Bluefin HC3 and expodisc

I have been reading about users of the Bluefin HD replacing either of the flip down lenses with an expodisc for the purpose of white balancing, very cool. I am trying to determine if the same thing can be done with the L&M Bluefin HC3 housing; I don't physically have the housing yet, so some of my questions can probably be answered just by having one in hand. Has anyone done / tried to do this, I would love to hear the results. If anyone can answer a few questions for me, I would appreciate it:

1) Does it even look plausible? We could use a URpro filter attached directly to camera and replace the flip down filter with an expodisc.

2) Which URpro filter to use? The FX1 filter diameter is 72mm, but they seem to be using a 67mm for this application. The HC3 filter diameter is listed as 30mm.

3) How large of an expodisc to use? Anyone know how large the internal flip filter is on the L&M HC3?

Thanks for your help.

I made one for another customer that replaced the internal flip filter w/ an expodisc. The customer then had to use an external urpro filter... I had to cut down another expensive expo filter to make this modification, and the customer had to buy another filter, so this got to be pretty spendy.

If I were doing this for myself, I would just use one of the expodiscs in water, and hold it on when I needed to white balance. Expo seemed to discourage this, but after taking one apart and cutting it up I"m confident it would survive underwater.

Closeout prices are available on the older models-

http://www.expodisc.com/products/product_d..._Balance_Filter

I have been reading about users of the Bluefin HD replacing either of the flip down lenses with an expodisc for the purpose of white balancing, very cool. I am trying to determine if the same thing can be done with the L&M Bluefin HC3 housing; I don't physically have the housing yet, so some of my questions can probably be answered just by having one in hand. Has anyone done / tried to do this, I would love to hear the results. If anyone can answer a few questions for me, I would appreciate it:

 

1) Does it even look plausible? We could use a URpro filter attached directly to camera and replace the flip down filter with an expodisc.

2) Which URpro filter to use? The FX1 filter diameter is 72mm, but they seem to be using a 67mm for this application. The HC3 filter diameter is listed as 30mm.

3) How large of an expodisc to use? Anyone know how large the internal flip filter is on the L&M HC3?

 

Thanks for your help.

I made one for another customer that replaced the internal flip filter w/ an expodisc. The customer then had to use an external urpro filter... I had to cut down another expensive expo filter to make this modification, and the customer had to buy another filter, so this got to be pretty spendy.

 

If I were doing this for myself, I would just use one of the expodiscs in water, and hold it on when I needed to white balance. Expo seemed to discourage this, but after taking one apart and cutting it up I"m confident it would survive underwater.

 

Closeout prices are available on the older models-

http://www.expodisc.com/products/product_d..._Balance_Filter

I was thinking about the underwater idea; all i need is one more piece of dive gear to lose

If I follow you correctly, your customer had to purchase 2 total new items, an expodisc and the external URpro filter. I am not even sure this would work as now the red filter is after the expo and not before the expo. I could also be confused completely. Thanks for the link to the expodisc sale.

By the way, nice username, my name is Ryan as well...

Ryan

Even though this topic has not generated much interest i figured I would update everyone on my progress.

I now have the housing in hand and have had some conversations with the folks over at URPro filters. I can buy a threaded URPro filter for the HC3 camera; it has a 30mm diameter filter ring. So removing the internal flip CC filter should not be a problem; affixing the red filter directly to the camera means it cannot be removed, but I am usually shooting with it anyway.

The only hitch to my plan is getting an expo disc to fit in the housing without snagging on the camera and/or housing. By my calculations, I have about 5mm of space to use with the built-in flip down holder. There is not much room between the flip and the camera; I have read that the expodisc is 6mm wide. This may cause a problem when trying to flip the filter into position, but I won't know until i try.

Ryan, it sounds like you were able to get the expodisc to fit? Can you please explain how you did it?

I am surprised that nobody else has shown interest in this...?

on the FX1/z1 we thread the retaining ring into the camera so the URpro filter sits back in the lens barrel of the actual cam. That way you have all the room you need for the expo disc.

BTW, i have talked to a lot of folks regarding the expo disc. i have built my own but have yet to use. so far the reviews have varied a LOT. Some folks swear by it and others are saying it just doesn't do it for them. Both sides are respectable shooters. I am wondering if it comes down to the type of conditions you are shooting in.

I am pretty happy with my WB without using the expo (hence the reason i haven't rushed to use it...other reason is i have been shooting mostly project stuff lately and can't afford to experiment with limted footage). WB techniques still seem to be the lead solution to good WB. That being said, I plan to more fully test the Expo in December.

Shawn

I have the parts to make a pair of internal expodiscs for my Bluefin FX1 (4" x 4" Expodisc and a pair of spare flip arms) but I rarely do a dive that doesn't require a few artificial light shots and I found (with only very limited testing so far) that I couldn't get a good manual white balance with lights + blue water filter. Also like Shawn I'm pretty happy with what I'm getting the old fashioned way.

I'm now thinking of mounting my 4x4 expodisc on the outside of my housing on the end of a locline arm as discussed in the other thread. Thank god I didn't cut it up yet. I would need to zoom in a bit to make it fill the frame.

Shawn/Bubblevision, thanks for your comments.

Bubblevision, I am slightly confused by your artificial lights comment. When you say you could not get a good WB using lights + blue water filter, are you saying with the Expodisc in place? Please explain.

Shawn, what to you typically use to WB?

I guess I light the option of the expodisc being there, ready to use. I was also under the impression it would not hold up underwater, but even earlier in this thread Ryan thought it would hold up.

Has anyone used an expodisc underwater without it being protected?

Scubanerd, I was interested in trying out this Expodisc idea, replacing either the flip red filter or the flip macro in my Bluefin depending on the dive (i.e. replace the flip macro filter for pelagic/wreck dive or the CC filter for a dive where you want macro shots).

But if you replace the flip red filter then you need to put a red filter somewhere else, so folks here have been recessing a circular UR-Pro filter right in the front of the camera for the whole dive, where's it's fixed and can't be taken out.

That's great for ambient (available) light shots but if you want to take some close-up shots with aritificial lights on (as I tend to do on almost every dive I make), then you've got to manually white balance or else the shot comes out very red.

So as a test, before I cut the Expodisc I tried white balancing with the housing's UR-Pro flip CC filter in place and with my lights on (Sunray halogens on one of the lowest 2 settings), pointing at the white gaffer tape on my fin at something like 12-18 inches away (a typical artificial-light macro range). Unfortunately the image still remained very red after the manual white balance.

I must stress that this was a very brief test and perhaps it would work better next time, but the results that particular time indicated that all my close-up artificially lit shots would come out way too red. Or would the Expodisc sort out those artificially lit shots as well as the available light shots? I tend to think it would be even worse as the Expodisc would be collecting greenish light from outside the artificially lit area as well as the reddish light.