Underwater Bubble Blowers User Group Thread NEW

[Jeff Whitehurst]

Yes, they do. Artifical lighting is subjected to exactly the same filtration as ambient as it travels through the same type of water. The only difference is that the artificial light path is from the light source to the subject and back to the camera. This combined distance in combination with the actual water colour absorbtion index will determine the final colour imbalance.

If you are going to film sharks, the combined distance is often more than 5m, which means that you would use at least 2 stops of filtration just for the artificial light (night time) and even more if you mix it with ambient light (daylight). In geen water it may add another two or three stops as the filtration is more intensive than that of pure water. When filming a sea dragon, for example, the combined path will be only between 1m - 2m, so the filtration you would use would be relatively mild, about 1 stop or less.

Ideally, you would like to override most of the ambient light for the foreground subjects. This is easier said than done! I usually use 24,000 lumens of tungsten light and still struggle on a bright day. In practice, the actual light will be a combination of ambient and artificial and, depending on the proportions of those two, you would select a filter that falls in between those two.

Because of all the variability, dependance on the subject distance and depth, one would usually try to find a compromise filter that would get the colour balance closer to nutral in most situations. Then, fine tune it in post. The less you need to adjust in post, the better.

That's what I was thinking, the water quality is going to produce an effect based upon the same factors that effect ambient, but potentially manifest differently within the artificially lit area. I've shot underwater for years, but rarely used lights as the diving I do in Hawaii is relativity shallow and clear. The magic of filters and post correction usually makes the subjects look more colorful than I even see through my mask. The times I've used lights, I didn't use a filter due to the undesirable colors produced in the lit area, but then anything out of the light cone looked a lot different. After reading about the idea of shooting RAW underwater without filters, it just got me thinking about how RAW acquisition might enable a UW shooter using lights to make the transition between foreground and background less obvious. Maybe use a less aggressive filter to help some with the mid/background, but still within correctable range in the foreground artificially lit area? I guess I'll need to get my rig underwater and figure this out for myself, but thanks for your thoughts in the meantime.

[Ron Lagerlof]

Hey John

Nice images how does that lens compare with the Duclos 11-16?

Ross, the 10-17 rocks the Tokina 11-16 corner to corner. I found the 11-16 to be very sharp in the center, with considerable fall off on the edges, even with a 2.0 diopter.
The 10-17 is a fisheye zoom, but underwater that works to your advantage, as long as you're not on the far wide end as it tends to make things like sharks look long and skinny. The close focus working distance is also really great. An animal can literally bump the dome port and you can still take its picture - in focus! What I have found with the Epic is that one needs to be much more diligent about focus. With the still cameras and same lens (both Nikon and Canon) the depth of field is far more forgiving than with the RED.

Ron

[Ron Lagerlof]

PS - Shot with 11-16. You can see the fish on the outer edges getting distorted.
http://vimeo.com/41601315

[Pawel Achtel]

I just saw "The Last Reef" IMAX. My mini review here: http://www.reduser.net/forum/showthr...=1#post1004655

In a word: disappointing :(

Anyone else who (hopefully) felt differently?

[Michael Hastings]

Quote : " For alumunium is that the same like DSLR housing like seacam, nauticam which is they make from solid with CNC casting or it just tubular alumunium.
For the camera control, is it posible if I want to have some other important button not only basic function. And for the focus do you have manual focus gear or should be all in auto?

I haven't try PVC housing but is it strong enough like alumunium or not? What do you prefer from pvc or alum?
How about the shipping cost? How many kg total weight for all of that." End quote.

This customer was actually asking about an Alexa housing but I get the same basic question all the time. Here is my response (LCD control info added for epic housing):

It is tubular aluminum - same size (9"OD) and thickness (.5") as PVC but aluminum has 8 3" wide flats machined in to reduce weight. PVC at .5" thick is VERY strong. Many are snobbish and demand aluminum but I actually prefer PVC (edit and i think i may have convinced tom hamilton of this after he used one) as it is very easy to adjust balance and buoyancy no matter what combination of lenses, ports, lights, etc. that I use. The pvc requires 5 to 9 pounds of lead ballast to be neutral. (obviously for surf stuff you can easily remove that weight) With aluminum (and this is true of every aluminum or titanium epic housing available) when you use cinema lenses and/or glass ports the front gets very heavy so you have to use buoyancy tubes or floats to make it neutral. All of the metal housings (unless it is very oversized like a converted R1 or film housing) are very close to neutral or slightly negative in their basic configuration so when you add anything negative like lights, battery packs, glass ports, tripod mounts, external monitor, etc you have to add buoyancy which obviously increases size but also more importantly drag.

With PVC I also don't worry about corrosion at all.

As far as camera controls, standard is power/trigger; two controls for rear lcd for user buttons - (white balance, magnify, etc) and two lens controls which provide a rotary friction (not gears but works quite well) for lenses like the ultra primes. We would have to discuss your needs for other lens controls, like a red zoom or whatever. If they are relatively simple like the red zooms, duclos 11-16, ruby 14-24, optitek nikon, etc. - we would provide the alternative at no charge.

The front plate is aluminum with mounting for the threaded Aquatica ports as well as an additional o-ring groove and mounting screw threads for other port options like our flat port extension for larger lenses and anything not covered by the threaded ports.

Expect shipping weight to be about 40 to 60 pounds (18 to 25 kilos)

PVC $5795 alum $7895. Look for a special group buy discount offer this weekend.

[Rudi Herbert]

I just saw "The Last Reef" IMAX. My mini review here: http://www.reduser.net/forum/showthr...=1#post1004655

In a word: disappointing :(

Anyone else who (hopefully) felt differently?

Wow! Sounds like it was a horrible experience. With so much technically wrong, could it be the projection system was not calibrated properly? I have not seen any other productions from these people although they do have a name in the community, so I find it strange they would have gone out there with what has to have been a sizable budget and underperform so vastly across the entire spectrum...Then again, without a story to follow, even the most technically accomplished images are nothing more than eye candy.

[Frazier Nivens]

Beauty is in the eye of the beholder...some see only the worst in things. I can't imagine the IMAX film being as terrible as that. Depends upon if you are there to enjoy the film or pick it apart. One persons opinion only. I have to go see it now.

[paulherrin]

Nice! That's the shot I was hoping you'd show. Love how the orange tones pop out in the CC version. The spot lighting makes the diver look like a hero, dig it!

Thanks, Jeff :)

Here's another before/after I had on hand... This is a pretty good example of what we had going on for most shots. Remember, we were only doing primary color correction, so nothing fancy - just the basics. In the last shot I shared (diver on the rock face) I barely snuck in a little power window to spotlight the diver after Johnny dozed off on the couch one evening... shh, don't tell ;) I actually had to tone that one down a bit and bring some blue back in to make it feel like we were in the water with him. It might still be pushing the edge (literally...) a little bit, but I think it does alright in motion because as the camera pulls back, more water/blue is introduced between the camera/subject and gives you a sense of depth.

[Tom Hamilton]

Many are snobbish and demand aluminum but I actually prefer PVC (edit and i think i may have convinced tom hamilton of this after he used one)

I was initially worried that PVC wouldn't provide adequate heat dissipation, but after the last job, I am pretty much sold. The Epic never overheated, even after the boat captain accidentally powered the camera up when he bumped into the housing. I didn't find out about that until a couple of hours later, the Epic had been on the whole time, inside the housing, in direct sunlight.

For the kind of work I do, the travel weight savings advantages are very significant, so for me, it's PVC for now.

And since this business is so full of acronyms, I thought of a really slick sounding marketing one, the AV-SSP (AquaVideo-Submersible Sewer Pipe)

(Just kidding Mike, think I'll save that one for a titanium version)

[Johnny Friday]

Here's another before/after I had on hand... This is a pretty good example of what we had going on for most shots. Remember, we were only doing primary color correction, so nothing fancy - just the basics. In the last shot I shared (diver on the rock face) I barely snuck in a little power window to spotlight the diver after Johnny dozed off on the couch one evening... shh, don't tell ;)

Hey...i thought we agreed no Secondaries....no wonder why we took so long....
Actually that before/after is a very good example of a primary color grade and how the RAW data is bland and then can pop after a small bit of work....not really work, but just a few effects applied to make it stand out...Now this may not be a great shot and slightly out of focus at edges etc....and keep in mind the animal is over 6feet away from me and moving away...that said, on a 50" screen it's really sharp around the subject matter and stands out well with the rest of the shots in the sequence.

But as pointed out by another poster: Story drives everything! Just look at what's on tv these days and on the NG channel....not very compelling images if we rate the imagery itself, but some danged good stories--what comes to mind for me is the Alaska Gold mining show....some of the worst imagery, but the story is so compelling that you don't really care. Not that i would suggest we shoot less than beautiful imagery...but each day presents its own set of challenges and based on time/budget/water conditions and what happens that day.....you get what you get and shoot as best you can. We all know that many situations happen only once and hard to get an animal to come back for a second shot or line up for a critical focus--but this is just where talent/years of experience all add up....not that i am advocating i have any of those...but it's easy to see who these folks are when you work with them and understand the challenges of nat. hist. doc shoots. Hats off to you guys!