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Homemade Expodisc...

PostPosted: Sat Jun 25, 2005 10:18 pm
by waspo
Hi guys,
Just been playing around with a piece of fluoro light cover which looks very similar to an expodisc.

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I tried it out under downlight conditions and was quite surprised by the result.

Here is the 'Fluorescent WB'

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Here is the 'Auto WB'

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Here is the 'Incandesant WB'

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...and this is with the Fluoro Light Cover.

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Judging by the colours, it's pretty spot on.
Will have to test it in natural lighting conditions to see how it performs.
More later...

PostPosted: Sat Jun 25, 2005 10:29 pm
by mudder
What-ever colour casts are involved the last seems the most errr, natural(?). Interesting choice of subject ;)

I assume you're shooting jpeg?

Cheers.

PostPosted: Sat Jun 25, 2005 10:35 pm
by waspo
Hiya Andy! Yeah I shot jpg just to speed things up. Not sure if that makes a difference. Will have to try it at the Zoo tomorrow. :lol:
I'm off to LaLa land now, so I'll catch you tomorrow. Should be a excellent day.
Cheers, Jase :D

PostPosted: Sat Jun 25, 2005 10:56 pm
by kipper
Guess I'll have to go jigsaw a fluoro diffuser at work :)

PostPosted: Sun Jun 26, 2005 8:34 am
by Killakoala
Nice idea and will work better when you do a PRE-WB, but it won't be as accurate as the Expodisc as it doesn't have the calibrated grey plastic bit as well. Of course there's nothing to stop you using that flouro filter and a grey card as well.

Nice innovation though. 10 out of 10 for you. :)

PostPosted: Sun Jun 26, 2005 8:37 am
by waspo
kipper wrote:Guess I'll have to go jigsaw a fluoro diffuser at work :)


That's where I got mine. :lol: I still have plenty left, so if anyone wants one give me a bell.
Not sure if I'd jigsaw it, they're fairly brittle. I used a hot cutter in the shape of a circle we use at work.
Looking at the last pic, even though it looks fairly spot on I do think there might be a slight blue cast to it. Possibly need to dial in a -1,-2 value.
...Still testing.

PostPosted: Sun Jun 26, 2005 8:50 am
by birddog114
Get a Pringle potato chip and use its lid, it's still far better result then.

PostPosted: Sun Jun 26, 2005 9:09 am
by Heath Bennett
What is an expodisc? Some kind of colour correction tool?

PostPosted: Sun Jun 26, 2005 9:12 am
by fozzie
Heath,

For your benefit and may be others:

http://www.expodisc.com/

PostPosted: Sun Jun 26, 2005 9:24 am
by waspo
Birddog114 wrote:Get a Pringle potato chip and use its lid, it's still far better result then.


Yes, I have to try this. Apparently it works great too! :)

PostPosted: Sun Jun 26, 2005 10:58 am
by gleff
Birddog114 wrote:Get a Pringle potato chip and use its lid, it's still far better result then.


Pringles have transparent lids now, so unless you have a really old can of pringles, that won't work :)

Geoff

PostPosted: Sun Jun 26, 2005 11:02 am
by Heath Bennett
I would have thought the new one, not the old one would work. Not sure though.

PostPosted: Sun Jun 26, 2005 3:39 pm
by digitor
A while ago I made this disc from some perspex-like stuff we use at work for light-source diffusers. I've checked it with a colorimeter, which (in colour temp mode) reads about 60 deg difference when the disc is placed in front of an LS-65 standard light source, set to around 3000K.

I've got no idea how this compares with the 3% accuracy claimed by Expodisc, but the results indicate it works well. It's particularly useful for getting a good result under fluoro lights.

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Cheers

PostPosted: Sun Jun 26, 2005 4:06 pm
by birddog114
Heath Bennett wrote:What is an expodisc? Some kind of colour correction tool?


I'll bring one to the meet on the 9th July for you to see and have yourself a judgement.

PostPosted: Sun Jun 26, 2005 7:03 pm
by Heath Bennett
thanks birdy