I did some tests today which only left me confused. I used the 85/2
manually focused at f/2, 2.8, 4, 5.6 and 8 but all shot at f/2. Was the
best shot focused at f/2. No, the best one was focused at f/8. The f/4
shot was grossly out of focus and the others were pretty close to being
in focus as judged by using the Tokina 28-80 at 2.8 in autofocus mode.
But I didn't feel really bad since even one of the autofocus shots was
as bad as my worst. Not sure what happened there.
All of this caused me to question my shooting without glasses. I use
only the built-in dioptric adjustment which does not correct for my
astigmatism which is maybe worse than I realize. So I tried another
test using the Tokina in both auto and manual focus modes but this time
I changed the dioptric adjustment so that all was correct using my
reading specs. Then I was able to take the sharpest shot of the day by
focusing the Tokina (using the DOF preview) at f/5.6 and (without
thinking) shooting at f/5.6 instead of wide open at 2.8. Focus or DOF.
I don't know. I'm tired of testing and going to quit for the day.
Anyhow, I don't really believe the Ee-s screen is an impediment to
manually focusing above f/2.8.
Chuck Norcutt
Chuck Norcutt wrote:
> For those not in the know, the Canyon Ee-s focusing screen is designed
> to assist manual focus for lenses of f/2.8 or larger apertures. If I
> get a chance today I'll try a comparison test with the standard and Ee-s
> screens with the Zuiko 135/3.5. I did try a couple shots with it
> yesterday which seem to be fine but I didn't compare. I did notice that
> metering was quite accurate at f/8. The Ee-s screen works fine with the
> Tokina 80-200/2.8 on auto but, with my eyes, I haven't even tried
> manual. That lens has a minimum focusing distance of 1.8 meters and I
> don't have a Canyon mount extension tube so it doesn't get used with
> anything even approaching macro which is where I'd probably choose
> manual focus.
>
> Chuck Norcutt
>
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|