I have an original Canon 5D. I cannot get good, sharp, clear photos no matter how much I try. They will look clear at one area, and distorted looking in another area. Not Bokeh or bad focus, but just distorted looking. This happens indoors or out. I shoot in RAW, but it has also happened in Auto, and Program modes when I've checked different settings with the same results. I have a couple of fast lenses 50mm 1.4, 24-70mm 2.8, and a 35mm f2. I bought the camera used and was told that the Focus Screen had been replaced in it at one time. Could I possibly have the wrong FS in it and need to replace it to accommodate my faster lenses? Any help or advice is greatly appreciated. TIA
The focusing screen has nothing to do with:
- Autofocus performance. There is a separate optical path to the PDAF sensor that does not pass through the focusing screen.
- The actual image recorded by the camera when the shutter is open and the photo is exposed. The focusing screen is not in the optical path at the time the image is recorded.
The focusing screen does affect:
- What you see when looking through the viewfinder. If the view is distorted or out of focus only in the viewfinder but not in the resulting photos then the issue could be with the focusing screen. If you are manually focusing then a misadjusted focusing screen could make subjects that look focused in the viewfinder appear blurry in the resulting images.
- What the camera's light meter measures. The focusing screen is in the optical path between the lens and the light meter located in the prism housing. If an optional focusing screen has replaced the original Ee-A focusing screen, it could affect the amount of light allowed to pass through prior to being measured by the light meter. If the replacement focusing screen is the Ee-D (precision matte grid lines) or Ee-S (Super precision matte for lenses faster than f/2.8) then the camera's menu will allow you to specify such in the settings. The camera will then compensate for the slightly different amount of light allowed to pass through the focusing screen that reaches the light meter. But a slight inaccuracy in metering should not cause your photos to be distorted or blurry unless they are overexposed enough to cause pixel blooming.
Without seeing some example images it is hard to guess what is going on with your camera. It may be that the lens mounting flange is no longer square with the imaging sensor or vice-versa. This could lead to images that look like they were taken with a tilt lens or with a lens with misaligned elements. If the reflex mirror is slightly misaligned it would affect both what you see through the viewfinder and the accuracy of the PDAF system, but wouldn't have any effect on the resulting images (other than an incorrect point of focus - but something that is either closer or further than the intended subject should be in focus).
just stating the obvious
did you try different lenses? you mentioned you have several lenses but did not precise if you tried changing them. if not, you may have a bad lens.
some early models of the 5D had faulty mirror mechanisms. sometimes they would fall or drop and distort the image....also since the focus screen was changed it may not be fixed properly...
but you would see that on the viewfinder before taking the pic....unless you do see it...
if that´s so, you can easily reposition the fs yourself or send it to be adjusted.