Contax introduced their last lens mount in 2000, called "N-mount". The N-mount is for 135 format (24mm x 36mm), and features a very wide mount throat, autofocus, and fully electronic communication with no mechanical linkages. There are 3 camera bodies and 9 lenses in the line-up, all discontinued. A chart showing N Series Auto Focus Lens Compatibility is published by Contax UK.
The 9 N-mount lenses are:
Full information about N-mount lenses, including their MTF curves measured from actual production lenses, is published by Zeiss.
We are narrowly focused on Contax N or 645 lens to Canon or Sigma camera body for the time being. Sorry we are otherwise unable to confirm, deny, disclose or comment on anything about our future product plans. For Sony NEX users, Metabones makes a Smart Adapter which adapts Canon EF mount lenses to a Sony NEX camera body with electronic aperture control from the camera body and partial autofocus support.
Unfortunately, a mechanical-only, electronics-free adapter/modification is not feasible due to the electromagnetic aperture diaphragm (EMD) equipped with every Contax N-mount lens. The aperture of a Contax N mount lens cannot be operated unless the camera body sends the lens the proper commands. Although there is an aperture ring on every Contax N-mount lens, that aperture ring is "fly by wire" and does not directly control the aperture diaphragm inside the lens. While many people can live with manual focusing it is unacceptable if there is no aperture control and the lens always shoots wide open. Without the necessary electronics, a Contax N-mount lens lens would not stop down on a Nikon/Olympus/Panasonic/Pentax/Sony camera body.
In LiveView mode, contast detect AF does not work.
The plastic tab protruding from the rear shroud of the lens has to be cut during installation. (The function of that protruding tab is to prevent you from sitting the lens pointing up without the rear lens cap and scratch the rear element.)
There may be an underexpose problem of up to 1 stop.
At the tele end, and the focal length recorded in EXIF is 86mm instead of 85mm.
There may be an underexpose problem of up to 0.5 stop.
Autofocus performance is unsatisfactory above 200mm.
On some camera bodies, it is not possible to use an aperture slower than f/32.
IMPORTANT: if you are buying a used, unconverted 70-300, please specifically test autofocus at 300mm and make sure the AF turns smoothly and optically if it is sharp wide open.
The lens is rotated about 5 degrees off center.
The aperture blades occasionally makes a click noise in preview mode, and when the camera turns off.
On D60 and Rebel T1i/500D, there is a periodic click noise.
The focal length recorded in EXIF is 86mm instead of 85mm.
A conurus firmware update to 3.18 (2011/04 or later) is needed for a converted NAM-1 adapter to be compatible with the 645 Mutar T* 1.4x teleconverter.
645 Vario-Sonnar 4,5/45-90
You will not be able to store AF microadjustment values in a converted NAM-1 adapter for both the 45-90 zoom and the 45mm, 55mm and 80mm lenses, because their focal lengths overlap and a converted NAM-1 adapter will only remember one set of adjustment values per focal length.
No. You will always be really shooting wide open. The aperture display may be affected, but never the actual aperture.
At the tele end, 85mm for the 24-85, the maximum aperture is exactly halfway between f/4 and f/5.6. Your camera has a custom function which selects whether the aperture is displayed in 1/2 stop steps or 1/3 stop steps. Not a problem if you select the former on your camera body. If you select the custom function to be 1/3 stop steps, should we round up or round down? It just so happens that the camera body rounds down and displays the nearest slower 1/3 stop.
This is all just some rounding taking place. It cannot be overemphazied that the maximum aperture remains the same. Did I say only the display of the maximum aperture is affected?
When a Vario-Sonnar 24-85 is zoomed to 85mm the focal length recorded in EXIF is 86mm instead of 85mm. This is NOT a problem because a Contax N-Digital camera body exhibits the same behaviour. The 1,4/85 Planar records 86mm in EXIF, too.
If the rear element does not protrude beyond the end of the lens mount, it is impossible for the mirror to hit the rear element of the lens. 7 out of the 9 lenses in the N-mount line-up satisfy this criteria.
The 24-85 has a plastic rear shroud which protrudes by a negligible amount, and the Planar 1,4/50 has a rear element that protrudes by 0.4mm. They will still clear the mirrors of 5D, 5D mark II, 5D mark III and all 1Ds series cameras without any mirror intereference issues. However, the Planar 1,4/50 may not physically fit on a Kenko/Tamron 1.4x teleconverter because of this rear-element protrusion.
Declicking a Contax N lens would not serve the intended purpose. The aperture ring of a Contax N lens is virtual and "fly-by-wire". Designed for still photography, it has finite resolution which is inadequate for cinematographic work. There will be visible disruption in the resulting footage, even if the aperture ring is declicked. The electromagnetic aperture diaphragm has 1/8 stop resolution, and the electronic aperture ring has even less resolution than that.
Our product is a set of replacement parts for converting a Contax N-mount lens to Canon EF-mount. After the conversion the lens will stop down the aperture and autofocus as commanded by the camera body.
A conure is a small parrot from South America. All New World parakeets were once classified under a single genus Conurus. Nowadays, the name is not used in scientific taxonomy anymore, but the pet trade still uses it.
I may have replied to you, but your mail server may have blacklisted our IP. I suspect that certain spammers used the same ISP as us, and as a result, mail services such as Yahoo has blocked all email coming from us.
The second reason might have been that I have a demanding daytime job and I only do this during weeknights and weekends. I may be working with my suppliers, solving issues for existing customers, working on firmware, mechanical design, electronics design, circuit board design, keeping the books, or updating this web site. I work 100 hours per week in order to bring you this unique technology. I will eventually answer your email. Thank you for your patience in the meantime.
Not any more. We used to think you could take our kit and pay a professional camera repairman/repairwoman to perform the installation on your lens, but so far none of our customers have been able to find a shop which is willing to do so. We know of a number of customers who attempted DIY against our recommendation, but their success rate was very low.
It is impossible to make such an adapter because the N-mount has a very large diameter. Unfortunately, the original N-mount has to be removed to make room. This has nothing to do with the conurus circuit board at all but rather physical fitment - it is the same reason why it is impossible to make an adapter to mount Pentax K lenses to Nikon F mount, for example, without losing infinity focus.
If you do not like the idea of modifying lenses, you will have to use Contax 645 lenses and a converted NAM-1 adapter.
Only Contax Japan stocks spare parts necessary for repairs. However, they would not accept a modified lens. So, you would need to send your lens to us first. Be sure to include your original N mount and electrical connector pins in the package. We will revert your lens to Contax N mount and forward it to Contax Japan for a repair estimate. We charge an additional fee for the reversion and subsequent re-modification. Click here for our repair fees.
Please note that Contax Japan repair service will discontinue in 2015. We must receive your lens by 2014/12/31 to allow us time to revert its mount. After 2014/12/31 no repair service will be possible.
If you are buying an unconverted lens from a third person and have that third person ship the lens directly to us for lens mount conversion, the package needs to include a memo or an invoice or whatever telling us where to send the lens back to (the return address). Otherwise the lens will be sent back to the sender's address.
Please be advised that you take legal title of ownership as soon as your lens is shipped from your lens vendor and you are solely responsible for the lens sale transaction between you and your lens vendor, as we are unable to assist you in that regard should any disputes arise. Caveat Emptor.
You are advised that there is some inherent risk in procuring a used lens, even if you buy from a reputable store. You are responsible for the condition of the lens itself, and we work on every incoming lens assuming it is good. We are unable to work on lenses which are defective-on-arrival (DOA), or have been tampered/repaired by unauthorized personnel, who may have caused internal hidden damage making conversion impossible.
Hundreds of lenses have been converted but so far we have not yet lost a single package, both incoming and outgoing. Hmmm, there is a first time for everything, but so far that first time has not yet occurred.
Although it occurs very rarely, customs may hold a highly-valued package for inspection. If this happens, there will be an extra delay of 3 weeks. Your package is safe with customs and there is no reason to panic. We will file all necessary paperwork and make all required tax payments to redeem your package. (Any tax we pay is reclaimed later, so no one gains or loses any money from this but everyone wastes time doing paperwork.) Most packages come into Canada unhindered but we apologize for any delays if your package is the rare unlucky one which gets stuck at customs.
The post office does not always deliver your package to our door. Rather, they may just leave us a delivery notice and we head to the post office to pick it up. This happens a lot and there is no reason to panic. We accumulate a few delivery notices before picking them up so this may take a few days.
Our estimates are NOT guaranteed service times, but they are just averages. By definition, half of the time an average is exceeded, but half of the time not met. Perfectly functional lenses in top condition are typically served much more quickly because we do not need to spend time investigating and resolving hidden problems. For your own protection, please do your best testing any Contax N lenses you purchased before sending them to us for conversion.