I have a canon 100D/SL1. I was swapping my lens today and when removed the lens I noticed something fell, turns out it's the focusing screen. However I powered on the camera and took some pictures and it seems to be working fine, maybe a little bit overexposed but nothing terrible.

Do I still need to replace my focusing screen? And if so, what are my options? Found the screen itself on eBay for cheap but couldn't find anyone that comes with the metal housing.

Edit: Added picture camera without the focusing screen

focusing screen and it's housing

  • \$\begingroup\$ I've added a picture. I tried again and it seems I can see clearly through the viewfinder. Am I missing something? \$\endgroup\$ Mar 6, 2021 at 22:55
  • \$\begingroup\$ Yes when I took of the lens, the focusing screen along with the metal frame and metal clip fell. Nothing is resting on the mirror. \$\endgroup\$ Mar 6, 2021 at 23:47
  • \$\begingroup\$ Fell where? Did you put it back in the camera? Or is it still out of the camera? Here is a link showing how to replace the focus screen on a similar camera. focusingscreen.com/work/550den.htm \$\endgroup\$ Mar 6, 2021 at 23:50
  • \$\begingroup\$ They're out of the camera. I've added a picture of them. Is the process of placing it back easy enough for a beginner like me to do without messing up the mirror or anything else? Especially since the camera seems to be working fine without it. \$\endgroup\$ Mar 7, 2021 at 0:22
  • \$\begingroup\$ The SL1 and other Rebel series cameras use a "Pentamirror" rather than a "Pentaprism" like most larger DSLRs. I am guessing the Pentamirror can still provide a somewhat usable viewfinder even without the focus screen. The focus points are part of the focus screen so I am still baffled as to how you are still able to use your camera. \$\endgroup\$ Mar 7, 2021 at 0:33

1 Answer 1


Your focus screen fell out with its' metal carrier ring attached? If that is actually the case then the focus screen cannot be replaced w/o a major service... it will almost certainly be cheaper to replace it buying used.

But I do not see any reason that you could not use it via live-view photography (LCD screen). It sounds like that is how you normally use it anyway.

  • \$\begingroup\$ so the focusing screen is only for the view finder and wouldn't affect my if am using the screen? I was able to look through the view finder and take pictures though \$\endgroup\$ Mar 6, 2021 at 20:44
  • 1
    \$\begingroup\$ Yes, the focus screen is only for the viewfinder... not having a screen there will not prevent you from being able to see through the viewfinder, but it will prevent the viewfinder from being in focus. \$\endgroup\$ Mar 6, 2021 at 20:54
  • 1
    \$\begingroup\$ It will also affect the readings of the light meter, which is located past the viewscreen in the optical viewfinder train. How it affects metering will not be predictable. More overall light getting past where the viewscreen used to be should result in underexposure (because the camera doesn't know the screen isn't still reducing the brightness of the light passing through it). But since the light is no longer focused on the viewscreen, the metering pattern will be gone and light from all areas of the frame will affect metering for specific areas of the frame. \$\endgroup\$
    – Michael C
    Mar 10, 2021 at 12:57

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.