Its just physic, you either need a big lens to maintain big aperture on a big sensor or use a smaller sensor to achieve the 10x. S23U 10x is already f4.9 with that sensor, if it uses the same 1/2.51" sensor, you probably get something like f8 unless you increase the size of the periscope which will affect the phone thickness ultimately.Bro, I dunno what you mean. The s23 ultra's zoom is 1/3.52" sensor. Isn't that smaller than the what you said about the XM13U?
If the 13U spec is true, i think the 5x periscope is quite redundant, it is only 1.6x the telephoto with possibly a slower lens. At least S23U periscope is 3x the telephoto which makes more sense.
It is a downgrade in size, but might not be the case with photo quality depending on the sensor and processing. Just look at apple and pixel, they have some of the smallest sensors on any modern flagship phones.Other than the main camera, the triple rear camera sensors would be very disappointing if it is true that they are the Sony IMX858. It seems that this sensor is only 1/2.51" in size, which would be a downgrade from the 1/2.0" periscope and ultrawide sensors on the back of the 12S Ultra. Also much smaller than the 1/1.56" zoom and ultrawides on the Oppo Find X6 Pro. Seems like Chinese brands are deliberately trying not to outdo Apple and Samsung in global markets.