2D classification1

Hello, everyone, when conducting 2D classification, it was found that the image was not clear, It’s like there’s a shadow on the grain, the molecular weight of the protein was 150KD, and DNA was added. The minimum diameter is set to 50A and the maximum diameter to 150A,the box size is 126 px,it’s fuzzy, may I ask if there is any way to improve 2D?thank you very much for your help

This is the original image