White balancing procedure?

[Macfionn]

Could someone please discuss white balancing with the HMC40?

Specifically,
1. What white balancing "hardware" (GretagMacbeth, WhiBal, Porta Brace,etc) is preferred.
and then
2. "HOW" do we white balance properly? The 'actual' procedure... from beginning to end.

Thank you!

[v3rlon]

1. You just need something white. A white piece of paper will do. It just needs to be all white.

2. I forget the exact procedure, but its in the manual...

Put your white piece of paper in the same light you will be shooting (if using ACTUAL paper, make sure it is on something so there is no shadowing from behind).

Zoom you camera in so that all it sees in the white paper, preferably from wherever it will be shooting from (i.e. on the same tripod in the same place you will film from)

Then do the white balance procedure in the manual (which I do not have memorized yet, sorry. I could only halfway walk you through it, but the instructions seemed clear to me when I read them and did it myself).

[dan.carter]

Macfion,

I use a small white baby washcloth that I can stick in my pocket as a WB target.

Zoom on white.

Use the WHITE BAL button to cycle to AWB Bch.

Hold the button down till you see AWB ABB Active.

Release button (LCD will go black for a second), then you'll see AWB ABB OK.

[BobDiaz]

Just a side note, not every white is a true white. I know that sounds funny, but we do have warm shades of white and cool shades of white. For example, a white wall may be painted with a warm white; where the yellows are reflected stronger than the blues. A wall painted with a cool white would have the blues reflected stronger then the yellows. If one white balances on an off white source, your color will be off.

One can find a pure white paper or card stock at any stationary store. Just make sure the paper or card stock is in the exact same light you plan to video in and be sure to zoom into the paper or card stock so it fills the screen. The paper does not have to be in focus for white balance to work.


Bob Diaz

[Robert M Wright]

I just use white copier paper. Works fine.

[Macfionn]

Thanks everyone. I appreciate the replies.

I've just been noticing that a lot of white balancing items comes with white, 18% grey and black.
The white I gathered, but NOT the grey and black.
And THEN you get something like the Tiffen color separation guide w/ gray scale. (http://www.amazon.com/Tiffen-Color-Separation-Guide-Scale/dp/B00009R7G9/ref=sr_1_97?ie=UTF8&s=photo&qid=1265048141&sr=1-97)


I've just been getting poor shots (in auto, of course) and so I'm trying to fumble my way through the advanced settings. I may be letting myself make certain elements harder than they are, but i just can't seem to find a "pro video camera usage 101" ;)

Thank you again! :)

[Bic Parker]

Sometimes you may not want a white or even grey card ...

A trick that a video producer friend of mine gave me (he's been shooting commercials for 30 years now) was to use a light blue card as a white balance reference when you want to warm the picture a bit (sometimes useful in certain indoor shots and shots where you are getting an overall blue tint to everything). I've added that reference card to my arsenal and it has solved my color balance issues in a number of instances.

An alternative might be to use something like a "warming" filter (I have one, btw).... but if you can get the white balance set to your preferences, that might not be necessary.

[Bic Parker]

Here is a link to a vendor that sells such types of WB warming cards:

http://www.warmcards.com/WC1.html

[Macfionn]

Thank you much, Bic! :)
How does the black fit in, though?

[v3rlon]

see the manual for the camera on "black balance" :)

Also...

How does the blue card white balance compare to doing the same thing in post? I mean, can't you do the same thing in your favorite color correction system and save $90 against those cards?

[Bic Parker]

see the manual for the camera on "black balance" :)

Also...

How does the blue card white balance compare to doing the same thing in post? I mean, can't you do the same thing in your favorite color correction system and save $90 against those cards?

The short answer is that I want the best quality and quantity of data per frame before going into post. You could do change the temperature in post, but that action may go against other adjustments or color corrections you make.

If I have the choice of correcting the image while shooting the raw footage or in post, I will take the footage any day. At that point (post), it is kind of like making a copy of a copy. Especially if you have other corrections or adjustments to make in post. You will essentially be affecting your histogram of data and will likely degrade the original data, or at the least introduce other artifacts with which you will have to deal.

Generally, if I am using the blue card, it is because I need to warm the image to correct it, not to over correct it. I'm trying to "center" the histogram in all of the colors as best as i can. That means I will have to most data to work with later on in post. More data means I will have more latitude with adjustments without degrading the image (although, if I have to make large adjustments, then I am not really doing my job right in the original raw footage).

[sonuxxx]

Do you white balance before you put on the 35mm adapter or after you put it on?

[Macfionn]

see the manual for the camera on "black balance" :)

RTFM doesn't apply to my question. I wasn't asking how to black balance.
I was asking "why".

I always hear about white balancing, but never heard of black balancing. How many people do it? And for those that do, how much does it improve your picture on top of white balancing?

[v3rlon]

There is an explanation in the manual... How to do it, when to do it (when you first get the camera is one, change of enviroment (temperature), or if the camera has sat idle for a long time) and so on. However, I do not have the manual with me, so I can't copy and paste the instructions for you, but they are in the manual. I am just not at home with the manual.

You specifically asked "How does black balance fit in?" So, I pointed to the manual that you (and I, not picking on you) should be trying to absorb because it tells when and how to do it. It doesn't say why, but I would gather from the when that it is like an extra fine tuning to help get things in shape. As to how much it improves your picture, I can't say. The manual said do it to a new camera, so I did.

Also, you could always google "why black balance camcorder" to land some meaningful results including this one (http://www.dvxuser.com/V6/showthread.php?p=107156) in these very forums. Does that help?

[ShugPro Digital Studio]

A black balance card serves no purpose with the HMC40...

from the manual:

When white balance adjustments are performed, black balance adjustments are performed at the same time.

Black balance
Adjust the ratio between the three RGB primary colors to reproduce black accurately. If the black balance is not adjusted properly, not only will black be reproduced poorly, but the color tones of the entire screen will also be downgraded. Black balance adjustment is usually not necessary, but be sure to perform it in the following cases.
• When using the camera for the first time.
• When using the camera after extended periods
of disuse.
• When using the camera after large changes in
ambient temperature.
• After setting the shutter speed to standard or low
speeds.
• After switching between progressive mode and
standard (60i) mode.

INSTRUCTIONS:
1 Use the AUTO/MANUAL switch to set to manual mode. (Page 40)
2 Set the shutter speed. (Page 50)
3 Place a white pattern in a location with the same lighting conditions and light source as the subject, then zoom in and fill the whole screen with white.
Something white (a white cloth or wall) near the subject can be used instead.
• Do not include bright spotlights in your shot.
4 Press the WHITE BAL button to display Ach or Bch.
The mode changes in order from ATW→ATW LOCK→P3.2K→P5.6K→Ach or Bch→ATW with each press of the button.
5 Touch the LCD monitor and display theFunction Navi.
6 Touch (the arrow icon) to display the operation menu.
7 Touch Ach or Bch. (you can store 2 user set white balance settings in the camera)
8 Press and hold the WHITE BAL button.
• Adjustment takes a few seconds. (The following messages appear on the screen.)
Message during adjustment AWB ABB ACTIVE
Message after adjustment AWB ABB OK
• An error message appears on the screen when white balance adjustment is not possible.
Message when adjustment cannot be done
AWB NG

[BobDiaz]

Do you white balance before you put on the 35mm adapter or after you put it on?

While I don't have a 35mm adapter, thus don't use one, I would say put on any adapter & filter(s) first, then white balance.

WHY?

Because in the unlikely event there's some slight color shift due to something you add on, this takes care of it.

Also, because it's something you have to do anyway, all that changes is the order on doing it, so there's no more work involved. As you can see, I'm pushing the "Just to be safe" logic here. :)


Bob Diaz

[Bic Parker]

I used to do a lot of astroimaging (cooled CCD) (still do from time to time) and there are different types of calibration images that have to be taken to address different types of systematic noise sources. One type (darks) addresses the imager/sensor noise while the other (flats) addresses optical train noise. For the latter, flats capture a lot of issues that aren't easily visible in the raw images, but significantly improve the quality of the final images. I learned a lot about how important the management of the optical train can be.

The white balance function is a type of calibration that works on both imager/sensor deviations as well as optical train effects. Anything you put on the optical train will affect the white balance. While the resultant effects may seem slight, they are cumulative with all other calibrations and may, in the end, have a very visible effect on the final raw footage, especially with respect to your signal to noise ratio. A powerful proof of this is to examine the comparative histograms of your images, bearing in mind that the tails of the histograms primarily contain noise.

So, essentially, if you do anything to change your optical train (lenses, filters, alignment of polarizing filters, etc.), you should re-adjust your white balance. You may not notice the difference initially, but it may likely be helpful in post.

[Macfionn]

Thank you Shrug.
Until I reformat my system, I am out in the cold.
adobe pro and reader are both corrupted and closing everytime i open a .pdf. remove & reinstall doesnt fix the issue, nor did an install of a third party reader such as foxit.
And no reformatting can be done until my new ext. backup gets here.

Since panasonic doesnt seem to think an actual 'book' would be warranted in the case of this 2000 dollar camera (wth?!), ive been hobbling on what i can find via what I find here & search engine.

[v3rlon]

Ouch..that one sucks, Macfionn. I had something similar a while back...


I had to uninstall reader, reinstall/repair acrobat, the reinstall reader, if I recall correctly.

The order made a difference.

[Macfionn]

Ouch..that one sucks, Macfionn. I had something similar a while back...


I had to uninstall reader, reinstall/repair acrobat, the reinstall reader, if I recall correctly.

The order made a difference.

I tried the repair, but not in that order.
I'll do that. would HATE to reformat if I can get around it. Rest of CS3 works fine. Just the .pdf issue.

[ShugPro Digital Studio]

in the meantime, i'd be happy to copy and paste here or email you jpegs of any parts you need.

[Macfionn]

Thank you, Shrug! Thats very kind of you. :)
i'll avoid cashing that chip in if I can, but still nice that you would offer it.

[Spec-Comm]

If you're considering purchasing white balance / color correction cards, another great option is the CoverLens.

It's a soft lens cover that goes over the hood. It includes, among other things, white balance cards. We were very pleased with the quality of the cards -- and since the 40 doesn't have a lens cap, it kills two birds with one stone. ;)

CoverLens (http://www.spec-comm.com/store/index.php?l=product_detail&p=760)

Best,

Jasmine Moore
Administrative Assistant
Specialized Communications / Noventri
20940 Twin Springs Dr.
Smithsburg, MD 21783-1510 USA
800-359-1858 (US)
301-790-0103
Fax: 301-790-0173
jasminem@spec-comm.com
www.spec-comm.com
www.noventri.com