Lack of sharpness at f1.8 on Canon 50mm STM

John Sheehy wrote:

norman shearer wrote:

All pics taken wide open by my 10 year old grandson who was using my 5D Mk1 for the very first time.

Looks like you may have done some cropping, which we really need to know to consider how the DOF is working out. Standing farther away and cropping increases DOF, and also brings the background relatively closer to the subject.

just a little off the top..

I will have to try this lens on the Mk2 and see if the focus needs some micro adjustment which is a possibility and I suspect part of the perceived variability. That said I think it is sharp enough on the 5D Mk1 to not be a concern,

You can look at that from two perspectives; if the camera you have is a 12.5MP FF, then there is less visible penalty for using a softer lens than there would be with a 21MP FF, but the 21MP will always have more resolution than the 12.5MP, even if the pixels look sharper from the 12.5MP at 100% pixel view.

I plan to test it on the 5D Mk2 soon although the recent arrival of the 70-200/F4L IS needs testing too. I guess I'll take out both bodies again and have the 50mm on the Mk2 this time.

One plus for the original 5D, however, is that its color filters are stronger and separate color better than the 5D2's filters, when you are shooting well-exposed images at low ISOs.

I didn't know they weakened the Bayer filter on the 5D2. I knew the colors changed on every model and some folks disliked the changes enough to revert back to earlier models. I've yet to form an opinion on that yet though.