Hello,
Finally I buy the 5503.
5503, doesn't solve the problem, massive vignetting even with the dome shade removed.
With the 8" (5510.45 + 5510.10), it's...work with the dome shade!
Ike D700, 8" dome (5510.45 + 5510.10), sigma FE 15mm F/2.8 EX :
(F/5.6, 1/60, 200iso)
Except the top right corner, wich is black. (the dome shade!)

Crop 100%

Sometime there is no black corner, it depend of the focus distance.
Not a big issue! Maybe with an another dome shade?