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M8 - White Balance and gray card


hiphop

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Need advice on white balance :

 

1 - can we use a gray card (in the hand) knowing that the focus with a 28mm at such a short distance is impossible (I believe a correct focus is needed when using the grey card - min 0.75 m)

we can drop it on the ground but in some cases it is better to keep it in the hand.

 

2 - do you recommand a grey card for the M8 or the options like Kelvin and DNG processing are fair enough

 

3 - any experience with the "WhitBal" gray card and if known would you recommand the small one or medium one for outdoors shooting ?

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Hiphop,

Couple of comments:

 

a) A whitecard does not have to be in focusyou can hold it close with your left arm for example. What is important is the light falling on the card and that you have the card filling your field of view.

Imagine a mixed light situation with bluish daylight and a tungsten light bulb. If you hold your whitecard close to the lamp, but you shoot your subect next to the window, you will be off.

 

B) In my opinion the best approach is to set an approximate whitebalance via the Kelvin option and for more critical shots use a whitecard or expodisc. You learn quite quickly how certain light conditions translate to Kelvin settings (say sunny daylight ~ 5600K; bluish shadows ~ 6000+ etc.). In addition you see the approx. result on your LCD.

 

I set most of the time an approx. Kelvin value, shoot, and look for something that should be neutral grey or white in the image via LCD; then adjust the Kelvin value up or down. And yes, for more critical cases, use one of the mentioned reference tools.

 

That way I have not had any significant problem with auto-whitebalance or the available presets - I don't use them at all. I always set my own Kelvin value.

 

Peter

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Do a search on "White Balance" in the forum, there's a lot of information here, and your workflow will depend on whether you need to set WB beforehand (JPEG) or in post (RAW).

 

Having said that, a grey reference is probably more effective than a white reference (the experts are split on this, but light grey seems to be the consensus).

 

But if you're doing a custom WB, then of course you want something light enough to give the camera a chance.

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I know a lot of people swear by Expodisc, but be careful, it isn't 100% foolproof.

 

If you point your expodisc covered lens at a bright red wall, then your colour readings are going to be out-of-whack. This should be obvious, but it can bite you. Expodisc works best if you point it at average coloured scenes which contain a general mix of colours.

 

Pretty much like reflected light-meters & light intensity readings really.

 

Speaking as someone who has struggled with colour balance for @ 10 years (having to shoot interior 360 x 180 degree panoramas), your best bet is to use colour reference cards. Either a white-card designed for WB (at a pinch a sheet of white paper will do), or else photograph a grey step-wedge colour calibration target. Ideally you'll do both :?)

 

This is for critical work and what I do. The WB card gets the colour balance mostly right. The multi-grey card contains a number of grey panels of differing intensity. You use a photo of the card as an eye-dropper target in your RAW converter or Photoshop to fine-adjust the RGB values at each different grey-intensity level.

 

And - oh yes - for really critical work you also have to use CC filters, for if there isn't enough blue light falling onto your sensor or film, then you've got to boost it via a filter (most of the time an 80B will do).

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I carry a (clean) handkerchief in my (left) jeans or shirt pocket pocket, and simply drape it over the camera (and lens!) - click and its done. Works fine - costs nothing. Yes you do have be a little careful where you point the camera. Costs nothing.

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Quite interesting...

 

Then it seems that people prefer :

 

1 Expodisc - the star

2 WhitBal (pocket) comes 2nd but very easy to use (or grey card)

3 Kelvin setting

4 handkerchief is my favorite but needs to be tested (too good to be true)

 

I have now all the most usual options and exciting time testing them...

 

Many thanks !

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Bill,

 

Yes indeed, a White (!) linen one - maybe need to take care that there are no excessive 'whiteners' in the washing powder - these might cause a 'blue tinge' rather than a neutral white - but it is all an approximation.

 

David

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I carry a (clean) handkerchief in my (left) jeans or shirt pocket pocket, and simply drape it over the camera (and lens!) - click and its done. Works fine - costs nothing. Yes you do have be a little careful where you point the camera. Costs nothing.

Works indeed. I just tried with a nice handkerchief (with tungstene light) Perfect !

I did it as well with a Leica lens cleaner (if you want to use professional tools... :-) works as well. Tomorrow I shall try with daylight.

If it works in other situation the same way I can start saving the money I would have spent with various other expensive options and soon buy an extra lense...

Great !

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I use the WhiBal and occasionally check things with a Gretag-McB color checker, an IT8 photoprinted target and Imatest. But since I am not making a living having skin tones come out where the owner of the skin thinks they should be, I tend to take color balance as an artistic tool, not a scientific question, and set it by hand sometimes.

 

scott

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