These are great, thanks a lot for your thourough run-through. And the good pictures to demonstrate.
(Maybe it works even better on the K20 than K10, since no exposure problems).
Originally posted by stevebrot Sorry you had a bad experience with the split-image screen. Many of us have a long history using this type of viewfinder on film cameras and usage comes as second nature, I guess.
In regards to the stock screen, good vision, etc...
The stock screen is indeed fairly bright. In fact, it appears brighter than it has the right to with most slower lenses. It has micro-lenses (or something like that) as part of the design that create a view with greater overall brightness. The stock screen also has a very even ground-glass field that should be excellent for manual focus. The problem is that it is not very good at all.
That sounds like a pretty blunt statement, but it is based on my personal experience with fast manual focus lenses that I own. Other users on this forum have a similar opinion. The problem is that the apparent depth of field in the viewfinder with the stock screen is greater than the actual depth of field provided by the lens. At taking apertures wider than f/4, the stock screen may present an in-focus image, while the actual final image is clearly out of focus. This issue is present on all of my lenses faster than f/4.
You can demonstrate this by putting a fast manual aperture lens on the camera. Start at the widest aperture and stop down until you see a change in depth-of-field. Typically, you will not see any change until about f/4. Ditto for apparent brightness. Repeat the same test with the KatzEye and you will see what I mean.
Simply put...The stock screen is not optimized for manual focus, nor can you really use it to evaluate DOF prior to exposure.
Sound like my experience also