As a fairly veteran and experienced Photoshop user, when scanning, it is really best to get the best scan possible, initially, than using Photoshop, afterwards, to try fix any issues from not having enough control of over the initial scan.
If you want/desire more control of your initial scanned images, look at VueScan and check to see if it is compatible with your Microtek scanner model.
I have been using this software for over a decade and it is very comprehensive and works very well on both low end and higher end scanners.
It is well worth the asking price.
Thank you :-)