The Canon 85 doesn't feel as sharp and has a little more CA than the Samyang. And personally I like the way the Samyang renders the OOF areas... a reason I might look to the Youngnuo 50mm over the Canon. I don't like the pentagonal highlights from Canon's nifty fifty which is why I finally ditched it.
But you hit the nail on the head, it's what you do with what you've got. Cheap, expensive or anywhere in-between, it's just a tool.
This appeared in Luminous Landscape's recent year-end wrap-up, and I think it says it nicely:
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"It's not the camera, it's the photographer." Right. We get it. You've now impressed us with how insightful you are. But in the world of music, there are few serious musicians, let alone performing pros, who wouldn't prefer working with a Strad or a Steinway. Good artists are made better though the use of the best tools. Enough said.
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The reality is, compare the premium 17-55/2.8 lenses versus the basic 18-55 kit lenses... It's hard to honestly say the premium lens is "worth" 5 to 10 times the cost. The kit lenses are capable of very good results, especially if shooting in good light, or with flash. Especially with most people just sharing their photos in social media, not printing wall-sized prints, your typical viewer will never notice the slight differences in IQ.
But the enthusiasts among us, including myself, to take some perverse pleasure in getting their images just a little bit sharper.. or getting the bokeh just right.
Our non-photographer friends and family, when viewing our photos, won't realize whether the bokeh is a little busy or not. They are unlikely to notice that the corners are slightly soft. But as our own eyes have become more finely trained, we notice it more.
I recall going on a cruise a while ago. Despite complaining I take too many pictures, my wife is addicted to getting the cruise ship photos as well. So she was trying to choose which family portrait to order.... And she kept going back to one that was, technically, one of the worst. It was clearly out of focus. It was front focused by a few inches, the faces were soft. This was in an 8X10, it was obvious to my eye. No need to pixel peep. But she didn't even notice if was out of focus, and simply liked the way our daughter was smiling in the shot. (After much persuasion from the cruise photography person as well, she finally chose a shot that actually was in focus).
My point...... Ultimately, the better gear can indeed produce better results. But the differences are often very minor, and won't even be noticed by the vast majority of people viewing our photos. On the other hand, we will notice -- so we are ultimately marketing towards ourselves.