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videodan

Expodisc White Balance Filter

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...snip...

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.

...snip..

a bit off topic but it might be handy:

you might want to try this tape, apparently it takes a lot longer to become a wad of gooey stuff. it's used on planes so it must be solid...

http://www.rescuetape.com/

btw i have not tried it, cos it's not easy to get in europe, but if you do try it i'd be interested to know the results

/paul

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Mike,

I have a connector screwed directly into the hard plastic cover which then clips on to my BCD when diving. I hate that transition period when handing the cam back into the boat especially when unprotected glass comes into the equation.

 

Dean, never had a problem with the springy black thing. If its good enough for the seals it's good enough for me. By seals I meant that the seals at Marwell zoo who's food is kept safe in a fridge freezer arrazy without shelves. No I wasn't referring to a group of grown men all dressed in black shouting gung ho slogans as they march to breakfast.

 

3@5, if you have problems getting that tape in France, which looks the mutts nuts by the way, imagine the problems I will face trying to get it here in Palau!! I have seen and used what is called Helicopter Tape in the past which was basically, at the time, being used to line the leading edge of a Formula Renault race car's front wing to reduce the bug damage when travelling at speed.

 

To all, will post results soonest. Crappy, crappy weather here in Palau at the mo so at least I can do low light comparisons today.

 

Cheers,

Mark.

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I was wondering what might have happened on this, given the other 5-page thread about the Expodisc. I am interested in the Expodisc too, but since I have an Ikelite housing (for my Sony SR1) I would have to use an external mount of some sort. I talked to ExpoImages and they don't have an U/W version available. They have considered it and said they are experimenting but have no projected date or anything like that.

 

I noted that they have the "cap" versions now, which work like a lens cover. I'm wondering about the possibility of borrowing from your idea, Mark, but finding some way to deal with the cap style model they have. I've ordered one for use topside but after I see it I'll see if I can come up with some way to seal it (after buying a larger version for the port size of my housing - the camera itself is a 2.5" diameter outside and the housing is 3" outside diameter).

 

Whatever happened to the issue of getting a more "red" image that desired below 30 feet or so? I didn't read much of anything new on the other thread about it after it was brought up. The ExpoImages person I talked to mentioned that without me even bringing it up when I asked about an underwater version of their filter, so there must have been some input from others to the company.

 

I have noted that they make two versions: 1) "Portrait" style which "warms" up the balance, and 2) "White Balance" which is I suspect is the correct animal to use for U/W video. So if someone did get the wrong version of the filter it seems that it could have caused a "red" effect compared to simple WB?

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Here's the first back to back test images. In my opinion the Expodisc gives a colder (my preference) image without having the red wash over the reef as many of the DV / HDV cams get when WB is set manually. You can see a slightly warmer feel to the image balanced on the dive slate. Today was an exceptionally bad dive day in Palau. Very dark conditions. Both of these images were shot at this depth because I couldn't get manual WB using the slate at greater depth.

 

Both images shot at f1.6 @ 1/60th with 15Db gain.......yeah, really crappy day.

 

Pablo, as the ad says, "Just Do It"..........don't waste time waiting for Expoimaging to release an underwater version. They been saying that for a long time now. The filters are relatively cheap, if water starts to noticeably deteriorate the condition of the elements heck they are just plastic, strip the thing down, clean it and start again. Thats what I aim to do.

 

Thoughts,

Mark.

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...snip...

3@5, if you have problems getting that tape in France, which looks the mutts nuts by the way, imagine the problems I will face trying to get it here in Palau!! I

...snip

oops ;) hadn't seen that....

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Mark you are the man.

Cheers for posting that.

 

Shall I get one or not???

I' like me flip macro to much.

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i like the colours on the bottom picture better....

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Both of these images were shot at this depth because I couldn't get manual WB using the slate at greater depth.
Mark, you were able to white balance much deeper using the Expodisc, correct? This is what I've been saying from the beginning. Using the Expodisc will allow you to get a very good white balance lock far deeper that you could without it. Mine is an absolute nescessity for shooting below 50', which is most of my diving.

Dan

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Mark, you were able to white balance much deeper using the Expodisc, correct? This is what I've been saying from the beginning. Using the Expodisc will allow you to get a very good white balance lock far deeper that you could without it. Mine is an absolute nescessity for shooting below 50', which is most of my diving.

Dan

 

 

Yep, that is what i want to know as well... that is the feature Dan originally mentioned when he introd the Expodisc here that captured my attention the most

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The only way I could get a WB lock using the Expodisc at deeper than 50ft was to slow the cam down to 1/30th. This was an exceptionally bad day in Palau. The attached still shows the result of that WB test. More grain than the Sahara and exploded reds which I do not like at all. I had to point the camera toward the surface as that was the only source of any light, albeit very faint. I thing this will be a definite bonus filter on clear, sunny days. Hopefully I won't have too long to wait until I can test in those conditions.

 

Cheers,

Mark.

 

f1.6 @ 1/30th with 18Db gain @ 18m / 54fsw +-

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I almost always white balance on the sun, except for close-ups. I have not had any issues with too much red or any other color. Below are frame grabs shot at 92' (28M) on a sunny day with great vis. This was well below the depth where I can normally lock white balance, except with Expodisc. These three frame grabs have absolutely no processing except for "save as JPEG". This was a recent Goliath Grouper aggregation in Florida. I would say these have accurate, and excellent color, especially for the depth.

Dan

 

122195882-M.jpg

 

122195886-M.jpg

 

122195890-M.jpg

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Here's a tip I forgot to mention, and this should help with any camera. White balance often when descending deep, at least every 20-30'. You cannot go straight to 90' or more and then expect to manual white balance at the bottom. Do it incrementally and it will help a lot. Below are two un-processed frame grabs that I shot three days ago in somewhat murky water at 60' (18M) with good sun. It's just sand and Lemon Sharks so there is not much natural color, more of a neutral scene for comparison. It looks awesome on an HDTV, and of course it was white balanced with Expodisc.

Dan

 

122200571-M.jpg

 

122200576-M.jpg

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Dan they look great.

 

We have those here but allot have been taken out by the Recreational Fish Heads. ;)

Cods that is...

 

Looks like I may have to get a Expodisk and mount it up like Mark has as I like my flip macro too much.

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Hey videodan,

Looking good. Maybe when the weather allows I'll be able to post some stuff from the deeper parts of Blue Corner and other benchmark sites here in Palau.

 

Wagsy, you're gonna have more filters and options on your housing than Mad Max had guns to keep that bald twat away from the gas pumps!! Good on ya. Go for the External mounted disc / square, nothing ventured nothing gained. Look forward to see what you get with it.

 

Mark.

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Thanks Wagsy. I've been waiting for others to try it, as I'm getting great results with it, as viewed on three different HDTV's and one HD Projector. I'm seeing it being called controversial, but I don't agree with that based on my experiences. Good luck to Mark, and I hope the vis clears up soon.

Dan

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Folks, i have mine fully built but haven't used yet. i think it is time to pull it out. i am diving the bahamas in two weeks and won't need my macro flip. I'll just swap it out and see how it rolls.

 

Dan, where you been lately...we missed you:) Also, very good colors with no POST. I usually get pinker in those conditions. I think for blue and low color reef, this may be the ticket. Honestly, for vibrant and shallower i have heard some negative feedback.

 

Thoughts?

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Hi shawnh,

Did you ever get the audio CD I sent you a few months back? If so how do you like the sounds? You using any of them for your clips?

 

If not it was b4 chrimbo and the mail from Palau is never the best at any time. Could still be on its way to you.

 

Cheers,

Mark.

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Hi Shawn, I've been busy diving, editing, working on a broadcast contract (maybe more on this in the future), and too many hours at my day job. I forgot you guys are coming here soon to go on the Shearwater. If you have any free time we can go dive our local Lemon Shark aggregation, which is getting better by the day. All natural and no feeding whatsoever! It usually lasts for 6 weeks or so. Plenty of time left. PM me if you want to go. As far as Expodisc goes, I don't shoot without it anymore. While I don't usually dive shallower than about 50', I have shot near the surface with great results. I have also shot vibrant reefs close up and wide angle with equally good results. Don't know why others may be having difficulties. Maybe using the warming filter by mistake, or putting it in backwards, or maybe it's their white balancing method, I really don't know. I just know it works for me.

Dan

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Mark, (or anyone else)

 

How thick is the 4x4 Expodisc? I'd like to get one to slide in and out of my EVO front port if possible. Otherwise I may engineer a flip down of some sort.

 

thx,

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I made a WB flip but it's not working to good. ;)

Having something to go infront of the Phenom port could be a handfull.

 

Congrats Dan on ya broadcasts gig. We are pitching stuff right now to some companies to try and get some GIGs going.

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How thick is the 4x4 Expodisc?

 

"Gulp"! Mine's embedded in a whole pile of silicon sealant so can't measure it. Its made up of three elements but all told I don't think its more than 1/8th". Anyone else?

 

Cheers,

Mark.

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Thanks Wagsy, but it's not a done deal yet, but good luck to you also. sjspeck, the three combined elements of my 77mm Expodisc are 6mm thick or .236". I would assume they would all be cut from the same material, so it should be the same for the 4 x 4. This is the thickness ot the filter elements removed from the holder. You can call Expoimaging for exact dimensions of the holder.

Dan

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sjspeck, the three combined elements of my 77mm Expodisc are 6mm thick or .236". I would assume they would all be cut from the same material, so it should be the same for the 4 x 4. This is the thickness ot the filter elements removed from the holder. You can call Expoimaging for exact dimensions of the holder.

Dan

Thanks for the quick response, but it sounds too thick for what I wanted to do. The existing plate is only a 1/8" thick and the slot is just under 1/4". So at .236, I don't think it would slide in/out. Not something I want to pay $200 for a filter to "modify" to find out.

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Yes, my 4"x4" Expodisc is 6.0mm thick. And the removable aluminium frame is 7.7mm thick. Now I just need to get around to fitting it.

 

Mark, the colours on your comparative stills look the same to me. Just the exposure is brighter with the slate.

 

Dan, your white balance is much bluer than I am getting with the Z1 using white duct tape on my fins.

 

In general I am finding white balanced video from the Z1 to be generally greyer and gloomier than my VX2000. Hence I'm now running a Picture Profile with the colour cranked up to +4. I think it's helping but I still don't have a proper monitoring method for the footage. Also in the day I was running in auto exposure mode a lot with the AE down at -1 or -2 but I've now just set that to 0 to counter the gloominess. Sometimes you've got to let the highlights blow out a bit can see the detail in the shadows.

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Here’s my “mini-saga†on the Expodisc WB filter. I have an Ikelite housing and the filter size for the W/A lens is 67mm - I didn’t know that at first. I was simply thinking about getting an Expodisc for use with my SR1 on land, so I measured the width of the lens including the outer focus ring and etc. and then ordered a 67mm “cap†style Expodisc for $55. The people at Expo Images made it sound like a lens cover and not a filter type arrangement, so that was the closest size given that the OD of the lens was 2.5†or 63.5mm.

When I got the “cap†style Expodisc it turns out that it is actually designed to fit as if it were a screw-in filter. The little push buttons on opposite sides squeeze in a segment of filter threads so that they can then expand into the inner threads of a lens or adapter ring. That’s a nice idea but they sure didn’t explain it very well, The people at B&H Photo didn’t seem to be very knowledgeable either.

 

While waiting for the filter to arrive I had ordered the Ikelite W/A lens. After the Expodisc had arrived and I could see it wouldn’t work on the camera for land use, I called Ikelite and they told me that the filter size (i.e., threaded) for the W/A lens they shipped is 67mm. So then I began to think how I could utilize the filter I already had for U/W since it was exactly that size.

 

The “cap†style Expodisc has an outer frame with an inner ring which screws into it. It has two slots to install or remove. I suspect the manufacturer had a tool made that was just the right size. I went to a specialty tool store and bought a tool that I could adapt and got the ring unscrewed. Then I removed the round discs (the two “white†ones with the thin film in between). Then I took some silicone seal and adapted a small nozzle to the tube so that I could squeeze a thin line of the sealant around the flat shelf or edge where the discs sit before you screw the ring back in. I coated it, worked it into the threads, then reinstalled the screw-in ring. Then I coated the outside of the ring and joint around the Expodisc. It isn’t necessarily pretty with a bead of goop around the outside, but perhaps it has a chance of keeping seawater out of the inner areas now. The outer flat surfaces of the two discs making the filter “sandwich†are still going to be exposed to seawater, but perhaps they will survive that OK if they get rinsed after each dive.

 

When I talked to Ikelite I suggested they look at the Expodisc and consider making a waterproof version for U/W use. They seemed very interested in the idea but whether it will amount to anything or not is another question altogether; and Expo Images owns the rights and would control anything that happened, etc.

 

Meanwhile, if any of you are considering the “cap†style for land use, it works the same as the “non-cap†style (not the 4†x 4†model which is different altogether) except that you squeeze two little knobs to insert it into the filter threads and then release them – so far as I can see that saves having to actually screw the Expodisc on and off. The size you order is for the size of filter threads you would otherwise order for any other screw-in filter. For land use, I ordered an adapter to take my SR1 from 30mm to 37 mm, then another to get from 37mm to 52mm and ordered another Expodisc of the 52mm “cap†style size. So I'm set for land use at least.

 

I don’t know how this modified item is going to work, and in any event it may not help me with the Ikelite red filter that fits on the W/A lens. But that’s my story and I’m sticking to it. I’ll report when I get back from Tahiti (leaving this Sat.) on what works or doesn’t.

Edited by pablo

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