Confusing White Balance Experiment !! Explanation Please :)

[fjrabon]

If it's an incandescent lamp the colour temperature will depend a lot on the wattage and the type. 2850 K is just an average value. Plenty of household lamps will have a lower CT.

Apart from differences in illumination (eg reflections from adjacent coloured materials, which can have a surprisingly significant effect) there are variations between the 'neutrality' of different grey cards:

Put the small card on the larger target to make sure they are in the same light.

Edit: I see that you did that while I was writing my response. As I said, different grey cards can be different 'greys'.

Thank you Helen, that explains it very well..

Now the big question, which one to use?

Really, now that you know the difference between the two, it doesn't really matter. Shoot in raw and then you can make a batch adjustment depending on which one you used, if it's not what you like. If you want to just know which one is more accurate, then see if you can find an expo disc and compare them. Expo discs aren't necessarily better than cards, though some people like them more, but they're a known accurate quantity when it comes to WBing. That would allow you to get a baseline, and then from there you can know how much you need to adjust WB wise in post depending on which card you used.

I'd probably use the little when when I didn't have space and didn't need the exposure balancing parts of the big one.

 

[Samerr9]

hence why I prefer an expo disc for WB. They cost a little more, but you don't really have to worry about these sorts of issues.

I am considering buying an expodisc or xrite color passport (next month). I preffered the passport because the expodisc will fit one lens, so I will have to buy many or change lenses everytime I need to set WB which is not very flattering for me..

I don't know what to tell you. I like the middle one best. I can see the difference in the small white balance card in the two samples. It's entirely possible that one of them is not 100% neutral. There isn't a whole lot of difference between the two when you look at the numbers.

True, they are giving different results and I like the middle one more also.

Why worry about the difference between the two? Pick one, and run with it.

That is what I do at the end But, if we have a better understanding and be picky for a while it will help us in the future and we will have better results.

Thank you all for joining and helping out

 

[Samerr9]

Really, now that you know the difference between the two, it doesn't really matter. Shoot in raw and then you can make a batch adjustment depending on which one you used, if it's not what you like. If you want to just know which one is more accurate, then see if you can find an expo disc and compare them. Expo discs aren't necessarily better than cards, though some people like them more, but they're a known accurate quantity when it comes to WBing. That would allow you to get a baseline, and then from there you can know how much you need to adjust WB wise in post depending on which card you used.

I'd probably use the little when when I didn't have space and didn't need the exposure balancing parts of the big one.

That is exactly what I will be doing. Thanks for the advice.

I was trying to be picky just to nail it and go on without thinking much about the WB issue..

 

[KmH]

Also white walls are rarely actually white. Most wall paint colors have a slight yellow tint to them.

By the same token, white copy paper is also rarely white. Most copy paper has a slight blue tint.

Not all gray cards or other gray targets, like the one in your test photos, are accurately gray.

Look at the Whibal card, if you want a good gray target to use for setting a custom white balance.

I used Whibal cards and the X-RITE color passport target.

 

[Samerr9]

Also white walls are rarely actually white. Most wall paint colors have a slight yellow tint to them.

By the same token, white copy paper is also rarely white. Most copy paper has a slight blue tint.

Very true.. I tried using grey things in the fram to fix the WB and it fails in most of the time. It always needed more tweaking..

 

[fjrabon]

hence why I prefer an expo disc for WB. They cost a little more, but you don't really have to worry about these sorts of issues.

I am considering buying an expodisc or xrite color passport (next month). I preffered the passport because the expodisc will fit one lens, so I will have to buy many or change lenses everytime I need to set WB which is not very flattering for me..

I don't know what to tell you. I like the middle one best. I can see the difference in the small white balance card in the two samples. It's entirely possible that one of them is not 100% neutral. There isn't a whole lot of difference between the two when you look at the numbers.

True, they are giving different results and I like the middle one more also.

Why worry about the difference between the two? Pick one, and run with it.

That is what I do at the end But, if we have a better understanding and be picky for a while it will help us in the future and we will have better results.

Thank you all for joining and helping out

You can use a step up adapter for different filter sizes. Though what I tend to do is just get an EXPOdisc for my most convenient lens, WB with that, and quickly change if need be.

 

[Samerr9]

You can use a step up adapter for different filter sizes. Though what I tend to do is just get an EXPOdisc for my most convenient lens, WB with that, and quickly change if need be.

I will check on the adapters. It is the first time I hear about them

Thank you for the tip.

 

[Helen B]

There's no real reason for an Expodisk to be inherently more accurate than a grey card, if both are properly used, is there? Equally, there's no reason a plain white Styrofoam cup shouldn't work just as well. The Lastolite EzyBalance folding target is one of the more accurate targets, it's quick to use, packs fairly small and it doubles as a small white reflector (it's grey on one side, white on the other). I guess the same could be said for your three step folding reflector, especially as it gives you three points to WB on in post. There's a heap of useful gadgets out there, like the Spyder Cube, all with a bit more functionality than a plain white or grey card.

As already mentioned, it's rare that white balance needs to be really accurate anyway, and when it is a single white or grey target isn't usually enough - you need to either use a full profile or correct neutrals and some colours. This is common in the video world, where between 6 and 12 (or even more) colours are used.

I've posted these a few times before, but I'll post them again. Here are the companion graphs I made with the grey card one above. Some day in the fantasy future when I have lots of time I'll update them with data from more targets. Notice how neutral the plain white Styrofoam (expanded polystyrene) cup is. Also notice how good the plain white kitchen paper is. In case you don't already know this, white kitchen paper makes a good clean white reflector.

 

[fjrabon]

There's no real reason for an Expodisk to be inherently more accurate than a grey card, if both are properly used, is there? Equally, there's no reason a plain white Styrofoam cup shouldn't work just as well. The Lastolite EzyBalance folding target is one of the more accurate targets, it's quick to use, packs fairly small and it doubles as a small white reflector. I guess the same could be said for your three step folding reflector, especially as it gives you three points to WB on in post. There's a heap of useful gadgets out there, like the Spyder Cube, all with a bit more functionality than a plain white or grey card.

As already mentioned, it's rare that white balance needs to be really accurate anyway, and when it is a single white or grey target isn't usually enough - you need to either use a full profile or correct neutrals and some colours. This is common in the video world, where between 6 and 12 (or even more) colours are used.

I've posted these a few times before, but I'll post them again. Here are the companion graphs I made with the grey card one above. Some day in the fantasy future when I have lots of time I'll update them with data from more targets. Notice how neutral the plain white Styrofoam (expanded polystyrene) cup is:

I don't think ED's are necessarily more accurate than a good GC, but they're a known quantity, mostly because of how popular they are. Random grey cards, some are awesome some aren't. I wasn't necessarily advising him to buy an expodisc, more saying since they're a known, single brand quantity, he could try to find a friend with one and use it as a baseline to figure out which of his two is more accurate. The Lastolite EzyBalance could work equally as well, since it's a known quantity. Really any of the most popular, name brands would be good for getting a baseline. The off brands, some work just fine, some aren't actually 18% grey, the only way to really know is to compare it to something that is known.

 

[table1349]

Now the big question, which one to use?

The one that most closely replicates proper color. Non scientific method, shoot the same three, or for my money the two targets but place in the scene a red object, blue object and a green object. No they won't be dead on right for true RBG, but you have the objects to compare too. Take the shots and see which one represents the colors most accurately. Choose that target and be done.