is 40mp too good for lenses?

In January, I moved over to Fuji, from Canon APS-C (M series). I spent a lot of money on lenses. I've never had to return/change so many due to inconsistant softness (more on one side than the other). I'm just returning a Tamron 18-300 and I want to change my 70-300 for that reason. I've never noticed it on any of my previous camera/lenses - all Canon. I only really notice it when pixel peeping, but it does annoy me.If it's the same softness both sides, I am OK with that - it's when one side is worse than the other that I want it fixing.

So, is the 40mp sensor too good and I am picking up inherent faults which have always been there on all lenses, or is Fuji (and Tamron) quality control just not that good.

I do have some lenses which are fine. My 16-80, my 10-24, my 23 & 33 - all seem OK. But the 16-80 is the second one.

I now have two X-T5 bodies. Which eliminates the body as a source of the problem.

Here's one from my 70-300. Right hand side is a lot softer than LH side

Thoughts from the experts?

Alan

If you have a 40 Mp sensor, you need lenses that are good enough to take advantage of it. Otherwise why have it?

😀

David

Possibly - but why so different?

No, I always have X-mount lenses.

Alan

Pixel peeking isn't really a good way of evaluating relative quality, because you're very liable to be comparing different magnifications. Suppose you compare 26 and 40MP images via pixel peeping. You're looking at the 40MP image at 1.24 times larger linear magnification, so don't be surprised if it looks more blurry. The way that imaging works is that all sources of blur contribute to the final blur. That includes lens aberration blur, diffraction blur and pixellation blur. Assuming the same lens and settings, then if you increase the pixel count you'll get less pixellation blur, and the overall blur will be smaller, that is the image will be sharper. If the lens is the resolution bottleneck then the extra sharpness will be very small, but it will still be there. Ideally a camera should have a pixel count high enough that all your lenses are the bottleneck, then you know that you're getting the best from all the lenses.
It's a funny thing, people wondering if their pixel count is too high. They rarely ask if their lens is too sharp for the camera, but that's essentially the same question.

To get the most of the lenses that you have. Increasing pixel count always increases resolution. If the lens isn't so good, probably not by much.

I don't mind a bit of blur, but what I expect is that it is the same on the left as on the right. If it isn't then I assume the lens is faulty.

Is my assumption correct?

Alan

Interesting reading. The first thing I notice is (assuming I've read it right) is that for a 300mm lens at F5.6, the target needs to be 9 metres away. Why so far away when the lens will happily focus much closer? blog.kasson.com/lens-screening-testing/lens-screening-distances/aps-c-lens-screening-distances/

Alan

Thank you. Yes, that explains it. But my issue with lenses is the differing levels of softness at left and right. I am not sure I need the complexity of a Siemens Star and all the tests I would need to run to see if a lens is not performing correctly. Actually, Donalds idea of turning the camer upside down would do nicely if I had a tripod mount on the top of my camera.

But in the absense of that, I will continue to test using bricks.

Alan