First, thanks for a load of good advice. Today was a rany day so I thought I might use the time to check out some of the suggestions made.
So, the first Issue I had to dealwith is locating the place to set the FL of the Lens. It took a bit of digging, but I found it and set the FL for each lens, e.g., The OM at 300mm. Second, I set the C4 button to shift from IBIS to No IBIS.
Third, I went into my treasure trove of Legacy lenses and picked out several WA lenses, to normal and tele, up to the 300mm OM lens.
And using my usual indoor target I began testing to see if the IBIS made any difference with the various FL lenses.
BTW, all of these tests we using a Tripod.
Bottom line is that for the UWA lenses the use of the IBIS seemed to make no difference to my eyes and my ability to detect a diference. All of these comparisions were at F8.0 my preferred aperature for use with these WA lenses. Perhaps wide open there mightbe a decernable difference, but I tend to doubt it given the DoF found with the WA lenses.
My 35mm Canon FD f2.0 seemed to favor the off setting, but the diference was very minor and could well have been due to minor vibration while taking the shots.
The 50mm f2.8 Digma Macro seemed to be slightly sharper when the IBIS was ON.
Suprisingly the 100mm Canon FD f4 Macro seemed to favor the IBIS OFF, but that too was a very small difference.
The Oly 300OM f4.5 seemed to favor the IBIS being ON and here the diference seemed to be much more apparent than with the shorter FL lenses. This prompted me to rasie a question about how IBIS works with shorter vs longer lenses?
Finally to try to get back to something like the real world I mounted the camera and the Oly OM 300mm on a Bushawk mount and went outside (under the portico) and shot several images of a flower pot that had a good deal of detail in its surface. I shot a sting of 5 images with IBIS on and five with it off, all at f4.5, ISO at 1600, and shutter at 1/250 sec. I did not changethe focus and I remained in a consrant position (sitting in a chair using my knee for a rest supporting the camera). Comparing the 1st(IBIS on) with the 6th(IBIS off) and so on for five sets. Bottom line is that four of the five sets favored the IBIS being ON. The image below is one example (set) of the diference that shorwed that IBIS ON seems to improve image sharpness. When using a hand held (Shoulder mounted) camera with the 300mm lens.
First let me thank all for helping me sort out this mess. It was indeed a mess of my ownmaking. I did not know that the FL needs to be set for legacy manual lenses. I did not fully appriciate that this is more likely to improve images when using longer focal length lenses. Of course it, in retrospect, makes sense since any jitter will be more evident with longer FL lenses. Finally, having come to the Sony system from FF Nikons, and never being able to use my legacy lenses on the Nikon, I learned a great deal from this experience and from the thoughtful responses I received to my initial questions.
I will now wait for a bright sunny day and take my OM 300mm lens out to try some Bird shots.
Thanks for all the excellent support.