Continuing from my Focus Screen and Sensor Cleaning article which I had written when I had my EOS 5D, I saw an opportunity to follow it up with a more thorough post when a friend noticed a spot in the viewfinder. Having risked it all before on my EOS 20D, 5D and the 5D MkII I said I would take a look the next time he’s in town. So the day came and I knowing that he’s hands-on enough when it comes to small  PC-related tasks such as handling screw drivers, I threw the ball right back at him and had him tackle the problem himself. It was a great learning experience for him and at the same time allowed me to document the steps we took to complete the job. I’ve divided this post into two practical parts.

Part 1: Removing (or changing) the Focusing Screen

This step guides you to quickly examine if the dust or grime is merely on the Focusing Screen. After removal of the focusing screen and blowing both sides, reinstall the screen to check if dust disappears. If satisfied then Phase 2 isn’t necessary. Follow the same steps if you want to swap out the original focusing screen with a new one such as the Canon EG-D (Grid) Focusing Screen.

Place the camera on a flat surface with the lens mount facing up to avoid dropping the focusing screen. I take the extra step of removing the eyecup too for reason you’ll understand when you are at this stage.
You can actually use your fingernail or a small tool to lift the attachment hoot to release the focusing screen. If you previously bought a replacement focusing screen from Canon, a “Special Tool” is provided (see 2 pictures down). Yep, Canon doesn’t even know what to name it but calls it “Special Tool”
I replaced my 5D Mk II’s focusing screen with an optional Grid screen. In case anyone is interested, the Canon part number is SCREEN-EGD CZ6-C218 3356B001AA as printed on the box. Focusing Screens on the 5D Mk II are slightly larger than that of the 5D so make sure you order the right item.
Gently pull the attachment hook to release the focusing screen holder from the hook. When done right, the screen slightly “pops” out for easy removal.
Using the Canon special tool or tweezer, removing the focusing screen is a no-brainer task. If you’ve bought a kit from Canon the box is where you can temporarily keep the screen should you require to proceed to more advanced stages of cleaning. The focusing screen is extremely sensitive to touch and will smudge very easily.

Instructions on Canon Focusing Screen kit reads … “Never touch the screen with your fingers or hold the screen in your hand. If the screen becomes smudged with a fingerprint or a foreign substance, the smudge will be very difficult to remove. Also be careful not to smudge the mirror or other parts of the camera when changing the focusing screen.”

For the small price you pay for an optional Canon focusing screen the “Special Tool” has its use long after you’ve installed a new screen. The tool clamps the mounting tab of the focusing screen firmly and is ready to be inspection of dust or grime. Warning: DO NOT (I repeat) DO NOT at this stage use a blower on the screen just because there’s dust on it. This clamp is NOT STRONG enough to hold it against “Hurricane Katrina”. You’ve been warned. I will not be held responsible for any stupidity on your part.
Ignore the manufacturer’s instructions for a moment and use some common sense. If you spot dust on the focusing screen, blow it off with a blower (I use a Giottos Rocket). I do not suggest using air from your lungs for this assignment. You do not want to get any moisture onto the delicate screen. Believe me when I say it’s delicate. I have screwed one up before and pretty much lived with my mistake until the camera was sent in for shutter replacement only then I asked for a new screen replacement.

Part 2: Removing the Metal Shims and Superimposed Display Screen
If however after completion of Phase 1 and you still see spots on the viewfinder, proceed as follows:

If the dust spot isn’t removed using the above methods, chances are the spots are on the Superimposed Display ie the clear plastic screen with AF rectangles overlay. You’ll need a set of these mini screwdrivers and you’ll want magnetized ones too for obvious reasons (if you don’t know why, you’ll know soon enough—when you’re missing some screws and you happen to hear some rattling noises afterwards) 🙂
Using the smallest Philips screwdriver, remove the two micro screws that secure the metal plate. Remember to use a magnetized screwdriver here.
There are no cool looking tools here except the obvious one. I used a tweezer to grab the metal plate firmly and slowly disloge it from the fitting making sure I don’t accidentally drop it onto the highly sensitive mirror underneath it. You don’t want to add a scratched mirror to your list of pain.
Next comes the three-piece copper shims. These are sandwiched between the focusing screen and superimposed display each has a attachment hook that prevents them from dropping down during camera operation. The idea here is to carefully undo them starting with focusing screen, then the metal shims then finally the superimposed display screen.
The metal shims come off rather easily. The final bit in the triathlon of viewfinder cleaning is the removal of each of these components. Note that you should always remember how they come off because you need to put them back in the order they were removed. The focusing screen for instance cannot be fitted the wrong way. Doing so will leave you with a blurred viewfinder.
Of the three tasks, I find the attachment hook that holds the superimposed display a little difficult to remove. The idea here is to use something flat so that you can lift the catch to release the superimposed display.
Using a tweezer, gently remove the superimposed display (“SD”) to inspect for dust or in this case, I discovered something more stubborn—an oil spot. How it got in there I think that’s open to a multitude of guesses.
Isn’t this cool? I just placed the SD under my flourescent table lamp, tilt it a bit and suddenly the cheap plastic screen looks like expensive jewellery. Here, you can see the stubborn spot. The spot refused to budge even after given it a dozen blows. It’s decision time—wet clean or leave it be. The owner of this camera (being new and somewhat clueless and inexperienced) was :O by one lil black dot in his viewfinder and asked me for help. I took this opportunity to proceed with a tried and tested wet clean method with a purpose of documenting this procedure.
Applying Eclipse methanol fluid on a new Sensor Swab (two drops). Soaking the swab with too much fluids will leave unsightly streaks on the SD. You’ve come this far, don’t let streaks (should they appear) freak you out. You can fairly easily remove the streaks with a newly prepared swab and sweep the SD a few more times. It takes practice to get things right. The point here is that the Eclipse is safe to use and does not attack the plastic.
Here is a picture of me applying a second sensor swab on the SD. Although the oily spot had disappeared, I inadvertently left some streaks which needed a second application. — Photo by Gavin

Disclaimer: The information contained in this website is for general information purposes only. No representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect my cleaning method or the information, products, services, or related graphics contained herein are made for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

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  1. Just reading this makes me cringe! No way am I even going to attempt this procedure man! I’ll leave it to the pros (like yourself) thank you very much! Hehehe!


    1. Is it possible to insert the SD screen in the wrong way round? In the photo above, I see two tabs of different width. Assuming their mating slots are also different widths then it would be should be impossible to insert it back to front. can anyone verify?




      1. Hi Trevor,

        Yes, it’s entirely possible to insert any of the removable items the wrong way around. Items include the copper shims, focusing screens and superimposed display even though Canon has engineered the tabs to be different. If you install the focusing screen wrong way around the entire viewfinder goes blurry. Fitting them wrongly is a great opportunity to learn from the mistake and you would exercise great care and observation next time before removing them next time. 🙂


        1. Thanks, Jan. My viewfinder appears to be in focus as it was before I cleaned the SD so I think it’s ok. Many thanks for the clear guide.

          What would be the effect of the SD being the wrong way round but everything else put back correctly? Would it be immediately obvious?



          1. Umm, I don’t know. I’ve never had the SD plate installed the wrong way round before so I can’t comment. However, if the rectangles on the SD are completely symmetrical, there’s a chance it may still work 🙂


    1. Thanks, Jan.

      Don’t think I’ve got it wrong as it focuses OK. I was just wondering. I really enjoyed doing this and am very grateful for the guide. I got myself some latex surgical gloves and food-handlers’ hair cover to help reduce the chance of any extra bits of skin flakes, hair, dandruff and anything else falling in while carrying out the op.

      Thanks again.



    1. For what is worth, I’m not offering any cleaning services. The purpose of this documentation is so you can attempt to clean the viewfinder or sensor yourself. If you don’t think you’re brave or knowledgeable enough to pull this off then I suggest you leave things alone. The methods can be applied universally to most modern digital SLR bodies. Good luck!


  2. Hah! So much fear! I am definitely going to try this. I was afraid of taking apart everything I’ve taken apart in my life, I’d never have learned anything. Thanks for the detailed walkthrough. This will be very very helpful. I hate those damned dust spots!


    1. Well Joe, dust is very much a part of our everyday lives, unfortunately. What I don’t understand is why the viewfinder cannot be designed with better sealing. So far I’ve only had to take the entire viewfinder apart once (excluding the penta-prism). Most of the “dust spots” I noticed subsequently are the ones caught on the focusing screen and those are very easily blown off using a blower.

      Someone has found the steps to be useful so I’m certain it’ll work for you too. All the best.


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  4. Received this email from a photographer in Canada.

    Hi Jan, i wanted to say thank you for the really useful article you did on the 5d mk2 SI screen.

    I did have a question that you might be able to answer for me before i open my 5d2 up, hopefully you’ll have the time 🙂

    I just came from a 1ds mk2, and the black AF squares in the VF on the 5d2 are getting to me, more so then i expected, i quickly came to realize these were not on the focusing screen, and were etched in on the SI, something your article confirmed for me…

    Which begs me to wonder if i have any options as to getting rid of them ? On the 1ds mk2, one could simply tweak the options and have the square light up red only when AFing, thus having an extremely clear VF, with just the general circle.

    I was wondering, what your experiences were with them on the SI screen ? Are they etched in ?

    Thanks for your time, and i hope you’ll get enough spare time to answer my question, if not no worries and good luck on your adventures 🙂 Nice contact picture by the way.

    Hi, that’s an Interesting observation—I hadn’t really paid much attention to the black lines inside the VF other than stuff that shouldn’t be in there. I owned a 1D Mark II a few years back and I do recall how bright it was. Then years later, with the 5D Mark II .. the VF is a lot brighter and much nicer to use overall. But you’re right, the black rectangles can be a little distracting if you’re not used to them being there. If you think 9 black rectangles are a problem just imagine what I have to put up with 9 black rectangles AND 5 black vertical and 3 horizontal lines—I have the Grid Screen 🙂

    The interesting part is how they appear black inside the VF but are clear on the SI screen. Yes, the rectangles and also grid lines are etched. Hope this helps (or not).


    1. Thanks for the reply!

      Yeah it gets very busy with the grid, that part does not bother me. But i was thinking of grabbing one of the Eg-S for some of my fast lenses and then removing the black af squares would leave the entire viewfinder much cleaner and pleasurable to work with.

      This would be especially nice for me when doing candids or street photography, where i don’t pay particular attention to lining up horizons and just want to focus on the subject matter.

      If the items are etched onto the SI, i am not sure why they are appearing black, perhaps there are some markings further into the prism ?

      I suppose its my turn to break out the screwdrivers then 🙂


  5. Hi.

    Thank you so much for this tutorial. I wanna ask you something.

    I try to clean my focusing screen (i have a 5D Mark II), the first one but I noticed that other screen from back have dirty “Superimposed Display Screen” i try to clean that screen with out get it out from camera but with out luck. My question is: is there any chance to change that screen from back? and if is it from where to buy another one. I talk about this screen.

    Thank you so much and i really need some help. My heart is broken when i look through viewfinder.


  6. Thanks for publishing this guide. I performed it on my 5D mk1 and the procedure is exactly the same.
    I used a Kinetronics Speckgrabber to remove some stubborn dust spots, and it kind of worked, but also created some small smudges on the focusing screen and SI screen. It’s probably easier to use a sensor swab…

    When I took out the SI screen, it slipped from my tweezers and I got a superficial scratch and some smaller marks on it. Fortunately it doesn’t display in the viewfinder at all!

    Most of the dust in my VF was on the backside of the SI screen and on the pentaprism: most of it was actually removed by blowing on the prism with my rocket blower. I’m really glad I went through this because I got rid of some annoying particles in the middle of my VF, and now just two smaller ones on the perifery are left. A good result if you ask me. 🙂

    Next project is the sensor — I haven’t been able to remove the smudges in the corners yet and those swabs are so damn expensive…


    1. Thanks Benjamin. Glad you found the tutorial useful. Once you get a hang of the procedures, everything becomes routine. That said, routine also introduces deterioration which is completely unavoidable no matter how careful you may be. Over time, it’s more economical to just put up with the minor irritation. Keep me posted how you get on with the “sensor project.” 🙂


      1. In the meantime I got some sensor cleaning materials that aren’t as expensive as the ubiquitous sensor swabs. Copper Hill Images has something called the “Sensor Swipe”: a specially shaped plastic stick around which you can wrap strips cut from PEC pads. That way it’s extremely economical to wet clean your sensor (with Eclipse cleaning fluid).
        I also got a sensor loupe and a good sensor brush from them, and they are much more economical than equivalent products from other brands (some charge ridiculous prices IMO).


        1. Hey Ben,

          There has been a lot of debate regarding the (safe) use of PEC Pads in the place of the more costly Swabs but at the same time there has also been just as many testimonials from people who have done so for years without detriment.Before the Swabs, I used to clean my EOS 20D sensor the same way, no problems. I just haven’t so with both my EOS 5D Mark II.


  7. Hey Jan, I follow your way and screwed my focusing screen already by applying some liquid that I bought in Henry’s especially for cleaning sensor. I know, my mistake. One can’t apply it to plastics. Where to get this “Eclipse methanol” for the future references?


    1. Hi Sergey,

      I hope you’re getting the Eclipse Methanol solution to clean the sensor and not specifically to clean the focusing screen. While I successfully used Eclipse to clean the screen, it’s best to not have to touch it unless absolutely necessary. Check out the manufacturer’s website


      1. I made it yesterday night (couldn’t help itching to get rid of the dust and grease in viewfinder) with methanol and fancy swabs from Vistek. It is not so easy as it seems, but it works. There is still a couple of tiny dust dots, but comparing to what was there – it’s perfect now, considering “night shift”.
        A couple things I dare to add to your instructive article:

        1. one has to wear gloves (during the cleaning my hands became wet and thanks to gloves I didn’t screw it)
        2. a big loupe is essential for this job.
        3. avoid using blower closer then three inches from the surface of an object. It can make grease spots.



        1. Great that you found gloves to be useful. Unless you use surgical gloves, most fabric ones will shed a lint or two and can be frustrating to work. Over time, you’ll find that desensitizing yourself to presence of dust spots make photography more enjoyable. These days, I usually just pop the focus screen out, give it a good blow or two and pop it back in without relying on any tools other than a good blower, of course (useful when shooting in the field). Thank you for sharing your steps.


  8. A reply to an email from Jean Claude that’s worth sharing with folks who find themselves in similar predicament.

    Hi Jan,

    First of all thanks a lot for your blog’s tutorial .. I own a 5D mk II and I’m an amateur photographer.

    I’ll go straight to the point… I’ve been a really bad 5D proper cleaner and now I even found that I made few mistakes that got me with a scratched few parts .. hopefully not the sensor but I’m sure the Focusing screen is .. and I realized the SD plastic panel (the cheap plastic panel that looks like expensive jewellery 🙂 … and I was wondering if you know where to find such SD replacement part .. possibly not from Canon which I doubt it’ll be a “cheap piece of plastic” to replace then…

    I’m considering new focusing screen too and I’d like your opinion about which one would you prefer and why. Looking forward to hearing from you and again thanks for all the inspiring words I read on your blog.


    Jean Claude

    By SD I think you mean the “PLATE SUPER IMPOSE INDICATE” which is printed on the box it came in. You can get the replacement part from your nearest Canon service centre. Let them know you’re looking for Part No. YN2–9869–000


  9. How would you manage cleaning the inside of the view finder window (the bit you put your eye too!!). Just come back from a gig with a bit toooo much rain and we’re all steamed up in the view finder and its just not clearing.
    Any help would be great.


    1. The only thing I think would help is to leave the camera inside a dry cabinet. How long you would need to leave it there depends on how “dry” the setting is versus the amount of moisture that’s trapped inside. This method helped dry a non L lens that accidentally took a dip in the river and that took 3 days before all traces of moisture disappeared. Good luck.


  10. I’ve done this on my 50D. The only difference is there’s only one copper shim.
    Guess what, I’ve accidentally scratched the SI plate, and also put a bit of finger sweat! Ouch! Tried to clean it with pec pads which made it worse! I’ve now ordered a new SI plate and its on its way!


    1. Richie – I can’t figure out how to fasten the copper shim to anything in the 50D. It just flops there. No matter which way I put it back in, it doesn’t seem to fit into any tabs. Help??? Thanks!


      1. I have not handled a 50D so I have no idea what the chamber looks like. The shims in the 5D Mark II do not fasten to anything either, they (2 or 3 pieces I can’t remember) are sandwiched in between the Super-imposed plate and focusing screen (see pictures above). But having said this, the shims do not float between the SI and screen but instead have cut outs that slot into the bottom part of the chamber. Take another look (use a torch light if necessary).


        1. thanks Jan. There don’t seem to be slots in the bottom of the chamber on the 50D. Unfortunately I didn’t take note when it originally sprung out after removing the screws. It’s one shim, and it has two prongs on both top and bottom – two are wide, and two are more near each other. I feel like I’m going crazy here, because I had it back together today (but it was blurry, so I knew I put it back wrong) and I had scratched the SI plate so I had ordered new ones anyway. So I thought I’d check it out more in depth tonight and now can’t get it back together 😦 I guess there are no photos of the 50D innards online.


          1. UPDATE: I had the SI plate in upside down. It doesn’t look like the 5DII screen, it has one big tab and two others that are spaced. This is my own fault, I should write a how to on the 50D and stay out of 5D pages……. sorry!


          2. I was about to suggest that you may have either installed the SI Plate or Focusing Screen wrong way around if your viewfinder appears blurry. I have had this happen to me before from first hand mistake.


          3. It’s expected that the shim(s) have prongs on them. The bottom prongs are designed to slot into existing “compartments” to hold them in place. The prongs on top are stopped by these “catch” (indicated by the arrow) so they don’t fall out when the focusing screen is removed.


  11. After reading this I am ok with the dust specks in my viewfinder.

    My 30D after years still didn’t have anything in the viewfinder, but also didn’t have the option to switch focusing screens.


  12. I had a disappointing surprise when i removed the lens of my photo class’s new 5dmkII and the focus screen popped out. I’m hoping I don’t have to go through all of this to put it back into place. I am concerned though why the hinged screen holder was out of it’s secured position.


  13. hi Jan, thanks so much for the info re black dots on the view finder which i have on my t21 rebel. the question is: does black dots normally shows up on viewfinder ? like dusts on the sensor? i would understand with regards to dusts on the sensor but not the black dots on the veiwfinder bec the viewfinder shlould be sealed ??? i send it to the canon service ( since it is still under warranty ) and now the veiwfinder has more blackdots.. getting frustrated


    1. You’re welcome. Over the years, I got immune to dirt that mysteriously creep into the viewfinder. Nothing surprises me anymore considering I have even found a tiny spec of dust inside an L lens (whether that was already there from the factory is anyone’s guess). Since viewfinder dirt do not affect picture quality it’s easier to ignore them.


  14. What a great article and thank you Jan. I have one small tiny spec on the focus screen that I can’t get off. I tried to loosen it with a tiny bit of Eclipse (with corner of swab) and the arctic butterfly brush… but its a no go. I suppose I could try it a bit more aggresive and if it damages it, I’ll just replace it with a new one clean free.

    With the sensor, I hesitated before purchasing the artic butterfly but I think it does help when there is a small spec of dust after the sensor’s swabed with Eclipse.

    Thanks again : )


  15. My dusty viewfinder has been annoying me for months. Thanks for the tutorial. All worked a charm and I now have a clear viewfinder. Thanks for doing this tutorial.


  16. Hello,

    was trying to clean my camera sensor and also the viewfinder screen and the focusing screen but made ​​a mistake and I scratched somehow and a small line was formed, I would like to know where I can buy the parts (YN2 -9944-000 000 B 1 SCREEN FOCUSING SCREEN-EGD or CZ6-C218 3356B001AA) if you can help me with this information I will be very grateful



    1. Hi Diego, over here in Asia we get our parts through Canon Service Centre as nobody else stocks them. There isn’t a CSC in my country so the nearest one is Singapore or Malaysia. You’ll have to contact one nearest to you for these things. I hope you find them without must fuss.


  17. Hi Jan. Thank you for your tips.. I use a Canon EOS 1000D. Can I clean the focusing screen on the Part 1 of your tips without remove it from my DSLR with a new censor swab (without the fluid)?


    1. I don’t know what the focusing screen on the EOS 1000D looks like. There’s a chance that on an entry level the focusing screen may not be removable in which case if you tried to clean it you may end up scratching it.


  18. Hi Trevor Rymell.
    i tried to clean the super imposed screen with wet cleaning method. and now the small squares that is visible through the view finder is dimmer before cleaning. i can barely see the red squares when i focus on an object. is it due to the wet cleaning? if so do i have to replace the super imposed screen?. tnx.


      1. Hi Jan
        i tried it in both sides. one side was the same, the red lights are barely seen. and the other side there was no red illuminated squares. so i guess its the wrong side. in the correct side i could feel the squares maybe some solution is inside the squares. so do i have to replace indicator plate? tnx


        1. What solution did you use to wet clean the plate? If it’s sensor cleaning solution such as Eclipse, the alcohol dries up and disappears in seconds so there really shouldn’t be any wet residue left on the plate to cause the problem you’re describing. Having tried both sides I think there are no longer other ways to fix this other than replace it with a new plate. I have cleaned the plates on both my 5D Mark II the same way and have not encountered any issues although these days I tend to ignore the dirt and micro scratches on them.


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