I have dreamed 4k video for a while, but think technology and prices are so good now that it was time to skip from full-hd. The transition from fulll-hd / 1080p to 4K goes much slower than expected, much because of. 4k requires powerful hardware for playback and, not least, editing, as well as a lot of bandwidth and much use; storage. I'm above average interested in photo / video and read some tests and saw more comparison videos on youtube before I landed on the AX53.
AX53 vs. AX33: AX53 is the successor to AX33 and the main reason why I chose AX53 is improved optics and that it is significantly better in poorer light conditions due to. larger sensor (eg morning / evening or indoors). 20x optical zoom and 40x full-HD / 1080p without quality loss. - Improved focal length in both directions (26.8-536mm). Aperture of f2.0-3.8, versus f1.8-3.4 on the AX33, which provides better depth of field and due to. larger sensor, it is insignificant that the largest aperture is a little smaller on the AX53.
Sony has by far the most superior image stabilization, with the whole camera body stabilized as a gyro, and not just a lens like "traditional" image stabilization! It's no problem to get a stable image at 20x optical zoom and even demanding conditions like running in terrain runs smoothly! You can choose between standard or active image stabilization, or turn it off completely. For scenes with very much motion, you can shoot full-HD / 1080p with 60fps or 120p (slow motion). It can also take time lapse. There are a variety of manual settings to choose from that are operated with a large "zoom ring" and you decide what the ring should control. Auto mode Sony calls intelligent auto works brilliantly and recognizes and selects settings (auto focus, exposure, image stabilization, etc.) depending on the objects and scenes you are shooting. It will also recognize if you use tripod / tripod. Image stabilization, auto focus and zoom are fast, smooth and, not least, silent, both in use and video recording! Image quality is very good at 4k 100Mbps at best setting (45gb / per. Hour). If you have a 512GB SDXC, you can film for 10 hours. It can also film to .mp4 while it movies to the sony format xavc. Mp4 files are very compressed and become like a "video thumbnail". The colors are natural and the autofocus is usually very good. Mastering demanding lighting conditions like morning / evening with light skies with shine. It overexposes the sky a little, than to underexposure what's in focus. It can also take pictures and the image quality is overwhelmingly good for being a camcorder. It can also film with IR illumination, to film in the dark, which in my part becomes a gimmick, but it's okay to have the option :) The touch screen is sharp and works well even in sunlight (2 brightness settings). Good sound quality with up to 5.1 surround and it can also have external microphone if you prefer (have not tested this yourself yet). Transfer to data and mobile with WIFI or usb and it can also stream! The size and weight are for my use, of course there are smaller and lighter cameras, but then it will go beyond something (eg optics). It is also a bit easier than the AX33.
"Negative": Autofocus, if you do not use intelligent auto, struggle with demanding objects (eg dog) where there is a lot of motion and "untidy" background (eg high grass and scratch). Autofocus often focuses slightly behind the object. This is especially true in poor lighting conditions (morning / evening). With intelligent auto on, there is no problem and you can use touch auto focus.
Negative other on the web have said about the AX53:
Image stabilization is disabled when using tripod / tripod. As said, this only applies if you use intelligent auto. Do not understand why this should count negatively, unless you have a bad tripod ?!
The screen must be open when transferring images using USB or using an external microphone. Again, do not understand why this should be a problem. The fewest people use the applicant anyway.
Some reviews from 2016 say that meta-data (such as length, size, bitrate, etc.) is not registered on .mp4 files. This is fixed in firmware since then.
Conclusion: Definitely 10 out of 10 stars! You can rate the AX33 if you do without slow-motion / 120fps, "only" 10x optical zoom in 4k (possibly going to film most in full-HD / 1080p with 20x zoom), and do not need such a good camcorder as possible in poor lighting conditions. For my part, the price difference is definitely worth it!