p.2 #1 · Contax N to Canon conversion - initial results
Yes, on a tripod. Lens was wide open. No sharpening was used (which does improve it significantly). I'm still trying to ascertain if I am getting accurate infinity focus. I had to adjust lens mount thickness once (the Zeiss lens uses thin copper shims behind the lens mount to accurately dial-in infinity focus.) I will probably try another reduction in the shim thickness ansd see if there is a difference. Here is the source file for the crop. http://gallery.photo.net/photo/4873574-lg.jpg
p.2 #2 · Contax N to Canon conversion - initial results
Son - you're planning on doing your own conversion with the N17-35? Or buying and fitting the Conurus version? I'm in the market for a converted N17-35 if you find yourself with a spare or two . . .
p.2 #4 · Contax N to Canon conversion - initial results
Lotusm50,
You may consider comparing this N lens to the Canon version to see the differences. Also the Zeiss are known to be best at F5.6 and F8 and the edge of the image. I am interested to see the CA as well.
On another note: That was a great timing to sell off your N Digital.
Mark,
I sent you an email regarding to your inquiry.
Son
Edited by Pham Minh Son on Aug 30, 2006 at 05:37 PM GMT
p.2 #7 · Contax N to Canon conversion - initial results
Pham Minh Son wrote:
The information is in the revealing process and the testing must be confirmed first as to the modification procedure and the lens optical performance.
Thanks, Son. Yes, there are many variables that need to be sorted out here. There is the effectiveness of the conversion/modification -- does it mechanically work and does it reach infinity focus; Does the camera focus the lens correctly? Are there differences in manual focus and auto focus, does the focusing screen play a role here (I have three Ee-A, Ee-S, and a Brightscreen), does the camera's autofocus need to be calibrated (a frequent issue, I am now learning) -- and all this is before we come to absolute questions of the len's optical performance. Comments are useful on these interim test images as they assist in sorting out what is right and what needs work. Further, the camera body itelf (the 5D) is new to me and unfamiliar (I spent the last 20 years with another brand). Tests of the lens at wide open apertures at infinity are going to be the most challenging to conduct. If anyone has any suggestions as per appropriat test subjects and/or methodologies please feel free to let me know.
One thing I have confirmed so far is that I can not rely on the 5D's focus confirmation information as it is proven itself to not be sufficiently accurate -- whether it is out of calibration or just inherently inaccurate remains to be seen. I have also seen the auto focus select one focus setting for an object at infinity that the split image of the Brightscreen would suggest is wrong. So there are still a number of variables to sort out. Your support and patience are appreciated.
At this point we can clearly say that the conversion works -- both autofocvus and aperture control work very effectvely. As for optical performacne I can sya atthis point that light fall-off seems to be gone pretty much gone by f8 at 85mm and by f11 at 24mm (which is more than expected). Preliminarily it seems that at near focus distances (5-15 feet) it appears pretty sharp at all apertures being a touch softer wide open, more noticable in the extreme corners.
Right now it is an exersize in millimeters, or even tenths of millimeters, as we fine tune the lens and camera calibration and adjustment to ensure that everythimg is working as it was designed to.
p.2 #8 · Contax N to Canon conversion - initial results
RobertP wrote:
This is freakin' sweet...but do you have any N prime lenses, and can they be converted?
There were 3 N primes lenses -- the 50mm f1.4, the 85mm f1.4 N-Planar and the 100mm f2.8 Makro Sonnar. A conversion for the 100mm is available now, the conversion for the 85mm will supposedly be available soon and the conversion for the 50mm is a few months away.
p.2 #9 · Contax N to Canon conversion - initial results
Lotusm50 wrote, "Preliminarily it seems that at near focus distances (5-15 feet) it appears pretty sharp at all apertures being a touch softer wide open, more noticable in the extreme corners."
You nailed this one right on the bulleyes. I will share with you my experience in this area regarding to the medium format as well later on once my informations are in and summarized. Great observation on your part here. Also the theme of focus confirmation on the Canon body is and has been a subject of discusion and therefore I am not surprise that it will arise again here at this new exciting topics.
Folks, you must be patient for the careful analysis to be updated by Lotusm50 or myself. My hope is by teaming up the works will give us a faster results and fortification of the gathered data.
p.2 #10 · Contax N to Canon conversion - initial results
Pham Minh Son wrote:
Congratulation on the successful modification. I look forward to your fine tests. In the meantime, I have several brand new Contax N 17-35 VarioSonnar in which I will modify and report the performance later.
I hope that the Apotessar 4/400 can be modified in which I will also go ahead and make this modifications on my copies as well.
-Son
Alright Son.... I gotta ask.... how many VS 17-35mm f2.8 lenses ya got and when you get a conversion/adapter on one of these, can I have first dibbs on it
Who's got a 400mm f4 N mount lens..... I saw a few on sale for around $4000 - I wonder how it compares to the Canon EF 400mm f4 DO or the Canon EF 400mm f5.6. Anyone got pictures of this lens mounted on a body they can post here ?
p.2 #12 · Contax N to Canon conversion - initial results
conurus is my brainchild. If any of you have any questions about my product, its installation, or anything, I will try my best to respond.
What we are witnessing here is a historic milestone. For the first time, an alternative lens is fully electronically coupled to a digital body. I am inspired by this message board in the way people are driven by the love of optics. My work is homage to your passion, expertise and dedication.
p.2 #13 · Contax N to Canon conversion - initial results
cyberstudio wrote:
conurus is my brainchild. If any of you have any questions about my product, its installation, or anything, I will try my best to respond.
What we are witnessing here is a historic milestone. For the first time, an alternative lens is fully electronically coupled to a digital body. I am inspired by this message board in the way people are driven by the love of optics. My work is homage to your passion, expertise and dedication.
Hi,
can you provide some infos about the 17-35mm conversion: availability, test shots, etc? Could I suggest to make some video-tutorials in which you illustrate the conversion process step-by-step? Have you considered to make directly the conversion @ a competitive price (say for example the cost of the package + 100USD) ? I think it would be great for us in having more options and less trouble.
p.2 #14 · Contax N to Canon conversion - initial results
The ability to use Carl Zeiss lens and AF on EOS body is excellent!
However, I do have some reservations:
1. Sigma had lenses that runs into problem with newer Canon bodies.
2. The 24-85mm lens isn't really worth doing the conversion. U can get the Sony R1, with Carl Zeiss 24-120mm lens and 10.1MP APS size sensor for a song, relative to the price of the N lens and conversion cost.
p.2 #15 · Contax N to Canon conversion - initial results
Congratulations on your achievement cyberstudio, your ingenuity is amazing.
I would like to second Emanuele's question as to whether you intend to offer a fitting service for this product.
If you have the time and inclination to do so, I think it may prove a popular service.
p.2 #16 · Contax N to Canon conversion - initial results
weekh wrote:
The 24-85mm lens isn't really worth doing the conversion. U can get the Sony R1, with Carl Zeiss 24-120mm lens and 10.1MP APS size sensor for a song, relative to the price of the N lens and conversion cost.
I don't know how much you think N 24-85mm lenses cost, but you can find them for $300-400 on ebaY. It is also a much higher quality lens than the one on the R1 (which itself isn't to shabby), and will can be expect to outperform it in many different way. This may not seem worthwhile to the casual user, but to others, using the N lens on a EOS DLSR (like the 5D or the 1D's) will give you capabilities, flexibility, speed, and output that will readily exceed that of the R1.
p.2 #19 · Contax N to Canon conversion - initial results
KEH has some in stock for around $400-$449 all the time. Good deals for now..... lets hope the price does not shoot up because of canon users buying these out
p.2 #20 · Contax N to Canon conversion - initial results
$400-500 (+ 269 for the kit, + self installation) could be a great price, depending on the results on the wide end. Looks like the shots posted here have been at the normal/telephoto end? How does the lens perform at 24mm on a FF? How about some FF shots with corner crops at 24mm?
As weekh mentioned, something like the Sony R1 does a very good job at 24mm (effective), goes all the way to 120mm and doesn't cost much more. Also, if the adapted lens only performs well at the 35-85 range there are other good optiuons, like the Zeiss 35-70/3.4
