Coffee Filter For Custom White Balance Settings?

[stewart_photo]

Since I recently lost my white plastic sheet, I'm looking for a replacement (something different) to obtain custom white balance settings with my K10D and K20D. I see some use Expodiscs, Expocaps, ClearWhite, and similar products, but must admit the plain old coffee filter especially appeals to me.

So I'm looking for some specific advice regarding the latter. Is there any particular coffee filter brand to use or is this based on the notion that most white paper is generally white enough? Is there any trick to using this under various lighting conditions - ambient, flash, indoors, outdoors, or whatever? What if the light where you're standing is not the same as the light on the subject some distance away?

Thanks for your kind advice and guidence.

stewart

[Wheatfield]

Heck, I've used everything from paper towel to Kleenex to bond paper for white balance. It all seems to work fine.
I recall seeing a specialized white balance tool that was slightly blue, which would push the WB to the warm side, and with this in mind, I would stay with white or bleached paper, which tends to have a slightly cool colour cast. My guess is that unbleached paper will impart too cold a WB to be pleasant.
As white balance really must be measured from the subject, if you can't get to the subject you are probably best to shoot RAW and tweak the white balance during conversion.

[Peter Zack]

In my bag are a couple of large diameter old filters that are the same size and the glass removed. I just took 1 (Melita I think for our coffee machine) filter and sandwiched it between the 2 rings and screwed them together. Stays flat and I just point the lens at the subject and correct the camera. Fast, simple and seems to be quite accurate.

Like WF I've used just about everything from walls to t-shirts and all do a decent job.

[kerrowdown]

Hey, I'm just mean (no confirmation on this please ), cos I'm still using the old Kodak Gray Card I bought twenty odd years ago.

You remember them, grey one side white the other.............................

[Frogroast]

I've used white towels, white shirt collars (4 layers of whiteness), socks, whatever works! One thing I haven't tried - tidy whiteys, White cotton undies, boxers, or briefs

I've heard a lot about the coffee filter trick though I've never tried it myself - anyone have any opinions on this?

[J.Scott]

I use the Whi-Bal card. It's very consistent and accurate. Whi-bal

[stewart_photo]

Originally Posted by Wheatfield

Heck, I've used everything from paper towel to Kleenex to bond paper for white balance. It all seems to work fine. (snip)

I've often used available sources of white as well, but it's occasionally nice to have a predictable source (a fixed point that can be reproduced). For example, once I've obtained the colours sought by a particularly picky client, it's just easier to tweak the WB settings for subsequent images or reshoots when starting from a fixed WB point.

(snip) As white balance really must be measured from the subject, if you can't get to the subject you are probably best to shoot RAW and tweak the white balance during conversion.

The reason I asked about a subject some distance away is because I can often obtain custom WB settings using a card in these situations (have subject hold the card and zoom in) and was wondering exactly how this was handled with these devices. I encountered a situation like this recently (a model in a pool lit mostly by pool lights versus me roughly 10-12 feet away under a different type of lights), so this was simply on my mind.

As for Raw & post-processing, since clients often want to see something close to the finished results before declaring a session finished, I usually try to get things as accurate as possible in the camera while shooting.

stewart

[stewart_photo]

Originally Posted by J.Scott

I use the Whi-Bal card. It's very consistent and accurate. Whi-bal

I've used cards (my own white plastic sheet), but have never tried these devices attached to or held in front of the lens. That's why I posted questions here. Based on what I'm reading (and have read elsewhere), another card may still be my best choice.

stewart

[Mike Cash]

I made a Flickr set showing how I used an unused step-up ring and a lens guard (clear) filter to make a coffee filter WB disk. Makes it easy to hold it over the end of the lens and you can just slip it in your pocket like a lens cap.

Here's a composite showing how it did on the K100D with AWB on the left and the coffee filter on the right. This was taken under very harsh sodium floodlights. The white should be a little off-white (as it is) since I am not the most diligent person in the world about washing my truck.

Click on the image to view it in a larger size

[Wheatfield]

Originally Posted by stewart_photo

I've often used available sources of white as well, but it's occasionally nice to have a predictable source (a fixed point that can be reproduced). For example, once I've obtained the colours sought by a particularly picky client, it's just easier to tweak the WB settings for subsequent images or reshoots when starting from a fixed WB point.

IF I'm shooting under studio lights, I have a fixed WB that I dial in. I spent some hours one day dialing every camera we use into the same WB so that all our work would start from the same point.
Beyond that, for us it just doesn't matter that much.
I would be a lot more dependent on a white card if I was still doing significant amounts of product shots though.

The reason I asked about a subject some distance away is because I can often obtain custom WB settings using a card in these situations (have subject hold the card and zoom in) and was wondering exactly how this was handled with these devices. I encountered a situation like this recently (a model in a pool lit mostly by pool lights versus me roughly 10-12 feet away under a different type of lights), so this was simply on my mind.

Gotcha. In this case, I don't really think it matters what the distance is, as long as you can get enough of the white card for a reading, you should be fine

As for Raw & post-processing, since clients often want to see something close to the finished results before declaring a session finished, I usually try to get things as accurate as possible in the camera while shooting.

stewart

Our strategy is to send the client away for a few minutes while we quickly download the images to our preview computer. We do a very quick cull of the obvious garbage and can do a global WB/ exposure tweak at that point if need be

[stewart_photo]

Originally Posted by Wheatfield

(snip) Our strategy is to send the client away for a few minutes while we quickly download the images to our preview computer. (snip)

I wish it were that easy to get rid of my clients for a while. I made the mistake over the years of being a bit too friendly with them or their employees, so now many like to "help" wherever possible. It's fun at times (try to make it so), but an irritation otherwise (especially if things arent' going well and I'm trying to concentrate).

stewart

[stewart_photo]

Originally Posted by Mike Cash

(snip) Here's a composite showing how it did on the K100D with AWB on the left and the coffee filter on the right. (snip)

Interesting, Mike. I've seen that image before sometime back, but wasn't aware it was accomplished with coffee filter. I'm going to experiment with all this for a while and then make a decision.

stewart

[Peter Zack]

In the case where the subject is further away and when possible, I'll walk up to them and use the coffee filter disk to take a reading close to them. The best device I've tried (but don't own) was "the colour balance coach". I was at a 'hands on' weekend seminar with Jean Francois O’Kane and he used these all the time. I used it quite a bit in studio and outdoor shooting, fast and spot on accurate. http://www.boothphoto.com/prod_detai...etail_data.cfm
They are like the POP tent designs with a flexible wire in the rim to twist and fold up small and made from a colour fast fabric. Gray cards are good for about 2 years (they fade and cardboard/paper will not hold a dye accurate forever ) and these are supposed to last a lifetime.
The idea of the disk was to get both an accurate WB but also a perfect exposure.

The thing works perfectly and I will get one myself this year as work increases.

[TaoMaas]

Originally Posted by Wheatfield

I recall seeing a specialized white balance tool that was slightly blue, which would push the WB to the warm side, and with this in mind, I would stay with white or bleached paper, which tends to have a slightly cool colour cast.

I think they're called WarmCards. Videographers use them a lot. I usually just carry a folded up sheet of copier paper in my back pocket and use that. I'm sure it's not ideal, but it's cheap, pretty accurate, and so easily carried that I have no excuse not to use it.