Expodisc

They were very popular at one time, but I think they'd need careful use, how would the sensr know what was a light source and what was reflected light? I think a colour checker passport is a more sensible option for critical work.
 
It works as advertised, though it's a flawed concept in some situations and IMHO there are better and easier ways of setting accurate white balance - like a simple white balance card.

If you want to go that route, there are far cheaper alternatives, eg £7 https://www.amazon.co.uk/JJC-White-...528715&sr=1-1&keywords=lens+cap+white+balance Though the Exposdisc also does 18% grey incident light meter readings and it's not clear if these cheaper options also do that out of the box.

Agree with Phil, if you're after really accurate colour, then the Macbeth system with camera calibration is the way to go, eg ColorChecker Passport.
 
Opps sorry forgot to thank both of you for your advice, still thinking to get or not.
 
Well decided to get one,right or wrong. The colour red on my Nikon D800 has always caused me a problem not that this will get it sorted but have to try. So as I have a bit of spare cash now etc etc. Had to ask other half, well I am usually in trouble with her for something or other ,but as I made her have a space saver tyre for her new car and she recently needed it against one of those blow up thingies she agreed as she had to spent out on a new tyre. Pothole damage.


Give me a few days and i will, if I remember to give my thoughts on it. Hopefully it will arrive 29/4/2014
 
Exciting day today, Waiting for a parcel via Parcel Force. Ok what is it? I hear you ask.
it is an ExpoDisc 77mm 2.0 Neutral and Portrait White Balance Filter.

That has you stumped ? yes ?


let me try and explain. for those new to photography

Digital camera have preset filters such as sun shade flash cloud and indoor lighting varients. Also auto white balance where the camera has to guess at the amount of light (grey) hitting the sensor for the right colour.

As a camera initially sees everything in grey it it guesses the nearest grey to the scene. could be 30% or 10% grey a wild guess at best.

The correct amount of grey is 18% to get the best colours out of a camera. So what this filter does is give the correct amount 18% grey then you get true colours.

Light varies, so in any given situation this filter fits onto the camera lens and with the camera pointing towards the light source can capture 18% grey (the correct amount) thus making another filter in a camera preset filter range instead of shade sun etc.
This then gives the true colours and overrides what the camera thinks is ok.
This 15 second operating setup of the camera can save hours of work with editing to get right what the camera misreads.


Hopefully when i have had a play with it I will be able to put up the difference this filter makes



Which had the expodisk fitted??? . No editing involved apart from resizing


There are several tuts in youtube for anyone interested
 
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dave_bass5 said:
I remember when people used to use the lids off Pringle tubes to do this. On paper these things are great, but i bet you wont use it much unless you are shooting in a studio.
Click to expand...

Ha... they got wise to that... Pringles now produce near transparent lids. I imagine they're in cahoots with Expo disc manufacturers!
 
A bit late to the party but I've found these two datacolor products useful ...

Datacolor Cube

Datacolor Patch

Shoot in RAW and then calibrate in LR/PS :)
 
I have the ColorChecker Passport,works great.:)
 
chuckles said:
Ha... they got wise to that... Pringles now produce near transparent lids. I imagine they're in cahoots with Expo disc manufacturers!
Click to expand...

Yeah, they changed them a long time ago unfortunately. Still, they work well as drink coasters, same as those UV filters everyone buys when first starting out and then never uses them lol.

Ive also got a WhiBal card, and again, great idea but for shooting out and about (as i do 90% of the time) its a pain to use. This is mostly down to the way Canon have implemented the Custom WB set up on their DSLR's. I don't know about Nikon etc, but its a long winded process on the Canon bodies. Even my Powershot is easier to set this up.

EDIT: Oppps, so many typos. Bloody iPad keyboard.
 
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ExpoDisc works, but not as described above - exposure and white balance are separate and unrelated.
 
What an ExpoDisk does...
For setting WB it blurs all of the light together into a single color. This is then used to set a custom WB offset to remove that "overall color cast." Or, in the case of the portrait versions it removes the color cast but adds a bit of warm color cast.
For setting exposure it transmits 18% of the light effectively making the disk an 18% grey reference. It *must* be an incidence reading (picture of the light source) otherwise it will result in underexposure.

It actually does both things all of the time, but they serve different purposes.
 
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