You asked
What are the alternatives to the voigtl nder ultron vintage line 28mm f 2 aspherical?
I don't list other lenses against the Voigtländer Ultron Vintage Line 28mm f/2 Aspherical yet. Its page only covers the Leica M bodies it fits. It's a full frame, manual focus prime.
If you want 28mm for street work, the Street guide points to the Ricoh GR, a 28mm equivalent compact that fits in a trouser pocket. It's a different route, since you'd be giving up interchangeable lenses. The same guide also suggests a small mirrorless body with a pancake prime if you want to keep changing lenses later.
If a slightly tighter view appeals, Voigtländer's 35mm f/2 Aspherical is the sibling lens. Check its page for the cameras it fits.
Written by Claude from this site's pages.