Hi everyone,
I would like to seek some of the experts' opinions on the problem I am facing. Your comment and advices will be very much appreciated. I collected this lens yesterday and after taking several photos, I discover something don't seem to be right to me. It seems that photos taken at f4.0 and below (smaller f-stop number) were not sharp at all. Sharpness is ok at f5.6 and above (bigger f-stop number).
The following photos were taken with a tripot this morning. Auto focus was switched to "manual" once focus is locked on. In others words, all of the photos were taken without any change in focus length. They were also cropped to 100% and then compressed. No PP was done either.
This test were repeated several times and the results were consistent.
Taken at f2.8 (cropped to 100% and then compressed)
Taken at f3.5 (cropped to 100% and then compressed)
Taken at f4.0 (cropped to 100% and then compressed)
Taken at f5.6 (cropped to 100% and then compressed)
Could this due to FF or BF problem at f-stop below 4.0? Please give me some advice before I decide to send the lens and camera for adjustment.
Many thanks to all of you.
I would like to seek some of the experts' opinions on the problem I am facing. Your comment and advices will be very much appreciated. I collected this lens yesterday and after taking several photos, I discover something don't seem to be right to me. It seems that photos taken at f4.0 and below (smaller f-stop number) were not sharp at all. Sharpness is ok at f5.6 and above (bigger f-stop number).
The following photos were taken with a tripot this morning. Auto focus was switched to "manual" once focus is locked on. In others words, all of the photos were taken without any change in focus length. They were also cropped to 100% and then compressed. No PP was done either.
This test were repeated several times and the results were consistent.
Taken at f2.8 (cropped to 100% and then compressed)
Taken at f3.5 (cropped to 100% and then compressed)
Taken at f4.0 (cropped to 100% and then compressed)
Taken at f5.6 (cropped to 100% and then compressed)
Could this due to FF or BF problem at f-stop below 4.0? Please give me some advice before I decide to send the lens and camera for adjustment.
Many thanks to all of you.