GrandmaG wrote:
I have the same question as the OP and I found your answer helpful. However, I was also considering upgrading to the a7R4 or a9. Do you prefer one over the other?
As far as Sony full frame camera bodies go, I have the a9, a7Riv and two copies of the a7Riii. My favorite and most used are the a7Riii bodies. I find that 42 megapixel sensor to be sublime; I love it.
I rarely need the speed of the a9. I do, however, like the extra dial on top of the a9. Since some of the functions are on that dial instead of in the menu like on the a7 series, it has, on occasion, caused me to pause to think when working with both the a9 and one of the a7 series bodies. If working with only an a9 series body, the selection of those functions can be a tiny bit faster - probably just a fraction of a second if you’re proficient with both bodies.
For me, I do like to use the a7Riv with the 100-400 (or other lenses like 135mm or 90 Macro) when I go hiking or trying to catch birds in flight so I can crop heavily in post processing. Of course, I can also crop a lot using the a7Riii, just not as much as the iv.
The a9 and a7Riv may have a little more responsive autofocusing but I haven’t noticed much difference from the a7Riii.
I guess you can already tell my love for the a7Riii. In my opinion, it’s the best bang for the (now reduced) cost. The extra speed or extra resolution provided by one of the newer bodies is overkill for most users.
A couple of more comments:
My copy of the 100-400 does exhibit lens creep. It extends completely to 400mm while hanging by my side. It doesn’t bother me though. Most of my shots are taken at the 400mm focal length anyway. I’m still surprised how sharp they are.
Last year, my first a7Riii with 100-400 lens dropped from about 3 feet. Of course, I cringed when I heard the thud as they hit the wood floor. Sure enough, both were damaged. I had Precision Camera out of Austin send them to Sony for repair. (I know how blessed I am to have been able to ...) immediately order a new copy of each. I love them both and couldn’t bear to be without either. When the repaired items came back, I kept the a7Riii body. That’s why I have two. Can’t bear to part with either of those identical bodies. I sold the repaired 100-400 to a fellow photographer (who is one of the best photographers I know and way more knowledgable than me). She recently used that repaired 100-400 lens almost exclusively on an extended photo trip to Africa.
Hope this helps a little bit.