Expodisc White Balance Filter

I usually shoot full wide as there is no vignetting, just occasionally the slightest amount of corner darkening on overscan only, never see it on playback. Could be due to me always using steadyshot. Screenshots in jpeg do no justice to the richness of colors you see on an HDTV. Normally I would do "levels", "saturation", and "sharpening" in Photoshop, on any screen grap to be shown online. These had no post processing done. Also remember these were shot on a really crappy day, so I'm very impressed. I'll post some good ones as I get them, which for me will be next weekend if conditions are good.

Here's some unprocessed frame grabs from day one with Expodisc. Conditions were: "today was a mediocre dive day in South Florida. Heavy, dark overcast all day, and 40-50' vis at best, with a lot of particulates in the water". These scenes look much sharper and richer in color when viewed on an HDTV.

Very nice Dan,

I ordererd the Expodisc today and will hopefully use it with my new dual 50W HID lights next weekend. Thanks for all your input and information.

Sincerely

Anders

Good work Dan.

I can get the colour anyhow but it would be usefull at deeper depths thats for sure.

Nick. if you get a set of HOYA 67mm diopters you take out the glass from the ring and then the glass will fit in the flip arm.

Then with the empty ring you put the URPRO filter in it and then it will fit inside the end of the camera so you can still use the flip arm which is comes very close to the end of the camera.

You need to place abit of soft tape around the now URPRO filter ring to take up the tiny bit of gap. Screw it onto another ring so you can push it in and take it out of the end of the camera with.

Then you have a choice of two arms with the standard 94 port or new macro dome port or just one with the 94 modified lens. I think I might stay with the two arm option, just means I have to zoom in abit.

Hows this, one guy told me that the vignetting on the phenom's is different from each setup due to different slighthly SONY CCD/camera specs from camera to camera. One he came acrross had no vignetting what so ever...work that one out....

Does that make sense

Yes that doesn't surprise me at all having seen slight differences on 3 different Panasonic cameras I owned (same model). Maybe you just need to smack your camera about a bit until the CCDs are sitting where you want them

Thanks for the explanation. Yes it makes sense and the pic in your review (showing coin) also helps.

Hi Dan,

Fascinating thread - very good idea on your part.

Any news on a likely timeline for a waterproof version for use outisde the housing?

Wagsy-

Any ideas on how to get it to work on the A1? I'm using an Amphibico housing and this sounds very interesting if it could be used.

Yes..I'm also very interested..

Dive safe

DeanB

I'm just as interested using a Gates housing for the A1-U-Steve B)

I'm very anxious for others to try the Expodisc, as it definitely made a huge difference for me. When I first started shooting the FX1 underwater in early 2005 with an Aquavideo housing, I immediately noticed the FX1 didn't like to manually white balance below 50' very well. Been trying to figure out why, ever since then. I heard about the Expodisc on a still camera forum, and went to a local camera shop to try one out. In the dimly lit store I tried white balancing on various areas. When the camera would not balance, I tried the same area with the Expodisc, and got immediate white balance lock. Then I had a strong feeling this would really work well underwater at depth, where I've been having problems. It works unbelievably well underwater, in all situations, and very quickly. Now manual white balancing deep underwater is enjoyable. Excellent colors, no blown out reds, and never too much or too little of anything else. Plus no more endless blinking when it couldn't lock in. For me, this will always be in my housing. Ready to hear from other happy users. I did post this information to help others, as I knew I was not the only one having these difficulties. Happy shooting!

Daniel, you the man...

Your info is very much appreciated.. If it works for me I will gladly by you a pint, or 5....

Dive safe

DeanB

Mmmmmmm, cool delicious beeeer!!!! Always glad to help when I can, and this was certainly a discovery worth sharing.

So there must be some other Expodisc users out there with some comments. I think we would all like to hear your experiences. I have read in other posts that some of you have bought them, and others have PM'd me. Must be someone who has shot with it by now. Anyhow, I went out this past weekend, and am still incredibly impressed with it's performance. It was another less than perfect diving day, but shot some really good video despite the conditions. The color balance and saturation acheived by white balancing through the Expodisc is stunning, besides the fact that it white balances down deep whithout hesitation.

As far as Expodisc making a waterproof external version, they would like to, but there are a few issues. Here are some of them. If anyone has some good suggestions, I'm sure they would like to hear from you, or post it here.

1. Waterproofing - can be done, not a real big issue.

2. Size - There are many lens sizes and shapes to work with, and the Expodisc needs to filter all of the light coming in to work properly. I'm pretty sure it needs to completely cover the lens with no light leakage. How many sizes would they have to make, and what would be the best sizes?

3. Stowage and Use - External waterproof Expodisc would need to be easily installed, removed, and stowed while shooting. As with all manual white balancing, you need to do it often. How to best attach it to the camera lens, and stow away easily?

For now, all I can say is if you can fit one in your housing on a flip arm, do it. You will be really impressed with the performance.

Dan are you noticing a difference in result depending on which general direction you point the camera to white balance? I would guess that if you white balance pointing out into the blue you would get a warmer result than if you you point in the general direction of a coral reef, and if you want the most neutral result you would point towards the surface. I know the Expodisc averages the light but it can only get light from 180 degrees or less.

If I bought the same housing as you I would really not want to lose the flip macro arm for many dives because I like to get stuck into some macro even on dives where big stuff is the main goal, so I think I would want to run the Expodisc in 2 different ways:

1. Wide-only shoot (e.g. Pelagics): Replace the flip macro with the Expodic and keep the UR-Pro flip filter in (like you've done).

2. Mixed or macro shoot: Replace the UR-Pro flip filter with the Expodisc and keep the flip macro in, and add screw-on or gel filter to camera.

How does that sound? And did that screw-on UR-Pro filter that you bought fit behind the flip arms or not?

You think I'd need a spare pair of arms for the Bluefin to fit an Expodisc or would it be easy enough to just swap within the existing arm?

Nick

I have not tried the option of replacing the red filter with the Expodisc mounted in a "macro" frame. If it fits, I will probably do that instead. I have the lights now so I also would rather want to keep the macro lens if possible. Has anyone tried this?

I have only tried the Expodisc on one dive so far, and it did not work well at all. It was a low light wreck dive to 140' and the camera did not want to lock in. I will try it again in a couple of weeks with the lights correctly rigged up, and hopefully it will work better then.

Anders

Good to hear Dan...I got side tracked and forgot to order mine...will do tomorrow.

Problem is though I want the macro +2 option on the flip arm as it gives me a closer zoom in range + macro when needed. I take it if I get a 67 mm one it should pop straight into the flip arm once I take it out of the ring.

Dan how thick is it again?

Maybe get it on a thin second custom flip arm or modify the second arm to allow it to slide in there for a WB with the 94 degree lens on. Keep the URPRO filter always on the end of the camera.

2 arms will work with the Macro Dome Port on no problems.

If the expo disc took the place of the ur filter in the housing, how would the WB be correct since the lights you are using would not be part of the WB procedure? Even if the disc fit over the port externally, once again, you would be WBing sans lights and therefore, the WB would be off. Can anyone explain this to me?

Steve B)

Guys,

Very interesting thread...in my travels recently i missed it. Dan, as you know I have the L&M Bluefin HD housing as well. I was just in cocos and had trouble WB deeper than 60 feet (pacific murk). I wound up balancing at 30 feet to keep the reds from oversaturating deep down. I would be very intersted in the Expodisc as well. To save me some time, could you share some tips on shaping the disc and installing it in the flip arm? Is it as simple as maching the macro glass diminsions? What did you use to cut the material with?

shawn

In reply to Nick, Anders, Wagsy, Steve, Shawn, and everybody else.

I have been white balancing on the light source (surface, sun) for WA, but I have also balanced directly on the subject for close-up. This gives great results. Since the Expodisc blends the incoming light, you can balance on just about anything you point it at. I did not want to give up my macro lens, but the benefits of great white balancing at depth outweighed my desire for macro. The 80°WA shoots pretty fair close-up without the macro lens. And soon the UWA will be out, and that will have much better macro ability than the 80°WA/Flip Macro combination. The 72mm screw in URPro CC filter definitely blocks the CC flip arm on the Bluefin. It does not hit the Macro flip arm, but does hit the screws, which could be replaced with flatheads to clear. The L&M UWA is supposed to extend further into the housing, but not past the CC flip arm. So I think to mount UWA, I will remove screw in URPro CC filter from filter mount, and install in camera with thin retainer. Then remove CC flip arm, and space Macro flip arm back as far as needed with Expodisc installed. The macro flip arm is much more robust and detented. For those keeping the 80°WA and Macro flip, I’m sure you could mount a modified Expodisc fairly easily to the CC flip arm, and mount a URPro filter same as I described above. For those who do not have Bluefin HD, I can’t help you much with mounting the Expodisc, but I’m sure someone will find a way. BTW, the Expodisc elements (3) combined are .235†(6mm) thick after removing from filter mount. I cut mine with a hacksaw and filed the edges smooth, after using the macro lens as a template. Then sanded the contours off of the macro flip arm retainer before screwing the macro flip arm back together. I have not used Expodisc at night yet, but I did use it late afternoon during a dark thunderstorm with HID lights. I had to aim the camera and lights at the sand from only a few feet away to get white balance, but it balanced very well. Did not balance on anything beyond the reach of the lights. As is normal procedure, shoot with CC filter during daylight, and without CC filter when using lights. The Expodisc white balance filter is only for white balancing, and must be flipped out of the way before shooting. If shooting with CC filter, you must white balance through both (CC 7 Expodisc) filters, with CC filter between camera and Expodisc. I have contacted Expoimaging about the possibility of making a thinner Expodisc, and am waiting for a reply. For us, space is at a premium, and the thinner they can make it, the better. Will keep you updated, and hope I answered most of your questions.

Dan

Correction.

(CC 7 Expodisc)

For Bluefin HD 80°WA with Expodisc in place of Macro Lens close-up example, see the Arrowhead Crab picture (#1) in [Post#22] above.