Tamron 70-300 VC sharpness issues - Printable Version +- Opticallimits (https://forum.opticallimits.com) +-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4) +--- Forum: Just Talk (https://forum.opticallimits.com/forumdisplay.php?fid=17) +--- Thread: Tamron 70-300 VC sharpness issues (/showthread.php?tid=3534) |
Tamron 70-300 VC sharpness issues - Guest - 11-27-2010 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... Tamron 70-300 VC sharpness issues - Rainer - 11-27-2010 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. Tamron 70-300 VC sharpness issues - Guest - 11-28-2010 [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. Tamron 70-300 VC sharpness issues - Rainer - 11-28-2010 [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. |