I've owned the C/Y Zeiss 18mm f4 for several years, and always been very happy with its performance. It's produced several of my favorite landscapes: great color, great drama, no CA.
I recently acquired a Zuiko 18mm f3.5 after a long search, and decided to do some comparison shots of these two lenses against each other. This comparison has been done on this forum before, so I'm not going to post a lot of images. Images from the Zeiss lens appear as the first of each pait that follows.
Both lenses show marked vignetting wide open, but the Zuiko surprises by being as or nearly as sharp center frame as the Zeiss:
I come to the same conclusion other testers have come to: the Zeiss is very strong center frame, but the Zuiko outpulls it in the corners all the way through.
If the Zuiko is a winner here, the Zeiss is far from a loser. This lens is certainly capable of producing a stunning image.
In the end, however, you have to just marvel at these tiny Zuikos.
I've owned an MM version for several years and it was much sharper than this in the corners. I believe most Contax lenses, wide angles in particular suffer from too thin cheap adapters. On a poor adapter, practically all adapters under 90$, the infinity point is at around 3 meters with the distagon. Focusing by eye on such lens, even with live view, is impossible. The only way to do it is by focusing scale, hence the problems. Fortunately for the Zuikos, they don't seem to have adapter issues. In my experience (and a high quality adapter), the Contax should be sharp even in the extreme corners at f/11.
edwardkaraa wrote:
I've owned an MM version for several years and it was much sharper than this in the corners. I believe most Contax lenses, wide angles in particular suffer from too thin cheap adapters. On a poor adapter, practically all adapters under 90$, the infinity point is at around 3 meters with the distagon. Focusing by eye on such lens, even with live view, is impossible. The only way to do it is by focusing scale, hence the problems. Fortunately for the Zuikos, they don't seem to have adapter issues. In my experience (and a high quality adapter), the Contax should be sharp even in the extreme corners at f/11. ...Show more →
edward,
The Zeiss lens here is on exactly the $90 Haoda Fu adapter you're calling for, and focus was achieved via focus scale. My experience with Pham Minh Son's thin adapters does not follow yours, however; my Distagon 28 performs better on the thin adapter than a slightly thicker one, after it's adjusted for infinity focus.
Since infinity focus adjustment is so dependent on eye focus, however, it's much more difficult to achieve with the Zeiss 18.
The Zeiss 18mm was found to have similar corner (un)sharpness in a test done by Mike Hatam a few years back here on FM. He tried several adapters. His test is what convinced me to buy the Oly 18/3.5. The Zeiss corner performance also shows in Zeiss' own MTF's for the lens. It is a very old design.
I cringe at tests like this. C/Y wides are notoriously difficult to adapt to Canon bodies. Even ZF wides are problematic on Canon bodies. I think we've all seen the samples that Rick (rfkii) put up of the same ZF18 of the same scene on a D700 and 5D: the ZF18 adapted to the 5D showed noticeable quality loss. Also, I don't know much about these things, but couldn't field curvature differences partially account for some of the differences we're seeing in the bottom left corner? It seems a variable worth considering.
Anyway, there's no question the OM18 is a great little lens, and I really want one. As always, thanks for the test! The crops and opinions are informative.
Steven, I agree about the field curvature issue on the Zeiss. It's actually a little sharper at f22 in the corner, but there's more noticeable diffraction in the center frame. I think the len's optimal aperture is in the f8-f11 range.
It's a good idea to remember that you're looking at these images cropped at 100%, 72 dpi. You're never going to "see" these images at 100%. I have Zeiss images framed on my wall of scenes up-rez'd to print 12 x 18" at 337 dpi, and no one has ever said to me, "Hmmm, looks a little soft in the corners."
The Zeiss 18 is a great lens, IMO. Anybody considering obtaining one would be crazy to walk away from it because of a test like this.
I'm looking forward to pulling some prints from the Oly 18 at large sizes - that's the pudding I look to for the proof.
Diffraction is a function of the wavelength of light, the aperture and the pixel density on the sensor. How does one lens perform better on diffraction than another?
David, thanks for the tests. Great to see the oly doing so well! Agreed that the zeiss is no slacker, certainly, but impressive nonetheless that the Zuiko is noticably better.
It's interesting to hear that the Zeiss lenses are finicky about adaptors - I have read that before but didn't find any conclusive consensus. Some say 1.42mm is right, some say 1.5mm is right. Other than not reaching infinity (maybe) I can't see how the thickness could affect things too much... I need to do more research perhaps.
is there a consensus on the best adapter? Haoda Fu, Cameraquest/kindai, fotodix pro?
StevenPA wrote:
I think we've all seen the samples that Rick (rfkii) put up of the same ZF18 of the same scene on a D700 and 5D: the ZF18 adapted to the 5D showed noticeable quality loss.
I bet his problem came from the AF chip or an uneven adapter. The AF chip can acutaly become loose a bit and slightly lift the adapter on one side, not enough to bother a standard lens but enogh to cause problems on a WA.
I'm not sure the adapter is as important with the Zeisses as the infinity focus adjustment. The Pham Minh Son adapter on my Distagon 28 is only 1.24mm, if memory serves, whereas the register difference between Canon and Contax is closer to 1.44mm (never trust a faulty memory). Initially, the Distagon wouldn't focus to infinity on Pham's adapter, so performance was a problem. After adjustment, the elns and adapter perform perfectly.
Infinity focus adjustment is tricky to do on an 18, though, because the DOF is so deep.
I've tried Pham's (great with adjustment) and Haoda Fu - also excellent, IMO. I think what Edward was warning against was the cheapie rings you find on ebay for $12 - and I agree with him.
I've been using Fotodiox consumer grade adapters on my Olys and never had a problem. I did have a problem with the Fotodiox Pro on the Oly 55 1.2 - front focus issues at f1.2, everything fine from f2 on.
IMHO, infinity adjustment is a recipy for disaster as you're fooling with the entire lens formula, with all due respect to Pham Minh Son. In my experience, you need exactly 1.49-1.50 mm to get infinity focus on an untampered with lens. The only adapter on the market that does this afaik is the Kindai/Cameraquest, plus an unknown brand called Phepan that I discovered by coincidence. I got infinity focus exactly at the infinity point on all my 13 Zeiss lenses (that I've just sold) with the mentioned adapters. I have 13 fotodiox consumer adapters sitting in my closet as they are useless. They made the lenses reach infinity several millimeters before the infinity mark. This messes with the lens optical formula and increases CA etc, unlike slightly thick adapters that act like extension tubes. Haoda adapters are no different, just with an added chip. This is my personal experience, ymmv.
davidearls wrote:
Ed,
I'm not sure the adapter is as important with the Zeisses as the infinity focus adjustment. The Pham Minh Son adapter on my Distagon 28 is only 1.24mm, if memory serves, whereas the register difference between Canon and Contax is closer to 1.44mm (never trust a faulty memory). Initially, the Distagon wouldn't focus to infinity on Pham's adapter, so performance was a problem. After adjustment, the elns and adapter perform perfectly.
Infinity focus adjustment is tricky to do on an 18, though, because the DOF is so deep.
I've tried Pham's (great with adjustment) and Haoda Fu - also excellent, IMO. I think what Edward was warning against was the cheapie rings you find on ebay for $12 - and I agree with him.
I've been using Fotodiox consumer grade adapters on my Olys and never had a problem. I did have a problem with the Fotodiox Pro on the Oly 55 1.2 - front focus issues at f1.2, everything fine from f2 on....Show more →
I have to echo what Edward is saying, to a certain extent, anyway.
When I got my CZ21, I bought a cheap 1.5mm e-bay adapter (despite all the noise about "better", "thinner" adapters). It worked absolutely perfectly. Infinity was "bang on" and the lens performed better than any samples I have ever seen from the CZ21. You've all seen what my copy of the CZ21 could do. So keep in mind that it was with a cheap 1.5mm adapter. That adapter is still mated to the lens, to the best of my knowledge, because it "just works".
I always thought I was "just lucky", but what Edward is saying about thinner adapters is true, if the lens is a floating element design. Situating the lens closer to the film/sensor plane than intended messes with the whole optical formula.
I am not sure though. Is the Zeiss 18 a CRC (floating element) design?
cogitech wrote:
I am not sure though. Is the Zeiss 18 a CRC (floating element) design?
This what Zeiss site says:
The new version of this lens provides the same
image quality as the well-known and time-tried
design when photographing subjects at a
long-distance. New, however, is the design of the
focusing system. When the lens is focused to short
distances, the positions of the lens groups change
in relation to each other. This counteracts the loss
in image quality in the outer zones of the image
and extends the useful range of the lens to 0.3 m.
I guess this makes the MM version a floating element design but not the AE
I read some where that both MM and AE versions are floating element design. I think it was a pebbleplace review. I could have just misunderstood that both versions are but I am sure that I read that the MM is.
davidearls wrote:
The Zeiss is predictably soft in the corner wide open. The Zuiko is better at f3.5, and will perform better throughout the aperture ranges:
If you want to compare foreground details, you should focus on the foreground. Not on the
background.
edwardkaraa wrote:
IMHO, infinity adjustment is a recipy for disaster as you're fooling with the entire lens formula, with all due respect to Pham Minh Son. In my experience, you need exactly 1.49-1.50 mm to get infinity focus on an untampered with lens. The only adapter on the market that does this afaik is the Kindai/Cameraquest, plus an unknown brand called Phepan that I discovered by coincidence. I got infinity focus exactly at the infinity point on all my 13 Zeiss lenses (that I've just sold) with the mentioned adapters.
I have three Huppert adapters, each of which perfectly matches a handful of Zeiss lenses.
