Home-made Expodisc

[geraldkhoo]

Hi, but will the white paper turned dirty overtime? Possible to stick the rubber matting on both sides?

Maybe you can give it a try and see what the results are like.

Anyway, I've tested the Mennon WB cap and the results was that it was that the WB became too cool...

 

[Henessy]

For S$5, you can get yourself a Delta Standard Gray Card (US made). I will prefer to use a gray card (an alternative to the Expodisc) instead of spending S$8 for an Ikea drawer lining.

Hi, may I know where can I find the gray card? How to use it. Is it place the card over the lens, covering it?

Thanks

 

[catchlights]

Oriental Photo @ SLS.

 

[Henessy]

Oriental Photo @ SLS.

Haha, nice illustration. But that is only possible for near objects. May I know how do you actually set the white balance using the gray card when shooting far objects using tele lens?

 

[eow]

Haha, nice illustration. But that is only possible for near objects. May I know how do you actually set the white balance using the gray card when shooting far objects using tele lens?

use
translucent plastic bag from hawker...tissue paper from or the cup lid from 7-11

 

[Henessy]

use
translucent plastic bag from hawker...tissue paper from or the cup lid from 7-11

Hi dude, I think you might have misread my question...

 

[eow]

Hi dude, I think you might have misread my question...

they work similarly as the expodisc ...it allow u to take or read 'corrected' colour temp by creating similar condition from near to far distance object. however the further the away the object from u. the more u are required to meter correctly for the right exposure especially if it dim....otherwise it won't work that well

 

[catchlights]

depend how far is far.
if you where you stand and the subject is in a distant, you sure both of you are under same type of lighting, you can place the gray card near you and take the custom WB, use the same setting to shoot subject in a distant.

if not in a same lighting, you won't get a correct results.

 

[pcgarage2001]

depend how far is far.
if you where you stand and the subject is in a distant, you sure both of you are under same type of lighting, you can place the gray card near you and take the custom WB, use the same setting to shoot subject in a distant.

if not in a same lighting, you won't get a correct results.

I believe theres 2 ways to do colour balance. Correct me if im wrong.

1) Perform Custom WB from camera itself by shooting at grey card (or similar devices). Hence, the camera will do the white balance. Upon loading the pictures into PC, the white balance will already be corrected and you'll mainly need to do some toning ( exposure, etc etc)

2) Just shoot the scene with the grey card it in once. then proceed with your shooting without the grey card unless theres change in lighting. For this method, white balance can be done in PS or LR am i right. But must it be shot in RAW? or Jpeg will do fine?


Are there any other ways im not aware of?
Also, what do you guys think of WhiBal neutral reference card?
http://www.pictureflow.com/products/whibal/index.html

The description seems very good..

 

[catchlights]

I believe theres 2 ways to do colour balance. Correct me if im wrong.

1) Perform Custom WB from camera itself by shooting at grey card (or similar devices). Hence, the camera will do the white balance. Upon loading the pictures into PC, the white balance will already be corrected and you'll mainly need to do some toning ( exposure, etc etc)

2) Just shoot the scene with the grey card it in once. then proceed with your shooting without the grey card unless theres change in lighting. For this method, white balance can be done in PS or LR am i right. But must it be shot in RAW? or Jpeg will do fine?


Are there any other ways im not aware of?
Also, what do you guys think of WhiBal neutral reference card?
http://www.pictureflow.com/products/whibal/index.html

The description seems very good..

both ways which you mention are able to address WB issues, #1 is by doing custom WB in camera, #2 is correcting WB at the post, when shooting in RAW, you able to alter the WB, but when shooting jpg, you only can set the gray point, for more details, read up photoshop books.

My post is address to Henessy's question, what to do when the subject is in a distance, not possible to place the gray card on the subject to do custom WB.

 

[pcgarage2001]

both ways which you mention are able to address WB issues, #1 is by doing custom WB in camera, #2 is correcting WB at the post, when shooting in RAW, you able to alter the WB, but when shooting jpg, you only can set the gray point, for more details, read up photoshop books.

My post is address to Henessy's question, what to do when the subject is in a distance, not possible to place the gray card on the subject to do custom WB.

So by setting grey point, doesnt that correct the colour balance as well?

 

[airconvent]

Sorry..know this is an old thread but anyone can explain why an ikea rubber mat?
Can we not make do with , say , coffee filter or simply A4 paper instead?
Thanks....

 

[geraldkhoo]

Sorry..know this is an old thread but anyone can explain why an ikea rubber mat?
Can we not make do with , say , coffee filter or simply A4 paper instead?
Thanks....

Disclaimer: I dun get any priviledges from Ikea for using their product here :bsmilie:

After getting an Expodisc, I asked myself if I could reproduce something that would come close to the Expodisc. So I tried different materials, and since I had some spare Ikea rubber mat at home, I decided to try using it... and it turned out pretty good... better than a Mennon WB cap even. Well... you can use a coffee filter or simply an A4 paper... as they would work to some degree as well.

So... to answer your question why Ikea rubber mat... hehe... it was just one of various materials I tried and it turned out that this combination of white A4 paper (I use 'Double A') on Ikea rubber mat (the translucent kind) that produced the best results for me.

 

[photobum]

Sorry..know this is an old thread but anyone can explain why an ikea rubber mat?

Simple. The Ikea rubber mat has thousands of tiny bead-like dimples that act like miniature fisheye lenses which help capture, transmit and equalize light coming from all directions. This 'equalised' light eventually get recorded by the digital camera's CCD sensor for white (gray) calibration.

 

[airconvent]

Simple. The Ikea rubber mat has thousands of tiny bead-like dimples that act like miniature fisheye lenses which help capture, transmit and equalize light coming from all directions. This 'equalised' light eventually get recorded by the digital camera's CCD sensor for white (gray) calibration.

thanks photobum/geraldkhoo..
If beading is desired, than possibly a bubblewrap will also do nicely too?
In anycase, the key to choosing a test medium is not a translucent one but one with indentations that will split the light source...If yes I will start looking for a acheap replacement. Incidently, some photo magazine I purchase some time back actually gave a free grey card...but I can't seem to find it now..:cry:

 

[photobum]

If beading is desired, than possibly a bubblewrap will also do nicely too?

Bubblewrap won't work as well as Ikea rubber mat. Reason is simple. The air cushions on the bubblewrap are soft and uneven. This will cause an inconsistent white (or gray) reading recorded by the CCD sensor. The best material still has to be something relatively rigid and transmit light evenly across the sensor.

 

[airconvent]

Bubblewrap won't work as well as Ikea rubber mat. Reason is simple. The air cushions on the bubblewrap are soft and uneven. This will cause an inconsistent white (or gray) reading recorded by the CCD sensor. The best material still has to be something relatively rigid and transmit light evenly across the sensor.

Thanks, photobum!
A thought occurrred to me...if this is such an important feature for all DSLR, why do they not include a flip function within the camera to do this? i.e. switch to filter mode in manual WB. That way, it will make it easier for the user.