Telephoto conversion lens with Olympus TG-2: image sharpness expectations

[tr88]

I have an Olympus TG-2 and am thinking about getting the TCON-T01 lens for it. I ride my bike in a place that gets migratory birds and they perch in trees about 25 yards from the bike path. I thought I could get some decent pictures of them with a telephoto lens at that distance. But I've read that you have to max the camera's digital zoom to prevent vignetting. When I max the digital zoom with the standard lens, things 25 yards away are quite blurry. Does the telephoto lens correct for that, bringing what is blurry with the digital zoom alone into sharp focus?

P.S. Or is the vignetting not at all extreme when the digital zoom is set to minimum? I haven't found a picture showing the vignetting effect on a small object like a bird at 25 yards distance.

 

[KJ_North]

I quickly took a look a look at the specs of the TG-2. with a native focus range of 25-100 even after adding the convertor (1.7X) your barely out to 170 in reach. I simply do not think that is going to make that much of a difference. For the most part taking decent photos of birds requires zoom up in the 400+ range, and even then you are often cropping more after the fact. Anyways just my 2 cents worth.