ATW (auto white balance)

[ramkuma]

I am getting better imagery with the ATW then when I manually set the white balance with a white card. The manual adjustment is too blue/cold. The ATW is warmer and more accurately reflects reality. Anyone else experience this? The intersting thing is that the Vector Scope shows an accurate reading when in manual white balance, but veers to the red and yellow with the ATW. Which would imply that the HMC 150 veers towards a blue (unreal) look.

 

[Barry_Green]

Look at your COLOR TEMP settings. Maybe you have ATW on Ach and manual on Bch, or the other way around, and your COLOR TEMP settings are different for each channel? In any case, you can use the COLOR TEMP setting to manually warm up or cool off each channel to your liking.

 

[averan]

i discovered the same effect, but also noticed that ATW would still come out a little cold.
i edited my scene files to adjust color temp on both my ATW (set to A) and manual WB (set to B), correcting my ATW WB by -1 and the manual WB by -4. to my eye, this produces properly white balanced images, closer to natural 5600k, or what my eye sees.

i made these changes after noticing how consistently red my ATW and manual WB shots all were. i had almost concluded that Panasonic had hardwired red tones into my camera!

now i hardly use manual WB and instead, set it to ATW, then lock the WB using an assigned user button. this way, if i move to another room or the sun comes out on a cloudy day, i can simply click the lock/user button to unlock ATW and let it auto adjust again. its not much different from using manual WB, with the exception that ATW seems to be able to set a good WB without actually having the camera pointed at something white.

 

[ramkuma]

@ Barry:

The ATW is set to the PRSTCh.
Next question would be: if you have to adjust the color temp setting to get a proper look, what is the point of having a white balance? They should call the adjustment a color temp balance.

Thanks to you both for the feedback.

 

[ramkuma]

now i hardly use manual WB and instead, set it to ATW, then lock the WB using an assigned user button. this way, if i move to another room or the sun comes out on a cloudy day, i can simply click the lock/user button to unlock ATW and let it auto adjust again. its not much different from using manual WB, with the exception that ATW seems to be able to set a good WB without actually having the camera pointed at something white.

Why would you lock the WB? Doesn't the ATW automatically adjust the WB, so there is no need to lock it? Or maybe you want to stay in manual mode and and there is no option on the camera (unlike irs and focus) where you can automate the ATW, in the Auto SW settings so that it can override manual?

 

[ggrantly]

ramkuma,

If you use ATW during a shot, the WB may change during the shot, giving you an inconsistent look. The same holds true for auto iris and especially auto focus. All the auto features have there place, but usually not for anything serious.

 

[Mike Harvey]

I almost always only use either the 3.2k/5.6k presets (unless I'm under un-color balanced fluorescent or other oddball lighting). It's always consistent and accurate. Since almost all non-florescent (and more and more fluorescent) falls into one or the other category, it helps eliminate getting "off" looking colors.

 

[averan]

like ggrantly and i said, ATW can change when you don't want it to. locking it solves this problem. imagine a scene in an office: there's an RGB lcd computer monitor on a desk, giving slightly bluer whites, some white office furniture that is painted off-white, a desk lamp closer to 3.2k, and full 5.6k daylight slanting in through a window. ATW would shift all over the place depending on which of those whites you have in the frame. the image would morph from balanced/natural looking, to cold and blue, to orangey-red and back again. so if you're using ATW in this situation, you'd want to lock it once its balanced to the white you want. otherwise, you should use the preset 5.6k or manual wb.

if you're shooting short narratives or something similar, you'll probably be happy with manual or preset WB. i shoot short documercials with LOTS of broll and so am rapidly changing locations with sometimes very different lighting. ATW is faster than manual WB in this situation.

i like taking advantage of the auto functions, like setting the iris to manual, but then pressing the little auto-iris button to quickly set exposure and using ATW but with one of the user buttons set to LOCK ATW so that it doesn't change when you don't want it to.

i used to shoot almost everything with the preset 5.6k, but unless i am outdoors, it is usually slightly off. with a slight colortemp adjustment to my ATW, i get great results and can easily and quickly WB when moving from inside to outside or vice versa.

its what works for me.