I have shots of the same subject taken with two different lenses of the same focal length. However, one set of shots was done with a 6MP cam, another set with a 12MP one. When I look at the images in Photoshop, a 100% view of the 6MP shots is about the same size as a 66% view for 12MP. Is it fair/correct to compare sharpness in such a setting?
[quote name='Sammy' timestamp='1301678730' post='7298']
I have shots of the same subject taken with two different lenses of the same focal length. However, one set of shots was done with a 6MP cam, another set with a 12MP one. When I look at the images in Photoshop, a 100% view of the 6MP shots is about the same size as a 66% view for 12MP. Is it fair/correct to compare sharpness in such a setting?
[/quote]
No, the downsizing of the higher res. image, be it via downsampling of the actual data (which creates softness) of the viewing at 66% (creating very crappy results), puts the high res. image at a disadvantage.
Best is to print at same sizes without any up or down sampling.
[quote name='Sammy' timestamp='1301678730' post='7298']
I have shots of the same subject taken with two different lenses of the same focal length. However, one set of shots was done with a 6MP cam, another set with a 12MP one. When I look at the images in Photoshop, a 100% view of the 6MP shots is about the same size as a 66% view for 12MP. Is it fair/correct to compare sharpness in such a setting?
[/quote]
Well, if your aim is "to test the lenses at home" (as the topic header suggested), you better test them on the same body. Because given that you don't have a lab (at home <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' />), you will be testing the "system" not the lens. So if you use the same body for two different lenses, you can evaluate the performance of the lenses in a more decent way.
Serkan