first pic taken wont have the specified white balance, the second one will

[aguaviva]

Repro case:

import gc
import machine
import time
import camera

class webcam():

    def __init__(self):

        self.saturation = 0
        self.quality = 10
        self.brightness = 0
        self.contrast = 0
        self.vflip = 0
        self.hflip = 0
        self.framesize = 8
        self.led = machine.Pin(4, machine.Pin.OUT)

        res = camera.init(0, format=camera.JPEG)      #ESP32-CAM

        camera.speffect(camera.EFFECT_NONE)
        # WB_NONE (default) WB_SUNNY WB_CLOUDY WB_OFFICE WB_HOME
        camera.whitebalance(camera.WB_OFFICE)
        camera.saturation(self.saturation)
        camera.brightness(self.brightness)
        camera.contrast(self.contrast)
        camera.quality(self.quality)
        camera.flip(self.vflip)
        camera.mirror(self.hflip)
        camera.framesize(self.framesize)

    def snap(self):
        image = camera.capture()
        return image

import uos
uos.mount(machine.SDCard(slot=2, width=1, sck=14, mosi=15, miso=2,  cs=13), "/sd")

server = webcam()

def getTimestampStr():
    rtc=machine.RTC()
    y,m,d,w,h,m,s,_ = rtc.datetime()
    return 'wb_%02d%02d%02d%02d' % (d,h,m,s)

def takepic():
    image = server.snap()

    time_str='/sd/%s.jpg' % getTimestampStr()
    print(time_str)

    print("sd:")
    print(uos.listdir('/sd'))

    with open(time_str, 'wb') as f:
        f.write(image)
        f.close()
    gc.collect()

#set 'home' white balance
camera.whitebalance(3)

# this first pic wont ahve the correct white balance
takepic()
time.sleep(2)

#this one will be the good one!
takepic()
time.sleep(2)

camera.deinit()
uos.umount('/sd')

print("deep sleep...") 
machine.deepsleep(5000)

[aguaviva]

Actually it was the sleep what made things work:

camera.whitebalance(3)
time.sleep(2)
takepic()