> Is the extra weight of the Sigma actually worth the pain for portraits or should I just save the cash and stick with the Nikon prime? Honestly, save the cash. Having shot weddings for years, I can tell you that lugging a massive lens around for 8-10 hours is gonna kill your shoulders and your energy levels. The Nikon AF-S NIKKOR 85mm f/1.8G is genuinely one of the best value lenses Nikon ever made. It is razor sharp where it counts for portraits, the bokeh is super creamy, and it balances perfectly on a body like the D750. I used the Nikon prime for countless weddings and never once felt like the images were lacking. Sure, the Sigma 85mm f/1.4 DG HSM Art is a beast of an optic, but for portrait work, that extra bit of sharpness is often overkill. You are shooting people, not test charts. The weight difference is massive once you factor in carrying camera bodies and a flash all day long. If you are on a strict budget under 700 bucks, the Nikon is the smart move. Take the money you save and put it toward a good external flash or a backup battery, which you will definitely need for a wedding in Seattle. You will be plenty happy with the results, trust me.

Been thinking about your dilemma all afternoon. Honestly, I went through the same exact stress when I started shooting events. I splurged on heavy glass once and it was basically a total nightmare by the time the reception hit. My neck was killing me, and honestly, the client couldnt even tell the difference between the pro-tier heavy stuff and my more modest gear. Here is how I managed to keep things cheap but still get the shot:

• I picked up a used Nikon AF-S NIKKOR 85mm f/1.8G because the price was right and it saved me a ton of cash for other gear.
• I actually grabbed a Godox V860II-N TTL Li-ion Flash instead of spending the budget on an expensive lens, which honestly made my portrait lighting way better than just having a slightly wider aperture.
• Dont overlook the Tamron SP 85mm f/1.8 Di VC USD if you can find one used, the vibration control is a lifesaver for wedding shots when you're tired. I had issues with the Sigma being way too front-heavy on my D750, it just felt unbalanced all day. Save that extra money for a good camera strap or extra batteries. You really dont need to kill your budget to get sharp wedding portraits. Trust me, just get the lighter one and spend the rest on a nice dinner after the wedding is over.

Honestly, the Nikon AF-S NIKKOR 85mm f/1.8G is a total beast for the price. I remember shooting a spring gala with it on my D750 and the autofocus speed was just lightning fast compared to what I expected! It weighs next to nothing, which meant I was moving around the dance floor for six hours without my wrist feeling like it was gonna snap off. The chromatic aberration control on that glass is actually fantastic for the cost. If you really crave that extra stop of light, you could look at the Tamron SP 85mm f/1.8 Di VC USD. I love that it has image stabilization, which is a total lifesaver in those dim Seattle venues where you might be dragging the shutter a bit. The bokeh is super creamy and it feels way more balanced on the D750 body than the Sigma Art series does. Honestly, stick to your budget and grab the Nikon or the Tamron. You're gonna have so much more energy for the actual composition and posing because you arent carrying a lead weight around your neck all day. You'll nail those wedding shots for sure!