Jim, I'm wondering if my experience is typical to yours.
I brewed the beer Thursday, 4/26/18. Pitched yeast @ 21:30, at 50*. One pack of Wyeast 2206, dated 3/31/18, in Shaken not Stirred method (one Qt. wort). Which was started at ~12:00... maybe a bit late?
First airlock activity today (4/28) 09:00. ~36 hours.
My lager starters are about 10C cooler than my ale starters. So they are slower at showing sign of activity to the naked eye. Normally, I see activity in my ale starters at 6-8 hrs. 8-12 hrs for lagers. I see air lock activity, usually, with ales at about 24 hrs. But it could be well before that, I don't look every hour... I usually see airlock activity in my lagers by 36 hrs (Morning after 24 hrs) but...
First visible air lock activity is not the best method of determining end of Lag Phase. If your yeast are visibly active (off gassing co2) in your starter, the mothers have finished budding and are fermenting. Maybe some daughters are too. Some daughters are still budding. Bloop, into the main beer wort... more oxygen... more budding... basically "they" are immediately in Log Phase.
How long until they reach max density, and produce enough co2 to overcome retaining co2 at lower than ale temp, and create enough pressure to bubble your air lock? Dunno... But that's not the end of Lag Phase, start of Log Phase. They've been in Log Phase since you pitched the active starter.
By the way - air lock is not a good indicator of phases.
As to infection? I'm not seeing a pelicle, I'm seeing islands of white stuff that might be yeast rafts, or might be islands of foam, or might be... infection. Hard to say from just a photo
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