とみると・ とみてon judging that; taking it that
とみると and とみるや tell a story: someone sizes things up and reacts at once. とみて is the news form: the police or a company takes something to be so and acts on it. In both, みる is to judge, not to look.
sizes up, reacts
Once he saw that the other side was weak, his manner suddenly changed.
the news form
Police are treating it as murder and are investigating.
Sizing up, then reacting
Plain form + とみると/とみるや
とみるや is the sharper one, "the instant", and more written. A noun or a な-adjective can drop だ: 不利(だ)とみるや. Also written と見ると.
The news form
Plain form + とみて / A を B とみて
A noun can drop だ here too: 殺人事件とみて. A を B とみて is "taking A to be B". Ending a sentence: とみている. With nobody named: とみられる, "is believed to".
とみると・とみるや: sizing up, then reacting
Met in novels and other storytelling, mostly about someone else, and the reaction is often a calculating one. To a friend you would say とわかると: 弱いとわかると、急に態度を変えたんだ.
The instant he saw he couldn't win, he pulled out.
Once the child saw that his mother wasn't angry, he started playing up again.
とみて: the news form
Who is judging comes first: the police, an agency, a company. とみて gives their working view, which isn't proven, and then what they are doing on the strength of it. It is one to read; in your own writing, と考えて.
From security-camera footage, police believe the suspect headed for the station, and are making inquiries in the area.
Expecting overseas demand to keep growing next year, the company has decided to build a new factory.
The government takes the view that the impact will be limited.
The fire is believed to have started in the kitchen.
Close neighbours
とみえるN2
One kana more, and a different thing: the narrator's own "evidently", from what is in front of them. Nobody acts on it.
The children were evidently worn out: they fell asleep straight away.
ところを見るとN2
Your own guess from something you saw. The sign comes first and the guess ends the sentence. Said in conversation too.
The lights are off, so it looks as if nobody is home.
と考えられるN2
とみられる belongs to the news. A paper or a report writes と考えられる: a conclusion reasoned from evidence.
From the conditions above, the main cause is thought to be the aging of the equipment.
Check yourself
1Has it been confirmed that the man got away in a stolen car?
警察は、
Choose an answer to see why.
2What does 買わないとみるや tell you?
店員は、
Choose an answer to see why.
More sentences
The instant he saw things were going against him, he changed the subject.
The investigating committee took deteriorated wiring to be the cause of the fire, and called for checks on equipment of the same type.
From the latest observation data, the Meteorological Agency judged that the typhoon would move east, and urged coastal areas to be on the alert.
Going by the rainfall upstream, the city expected the river to rise further and opened evacuation centers.