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-   -   EX1 and the (Auto) White Balance (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/120962-ex1-auto-white-balance.html)

Piotr Wozniacki May 5th, 2008 10:34 AM

EX1 and the (Auto) White Balance
 
There have been many posts on this scattered throughout the forum, over the whole time period of this camera availability - but if I am not mistaken, no consensus was reached on whether it's yet another "feature", or "issue"...

While I understand that anything "Auto" is not regarded highly by the "Pro" folks, I still can find many situations when a good AWB system would be useful. Such an excellent system I used with great results on my V1E.

On the EX1, it's simply unfunctional. Or am I completely missing something?

If you guys have found any logic behind how it behaves, please share it.

If not, and you agree with me - has anyone complained about it with Sony? Aren't we being too forgiving about it?

PS: Also, with regards to manual adjustment; Eric wrote elsewhere that "Manual white balance leaves the magenta/green shift neutral, while white balancing with a card will adjust the magenta/green shift". Today I spoiled an important shot, after - having had balanced to 3400 in one room - I moved to another and continued shooting. To my horror, when watching the results later on the big screen, I saw an awful magenta cast in my picture (also, greens were biased towards blue). It was so alarming that - suspecting my camera is out of order - I returned to the location to re-shoot; in the viewfinder I still saw these awful colours and the WB was still set to 3400. I pressed the WB button and - even though it set the WB to the very close 3300 - the change in actual colours was dramatic (the colours became right again). Why is that? Is it normal?

Justin Carlson May 5th, 2008 01:02 PM

I noticed the exact same problem with a shoot I did yesterday.
When I manually WB to 3500 everything seemed a little too green. But when I set the camera to AWB it also read 3500 but had a nice warm feeling that the indoor lighting had.

Piotr Wozniacki May 5th, 2008 01:22 PM

Yeah, well... Another "Professional camera feature", like the infamous IR contamination problem?

I'd really appreciate feedback on the following two points:

1. Why is the AWB so (inconsistently) sluggish?

2. Why is it that the colours measured by the camera's WB system differ from those dialed-into a PP, even if the same Kelvin number is shown (Eric?)?

Mike Stevens May 5th, 2008 01:36 PM

Quote:

Originally Posted by Piotr Wozniacki (Post 872469)
Yeah, well... Another "Professional camera feature", like the infamous IR contamination problem?

I'd really appreciate feedback on the following two points:

1. Why is the AWB so (inconsistently) sluggish?

2. Why is it that the colours measured by he camera's WB system differ from those dialed-in, even if the same Kelvin number is shown (Eric?)?

Piotr:

1) The AWB reaction speed is adjustable. Just go to the camera set menu and speed it up

2) I'd like to know too

Here is a hint: I have my manual WB set to switch A and leave switch B on AWB so it is very easy and quick to switch between them and compare.

Piotr Wozniacki May 5th, 2008 01:47 PM

Quote:

Originally Posted by Mike Stevens (Post 872482)
Piotr:

1) The AWB reaction speed is adjustable. Just go to the camera set menu and speed it up

Mike,

Sorry, but have to disagree again. What is in fact adjustable is just the speed ("shockless" to a varying extent) that the WB will be changed once the ATW system decides to change it in the first place. Whereas, what I call "inconsistently sluggish", is that - when lighting changes - the ATW system sometimes reacts at once, on other occassions - after several seconds, and quite often - never at all.

Mike Stevens May 5th, 2008 02:13 PM

Quote:

Originally Posted by Piotr Wozniacki (Post 872492)
Mike,

Sorry, but have to disagree again. What is in fact adjustable is just the speed ("shockless" to a varying extent) that the WB will be changed once the AWB system decides to change it in the first place. Whereas, what I call "inconsistently sluggish", is that - when lights changes - the AWB system sometimes reacts at once, on other occassions - after several seconds, and quite often - never at all.

Piotr:

You are right. I have just been outside with the camera and I think you have found another bug - hopefully firmware curable.

Try this: Do manual on A outside. Set to ATW outside and reading is same. Go inside so ATW goes down, now go back outside and it STAYS down. Now switch to A measured again to get back to original outside reading and then switch back to ATW and it now stays and reads right! The ATW is fobar! This is the same on all speed and shockless levels.

Mike Mona May 5th, 2008 07:59 PM

Here is a sample I sent to SONY. I had my camera at SONY in San Jose last month for this problem and they send it back without fixing it. It is going back next week, for this and for No Slow Zooming problem.

http://www.drmehr.com/test/ex1_atw.wmv

Guys, please help push SONY to have this issue fixed. There was no camera released in this range so far with such obvious problem left untreated.

What I noticed is that the camera in ATW is more responsive when going from low temp color to a higher temp color, or from bulb to sunlight, and is not responsive when going backward.


I posted about this two months ago but I didn't get too much support so I thought is a bug only in my camera.


Thank you,
Mike

Piotr Wozniacki May 6th, 2008 12:35 AM

Quote:

Originally Posted by Mike Mona (Post 872647)
Guys, please help push SONY to have this issue fixed. There was no camera released in this range so far with such obvious problem left untreated.

What I noticed is that the camera in ATW is more responsive when going from low temp color to a higher temp color, or from bulb to sunlight, and is not responsive when going backward.


I posted about this two months ago but I didn't get too much support so I thought is a bug only in my camera.

Mike,

Your three points above correspond exactly to my own experience:

- I also think that we should be demanding Sony fixes it

- I also noticed the lousiness of ATW on the very first day of having the camera, back in February. When I pointed my EX1 to the sky, it adopted some 6000K in no time. However, going back inside, I waited ages for it to go down to some 3000K, which would be appropriate in the indoor lighting. But then, I attributed it to my operator error, barely knowing the camera

- I also posted about it in my very first post here about my EX having arrived at last....

All in all, I guess this evident flaw has been tolerated becuase - unlike the main problems with vignetting and back focus - work arounds can be found for it (in fact, yesterday's shot was my first one spoiled becuase of the way WB - not even ATW ! - is acting on this camera). But I guess we should now push Sony a little, because - as I said - there are situation when ATW is indispensable (or at least highly useful).

One question to the newer fw users: do you have the same problems with ATW (my fw is 1.03)?

Sean Donnelly May 6th, 2008 05:35 AM

The reason you see different colors from an AWB resulting in 3500k and dialing in that number in the menu is exactly what Eric said. The auto will correct for green/magenta tints as well, where as the manual only affects color temperature. The reason this feature exists is to allow you to adjust the green/magenta bias separately. This IS a pro feature, and I for one am glad it's here. Sometimes you want to maintain the green cast from a mercury vapor lamp for an artistic effect, but still take out the warmth. You can do that by dialing in the appropriate WB manually. Otherwise, you can use the AWB function and make it neutral in both the blue-orange and green-magenta directions.

As far as ATW speed, I can't comment since I don't use it, but Mike it looks like you do have a problem. I usually just keep it in either a or b and WB without a uniform card if necessary. No problems yet.

-Sean

Piotr Wozniacki May 6th, 2008 06:09 AM

Thank Sean for the clarification.

This narrows the problem down to just the hesitant and sluggish way that the ATW is functioning.

Mike Williams May 6th, 2008 08:58 AM

Hard learning curve
 
My first few weeks with the EX made me appreciate how easily the Z1 makes great images.

The second is that the AWB drives me nuts. I need to just kill it somehow. I am still really green with the EX. The thing is almost too much for run and gun event style shooting. You better me on your game or you will butcher many shots.

Anyone else hitting the white balance button accidentally?

Funny I logged on to post about the AWB "feature" because it was driving me crazy :) There is a way to disable it completely right?

Piotr Wozniacki May 6th, 2008 09:04 AM

Mike, your complaining about hitting the WB button accidently is perfectly legitimate one (and no, I don't know how to disable it :).

However, the WB itself works pretty well; the problem you mention is more of the ergonomics nature.

While the ATW (not) functioning is about a real flaw, hopefully fixable with the firmware!

Mike Williams May 6th, 2008 09:20 AM

Button on the bottom
 
Hi Piotr,

For some reason when I had the cam in full auto ( VERY RARELY anymore) the white balance would shift when clouds would go by!!!

In a locked down postion shooting a partially shaded gazebo the color would shift noticeably to blue when clouds would darken the gazebo. Then warm back up as the sun came out again! Just way too much for me. I find the cam is not good in full auto even in a pinch!

The Z1 in auto was fantastic, and I know what the old pros are saying but... I fly the EX on a glidecam and need the auto mode to give me a usable image without a ton of post. I am learning slowly how to make it work but it has been tough.

Mike Mona May 7th, 2008 07:12 PM

Hi Mike W,

It is normal for the White Balance to shift when you change color's temperature(sun to shadow) without readjusting the White Balance.
Your gazebo is turning to blue when clouds go by because the ATW is not working in Full Auto, not because is wrongly working, and that's exactly what we try to say in here. That the ATW is not working either when the White Balance switch is on "B" position(ATW) or in Full Auto mode. Have you seen the clip I posted here on a previous post? It was filmed in Full Auto. Can you try that with your camera, going from sunlight to bulb light in Full Auto mode?

Thank you.

Sean Seah May 30th, 2008 10:47 AM

I noticed the same problem tonight in a hotel ballroom. The lights were orangy and the EX1 was on ATW, Full Auto. The AWG doesn't respond to the temp change when the lights are dimmed or brighten. May I be advised how to handle such situations?


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