background: i do a lot of agricultural and construction site mapping, mostly orthomosaics and the occasional 3D model. been using a Sony a6000 with a fixed 16mm lens on a Gremsy T3 for about two years and honestly the image quality is fine for what most clients need. but ive been looking at the a7R IV just because the resolution bump would genuinely help on some of the larger sites where we need to cover more ground per flight and still hit the required GSD.

the problem is the weight difference is pretty significant and im already close to my platform's max payload on windy days where i need to carry extra battery capacity. curious if anyone has made a similar switch and whether the IQ gains were actually worth dealing with the reduced flight time and having to plan missions more carefully. also wondering if a lighter mirrorless with a better lens might close the gap more than i think ? never really pushed the glass side of things hard enough to know

made almost this exact switch about 18 months ago, went from a6100 to a7R III not the IV but similar story. the resolution is genuinely transformative for large site coverage, you can fly higher and still get your GSD which actually helps with flight time more than you'd expect ? the payload penalty hurts but flying at 120m vs 80m adds meaningful time back. that said you need to be really honest with yourself about whether your clients actually need it or if its more of a gear itch thing. for me it was real client requirements so it made sense.

what platform are you running it on if you dont mind me asking? because the answer might just be upgrading the airframe rather than compromising on the camera. i know that sounds like the expensive answer but sometimes its the right one. a heavier hex or octo with decent motors can carry an a7R IV all day and you get redundancy too which matters on commercial work. lenses though ? yeah dont sleep on that, a sharp 35mm equivalent on a lesser sensor will often beat a mediocre lens on a high res sensor for mapping clarity, depending on your processing pipeline