18% Grey Card App for the iPhone

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BertRoot

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Worth a look if you fancy it? At $0.99 it seems worth a try?

Independent iPhone developer Jeremy Bassett has announced iGrayCards 1.0 for iPhone and ipod touch, an alternative for the photo enthusiast to carrying physical Gray Cards. iGrayCards digitally generates a neutral 18% gray that can be used to balance white in image processing software.

The card can also be set to any gray setting from black to white, giving a wide range of gray cards in the photographer's pocket. 18% Gray is the industry standard used by professional photographers worldwide to compensate for different lighting situations. iGrayCards is the digital solution for the iPhone.

iGrayCards features:
* 436 x 320 pixel digitally generated card
* 18% Neutral Gray default setting
* Slider Control for setting 0 - 100% Gray
* Card Presets
* Info displaying Preset or Custom Setting when card is displayed

iGrayCards is the ideal App for the digital photo enthusiast who does not carry or own Gray Cards. Simply by including the running App in the frame to be photographed, it can be referenced in most modern image processing software to set the White Balance point for the whole image. Using just one image a whole set of images taken under the same lighting conditions can be set. Each generated Gray Card using the custom setting is digitally calculated to be perfectly accurate and the slick user interface enables the user to swap between the generated card and settings with one touch.

Supports all leading Image Processing Software including:
* Photoshop
* Lightroom
* Google Picasa
* PaintShop Pro
* Aperture

Pricing and Availability:
iGrayCards 1.0 is only $0.99 (USD) and available worldwide exclusively through the App Store in the Photography category.
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http://iclarified.com/entry/index.php?enid=7448
 
Does this not depend on how the brightness is in the phones settings? Surely not as reliable as a proper physical card in pocket.
 
for 59p I thought it worth a go, different brightness settings change the colour dramatically, I personally will stick to proper cards. Hopefully they will update with recommended brightness settings.
 
davekiddle said:
Why not just take a photo of a grey card on your iPhone and save 59p? :D
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:bonk: :lol: totally agree, the other issue being is the Iphone screen calibrated correctly and regularly. If it isn't, you won't get 18% grey :shrug:
 
Surely the biggest problem is that the program is generating a grey, and light can't reflect off this (but instead is produced by the screen?).
 
Kanine said:
Surely the biggest problem is that the program is generating a grey, and light can't reflect off this (but instead is produced by the screen?).
Click to expand...

No, the biggest problem is that cameras don't meter off 18% grey. Even if you got the tone 'right' the 18% bit would still be wrong. You can of course compensate relatively easily enough, but you need to a) know that you have to and b) know by how much.
 
But surely this generated grey would look the same grey regardless of the lighting/environment? Which wouldn't then work as a grey card...
 
Why not meter off your own palm (I mean of your hand, not some other type of smartphone :)) at approx +1.3 stops for white skin, which is what I need, or whatever works best for your own skin tone? Dark skin will need a lower figure.

BTW, grey cards are for setting EXPOSURE, not white balance. A palm makes an effective substitute for a grey card for setting exposure, if you know what adjustment factor you need. It does not matter if your palm is pink/brown/yellow, so long as you determine how bright (reflective) it is relative to a proper grey card. It doesn't need batteries and rarely gets left at home.

As for metering off an iPhone display - what a ridiculous idea! Seriously. It's just plain nuts. Grey cards are about measuring reflected light from a surface of known reflectivity, not a device which itself emits light and has all sorts of other variables with reflections etc.. What sort of exposure reading would you expect to get from an iPhone in the dead of night in a pitch black room?

A grey card might function as a white balance card too, if it is neutrally toned, but they are not all designed for white balancing purposes and may not be spectrally neutral. The idea of using a grey card (white balance card) for setting white balance is to assess the colour of the incident light hitting the card. Again, what possible use is it to measure the light being emitted by an iPhone? The app isn't worth 1p. It's not even worth 0p since it's a waste of time if not money - unless you use the iPhone as your only light source.
 
Right, thread is making me dizzy...gone round in circles just ten too many times.
 
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