Look, if you are chasing raw resolution numbers and that clinical pop for a wedding, the 75mm is a total beast, but honestly it is way too long for most indoor venues. I remember shooting a reception back in 2018 with just the Olympus M.Zuiko Digital ED 75mm f/1.8 and I spent the whole night backed into corners just trying to get more than a tight headshot. Technical specs-wise, it is basically flawless from f/1.8, but that focal length is a trap for a main wedding lens. In my experience, if you want that Pro-level sharpness without spending twelve hundred bucks on the f/1.2 glass, you absolutely have to look at the Sigma 56mm f/1.4 DC DN Contemporary for MFT. I have run side-by-side tests against the Oly Pro primes and the Sigma actually holds its own in center sharpness even wide open at f/1.4. It gives you that 112mm equivalent reach which is basically the sweet spot for portraits where you still want to see some of the background and dress detail without being fifty feet away. The Panasonic Leica DG Summilux 25mm f/1.4 II ASPH is a beautiful lens, but you are right, it has more soul than surgical sharpness due to some spherical aberration at the edges when you are wide open. For a wedding where you might need to crop in later, I would grab the Sigma and maybe a used Olympus M.Zuiko Digital 45mm f/1.8 as a backup. That combo will smoke your kit zoom in low light and leave you with some cash left over.

Had a sec to think... if you want biting sharpness without the Pro price tag, check these out. I am super satisfied with them. Take a look at Lenstip reviews for the technical charts.

• Sigma 56mm f/1.4 DC DN Contemporary is basically the sharpest thing I have ever glued to my camera.
• Panasonic Lumix G 42.5mm f/1.7 ASPH Power OIS is punchy and works well for close-ups. Both are way under budget and plenty fast for that wedding.

Just noticed this while browsing. Honestly, be careful with that 75mm choice for a wedding. If you're in a tight venue, you'll be backing into walls all night just to get a headshot. Its a great lens, but seriously limited indoors. Since you're on a $800 budget, you might want to consider the Sigma 56mm f/1.4 DC DN Contemporary. It is widely considered one of the sharpest lenses ever made for micro four thirds, even beating out some of the pro glass in lab tests. I'd also make sure to look at the Sigma 16mm f/1.4 DC DN Contemporary if you need something wider for the dance floor. It's bulky but way sharper than the older 1.8 primes. You could actually buy both used and stay under your budget easily. TL;DR: Skip the 75mm for weddings. Grab the Sigma 56mm f/1.4 DC DN Contemporary for portraits and the Panasonic Leica DG Summilux 15mm f/1.7 ASPH for wider shots.