Expodisc White Balance Filter

Deeper than 30 feet, the white balance achieved with the ExpoDisc starts to get too brown/red for my tastes.

This is going to sound bizarre, but what kind of fins do you use? I have a pair of Mares Quattros that might qualify, which would be great for me.

I've been using the Atomic Biofin XT. They work well.

It's hard to tell while underwater. My L&M rig has three ways to see the image -- viewfinder, top LCD, and monitor. The monitor is way oversaturated, and when WB is correct the reds look like they are going to blow a hole in it. I have to look in the viewfinder to see what I'm going to get.

I have to look in the viewfinder to see what I'm going to get.

Agreed. I'm finding the viewfinder the most reliable, personally.

Me too, the top LCD is much pinker than the viewfinder. But why would that be? They're well matched topside. My other cameras' monitors also appear reddish when manually white balanced and I've never really understood why this is. Is it just that the surroundings are so green/blue?

I would pay big money for a pair of white Mares Quattros (or the ones with 3 flutes). Even better, very pale pink ones. I've got an old pair of Plana Avantis in white but they're too big. Only fit my drysuit. The only white fins I can find are those little Japanese fly swats.

Nang's taken over my VX2000 Gates housing now and did her MWB on the sun during her last Similans trip. The results are not as good as white balancing on white tape on a fin.

Eric, do you have the Expodisc warming filter by mistake? I normally shoot in the 70-90' range, and get fantastic results with the standard Expodisc. My FX1 has great difficulty locking white balance below about 50', but does quite well much deeper with the Expodisc. The colors acheived are also excellent, very even and saturated, and no blown or washed out colors. I'm back to using the 80°WA lens and the flip CC Filter on my Bluefin HD. Had poor results using a screw in CC Filter, probably because it was too close to the camera and the color correction effect was not as concentrated as when it is further away from the lens. Any other Expodisc users have any comments? I am very happy with the results I'm getting.

Dan

I'm guessing that if Eric's footage is coming out brownish, then perhaps he's aiming in a generally blue (complementary) direction when hitting the MWB??? Perhaps aiming towards the sun or a mixed reef scene might give better results??? Just speculating as I haven't used my Expodisc yet.

Nick - in many circumstances there is nowhere I can aim to get something that is not brown -- including straight up into the sun. Believe me, I've tried.

I'm pretty sure I bought the normal ExpoDisc.

Maybe I'll do some final tests while in Indo in February. My tests were done in not-so-ideal conditions: Galapagos and Revillagigedos Islands...

Then there is the fact that just because you are WB ing on a white board, does not mean that's the colour you are after in ceratin shots. That's why I don't use one, just kind of know what I want just by looking at the High Res LCD or the peep hole thingy bog...

Eric switch the shutter, and db gain to auto if you are having trouble WBing at the sun as it can sometimes help, then back to manual once you get a lock. Works for me.....

Then there are times where you need to be on auto WB for certain shots like if you are swiming through different colour water...light green, dark green, blue- light / dark and how dirty the water is. Yep we get that here sometimes...

Then if all else fails you always have EDIUS

Had poor results using a screw in CC Filter, probably because it was too close to the camera and the color correction effect was not as concentrated as when it is further away from the lens.

Dan

Dan, could you please expand on this? This is something I find interesting.

I'm guessing that if Eric's footage is coming out brownish, then perhaps he's aiming in a generally blue (complementary) direction when hitting the MWB??? Perhaps aiming towards the sun or a mixed reef scene might give better results??? Just speculating as I haven't used my Expodisc yet.

Eric's clips are brown because he was diving here!

Oh my life..Thats gross on a gross scale of grossness.

Thats a hell of a lot of home delivery Curry and chilli those fish ordered I wonder who will be eating the fish later....

Dive safe

DeanB

Eric's clips are brown because he was diving here!

Dan

Sydney ...Bondi use to have the same thing..they extented the pipe out further now I think.

Drew, right after I started MWB with Expodisc and was expecting the UWA lens, I ran a test. I had the Expodisc still in the Macro flip arm, the standard L&M (plastic CC Filter made by URPro) CC Flip Filter, and a glass URPro screw in CC Filter on the camera. With just the glass CC Filter, I could not white balance on anything below about 30', which was very strange to me, and that was both with and without the Expodisc. Normally my FX1 is very good down to about 50', and then the Expodisc is invaluable below that. However, with both CC Filters I could MWB from shallow to 80' (deepest part of dive) easily with the Expodisc, although it was a little too red due to two filters. Kirk at URPro assured me the two filters were identical composition, other than one being glass and one being plastic. I never followed up with Kirk after that, although I should have. So, should glass or plastic make any difference as far as functionality? I'm not sure, but I don't think so. So the other variable is the distance from the camera. The light entering the housing is tapering inward toward the camera. A filter further from the camera will have more surface area exposed, and closer to the camera would have less. I think it is probable that being so close to the camera, only a small portion of the filter is being used, therefore it would have less of the filtering effect by being right on the camera lens. I have not had time to do any more testing, but it would be great to have a good screw in CC Filter, so I can put my Macro Lens back in. Anyone having luck with a screw in CC Filter? Would appreciate any input. Most of my diving is in the 70-90' range, sometimes less, sometimes more.

My Expodisc MWB method: We normally have good sun and clear water here (South Florida, except near the sewage outflows) so I normally balance on the sun for medium to wide angle shots. Close up shots with the sun above or behind me, I will usually balance right on the subject. I don't care what anyone else thinks or says, I'll always use the Expodisc for white balancing, it is that good!!! The proof is on my 50" SXRD.

Dan

Sydney ...Bondi use to have the same thing..they extented the pipe out further now I think.

BTW, white balancing through an Expodisc is quite a bit different than white balancing on a slate. You should try it! You'll probably be pleasantly surprised.

Dan

Hi Guys 'n Gals,

Been a while. Well I may be a bit late in the game but I'm in the process of trying an exterior fitting expodisc in conjunction with my Gates Z1 rig.

I basically ordered a Neutral square 4"x4" Expodisc and then set about trying to fit it externally. Armed with a Dremel Tool I hacked away at one of the Gates plastic dome port covers. As the attached will show I'm not surgically precise in my hacking attempts. Once I had the square cut out I then cut a square retaining gasket from 1/8th" Aluminium (Alu-min-eee-yum) which fits exactly to the four water drainage holes for the Gates protective cover. I then just screwed the gasket down into these holes and used the natural shoulder of the Expodisc as a resistance face for the gasket.

I must also add that as of the past week I am now shooting the daily stuff with the Sony VCL-HG0872 WA lens attached directly to the camera as the Fathoms 120 SWA is both too wide and expensive to get dinked during a $100 DVD shoot. The Fathoms will only be used for specific shoots i.e Wrecks, Jellyfish Lake or any other dedicated shoot. Nice glass option to have though. Which then takes me on to WB options when using the Fathoms.

Seeing as Gates only have one manually adjustable filter holder, normally occupied by the CC filter I have, in both setup scenarios, opted to place a CC filter directly into the lens barrel of the Z1 held in place with a 72mm retaining ring. I have now, with my trusted (new) Dremel Tool fashioned a WB flip arm to use directly with the Fathoms. The reason I opted to go this way is that by having the WB flip system I can operate the WB with the lens as wide open as possible therefore collecting lots of nice sunshine from the lens' 117 FOV rather than having to zoom into a white card or slate from a distance. I dunno, just this old dog's way of thinking: Have the cam wide open to get better light collection for WB.......anyway this is all new stuff. The last things remaining to be done is to line the whole external Expodisc excavation with marine sealant to as an added protection against the elements. I should have the first tests ready within a few days so will keep you all posted.

Cheers,

Mark.

I was pretty much posting the progress as I went with regards to the building of the external trial disc this morning. Now at the end of the day the Expodisc sits firmly embedded in the protective cover of the Gates dome port protector. Having sunk in the 4"x4" square I have now sealed everything with black marine sealant / adhesive and to darken the gasket, in keeping with the Gates aesthetics, I have added a liberal helping of good ol' duct tape. See how long it is before this becomes a wad of gooey gunk attracting all sorts of dust and crap to the cover!! Easy to replace though.

Attached is the prototyp externally fitting Expodisc ready for action. I'll be attaching the external WB slate from Gates in order to do back to back tests on exact same subjects at almost immediate back to back timeframes within the next few days. Got a bit of a lull at work but then back into the swing of things. Plenty of time to work this short test anyway.

Cheers,

Mark.

very interesting Mark.

Do you have the lens cap attached to the housing or do you plan to take it off and shove it in a BC pocket once you have done the WB?

Mr Thorpe is another fine example of a child from the 'Blue peter' years...

Its like being back in the day...

Good show Marky

Dive safe

DeanB

Good job Mark

Looking forward to seeing your results.

One thing I've noticed..

Is that little plastic lanyard all that holds the 'Beast' from Davy Jones locker.

It looks more fragile than the one I've got holding my 'Prince Albert' piercing to my nose ring.!!!!

Dive safe

DeanB