Canon 10-22mm EF-S to EF conversion:

I converted my 10-22mm to be able to be used on FF over the weekend.  I wouldn’t call it a full conversion as it’s NOT and EF lens, and you CAN damage your FF camera (and possibly 1.3) if you’re not careful, so proceed at your own risk…  But, taking canon’s rear baffle out and adding one that will mount on any canon camera is VERY easy.  Watch the video above and you can see it takes about ~30 seconds from start to finish.  From there you just have to be careful not to shoot at wider than 12mm as the rear element can touch the mirror if you do so.

To get the part needed, call canon’s parts department at 1-866-481-2569.  The part number is CY1-2759-000, but I didn’t know it when I called, I just asked for the 28-70mm rear baffle and it was the right part.  It cost $11.xx including shipping and I got it the very next day (NJ to RI ground UPS is always this quick).

41 thoughts on “Canon 10-22mm EF-S to EF conversion:

  1. Have you tried a short extension tube with the lens? I think it would add some crop factor, but it might move the lens out away from the mirror allowing for usage of the full zoom range?

    • an extension tube means you lose the ability to focus at infinity, so for landscape work this doesn’t work. But a 1.4 TC DOES work if you get one with a recessed element on the lens side. It basically grabs the center portion of the image circle of ANY lens and stretches it a bit to make it fit on FF, so it takes a lens with a cropped image circle and does the same thing. With canon’s 10-22 it works down to around 12mm. With a sigma 10-20 it works all the way to 10mm.

      the first 2 shots in this post:
      are with a 7D and the 10-22 but the rest are with the 5D, 10-22 and 1.4 TC.

  2. I tried to pull the baffle off but can not grip it well. Did you loosen any screws? If an an extension tube works, which one?

  3. Thanks for the quick reply! I managed to get it off after I found a similar solution to yours Great idea and it works!! Solves my problem. Now I don’t have to sell my 10-22 . I can use it on my new 5d Mark II and continue to use it on my 30D. Putting a piece of wire around the lens (exteriors lens, not the inside) prevents you from taking it down to 10mm. Thanks!

    • the front element of the lens moves in and out a bit as you zoom. If you sandwich a piece of anything, wire was an example, between the front element (the black surrounding plastic piece) and an old filter it will prevent the lens from zooming any wider than 12mm… hope that makes sense.

    • CY1-2759-000

      and check the corners on your 5Dii. The reason I ended up using the 1.4 TC route is because the corners seemed quite soft for me when used on the camera alone, even stopped down. The vignette does go away, but it’s just soft all the way through the range. If you go the TC route, you NEED the new rear baffle anyway as the lens won’t mount on kenko’s TC with the EF-S baffle.

      So the EF baffle with the part number above AND the kenko TC is the way to go IMHO.


    • Thanks Ben! I will try it this way first. I usually use the lens for interior shots of real estate, but that is not my main focus in photography. That’s why I was so glad to find a fix for the 10-22. I really didn’t want to spend a whole bunch more money for another wide angle since real estate is not my main focus.
      Again, thank you so much for your invaluable tips and info.


  4. Did the conversion of this lens today as i wanted a widest possible landscape lens for my Canon 1D Mark IV and am very happy with the result.
    Just wanted to let you know that besides the rear baffle of the 24-85mm you can also use the same rear baffle of the 28-105mm or like i did the very cheap 50mm F1.8 wich i still had laying around.

    Another thing i did was to use a 67-72mm filter-adapter ring instead of a metal wire. I did not use a UV filter to hold the adapter in to place but just screwed my LEE filter holder on wich keeps it all in place. Besides the fact that this step-up ring looks better then a metal wire i think it also stays in place better ans you do not need a UV filter to keep it in place.

    By the way i noticed that i do have some vignetting at 12mm when using my LEE filterholder, but at 14mm the vignetting is gone.I can use the lens at 12mm when not having the LEE filterholder in place.

    Just some thoughts and a big thank you for your splendid video on this modification wich opened my eyes to the possibilities of using EF-S lenses for my 1D series camera’s!

    All the best and keep up your great work!

    Jeroen Stel

    • Jeroen,
      Thanks for all the additional info! I’m glad the video helped and you’re happy with your 10-22 on 1.3. I actually did NOT use the wire on mine, I was just careful not to zoom past 12mm… Worked alright but there was potential for disaster I suppose. I also want to try this on a sigma 10-20 f/3.5 just to see if it’s distortion is any better than the variable aperture version since you can use either sigma out to 10mm with a 1.4 TC… 14mm on FF that can use filters could be amazing if the distortion isn’t to complex to fix.


  5. Hi Ben,

    You are welcome!
    I did not know this was also possible with lenses from other brands..? I though the Sigma’s have screws in the rear baffle or am i mistaken?

    If this can also be done with other brands then the Tokina 11-16mm F2.8 might be an excellent choice because of it’s supposed good quality and F2.8 light strength?


  6. Or what about the Sigma 8-16mm..? With a 1.4 converter that’s a great 11.2 wide angle…(or would vignetting be visible even with a converter..??}


    • well, you actually don’t need to do ANYTHING with baffles for third party lenses. A sigma 10-20 or tokina 11-16mm will mount on a 5D and work at their widest setting w/o any issues with the mirror box. So with the TC they’ll work on FF w/o any issues as well. The trick is you’re converting the focal length with a 1.4 TC, but you have to beat an existing FF lens. So the 10-20 becomes a 14-28 THAT CAN TAKE FILTERS… Sigma already makes a 12-24mm that CAN NOT take filters w/o a lot of work (see how here: So using this trick on the 8-16 making it a 11.2~22 doesn’t make a lot of sense. It’s only .8mm wider. With the 10-22 you’re gaining 2mm over the 16-35 in terms of filter use. The 11-16 does work, but with a TC it’s a 15.4~22.4, so why not get a 16~35mm and not deal with the issues?

      So to me, the options are the 10-2x lenses, canon’s sigmas or tamrons. Behond that there are better wide options that work on FF w/o any tricks.


  7. Hi Ben,

    I guess you arr right..
    The only advantage could be using the Tokina (without a converter) instead of the Canon because of it’s F2.8 where Canon has F3.5-4.5 but i do not think that will matter that much when shooting landscapes on a tripod at F10-F22..
    I am going to look if i can try to make a metal ring (like the LEE Wide Angle adapter ring) wich will fit further backwards on the 10-22mm lens so i can place the filterholder further backwards and try to use at least 1 ND filter at 12-13mm without getting the vignetting caused by the WA adapter/filterholder.

    At the moment i am using a LEE filter holder but was wondering wether a Cokin X-pro system would work better in terms of less vignetting caused by the filter holder..?

    Kind regards,

    Jeroen Stel

    • I’m guessing you’re using the 10-22 w/o the TC then correct? When I used this setup with a TC on a FF body, I could shoot with my lee holder and 77mm UWA ring w/o any issues with vignetting. If you’re using it w/o the TC, the other issue you’ll run into is even when the corners are filled in with an image they’re quite soft. From what I saw (on FF) I NEEDED the TC or I wasn’t getting acceptable images in terms of sharpness edge to edge. The Tokina will work at 16mm on FF w/o any modifications, but it has the same issue with soft corners. It’s really only an issue with landscape or arch work, but it’s worth mentioning.


  8. Hi Ben,

    I am using the lens w/o the converter but must say i am pretty pleased with the overall sharpness even in the corners. Being a wildlife photographer and not a true landscaper (though i try to be…:)-…) might be the reason i am not seeing the difference. As for the vignetting…. I did a little DIY -project today…

    First of all i noticed that a metal wire with UV filter or the 67-72mm step up ring i used to keep the lens from getting past the 12mm was creating a vignette at 12mm so without filters i could only shoot at 12,5-13mm.
    Second my LEE filterholder and adapter ring (not a WA-ring though..) caused even more vignetting when shooting with filters and therefor i was only able to use the lens with filters from 14mm onwards. Owning a 17-35mm lens i was a tad dissapointed as i really wanted to use this lens at 12mm..

    So first things first….To eliminate the “internal-vignetting” from the wire or step-up ring i drank a nice diet coke today, stripped the can apart and used a small aluminum strip of around 3mm made from the coke can wich i glued on the insed of the lens at the top with some strong but very thin double sided tape. This stopped the lens form getting past 12mm but…as the aluminum strip was reflective i think it might also catch some light and reflect it back wich might reduce vignetting even more.

    Second i took a plastic ring the same size as my LEE filter holder and mounted the LEE filter holder slots on. Then agian using some double sided tape i glued an 8mm think foam strip on the inside and that way i could place this filterholder further down the lens in order to reduce vignetting caused by the filterholder.

    Now i can even use this DIY filterholder with 2-3 slots and not have any vignetting even at 12mm!

    ….mission accomplished….

    For some (very bad) pictures of the new set-up you can take a look here:

    Hope this helps anyone with the same problems trying to use this lens on FF or APS-H systems.

    all the best!

    Jeroen Stel

    • very well done on the holder modification. I’m also thinking the vignetting and softness issues we’re differing on have to do with the fact you’re on APS-H and I’m on FF? On FF I basically needed the TC, but you’re cropping out just enough of the circle that my sensor say it gets you away from the soft edges. Good to know (for me and anyone else who could read this).

      Thanks again, and thanks for the shots of your holder. I need to get some foam like that for my lee holder so I can use my 10-stop hi-tech panel holder. I haven’t found a Lee Big stopper in stock just yet…


  9. You are welcome!
    I was lucky to still obtain a Big Stopper last week but have not had much time to test it.
    Just did this shot when i was out on the beach with my son:

    I like it a lot from what i have seen and just using it on several shots down at the beach so far though i also own the Light Craft Workshop 9 stops filter i still have to see some shots side by side of both.


  10. Hi Ben,

    Just wanted to let you know i have bought a LEE wide angle adapter and shaved the inside out quite a bit, resprayed it black and have started using this together with the LEE filterholder with 3 slots as i did not completely trusted my DIY filterholder not to drop down on the floor whilst holding 3 filters…

    This works great and i have no vignetting at 12mm so just to let anyone looking for this option know that using a LEE wide-angle adapter works well as long as you shave out the insides a bit.



    • Whoops, I think it’s the 28-70 then, but check the post, the part number you need is in there now, just use that number when you call.


  11. Has anyone tried to debaffel (If thats a word?) the 10-22 and shoot in the live view mode on a 5D MKll. Unfortunately, Canon’s mirror lockup system is not photographer friendly. Love this lens and may try it on an old RT with the Pelicile(sp) mirror. Thanks for all the great info. This lens is excellent with the results to prove it and it would add an extension to the 24-150mm which gets more use than any of my lenses. Hopefully I can also use the 10-22 on my IR converted 10D

    • Converting it to EF from EF-S is effectively “debaffeling” it no? I’ve shot with it with the mirror down then taken pictures. Using the TC the wide limit is because the back element of the 10-22 touches the front element of the TC. W/o the TC it’s a matter of covering the sensor, so you’ll have the same widest options there as well.

      Good Luck!

  12. Thanks for the knowledge! I hope to confirm a few things before I head down this path, hoping that you can help me 🙂

    1) Can the 10-22 still mount on a crop and work without problems after you change to a EF buffle?

    2) With a 1.4x TC, can I confirm that you are shooting at 14mm (10mm * 1.4 = 14mm) without any issues (vignette, physical blockage, whatever)? Or do you have to shoot at 16mm (12mm * 1.4 = 16.8mm)?

    Really hoping that you can help answer these two questions of mine! =D

    • With the new baffle the 10-22 can be used in any canon body. It needs a 1.4 tc to work on ff without a hard vignette but the conversion also allows it to be used on older crop bodies before they made the EF-s mount. With the 1.4tc the rear element will touch the tc’s front element any wider than 12mm, so yes you are stick with only 16mm.

      Good luck!

  13. I also use 10-22mm on 5d II. I have been using it without tele converter, but I am looking into trying it out with the TC. The softness in the corners does not strike me as completely unusual, but I would not mind seeing it clear up a bit with the TC. Is there any chance you or Ben or someone could show me 100% corner with and without TC?

    Also, if you don’t mind me asking an unrelated question, what is the microphone you are using for this video and where do I do about getting one of these furry socks?

    • The microphone and sock are both from B&H. The mic is in the <$20 range and mono (which I then convert to stereo in post). The sock actually cost almost $50 IIRC. I don't have any 100% crops on the 10-20 on TC but it's pretty darn good. It's the kenko TC which is inexpensive enough I suggest getting one then returning it if you don't love the results. Good Luck! Ben

  14. Re:Canon-22mmFF-S to EF Conversion and your Video instructions on Aug 2010.
    I have tried to locate the baffle part CY1-2759-000 from Canon who advise that it is no longer available.
    Would you have any suggestions for this conversion for my Canon MK3?
    I am really enjoying your site with great tips and reviews.
    Thank you Ben

    • no idea on other part numbers, sorry. Good luck though. Remember, you don’t need the baffle, it just makes it look complete…

  15. Hi there

    I’ve just been doing this with my 10-22mm with my 5D mark ii.

    I’ve found that without the new baffle that you suggest – I did it the fugly way – that I can only shoot at 17mm without any vignetting.

    Have you tried it without the baffle part you suggested and got the same result.

    If I get the new baffle you suggested do you think this will allow me to shoot at 12mm without vignetting?

    thanks for your post its very valuable.

    Regards Grant Kennedy

    • Grant,
      The baffle is just for looks. It does not effect the performance of the lens in any way nor does it effect which focal lengths are usable. To go past 17mm w/o a vignetter you need to use a kenko 1.4 TC. Then you can get to around 12mm. At 12mm be careful though because the limiting factor is the lens in the TC touching the rear element of the 10-22mm. People have some creative options to avoid this but I was just careful and never had an issue.

      Good Luck!


    • Ok thanks Ben but wouldn’t the 10-22mm at the 12mm mark plus the kenko 1.4 TC = 16.8mm anyway hence only giving me a .2mm advantage aka not worth it?

      Or am I doing the calculations wrong?

      thanks for your help.

    • Grant,
      The advantage is you get to use an aps-c crop lens on a ff camera and it works well. This means you can have one lens for two cameras or if you’re upgrading you can use your existing wide angle as needed. If you’re building a dedicated full frame kit it makes a lot less sense but its still a great lens and is less expensive (but close to the 17-40 which is sealed) and its also quite a bit lighter.

      Good luck!


  16. Hello Ben
    Can you please tell me the exact name for it? Youve mentioned it a few times but still! I am welling to use a Canon 5D2 with a Canon 10-22mm.

    P.S Im away from the US and Europe

    • Weinek,
      The exact name for which part? The black plastic piece in the back is the “baffle”. That’s what canon calls it as well. The part number is in the post and the comments above as well. If you’re looking for something else let me know and I’ll help in any way I can.