Ive been shooting with the R series since the a7R II came out, and honestly, the jump to 61MP with the a7R V is a whole different beast. It really exposes every little flaw in your glass. I used to be obsessed with 85mm for everything, but my journey actually led me somewhere else once I started doing high-end commercial headshots for a living. I eventually settled on the Sony FE 135mm f/1.8 GM and it was a total game changer for my workflow. Here is why: when you have that many pixels, the compression you get from a 135mm makes the bokeh look way smoother than an 85mm ever could, even at f/1.4. Plus, the autofocus motors in the newer GM lenses are linear XD, which means they actually keep up with the insane real-time tracking on your body. Old screw-drive lenses just wont cut it anymore. One practical tip tho... that high resolution means you can use the APS-C crop mode and basically turn a 135mm into a 200mm equivalent while still having plenty of megapixels for a large print. Its basically like getting two lenses for the price of one. It is a pricey piece of kit, ngl, but if you are doing this for work, it pays for itself in the lack of missed focus shots. If the 135mm is too long for your studio space, the Sony FE 85mm f/1.4 GM is okay, but it is definitely showing its age compared to the newer glass on that high-res sensor.

Ive been shooting with the R series since the a7R II came out, and honestly, the jump to 61MP with the a7R V is a whole different beast. It really exposes every little flaw in your glass. I used to be obsessed with 85mm for everything, but my journey actually led me somewhere else once I started doing high-end commercial headshots for a living. I eventually settled on the Sony FE 135mm f/1.8 GM and it was a total game changer for my workflow. Here is why: when you have that many pixels, the compression you get from a 135mm makes the bokeh look way smoother than an 85mm ever could, even at f/1.4. Plus, the autofocus motors in the newer GM lenses are linear XD, which means they actually keep up with the insane real-time tracking on your body. Old screw-drive lenses just wont cut it anymore. One practical tip tho... that high resolution means you can use the APS-C crop mode and basically turn a 135mm into a 200mm equivalent while still having plenty of megapixels for a large print. Its basically like getting two lenses for the price of one. It is a pricey piece of kit, ngl, but if you are doing this for work, it pays for itself in the lack of missed focus shots. If the 135mm is too long for your studio space, the Sony FE 85mm f/1.4 GM is okay, but it is definitely showing its age compared to the newer glass on that high-res sensor.

Honestly, if you're looking for the best bang for your buck on that 61MP sensor, I'd go with the Sigma. The original Sony FE 85mm f/1.4 GM is a classic, but the Sigma 85mm f/1.4 DG DN Art is actually sharper when you're pixel peeping at that high resolution. I've used both on my R series bodies and the Sigma just feels punchier and resolves detail better in the corners. The bokeh is super smooth too, basically indistinguishable from the GM in most real-world shots. It's also way lighter which really helps if you're doing long headshot sessions. Plus, you save a ton of money. That extra cash could go toward lighting or even a Sony FE 35mm f/1.8 to round out your kit. For the a7R V, you really need glass that can keep up with the sensor, and the Sigma delivers.

I have spent a ton of time shooting with the a7R V and honestly, that sensor is a beast that really demands the best glass. While the 85mm debate is a classic, you really shouldnt overlook the Sony FE 50mm f/1.2 GM for pro headshots. I know it sounds a bit wide, but the resolving power is insane and it handles the 61MP resolution better than almost anything else. The bokeh is just butter. If you are dead set on that 85mm focal length tho, definitely look at the newer Sony FE 85mm f/1.4 GM II over the original. It is way lighter and the AF is actually fast enough to keep up with the a7R V's tracking. If you have the studio space to back up, the Sony FE 135mm f/1.8 GM is arguably the sharpest portrait lens Sony makes. It is basically a surgical tool for skin detail.

Just catching up on this thread. Before I give a final vote, are you mostly shooting in a studio with strobes or are you doing more outdoor/lifestyle headshots? It makes a huge difference in how much you will care about autofocus speed and lens weight. Basically, while the Sony FE 85mm f/1.4 GM has that beautiful rendering everyone talks about, it is getting a bit old. On a high-res body like the a7R V, the Sigma 85mm f/1.4 DG DN Art is usually the more practical choice. It is lighter, cheaper, and honestly resolves the 61MP sensor a bit better in my experience. The Sigma was designed for mirrorless from the ground up, whereas that older Sony GM can sometimes feel a bit sluggish with its focus motors. If money is no object and you need the absolute best integration, Sony is great, but the Sigma delivers 95% of the performance for way less cash. Are you planning on doing any video with this too, or is it strictly stills?