General Questions
What does your product do ?
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.How does your product work ?
A microcomputer emulates a N-mount camera while talking to the lens, and emulates an EF-mount lens while talking to the camera body.Why do I want to do it ?
If you are a Contax N-system owner, you may migrate to Canon while leveraging your existing investment in N-mount lenses.Where are you located ?
We are in Vancouver, Canada.What is the significance of your product ?
This is the world's first independent lens mount conversion which preserves autofocus and auto aperture.What does the name conurus mean ?
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.Usage
Do I set the aperture on the lens, or the camera body ?
Set the aperture on the camera body.How do I switch between autofocus and manual focus ?
For Vario-Sonnar 28-80/3.5-5.6 and Vario-Sonnar 70-200/3.5-4.5, there is an AF/MF switch on the lens which puts the lens in either autofocus or manual focus mode.For all other lenses, there are no AF/MF switches. Set the aperture ring of the lens to minimum aperture (f/16, f/22 or f/32 depending on lens) for manual focus operation. Set the aperture ring to any other position to put the lens in autofocus mode.
Summary: use the camera body to set the aperture, use the lens' aperture ring to set AF/MF.
How good is the AF ?
AF speed matches or exceeds that on a Contax N camera body, but lags behind similar Canon lenses. Due to slower AF compared to Canon you may not be able to reach 10fps, 8fps or 5fps in AI SERVO mode.How quiet/noisy are the lenses ?
Of course, a lens mount conversion does not make the lens any more or any less noisy. The following table is my subjective rating of several Contax lenses. Roughly, "quiet" is equivalent to the noise level of a typical Canon micro-USM lens.| Quiet | Vario-Sonnar 24-85 Vario-Sonnar 70-300 |
| Pretty good | Vario-Sonnar 17-35 Planar 1,4/50 |
| Moderate | Planar 1,4/85 |
| Noisy | Makro-Sonnar 2,8/100 |
Ordering
I do not have a N-mount lens. Where do I buy one ?
All of them have been discontinued, so I am afraid you will have to procure one on the second-hand market. Make sure you obtain the serial number from the seller and check it against the photo.net Stolen Equipment Registry and our Fraudulent Contax N Serial Number List before you pay.Ian Hobday of Osaka, Japan may have some Contax N-mount lenses for sale on eBay, and he would ship the lens directly to us in Canada for modification. Important disclaimer: if you go this route you take legal title of ownership as soon as the lens is shipped from Japan. Loss and damage during shipment are the responsibility of the courier. I will check the lens out for functionality, glass condition and exterior cosmetics before modification but assume no responsibility on the lens itself, although I have personally bought a N-mount Vario-Sonnar 2,8/17-35 from Ian and found him to be a great and dependable seller. No I do not receive a commission from him - I am advertising for him only because I keep on getting questions on where to buy these lenses!
If you prefer to buy a converted Zeiss 17-35, ready to go in Canon EF mount, go to Photo Village in New York.
How much do you charge for your lens mount conversion?
Prices start at CAN$369. Please review our price list.Can I buy the modification kit without installation?
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.Does the modification void my warranty ?
Modifying a lens certainly voids all warranties of the lens.Do you require me to send in a Sigma lens connector ?
Not anymore. The price was increased slightly so that the lens connector is now included in the price. If you are sending in those connectors anyway, please deduct US$10 or CAN$10 from the conversion price for each connector you send in.Why don't you make an adapter which simply attaches to a N-mount lens ?
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 wait for our C645 adapter.
How do I order?
If you are in the U.S. or Canada, please include a cheque payment, payable to "Coneos Imaging Corporation", when you send your lens in. Please send an email to
and we will reply you with our mailing address. If you are in Canada, we
collect GST or HST, and additionally PST if you are in BC. We post our prices
in both US dollars and Canadian dollars. Prices are revised from time to time due to currency fluctuations.
For all other countries, please use our shopping cart or send payment directly from PayPal to .
How do I ship my lens to you ?
Please do NOT ship your lenses by any express courier such as DHL, FedEx or UPS because they have NO access to our premises. UPS in particular is unable to do customs declaration properly, leading to a delay of up to 3 weeks using their "express" grade of service. Please use the post office. The post offices of most countries offer international parcel delivery with insurance and/or tracking, and that in our experience has been the fastest and the most reliable way of shipping lenses.When you ship the lens to me, please state on the customs declaration: "TEMPORARY IMPORTATION 9993.00.00. Photographic lens 9002.11.10.10 made in Japan for repair or alteration in Canada. Do NOT charge GST: special authority code 16-089Z1663." (The customs declaration may be to small to write all these but please affix a separate label.) This will get the lens into Canada without paying any taxes to the Canadian government. Our shipping address will be shown when you check out from PayPal. You may also contact us for our address.
Please check with your local authorities about documentation required to establish that you are temporarily exporting your lens abroad for alteration, so that when the lens is returned to you, you will not be levied duty, sales tax or VAT on the full value of your lens. In most countries, this means you keep a receipt showing where you purchased your lens from. No receipt is okay most of the time, but if you do have it, including a photocopy when you ship your lens to us will address any concerns that your customs officials might have. That way, you will be levied duty and VAT only on the value added by us (i.e. what we charge you).
The following table shows our past customs clearance experience, which is in no way indicative of future performance, so your mileage may vary.
| Austria | no clearance difficulties reported |
| Germany | required to establish the lens was exported from Germany |
| Japan | no clearance difficulties reported |
| Hong Kong | free port; no duties/taxes on photo equipment; please ignore the receipt requirement |
| Singapore | please include a copy of your lens' invoice when you send your lens to us |
| Taiwan | upon the lens returning to Taiwan you may be charged 5% duty plus 5% VAT on the cost of the conversion |
| United Kingdom | customs requested receipts of the lenses |
| United States | no clearance difficulties reported |
Help! I sent my lenses to you but when I track the package using the post office's web site it says 'failed delivery attempt'!
The post office does not deliver your package to my door. Rather, they just leave me a delivery notice and I head to the post office to pick it up. This happens a lot and there is no reason to panic. They probably do this to cut cost. It was not a failed delivery attempt. There is no delivery attempt to begin with! I accumulate a few delivery notices before picking them up so this may take a couple of days.Is it safe to ship lenses by the post office?
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.How do I track your progress ?
Note: After we have received your package, it is queued for unpacking and basic AF/AE functionality test. It may take 1-2 weeks before your lenses' serial number will show up in our lens tracking system.Can you mark the shipment as 'gift'?
Sorry but we do not lie on customs declarations.I emailed you a while ago to order your product but got no reply. How come ?
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.
What is the total turnaround time ?
| day 0 | lens arrives in Canada |
| day 3 | lens picked up from the post office |
| day 30 | lens modified to EF mount |
| day 41 | lens shipped! |
| day 53 | lens arrives at your door |
I am a member of the media wishing to review your product. Can I buy/borrow a prototype of your future product (such as C645 adapter) for review ?
We understand your review will make or break our reputation in the marketplace, but sorry we are not able to send you a half-finished product. We will fill your order at a higher priority when it is done, but as of today they are non-existant. Please be patient while we work on these.By the way, I read a lot of claims by the media that their reviews are 100% unbiased and their advertising department is totally separate from the lens reviews. I really believe in those claims. True, we will make our services more convenient and easily accessible to members of the media for the purpose of a test or a review, but we would not offer any compensation, discount or incentive which would constitute a conflict of interest.
I don't care about AF. Could you leave AF out and give me the future product now ?
No. The bottleneck is not the electronics. It is always mechanical design and machining the physical parts taking the longest time.Can you notify me on new product releases ?
Yes ! Please join our technical support forum. An email will be send out to all forum members when new products become available.Compatibility
Does your product work with all Contax lenses ?
No. At this point, the product is compatible with only the following lenses:- Vario-Sonnar 2,8/17-35
- Vario-Sonnar 3,5-4,5/24-85
- Vario-Sonnar 4-5,6/70-300
- Planar 1,4/85
- Makro-Sonnar 2,8/100
We do not support and have no plans to support the manual focus Yashica/Contax mount, the rangefinder G mount or the original rangefinder screw mount.
We will introduce an Autofocus Adapter for mounting Contax 645 lenses on Canon EOS bodies in 2008.
What do you mean by N-mount ?
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:
| lens | hood | case | filter |
| Vario-Sonnar 2,8/17-35 | GB-103 | NCL-7 | 95 |
| Vario-Sonnar 3,5-4,5/24-85 | GB-81(incl.) | NCL-1 | 82 |
| Vario-Sonnar 3,5-5,6/28-80 | GB-51(incl.) | NCL-6 | 55 |
| Vario-Sonnar 3,5-4,5/70-200 | GB-77 | NCL-4 | 67 |
| Vario-Sonnar 4-5,6/70-300 | GB-75 | NCL-2 | 72 |
| Planar 1,4/50 | GB-76 | NCL-3 | 67 |
| Planar 1,4/85 | GB-82 | NCL-8 | 82 |
| Makro-Sonnar 2,8/100 | GB-73 | NCL-5 | 72 |
| Tele-Apotessar 4/400 | (incl.) | NCL-9 | 46(rear) |
How do I tell if I have a N-mount lens ?
Look at the rear end of your lens. A N-mount lens has 10 gold-plated electrical contacts. Also, since the N-mount was introduced in 2000, any lens older than that cannot possibly be N-mount.Ok, my Contax lens is manual focus, in Yashica/Contax mount. Do you have any plans to introduce a product which supports my lens?
Really, no. Sorry but we do not have any plans at all, even though we recognize that in terms of market size, the manual focus Y/C mount is orders of magnitude larger than the autofocus N-mount. For manual focus Y/C mount lenses you are referred to other vendors such as Bob Shell, Pham Minh Son or Stephen Gandy. (Although I have never tried any of them. I simply don't have any manual focus Contax lenses!)Can you convert lens X to mount on camera Y ?
We are narrowly focused on one combination (Contax N or 645 lens to Canon body) for the time being. We are not working on anything else.Can you adapt Nikon F-mount lenses to mount on a Canon camera ?
You will lose autofocus and auto aperture. We do not sell such an adapter but you may get one from- Novoflex, Cameraquest and others, if the Nikon F-mount lens has an aperture ring, or
- 16:9, if the Nikon lens is a G lens which does NOT have an aperture ring (such as the new 14-24/2.8G, 200-400/4G VR and the 105/2.8G VR Micro Nikkor).
Does your product work with all Canon cameras ?
Either ourselves or our customers have tested with the following EOS models and reported success (Y) or failure (N). (O) means "works but not-recommended".| camera | 645 | 85/1.4 | all others | |
| Rebel XSi | 450D | |||
| 1Ds mark III | Y | Y | Y | |
| 40D | Y | Y | Y | |
| 1D mark III | ||||
| Digital Rebel XTi | 400D | Y | Y | Y |
| 30D | Y | |||
| 5D | Y | Y | ||
| 1D mark II N | Y | |||
| Digital Rebel XT | 350D | Y | ||
| 1Ds mark II | Y | Y | ||
| 20D | Y | |||
| Kodak DCS Pro SLR/c | Y | |||
| 1D mark II | ||||
| Digital Rebel | 300D | Y | Y | Y |
| 10D | Y | |||
| 1Ds | Y | Y | ||
| D60 | O | O | O | |
| 1D | Y | Y | Y | |
| D30 | O | |||
| 1V | Y | |||
| Elan 7E | 30E | Y | Y | |
| Rebel G | 500 | Y | Y | Y |
| 1N | Y | |||
| A2E | 5 | Y | ||
| 630 | 600 | Y | ||
| 620 | Y | |||
| 650 | Y | |||
I have a camera which is not in the above list. Will you support it ?
It may or may not work. If we do not have the same camera as yours and there is a compatibility issue, we would try our best to fix it but we would ask you to send in your camera. If we don't even have the camera we would not be able to solve any compatibility problem. There is no guarantee that every problem is solvable but we would refund the purchase price minus shipping if it does not work out.If you are an existing customer and you have access to a camera not on the above list, please kindly try it and report to us if it works.
Do you license any technology from any OEM ?
We and our products are not licensed, approved or endorsed by Canon, Carl Zeiss, Contax, or Kyocera.Are there any known issues with your product?
Well, I came from the software industry so our "release notes" are a list of mundane problems which do not matter to most people.| Vario-Sonnar 2,8/17-35 | 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.) |
| Vario-Sonnar 3,5-4,5/24-85 | At the tele end, the maximum aperture displayed is f/5.0 instead of f/4.5, and the focal length recorded in EXIF is 86mm instead of 85mm. |
| Vario-Sonnar 3,5-5,6/28-80 | - |
| Vario-Sonnar 3,5-4,5/70-200 | - |
| Vario-Sonnar 4-5,6/70-300 | 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 70-300, please specifically test autofocus at 300mm and make sure the AF turns smoothly. |
| Planar 1,4/50 | - |
| Planar 1,4/85 | 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. |
| Makro-Sonnar 2,8/100 | AF is the slowest and noisiest among all N-mount lenses. |
| Tele-Apotessar 4/400 | - |
From time to time, more issues may be identified and posted on our technical support forum.
My 24-85 displays f/5.0 instead of f/4.5 at the tele end. Is it a problem?
No. The Vario-Sonnar 24-85 is slightly slower than f/4.5 at the tele end, and got rounded down to the next 1/3 stop, f/5.0, by the camera. You will be shooting wide open, in any case.EXIF says the focal length is 86mm instead of 85mm. Is that a problem?
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.Are there infinity focusing issues with a converted Contax N mount lens?
No. Like other autofocus lenses, Contax N lenses focus slightly beyond infinity. Refer to our detailed explanation of infinity focus.Are there mirror clearance problems with a converted Contax N-mount lens?
| 5D | EOS 1-series | APS/1.6x | |
| Planar 1,4/50 | not recommended | OK | OK |
| other N-mount lenses | OK | OK | OK |
The 24-85 has a plastic rear shroud which protrudes by a negligible amount.
The Planar 1,4/50 has a rear element that protrudes by 0.4mm. It may or may not be compatible with your EOS 5D, but you are suggested NOT to try. Also, the Planar 1,4/50 may not physically fit on a Kenko/Tamron 1.4x teleconverter because of this rear-element protrusion.
More questions?
. It takes 72 hours or more to respond to your email, but you will get a much faster response from the technical support forum.
You may also call me with Skype if I am online.