ExpoDisc

I am not sure where to put this topic, so I will place it here.

I have been reading up on ExpoDisc. If anyone uses these, can you please share your experience with me?

The smallest size I see is 58 mm, would this work for the 50mm 1.8?


http://www.expodisc.com/products/products.php?catid=1&category=ExpoDisc

Expo-disc

Hi Stacy, yes I have the expodisc. They work very well in my experience. I think they are a worthwhile investment, but you have to carry them around your neck and have them available to use all the time. If you are taking photos in JPeg, then they are necessary, but in Raw, you can adjust in DPP.

There are cheaper discs out there (much cheaper), but I don't have any experience with them or how accurate they are. For the $200 I paid, I feel that it was far too much for such a cheap piece of plastic.

My expo-disc also has a string loop attached to it so I can attach a neck strap, but it broke. The company will replace it, but only if I pay US$35 postage, which is an absolute rip-off, since the disc is made of plastic and weighs only a few grams. Some of the discs have a metal ring with small locating ball bearings, which would be a better investment I should imagine....

Good luck with your decision...

Regards,

Barry.

There's a 4 inch by 4 inch Expodisc that's a bit more flexible, which is what I've used for some years along with the WhiBal card(s). The 4x4 card held flush to the front of the lens is no problem to use. I ended up drilliing a small hole in the metal edge and adding a lanyard after a year or so of use because I was afraid I'd drop it off a cliff or into a river someday and be out the $160 I paid for it at B&H Photovideo (they still carry it).

It works great, but I use it in conjunction with the WhiBal card as sometimes one or the other seems to be closer to my perception of reality. Usually they agree.

The main problem with the Expodisc is figuring out where to point it since it requires being directed toward the source light. Often that's just the bright sky if you can find some under a forest canopy (I'm a landscape photographer). That's when the WhiBal card is useful.

Mike

I had never seen that 4x4 inch expodisc on their website. If mounted on a larger black backing plate then it could be used in front of any lens including the large-diameter superteles even with a lens hood attached. It would also work with the small lenses.

It need not be 4x4 inch if there is a backing plate to prevent stray light getting past it and into the lens. The only requirement is that the camera see enough of a light spot to cover the partial metering area. The rest can be black.

The price should be way less than it is, and with this simple backing plate idea there need only be one expodisc for all applications instead of numerous different sizes.

- Alan

Alan,

I assume you looked and found it at BHPhotovideo:

http://www.bhphotovideo.com/c/product/358086-REG/ExpoImaging_EXPOD44_ExpoDisc_4x4_Neutral_White.html

Without adding any additional material around the edges, it still works with my 5D 16-35mm II combination, though I need to be at 35mm when I do the WB. Typically I just start out a field session doing a WB off the ExpoDisc - maybe it should be called "card" for the 4x4? Then as another point of reference, shoot my WhiBal card. They almost always agree within a few degrees Kelvin, whether I'm using LightRoom, PhaseOne, or ACR. Then as I move along, or the sun rises, etc., I take subsequent WhiBal shots for later reference. Using that approach I seem to get more consistent results.

As I mentioned previously, with the ExpoDisc, it's hard to get a good reading under a forest canopy. Under those conditions, the WhiBal card works far better for me. All I need to do is be aware when the light is changing and shoot another WhiBal frame, which I don't always have the brains to do in the heat of the moment.

Mike

You will laugh but I took a couple of cheap filters and cut a coffee filter to fit between them.

Ron,

You can laugh along too! Before I ended up spending $$$ on the ExpoDisc, I tried about everything in the kitchen and work bench that was translucent and seemed like a good candidate to shoot through and get something for a white balance. Cut pieces from plastic milk jugs worked pretty good, but not consistently. I think I missed the coffee filter one.

Over the years various forums seem to have had various threads on homebrew WB filters, so creativity in your kitchen might work out.

At least in the winter a good expanse of snow - if not too brightly lit - works somewhat, lacking anything else.

Mike