I just picked up a Sony 50mm macro lens, slightly sharper but not nearly as nice as the 90mm. Don’t get me wrong, the 90mm is a far superior lens but on a crop sensor it’s like having a 135mm macro. That’s just too much for my set up, my tanks are only 12” deep making top down photos only capturing half of most of my colonies. The 50mm does not have image stabilization and has a very noisy slow focus motor making it useless for video but cost about half of the price on the 90mm.
Here my macro lens journey…
I started doing macro with Sigma 70mm art macro lens for a Sony e-mount. This was a fantastic lens around $400 new at the time. Great fast focus and versatile lens that I took some incredible photos with. This is one of my favorites.

this is a 100% crop of a dragonfly that landed on my sons hand.
About 7-8 months ago I got the itch to try a better macro and eventually bought the Sony 90mm, it was love at first use, but at $1,100 it was an expensive upgrade. Took really incredible photos but on a Crop sensor camera (Sony a6400), I was not getting good light when taking close up pics through the aquarium glass. However with a photo tube I was taking incredible top down shots. Problem was because of my shallow tanks I could not get far away enough to fit whole colonies in.
Two day ago I picked up the Sony 50mm and so far I’ve only played around with it for about 45 minutes. The first picture in this thread is the third photo I took with the new lens. I really can’t wait to push its limits because so far it’s checking off all the boxes of my concerns/wish lists with the prior two macro lenses.