1945-S Wheat Question And Suggestions Needed

Weak strike or Struck Through Grease for sure. Not cleaned.
Pics are very good, bigger with higher resolution would be better.
The microscope pic is great, I wish I could do that.

The weak mintmark is the result of two things going on- it is an LDS(late die state) coin as seen by the heavy die flow lines in the close up and the mintmark was also a victim of a weak punch on the die. Prior to 1990, all mintmarks were applied to dies by hand with a punch. A mintmark could be strong if the punch was hit hard or it could be weak if the punch was hit softly.

As for improving your pics, the use of a tripod or copystand is mandatory for taking macro photos of coins. Lighting is also critical, you want nice white light but you also do not want to create glare or shadows. We have a nice photography section on the forum, I invite you to check it out for more in-depth details on camera settings and the like.

I'm not the expert but...

Your pics are on the right track. Lighting was somewhat off but not horrid. Focus was good. Date/mm shot is sweet. For general purposes they are great in fact better than most ebay pictures. For grading you will want larger but not necessarily better pictures.

The obverse pic's light was left sided. Try to even the light source out around the coin.
I like the bright white "daylight" fluorescent twist bulbs. I use one at 9 and and one at 3 o'clock and hold one over the camera when I shoot. I do not allow the flash as it tends to be too much.
The tighter the focus the more light you need so maybe that would account for the date/mm pic being dark.

Post some more in the photo section and you'll get feed back.

Nice 45S :)

Photos are OK as far as I can see. True could be a bit lighter but no big thing since the clarity is really great. Neat little double tail on that 9. 4 has a little of that too but the 9 is really noticable and looks like a 3D type of image.