I need to photograph a wall with multiple paintings with every painting under sharp focus. I believe depth of field doesn't play here as all the objects are at same distance. I tried with higher shutter speed and higher f-numbers but it only gets crisp image where focus points were floating.
Edit1: ●I am using kit lens 18-55 STM of Canon EOS 200d/SL2(alias in other regions). ●The wall is about 12×15 feet. To summarize, it seems like the camera is only capturing few objects in focus and thus sharp leaving the other objects slightly blur. This behavior can be observed in general photography too where only few parts of the Product(say a bag) would be crisp and other parts slightly blur.