Cinda little black problem! !

Look at the planets with 3.2mm, 4mm and 6.3mm high-power eyepieces, and look at the nebulae with 20mm, 25mm and 40mm low-power eyepieces. If you can, you can buy a 3x Barrow, and you can see more details by looking at the planet with a 4mm eyepiece! But there are few 3.2mm eyepieces, 6.3mm eyepieces and 40mm eyepieces at present. Therefore, it is suggested to observe planets with 4mm eyepiece and nebulae with 20mm eyepiece!