/downloads/G-system or via the Forum/G-system/downloads."



Or with less clicking, by provision of a direct link:
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By the way Dirk, it is not a good idea to use blank spaces in a filename/url as some browser will respond with:

Bad Request

Your browser sent a request that this server could not understand.

The request line contained invalid characters following the protocol string.
 

saspencr

Well-Known Member
it would also be helpful to know what the dof is for these lenses wide open.
 

afranklin

Well-Known Member
Hi Scott,

> it would also be helpful to know what the dof is for these lenses wide > open.


DOF is deterministic, as in, the same for a given focal length, aperture, film format (CoC) and distance:

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at 1M it's 0.047 m at 2M it's 0.194 m at 3M it's 0.44 m at 10M it's 5.232 m

with a CoC of .025mm. You can change that if you like to .033mm.

Regards,

Austin
 

saspencr

Well-Known Member
Michael, I did look read the manual.
Unfortunately, it only lists them at f/4, 8, and 16.

Austin, thanks for the help. Sounds like CoC is important in the calculation. Could you educate me some more?

Thanks, Scott
 

saspencr

Well-Known Member
Ok, the CoC is the circle of confusion. in lay terms i think of it as how large a point gets as it gets farther from the plane of focus. however, i'm not sure what it would look like in a photo compared to a number you might give it.
 

afranklin

Well-Known Member
Hi Scott,

> Austin, thanks for the help. Sounds like CoC is important in the > calculation. Could you educate me some more?

You're welcome! CoC is "Circle of Confusion", which is a deterministically calculated number, based on human visual acuity (which I believe is 1 arc minute) and a "standardized" viewing distance (which I believe is something like 1.5 the diagonal of the print), such that the image, when printed, is as sharp as the human eye can discern at that viewing distance. The viewing distance is based on the print size, so larger prints are to be viewed from further away.

Keep in mind, Depth of Field is not real, it is perceived, and is based on the above. There is only one plane of focus, and it is very thin. It is only becuase of the limits of our visual acuity that things "appear" in focus.

If you want to view prints closer than is calculated for with the standard CoC, simply stop down more...but you get to a point (~f11+) where you start to become diffraction limited, which means the image really won't get any sharper. The typical "sweet spot" is f5.6-f8 for maximum sharpness.

At least that's my understanding ;-)

Regards,

Austin
 
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