I’ve had a chance to try the Raynox 150 recently on both my Pentax M200/4 and my Pentax M100/4 Dental Macro.
The Raynox 150 and 250 are the same optics as the Raynox DCR 1.5 and Raynox DCR 2.5 but come together in a kit with the 52mm mounting plate. These lenses are very well made and are achromatic to deliver nice sharp images without aberrations.
These test results aren’t scientific or even done in a controlled atmosphere. They are just images for you to look at and evaluate to see the quality these lenses can produce.
The Raynox 150 is approximately a 208mm focal length with a diopter strength of 4.8, the 250 is about 125mm and an 8 diopter. Most people choose the higher magnifications of the 250 or 2.5, however with larger magnifications than 1:1 the DOF becomes very thin and the working distance becomes very close. I chose the Raynox 150 mainly for my longer focal length lenses to maintain a greater working distance for more light control while shooting. I bought the kit as I will probably want the 250 for my mid range standard lenses and will post results with those soon.