Focusing Screen Question

[KmH]

So it doesn't mess with the AF at all? I think I heard that somewhere.

The AF module is in the bottom of the camera.
50% of the light from the lens goes through the main mirror to a secondary mirror that directs the light down to the AF module.

The focusing screen is at the top of the mirror box and at the bottom of the viewfinder pentaprizm/pentamirror and is not in the light path to the AF module.

It might be worth discovering where the various sub-systems in your camera(s) are physically located.
The better you understand how your tools work, the better you can use their features and functions.

 

[frommrstomommy]

If you're having a difficult time getting focused properly on the 85mm, is it because you're shooting at f/1.2 all the time?

I just meant that it is a beautiful lens that produces beautiful results, but even in the best circumstances, I have found it to be a little bit challenging. I understand light, camera shake, shooting wide open will cause focus issues, etc, but to maximize my photos, I had heard that focusing screens are helpful.

I would guess not.

 

[o hey tyler]

I would guess not.

She never said she didn't shoot wide open, she said that she understands the limitations.

http://www.thephotoforum.com/forum/people-photography/328544-c-c-requested-working-sharp-eyes.html

 

[vintagesnaps]

I had to look up KatzEye - I already have cameras w/that type focusing screen, or with a split screen such as in a rangefinder, etc. I find those can be easier to focus - it just depends I think on what I'm trying to focus on, what lighting conditions I'm in, etc.

I learned using manual focus and is mostly what I still do - I sometimes get in focus and then keep turning the lens barrel til it starts to go out of focus then turn each way slightly to adjust from there. If I'm having trouble focusing sometimes I'll try to find an edge or line to focus on, then reframe the shot (of course the edge/line needs to be the same distance from the camera as the subject). If I'm really having trouble I'll lower the camera for a moment and give my eye a quick break then start over and then I can usually get focused.

 

[MLCIII]

I read many many reviews on this lens before ultimately going with the 1.8. My understanding is that this lens is know more for its crazy-wide aperture than its super sharpness, with many reviews stating a requirement to conduct some fine-tuning. Also, I've never heard someone say MF is more clear than AF. While I'm not doubting your eye, today's AF is pretty damn good.
And as already stated, your focus screen can't completely resolve the shallower DOF down at f/1.2, so there could possibly be a huge variation in where the center of your focal point actually is compared to what you see in the viewfinder when using the lens MF.