The phrase "at first obvious" is not correct in standard written English.
It can be used when discussing something that initially seems clear or evident but may require further examination.
Example: "At first obvious, the solution to the problem became more complex upon deeper analysis."
Alternatives: "initially clear" or "evident at first".
It wasn't at first obvious where Ms. Gelman stood.
Not that conformity to rules was at first obvious to anthropologists who were instead understandably dazzled by the variety in folk taxonomies.
It is not at first obvious how saturated Parade's End is with sex – with memories of it, hopes for it, and rumours about it.
And as it grapples, it is finding that what had seemed at first obvious middle ground -- a domestic partnership system that would offer all the benefits of marriage, like insurance and inheritance rights, without the title -- has few backers at this point.
Phylogenetic trees can tell us more about the patterns and process of evolution than is at first obvious.
Here's what I did not see, at least at first: obvious supporters of Hillary Rodham Clinton, the Democratic nominee who is now the only person who can prevent Donald Trump from becoming the next president of the United States.
AT first glance, it's obvious why "BattleBots," the robot fighting show on Comedy Central, would draw television viewers like passers-by to a car crash.
Although Philip Glass's mimimalism was the first obvious influence at last Wednesday's concert, the music's tight structures soon gave enough to let much more slip in.
That gambit was the first obvious failure at Change.gov, Obama's admirable attempt to create a portal for more open and transparent government.
Sarah Palin seemed at first the obvious suspect.
Even so, the synergies between archaeology and pharmacology are not, at first sight, obvious.
