EOS Rebel T7 How to position focus screen replacement inside camera

[Robert1966]

How the focus screen should be positioning inside camera? There is a different side latches  - one rectangular on the other side trapezoidal, looking from up side down (left side is "Rebel T7" mark at the body) hot to put focus screen inside?

[deebatman316]

No it won’t. The camera doesn’t know what focusing screen is in the camera. That’s why cameras with a user replaceable focusing screen. Have a custom function that tells the camera what focusing screen is installed. Canon doesn’t sell an OEM focusing screen for Rebel Series cameras. My old EOS 40D has a custom function that tells the camera which focusing is installed. A lot of newer DSLRs don’t have a focusing screen in them. Instead they use an LCD overlay in the viewfinder. This is NOT user replaceable if it breaks. It must be sent to Canon for repairs.

[Robert1966]

ok, will see

[deebatman316]

I don’t recommend that you attempt replacing it yourself. It clearly wasn’t designed to be user replaceable. Then you could cause more damage to your camera especially with the reflex mirror.

[normadel]

You aren't listening.  The focusing screen IS NOT USER REPLACEABLE!!!  Having gotten yours out, you may well have done some damage. Having an IT degree has nothing to do with it.

[Robert1966]

OK, Ok take it easy, just asked a question. As far as I concerned the focusing plate is literally piece of plastic mat one side (in fact with micro cuts) on which focus points detects sharpening. Quite strange that it's affected the camera soft.  Anyway, asked the Canon service at Wilmington and the told me that the cost should not exceed 75$ and it takes 10 minutes. Therefore I asked if service grant 10 minutes maybe will be possible to DIY. However thanks for help anyway

[deebatman316]

A focusing screen IS NOT made out of plastic. Its made out of glass or Fresnel lens. SO follow my suggestion and my colleague's @normadel you could cause more SERIOUS damage to your camera. 

[Robert1966]

Ok , will follow, get the service , but one issue - I know " curiosity kill the cat" but it is really any conection between focus screen and  AF? Using live view is Ok. o ly eye finder "cosmeticly" looks poor but even by this pictures are sharp.

Thanks in advance

[Robert1966]

By the way the Fresnel kens usually made if acrilic or polycarbonate material (not a glass), invent in 1822 (originally glass but now aclic or polycarbonate)

[deebatman316]

Viewfinder AF is carried out by sensors on the floor of a DSLR camera and are under the mirror. Live View uses the image sensor itself and IS not susceptible to front or back focusing. The focusing screen doesn't affect view finder AF.

 

[deebatman316]

Canon has lenses with DO (Diffractive Optics) or Fresnel optics and its glass NOT plastic.