Home-made Expodisc

[blurry80]

Dont relaly know if a styrofoam cup will survive in the bag for long.

 

[denniskee]

After owning the Expodisc for awhile, I was wondering how difficult it would be to have a home-made one... so I decided to try an experiment.

I took a piece of Ikea rubber drawer lining (see pic below), and pasted a normal white photocopy paper to it (I believe it is 80 GSM paper), and you can see the results of this test below. I did not edit the pictures I took, merely resized them.

Ikea rubber drawer lining

How the device looks

Next post on the pictures taken with this device...

why not cut it into circular shape that fit nicely into a 77mm filter casing?

 

[snapperz]

how do u paste the white paper onto the rubber lining? did u just use glue? wht kinda glue? if u used glue won't it give patches on the white paper and effect the light that is going through? Pls forgive me, for i know its only an experiment u had done for the DIY expodisc but i truly feel its a good effort and wish to know these minor details just for information, cos i want to try them out myself too.Thks..

 

[geraldkhoo]

how do u paste the white paper onto the rubber lining? did u just use glue? wht kinda glue? if u used glue won't it give patches on the white paper and effect the light that is going through? Pls forgive me, for i know its only an experiment u had done for the DIY expodisc but i truly feel its a good effort and wish to know these minor details just for information, cos i want to try them out myself too.Thks..

I used U-HU glue to stick it on... and if you look through the light, you can see little streaks but it works

Hope you enjoy trying this out and have fun using it

 

[geraldkhoo]

why not cut it into circular shape that fit nicely into a 77mm filter casing?

yep... you just took the thoughts out of my head

I was thinking about sticking it onto a clear filter... or maybe if there are people who have cracked filters or just the rim, to see how to attach it on so that it is also easier to use...

anyone has a clear filter to spare or spoilt filter that i can try out the next step of the experiment?

 

[geraldkhoo]

I was just at Ikea today... and the cost of that rubber thingy is $7.90.

Also, with a whole roll, you can also try out the home made flash diffuser... see the following thread...

http://forums.clubsnap.com/showthread.php?t=341199

 

[photobum]

Actually, from a professional standpoint, I prefer the image you calibrate with the Expodisc. It is more neutral. I have a yellow 'Beautex' brand tissue box in front of me. With my calibrated monitor, the colors on that image looks more real (at least the drawer top don't look so whitish). The one WB with your homemade device looks a little too blue (+5) and cyan (+2) (I am not sure if it will look good on portraitures).

By the way, if you add another 1/3 stop, you will get a better exposure. I adjusted the levels in Lightroom.

 

[geraldkhoo]

Actually, from a professional standpoint, I prefer the image you calibrate with the Expodisc. It is more neutral. I have a yellow 'Beautex' brand tissue box in front of me. With my calibrated monitor, the colors on that image looks more real (at least the drawer top don't look so whitish). The one WB with your homemade device looks a little too blue (+5) and cyan (+2) (I am not sure if it will look good on portraitures).

By the way, if you add another 1/3 stop, you will get a better exposure. I adjusted the levels in Lightroom.

Yes... the home made thing is cooler than the Expodisc. Thanks for helping find out the difference

I am actually exploring the use of other everyday items as Expodisc... and hope to be able to find something closer to the Expodisc... so stay tuned... will update when I discover something new

 

[photobum]

Yes... the home made thing is cooler than the Expodisc. Thanks for helping find out the difference

I am actually exploring the use of other everyday items as Expodisc... and hope to be able to find something closer to the Expodisc... so stay tuned... will update when I discover something new

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.

 

[denniskee]

yep... you just took the thoughts out of my head

I was thinking about sticking it onto a clear filter... or maybe if there are people who have cracked filters or just the rim, to see how to attach it on so that it is also easier to use...

anyone has a clear filter to spare or spoilt filter that i can try out the next step of the experiment?

i made mine out of the diffuser of the flourascent ceiling light box that you find in the office few years back. had it cut into a circular disc that fit nicely in the 77mm filter case.

when i forget to bring it, i use shoot piece of white tissue paper (20cent pack, mac, bk, etc) and use it to set the cwb, get the job done.

 

[photobum]

Here is my own version of the WB test. I am using a Fuji S5 Pro with a Carl Zeiss 50mm f1.4 ZF lens.

Specifications
Camera: Fujifilm FinePix S5 Pro (Firmware version 1.08)
Lens: Carl Zeiss 50mm f1.4 ZF
Exposure Mode: Aperture-priority
Aperture: f2.8
ISO: 400
Dynamic Range: Standard
Film Simulation Mode: Standard
Noise Reduction: Off
Illumination source: 38W Philips Natural Daylight Fluorescent lamp


Auto WB

Preset with White Expodisc (Factory Calibrated White Balance: Red 0.00, Green 0.01, Blue 0.00 / Density Rating 0.73)

Preset with 18% Kodak Gray Card (Silver Pixel Press 0-87985-754-4)

After thought
I feel that the AWB function of the Fuji S5 Pro does really a good job for a quick and dirty shoot. However, the Expodisc brings it to the next level. The colors came out very close to the actual scene, but I must say it is cooler (cyan is higher) than the rest. The 18% Kodak Gray Card (the industry standard for both still and motion photography) gives a much warmer look (the Martell carton looks nice), but far from reality.

The AWB of the S5 Pro falls in between the Expodisc and the Kodak Gray Card. Best of both worlds!

 

[photoboy]

Gerald,

Thanks for sharing your idea.
I like your DIY disc color in the room lighting.

When you are free can you try it out a comparison with the Expodisc on outdoor light.
Say late afternoon or early morning, or cloudy time and see how your DIY fare with the Expodisc.

Appreciate you post your sample shots.

 

[denniskee]

t2 awb, room light (flouresent lamp) + natural day light behind me.

t2 diy, room light (flouresent lamp) + natural day light behind me. cwb with diy expo-disc shot aiming directly at the lamp.

t2 tissue, room light (flouresent lamp) + natural day light behind me. cwb on tissue in the box you see here.

 

[cichlid]

why not cut it into circular shape that fit nicely into a 77mm filter casing?

Just to let fellow forumers know that NTUC has this Ikea drawer lining too. There are a few varieties too, saw them at Hougang Point today (2/2/08).

 

[denniskee]

there are some difference in color between my t2 diy and t2 tissue. but that is cause by the fact that

1) t2 diy does the cwb using the lamp as reference only.

2) t2 tissue does the cwb using the reflected light (lamp + natural day light) from the tissue.

in another set of testing, all else being the same as t2 except that i close the door. so only light source is the lamp. the result i get from using diy expo-disc and tissue paper yield very similar color.

as such, i suggest to use reflect light from a white paper or grey card (if you are very particular about color cast) under the same lighting condition as the subject you intend to shoot when possible.

 

[geraldkhoo]

Gerald,

Thanks for sharing your idea.
I like your DIY disc color in the room lighting.

When you are free can you try it out a comparison with the Expodisc on outdoor light.
Say late afternoon or early morning, or cloudy time and see how your DIY fare with the Expodisc.

Appreciate you post your sample shots.

Ok... will try and find some time to shoot something outdoors... in the meantime, found something else to act as an expodisc...

 

[geraldkhoo]

Found a new material to act as an Expodisc. It is a translucent corrigated board from Popular bookstore. The small piece costs $1.60. See the 2 different DIY devices in the following pic. I'll call the first one as Device 1 and the second as Device 2.

Some test shots coming up...

 

[geraldkhoo]

The following shots were taken using an Ikea throw up light with a daylight lightbulb. A piece of white A4 paper is put there for reference.

AWB

with Expodisc

with Device 1

with Device 2

with Device 1+2

 

[photobum]

The following shots were taken using an Ikea throw up light with a daylight lightbulb. A piece of white A4 paper is put there for reference.

Your home-made Device 1 performs better than Device 2. The blue is +25 higher in Device 1 than Device 2. Device 1 + 2 is only slightly better than Device 1 alone. Not surprisingly, the test image made with Expodisc is the most neutral.

FYI, all your test images are 1/3 stop underexposed.

 

[geraldkhoo]

Your home-made Device 1 performs better than Device 2. The blue is +25 higher in Device 1 than Device 2. Device 1 + 2 is only slightly better than Device 1 alone. Not surprisingly, the test image made with Expodisc is the most neutral.

FYI, all your test images are 1/3 stop underexposed.

Hi photobum... thanks for all the analysis. I'm new to this... and was wondering how you analyze the pictures and determine the +/- of colors and also how much they are over/underexposed. The computers I am using are not calibrated, so what I see on my laptop turns out different from what I see on my desktop... and yesterday, I brought some pics to be printed, and they tend to be underexposed, so the person had to adjust it up... appreciate your suggestions and also on what you do to analyze the pics