The Gentleman's Underwater Bubble Blower Thread

[Sean R.]

Thanks Matt!

Should be worth it at all depths. Although it does really excel at deeper depths in blue water.

I would consider not using it if the majority of shots will have your subject right at the surface, such as a diver or a whale floating at the surface in only the first half meter of water. And I would definitely avoid using it for split shots/over-unders due to the lack of IR cut. Infrared does not penetrate water very far at all so the lack of IR cut really shouldn't be an issue as long as you're not right at the surface.

 

[paulherrin]

nice work, sean. some really great images.

 

[Peter Lightowler]

Beautiful stuff Sean

 

[Travis Rummel]

Greetings,

We have a shoot coming up in Belize that we will need to shoot a freediving fisherman for a few days with our Epic-W. Curious if anyone is based in Colorado with an underwater housing available for rent for either a DSMC1 or DSMC2 Epic. We have a dragon and a helium in our kit.

Cheers
Travis

 

[Lee Kelly]

Im sure plenty of guys on here have passports...

 

[John J Ellerbrock]

Hi Travis --

if you don't find anyone in CO, you'll find many other options here:

https://www.gateshousings.com/rent-a-gates/

J-

Greetings,

We have a shoot coming up in Belize that we will need to shoot a freediving fisherman for a few days with our Epic-W. Curious if anyone is based in Colorado with an underwater housing available for rent for either a DSMC1 or DSMC2 Epic. We have a dragon and a helium in our kit.

Cheers
Travis

 

[Tom Hamilton]

Greetings All,

A quick invite to the bubble blowers here, diving with Fabien Cousteau this coming October at Grand Cayman, lots of equipment in play, Hollis Prism 2 rebreathers (open circuit folks also most welcome), Gates/Red gear, some interesting reef conservation initiatives/meet the local press, but above all, a fun week of diving, conversation and relaxation, at a really nice beach resort, and, a huge birthday bash for FC complete with chocolate fish cake (yum) & candles, and maybe some island rum, or three, hope to see some of you there!

PM me for further details, or call the numbers on the flyer.

Best,

T

 

[Hugh Miller]

Hi
I tested this port/optic a little while back. It is very sharp (at one focal length) but is shows a lot of distortion which to me was unacceptable for film work. Also it really only works at 28mm. You can zoom through but quality drops rapidly (and the bizarrely gets a bit better again). Need to use a ‘a low quality lens’ behind it because they tend to have a small front element diameter (which it requires). A Nikon 24-70 f2.8 won’t work - front element is too large.
The idea shows a lot of promise though and there’s no doubt that it can produce very sharp, very wide images and I’d love to not have to travel with a giant dome! Currently it’s best suited to stills.

 

[Jason Sturgis]

Hi Hugh,
Thanks for posting your findings on the port/optic. I have been wondering about that offering myself and its good to hear your thoughts. The option to have zoom through capability in something like that would be wonderful. Thanks again for your post.

 

[Hugh Miller]

I have mixed feelings about using these optics. On the one hand they are small, easy to travel with and excellent for getting into tighter spots. The downside is, they are fragile and expensive to buy and presumably repair (your not going to do it in the field), they could get moisture inside and suffer internal condensation which will ruin a shoot (I remember these kind of optics doing that in the past, they tend to be filled with nitrogen which eventually escapes to be replaced with humid air). Your never going to shoot a split level shot either so you'll need to have a dome too if thats on the wish list. So kind of a mixed bag. On the whole though if an optic is developed that works well and is small then it could be a great option.

 

[Peter Lightowler]

So who is taking the plunge and moving on to a Gemini?

After seeing how well that thing performs at depth, I am for sure.

 

[Tom Hamilton]

I was just about to ask that question here Pete. Do you have a link to some sample footage?

 

[Peter Lightowler]

Hey Tom. No I don't have that can be shown yet but there is some footage coming.

One shot in particular was the defining moment for me to decide to swap over. 96ft depth, the Gemini was running in low light mode at 48fps, so 1/96th shutter and shooting at F16.
My Scarlet W was running 30fps, 1/60th and I was struggling at F5.6 for light at the same depth.

Serious step up for us underwater shooters.

 

[Tom Hamilton]

That's impressive Pete, should open up a whole new range of uw shot possibilities with that kind of performance.

Does that sensor accept the DSMC2 H2OLPF? Gemini 8K just around the corner?

 

[Michael Hastings]

snip:
One shot in particular was the defining moment for me to decide to swap over. 96ft depth, the Gemini was running in low light mode at 48fps, so 1/96th shutter and shooting at F16.
My Scarlet W was running 30fps, 1/60th and I was struggling at F5.6 for light at the same depth.

Serious step up for us underwater shooters.

That's impressive Pete, should open up a whole new range of uw shot possibilities with that kind of performance.

Does that sensor accept the DSMC2 H2OLPF? Gemini 8K just around the corner?

That's an interesting comparison over the older dragon sensor but I would note that, according to the initial description from RED, Gemini is only one stop more sensitive than 8K helium sensor so you could have been shooting 8K at F11.

Further point: in either case - i.e. Gemini or Helium - you would actually be losing resolution due to diffraction limiting at F16 and F11.

There are definitely some situations where an extra stop would help, and Gemini is certainly a step up from Scarlet-W and Dragon 6K, but overall I'm not sure it is worth it for those with Epic-Ws ($5K to upgrade to 8K/60FPS and a year more of warranty), or those buying new rather than upgrading.

Further, regarding underwater shooting. Usually at the depths where light loss is an issue, you really need lights to bring back the best color, so it isn't necessarily low light shooting anymore.

Although a lot of people seem to worry about low light underwater, seems to me there are more times where we have too much light and need ND to get back to F-stops that don't create diffraction limiting. Even back in the days of 200 to 400 ASA film the old rule of thumb was "F8 and be at the boat at 8".

Also, BTW an 8k Gemini sensor would be 49.2mm wide which is 22% wider than VV monstro (40.96mm) and full frame still (36mm) so there really aren't any practical lenses (and particularly wide angle) that would cover that. Not to mention that it would probably be even much more expensive than the Monstro VV since costs - due to the increasing difficulty of making flawless sensors as the size gets larger - tend to go up exponentially.

 

[Hugh Miller]

I thought from one of the early tests that was posted, Gemini had very nearly three stops over 6k Dragon and again very nearly (but not quite) two stops over 8k Helium. For me thats enough to clinch it, plus no cropping on the higher frame rates. The low light aspect is very attractive for me - maybe I just end up in dark, gloomy holes more than sunlit shallows!
I don't think one camera is better than the other, they both clearly have their strengths, and both are very good. Ideally you'd be able to just pick the one you want on any given day! Haha.

 

[Tom Hamilton]

Further, regarding underwater shooting. Usually at the depths where light loss is an issue, you really need lights to bring back the best color, so it isn't necessarily low light shooting anymore.

Although a lot of people seem to worry about low light underwater, seems to me there are more times where we have too much light and need ND to get back to F-stops that don't create diffraction limiting. Even back in the days of 200 to 400 ASA film the old rule of thumb was "F8 and be at the boat at 8".

The beauty of the Gemini is the ability to switch between Low Light and Normal modes on the fly, so changing light conditions re depth, ambient/portable light etc should be that much easier to deal with. Hugh's comment regarding two cameras is perhaps closer to the truth than intended.

Does anyone know how the Gemini does this? Purely electronic? Dual OLPF?

 

[Michael Hastings]

I thought from one of the early tests that was posted, Gemini had very nearly three stops over 6k Dragon and again very nearly (but not quite) two stops over 8k Helium. For me thats enough to clinch it, plus no cropping on the higher frame rates. The low light aspect is very attractive for me - maybe I just end up in dark, gloomy holes more than sunlit shallows!
I don't think one camera is better than the other, they both clearly have their strengths, and both are very good. Ideally you'd be able to just pick the one you want on any given day! Haha.

Hugh: As you say, it is important to evaluate and base your choice on your particular situation.

My "F8 be there at 8" comment was just to point out that most relatively clear water diving is not really that low light.

I also wanted to point out the issue of diffraction limiting which many (including myself until just a few years ago) are not aware.

In your example - if Helium is 2 stops "slower" you would have been at F8 on Helium 8K which is about the highest stop you can use on Helium without getting into diffraction limiting.

Diffraction limiting starts at around F8 for Helium (3.6micron pixel pitch) around f11 for Monster (5 micron pixel pitch) and probably F11/F16 split for Gemini (6 micron pixel pitch)

There's a good explanation of diffraction limiting here:

https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm


According to that article diffraction limiting becomes significant when the size of the "Airy disk" is more than about twice the pixel pitch (and maybe stretches to 3 times when there is an OLPF)

Airy disk size is dependent on F stop regardless of lens or number of megapixels:

F16 21.3
F11 14.7
F8 10.7
F5.6 7.5
F4 5.3

I should also note that there are some tradeoffs here as we might push it a little into the diffraction limiting because the higher F stops help us with some of the loss of resolution and chromatic aberrations that come with the use of underwater ports (both flat and dome) which by there very nature are not fully corrected optics when in contact with water. And the article also goes into the fact that it diffraction varies a little with the difference wavelengths (colors).

The beauty of the Gemini is the ability to switch between Low Light and Normal modes on the fly, so changing light conditions re depth, ambient/portable light etc should be that much easier to deal with. Hugh's comment regarding two cameras is perhaps closer to the truth than intended.

Does anyone know how the Gemini does this? Purely electronic? Dual OLPF?

Electronic.

Gemini is an amazing camera - just not sure I want to give up 8K for that extra stop or so given that Helium is already pretty useable at 1600 to 3200 ISO. If I were doing more corporate, television, cinema work I would probably go with Gemini as 8K really isn't necessary for those and the lower light capability and increased frame rates at full sensor would maybe be more imptortant. I haven't done much at all with the Epic-W over the last year for a couple of other reasons, but my general aim is for underwater, travel, and nature shooting where I would like to have the full 8K for those productions as well as possible stock footage. The upgrade to 60fps is pretty big so for $5K I will probably do it.

 

[Hugh Miller]

Diffraction limiting starts at around F8 for Helium (3.6micron pixel pitch) around f11 for Monster (5 micron pixel pitch) and probably F11/F16 split for Gemini (6 micron pixel pitch)

There's a good explanation of diffraction limiting here:

https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm


According to that article diffraction limiting becomes significant when the size of the "Airy disk" is more than about twice the pixel pitch (and maybe stretches to 3 times when there is an OLPF)

Airy disk size is dependent on F stop regardless of lens or number of megapixels:

F16 21.3
F11 14.7
F8 10.7
F5.6 7.5
F4 5.3



Thats a really good read, thanks Michael.

 

[Sean R.]

well, I hope my mediocre cinematography skills do some justice to this amazing technology but here's my first outing with Gemini and H2O OLPF underwater:

https://www.youtube.com/watch?v=rxISm0PTKpg&t=31s

I tried to do as much as I could to manually WB underwater and not do too much in post to show you guys what it can do as it was shot, out of camera. With that said, of course I did some basic color correction to most shots, but very minimal overall and non at all to some.

From a shooter's perspective...my mind is fucking blown with this sensor. I've never used so many speed ramps in my life in an edit because I decided to shoot as much as possible at high frame rate, just to prove the point that you can. And still always ended up f8-f16. And that's at the 20-30 meter plus dives I'm talking about. I tried to switch off my lights on a lot of that, with the bulls just getting hit with the other shooter's lights that were to the sides of me. Really looking forward to getting this sensor into more available light only situations. Dark, cold, sneaky, ninja shooting situations...