I bought a gray card but it's too big for me to carry around. What am I supposed to do with this thing even?
[EXIF data available. Click here to show/hide.]
Camera-Specific Properties: Equipment Make samsung Camera Model SM-G900P Camera Software G900PVPU3BOG1 Maximum Lens Aperture f/2.2 Sensing Method One-Chip Color Area Focal Length (35mm Equiv) 31 mm Image-Specific Properties: Image Width 2048 Image Height 1152 Image Orientation Top, Left-Hand Horizontal Resolution 72 dpi Vertical Resolution 72 dpi Image Created 2015:12:08 10:34:52 Exposure Time 1/30 sec F-Number f/2.2 Exposure Program Normal Program ISO Speed Rating 80 Lens Aperture f/2.2 Brightness 2.4 EV Exposure Bias 0 EV Metering Mode Center Weighted Average Light Source Unknown Flash Flash Focal Length 4.80 mm Color Space Information sRGB Image Width 2048 Image Height 1152 Exposure Mode Auto White Balance Auto Scene Capture Type Standard Unique Image ID F16QLHF01SB
>>2717683
>I buy things without knowing why
>>2717683
I think those are pretty much unnecessary now that you can just change the white balance in lightroom.
>>2717702
lolwut.
I went to a camera store and asked the guy what I needed to take good photos. How do I use it? Can I cut it up into smaller pieces and do I have to like fill the whole picture with it?
>>2717683
This only tells me two things:
- You're not even wearing a backpack.
- You have a shit camera that can't into AWB.
>>2717707
Ken Rockwell advises travelling light. Backpacks are too much gear.
>>2717702
Gray cards are for metering, not white balance. Though they can help with WB as well.
>>2717706
It's for complicated lighting situations and very simple light meters that don't handle them well. You put the card in the light that your subject will be in, and then point the camera at it in spot metering mode. Then, you "match the needles" and you will have a perfect exposure.
Meters believe that everything should be that shade of gray, so it can get confused with white or black subjects, and tell you to expose incorrectly. But modern meters are pretty smart, and so the need for a gray card is sort of like the need for changing your oil every 3K miles.
>>2717712
LOL WUT
>>2717712
match the needles?
How do I do that? I just need to change EV or contrast or lightness to get a peak at some point in the histogram?
>>2717717
Ignore that guy, he has no fucking idea what he's talking about.
>>2717717
On your meter. When your lens is pointed at the camera, you make it so that the dot in your viewfinder telling you whether you're under or over exposed falls right on the center 0.
(in old film cameras, the meter was a needle that would move up and down, above and below that center needle, so to make your exposure +/- 0, you would "match the needles")
>>2717720
This is kind of confusing. Imagine I am in sunlight. I am going to photograph a totally white wall. How do I use the gray card to fix the exposure? Do I fill the whole frame with the gray card and get the exposure setting from the given light source? If I then take a photo of the wall won't the exposure be wrong? Then imagine if I did the same exercise with a totally black wall (not shiny).
Or are my examples bad? It's based on the idea that "normal" scenes are 18% gray I think? So if I take a photo of a normal scene and use the gray card beforehand like I described above, it'll work out ok.
>>2717724
Like I said, ignore that guy, he has no idea what he's talking about.
Grey cards are for white balance.
>>2717726
And, I mean, you COULD use a grey card for metering if you know that the card is going to be lit with the same light as your subject. In the case of your white wall, you would meter the grey card. There are lots of situations where you could totally fuck up your exposure trying to use a grey card, however.
[EXIF data available. Click here to show/hide.]
Camera-Specific Properties: Equipment Make SAMSUNG Camera Model SM-G900P Camera Software GIMP 2.8.10 Maximum Lens Aperture f/2.2 Focal Length (35mm Equiv) 31 mm Image-Specific Properties: Image Orientation Top, Left-Hand Horizontal Resolution 72 dpi Vertical Resolution 72 dpi Image Created 2015:12:08 11:41:00 F-Number f/2.2 Exposure Program Normal Program Metering Mode Center Weighted Average Focal Length 4.80 mm Color Space Information sRGB Image Width 563 Image Height 1000 Exposure Mode Auto White Balance Auto Scene Capture Type Night Scene Unique Image ID F16QLHF01SB_
>>2717739
No need for that shit in the age of histograms, instant review and WYSIWYG viewfinders.
>>2717734
Wow, you dumb.
Grey cards are used for metering.
Put it where your subject (that you want to be middle exposed) is, take the shot, remove card, take actual shot with same settings, edit gray card shot using gray card, copy settings to photo without gray card.
>>2717884
>Grey cards are used for metering.
They haven't been in like 15 years bruh. You're reading some outdated info.
>>2717888
Sooo the fundamentals of photography have changed???
That's odd. Because they haven't.
>>2717692
such is the burden of those with too much money and not enough self control.
I have a really nice 16 port gigabit switch sitting in the other room when my 8 port switch has only 5 of its ports in use. But hey, it was cheap on ebay.
>>2717917
Right, exactly. That's outdated info, nignog. Are you shooting film? Or are you shooting digital?
>>2717926
Digital. I took photos in a weird space and the colors were way different from shot to shot. So I asked the camera guy and he told me to buy that card. But it's too big for me to carry around. He also showed me this sort of folding cloth thing that was a reflector on one side and gray on the other.
>>2717926
that doesn't change the purpose of the card, it just means that the card itself is nolonger needed.
>>2717702
It would be useless if you COULDN'T change white balance.
>>2717952
It TOTALLY changes the purpose of the card. Far and away the most common use of grey cards these days is for white balance, which is what OP should be using it for.
>>2717972
OK. Is white balance determined by the 18% gray formula? The camera just takes all pixels then chooses white balance based on what makes the scene 18% gray? Or is the 18% stuff just for exposure?
>>2717991
>Is white balance determined by the 18% gray formula?
Nope.
And in fact it's better to take a white balance reading off a darker gray because it reflects less of the nearby objects.
>>2717745
None of that gives you an objective and consistent exposure.
Might not always be necessary, but for example with product photography you might want consistent results over multiple sessions and under varying lighting.
>>2717991
Isi posted something about using an out of focus ace of spades for a wb card
>>2718016
OK I'll try it in a sec and post the results.
>>2718016
Wait I can't do it. I was going to try and take 2 pictures 1 using the custom white balance on my camera and then 1 without. But the instructions for my camera say to shoot a *white* object. Seems like there needs to be a calibrated white card to do this then. That guy ripped me off.
>>2718023
Fuck me never mind. There's a note at the end of the instructions that say an 18% gray card can give better white balance. So I will try it.
>>2718024
Really, you should be shooting in RAW, not jpeg, and using lightroom's color dropper tool.
It made a difference that I can see. I guess the bottom one is better. I used flash in e-ttl mode I don't know if that matters for this test.
>>2718033
I always shoot RAW+jpg. I'm not good at figuring out the right colors after the fact.
>>2718011
using a reflective piece of card with an unknown colour quality.
Yep, that sounds like Isi.
>>2717712
A grey card is to get an accurate meter in camera as well as a white balance. For even more accurate colour balance, you use a ColorChecker Passport.
