Cederblad 51 is a part of the large Sh2-264 nebula,
nicknamed the "Orion's head". Meissa is at about 2.5° to the South.
Three main colors are represented: red of the large H-alpha emission
nebula (catalog name: GN 05.30.0), blue of the reflection nebulae (they are the Ced 51) and brown of the dust nebulae (many dark nebulae such as: LDN1574, 1577, 1580, 1581, 1597).
Total exposure is quite short due to veils and do not include a separate H-alpha exposure, so it can be improved much. I keep in the to do list!