It depends on the foundry. Several independent type designers have released "Septimus" as a freebie for personal use. However, a similar-looking premium font might exist under a different name (e.g., "Septimus Pro").
Septimus is typically categorized as a with transitional characteristics. It borrows the high contrast of Didone fonts (similar to Bodoni) but softens the sharp edges with bracketed serifs, giving it a warmer, more bookish feel. The "Regular" weight is the workhorse of the family—neither too bold nor too light, making it perfect for long-form reading. septimus regular font free download new
The spacing between letters is uneven. Solution: This is a kerning issue present in older, pirated versions. Go back to the source and download the "new" updated version. Legitimate foundries fix kerning tables regularly. It depends on the foundry