Just testing the 70-300 VC compared to the old non-VC Tammy. At 300mm the VC lens is just not sharp. The subject distance information in the EXIF data is astonishingly different between the two lenses. E.g. for a distant subject the old lens reads "infinity", the VC 28.2 meters, which is definitely incorrect. For a closer subject the old lens reads 16.8 meters, the VC 14.1 meters. What kind of focusing issue do I have here? Of note, the DOF for a subject in 15 meter distance at 300mm/f5.6 would just cover 0.55 meters. Looks as if I have to return the VC...
11-27-2010, 03:25 PM
(This post was last modified: 11-27-2010, 03:25 PM by Rainer.)
I wouldn't take the distance information in the Exif-data too serious.
(this is not a distance-meter ... its just a lens).
Compare an image that you focussed with AF with one that you
properly focussed via lifeview, and see if there is a difference worth
mentioning.
[quote name='Rainer' timestamp='1290871522' post='4499']
I wouldn't take the distance information in the Exif-data too serious.
(this is not a distance-meter ... its just a lens).
Compare an image that you focussed with AF with one that you
properly focussed via lifeview, and see if there is a difference worth
mentioning.[/quote]
Well, I suppose for contrast-based AF calculation of the subject distance is in a sense just a by-product. Anyhow, what I do take serious is the lack of sharpness, my sample of the Tamron 70-300 VC is obviously defect and will be on its way back next week.
[quote name='Sammy' timestamp='1290936915' post='4512']
what I do take serious is the lack of sharpness, my sample of the Tamron 70-300 VC
is obviously defect and will be on its way back next week.
[/quote]
You sound quite determined. Seems you already have excluded
any other cause of error.
