How do you date Canton export porcelain?

[Hmm]

I'm assuming plate 1-3 are pre-1850?  While plate 4, maybe around 1870s?  And lastly plate 5 being 1880s?  In addition, are they jingdezhen?
imgur.com/a/NGaAt

Thanks.

[peterp]

1 is Qianlong, 2+3 Qianlong to Jiaqing, 4 has a body that may be older than the decoration, 5 ??
1-3 look like Canton painted underglaze blue, not sure about the other two.