Some photographers know how to shoot flat clothes in the shed, but why can't they always shoot clearly? Feeling foggy?

Look, your equipment is a little messy. ...

Let's talk about vague questions first.

1 and 18-200 are dog heads, and low sharpness is normal. The solution is to change them.

The sharpness of 2.50D itself is not ideal, especially when it comes to Jpg. I suggest you convert after RAW.

3, 50D control noise will also reduce sharpness, try to reduce ISO.

4. I don't understand why F 14 is used. Generally speaking, the best sharpness of the lens appears near F8, 18-200. I'm not sure, but it should be about the same. You can check the MTF of this head.

Don't have too much confidence in the iron hand. It may be clear from the camera screen, but it is not necessarily placed in 100%. Let's make it clear and put it on the shelf.

6. If you are on the shelf, remember to turn off IS.

Let's talk about the gray problem first.

My understanding is that the contrast is not enough, one is to check the metering, and the other is the same as Jpg. Shoot directly with raw, and it will be ideal to adjust the contrast later.