There is nothing to do at home these two days, so I just sorted out current Canon, Nikon and Sony products so that you can navigate when buying a camera.
One, Canon
①Reflex Camera
• 90D (release time: 2019.9)
•7D II (release date: 2014.11)
• 800D (release time: 2017.3)
• 80D (release time: 2016.3)
• 200D II (release time: 2019.4)
• 1500D (release time: 2018.2)
• 3000D (release time: 2018.2)
②Full frame SLR camera
• 1DX III (release time: 2020.1)
• 1DX II (release date: 2016.4)
• 6D2 (release time: 2017.6)
• 5D4 (release time: 2016.8)
• 6D (release time: 2012.9)
• 5DS (release time: 2015.2)
• 5DS R (release time: 2015.2)
③Full-frame mirrorless camera
•EOS RP (release time: 2019.2)
• EOS R (release time: 2018.9)
④Reflex camera
•M6 II (release date: 2019.9)
• M200 (release time: 2019.9)
•M50 (release time: 2018.3)
• M100 (release date: 2017.10)
•M5 (release time: 2016.10)
•M6 (release time: 2017.2)
These are all sorted on official Canon website. You can see from product line above: Canon's product line is very rich and covers all price levels, DSLR, mirrorless, full frame and afterframe. Also for this reason, Canon has a large market share and a large user base.
Second, Nikon
①Reflex Camera
·D500 (release time: 2016.1)
·D7200 (release time: 2015.3)
·D7500 (release time: 2017.4)
·D5300 (release time: 2018.8)
·D5600 (release time: 2016.12)
·D3400 (release time: 2016.8)
·D3500 (release date: 2013.10)
②Full frame SLR camera
·D5 (release time: 2016.1)
·D850 (release time: 2017.7)
• D810A (release date: 2014.6)
·Df (release date: 2013.11)
•D610 (release date: 2013.10)
·D750 (release time: 2014.9)
③Full-frame mirrorless camera
• Z6 (release time: 2018.8)
• Z7 (release time: 2018.8)
④Reflex camera
Currently, there is only one microsingle Nikon Z50 (release time: 2019.10)
This information is collected from official Nikon website. You might think that Canon was created before Nikon just by looking at products. In fact, Nikon was created before Canon, and it is a real enterprise with a century of history. Nikon has strong models like D850 and D5 in terms of full-frame DSLRs, and after-frames of D500 and D7500 also have strong cost metrics.
Third, Sony
①Micro camera
a6600 (release time: 2019.10)
a6500 (release time: 2016.10)
a6100 (release time: 2019.9)
a6400 (release time: 2019.1)
a5100 (release time: 2014.8)
a6000 (release time: 2014.4)
②Full-frame mirrorless camera
a7rIV (release time: 2019.8)
a9II (release time: 2019.10)
a7III (release time: 2018.2)
a7rIII (release time: 2017.10)
a9 (release time: 2017.4)
a7II (release time: 2014.11)
a7rII (release time: 2015.6)
a7SII (release time: 2015.9)
a7 (release date: 2013.10)
Compared to previous two, Sony is younger, so some basic features are not as good as the previous two, such as stability, usability, etc. But also due to its young age, it has produced enough technology, such as everyone said, "Sony Dafa is good."
Summary: The above information is taken from official websites of Canon, Nikon and Sony.