Underwater Bubble Blowers User Group Thread NEW

[Will Keir]

It is no secret that domes do yield soft corners.

Do domes also intro fish eye effects?

 

[Will Keir]

Good to know. The trouble with the GoPro is the 2 hour minus battery life. So on a full day canyoneering I must open the housing at least 3 times. When I do, your advice might be get in the shade or a cool place for the swap, making sure hands are dry before commencement?

Hey Will,
Once you've prepped and are good then there should not be an issue with fogging due to the unit being used in a watertight / airtight container, if it's dry at the beginning it will be dry at the end. You will only get issues with water collecting on domes or flat ports that can be avoided by using a selection of tricks such as the potato scenario as mentioned.

I would prep cameras for tourist filming gigs that would see them closed at around 9am in the morning and not reopened until we returned from diving at around 4pm. All this time they would be on dive skiffs under Micronesian sun, albeit at times shaded, and would have zero condensation / fogging issues.

Cheers,
Mark.

 

[Will Keir]

Where are you putting the ND filter? You talking lighting or in camera?

Jim,
I'm off for shoot there in Sept. and shot there a few times...I see no reason to use ND there at that depth...near surface i'd probably use one...but on the deeper cages....i go skinny and will do the same on my sept. shoot there.

 

[Mark_Thorpe]

I think there are bags or something that are made to reduce the potential for moisture to get in when changing batteries etc. However if they have been kept in ambient conditions then you're not going to be able to avoid potential for fogging once you open the GoPro. You can try to jam in a silica gel pack but the casing of the GoPro is so limiting in possible space for that, one thing that really makes my mind boggle on the design.

I'd suggest grabbing the main meat of the footage during the life of the first battery? OR simply buy a couple more GoPro's and fire them up consecutively as batteries die?

Cheers,
Mark.

 

[Pawel Achtel]

Do domes also intro fish eye effects?

No. Domes have little effect on fish eye lenses and, when placed correctly, they do not introduce fisheye (geometric barrel distortion) effect on rectilinear lenses either.

However, because the virtual image is projected just inches in front of the lens, most rectilinear wide angle lenses (including Master Primes) suffer from considerable barrel distortions at short focusing distance. So, practically, the answer is "Yes", but it is the barrel distortion caused by the acctual lens operating at close focus distance to the virtual image projected by the dome and not caused by the dome itself.

The biggest shortcomings of underwater dome ports are: image plane curvature (infinity rendered as a sphere), astigmatism and loss of resolution on corners. These defects get worse with sensor size: expotentially! This is why it is so much discussed subject on this forum. It was not such a big problem with 2/3" and smaller sensors. I often (most of the time) see images shot on RED that are inferior to those shot with lesser cameras that use smaller sensors.

Why don't you guys just focus to infinity? Loss of sharpness/detail? Like land, are water optics sharpest at F 5.6?

You can't just set the focus to infinity. The DOF is very thin even at f/8 - f/11.

At 5 micron pixel size, all lenses start becoming diffraction limited around f/4.

Underwater dome ports perform very poorly at larger apertures due to image plane curvature, generally you would shoot at f/8 - f/16 with a dome port.

Nikonos submersible lenses do not have those problems and out-resolve the Epic sensor from corner to corner at f/5.6. Dome + land lens combination can't achieve this.

 

[Tom Hamilton]

Will, as Johnny suggested, take your reg and blow tank air into and over the GoPro housing as you are changing it out. Very dry stuff, should work to prevent any kind of fogging.

I have a u/w GoPro attached to my AV housing i was using in Maui last week for B-roll/reference footage, did not have any of the problems you are describing.

 

[Johnny Friday]

Where are you putting the ND filter? You talking lighting or in camera?

Screw on filter or a paper gel at the back of the lens and there's no need to worry about affecting back focus because we are always focusing to a sharp point and very rarely using the focus marks on the lens...so back focus is often not critical unless you need to know your focus marks AND in case of 3d needs to be dead on.....and I'm suggesting this with Nikon lenses that do NOT have the electronic functions built into the mount yet...when that happens, you then will be able to know at what focus mark and iris setting you are in focus for various ranges of distance. But each will figure this out with lots of testing and what works for each photographer.

 

[Johnny Friday]

Here is yet another example of a frame grab underwater using a DOME port to dispel the fud that is being spread here in this forum: this from RED 1 with M sensor shot @ 4k using 18-50...original tiff is 57mb and this is merely a 5mb file. Further evidence of a land lens/dome port combination that can actually resolve better than 200 lines of resolution.

I post this because i think this marketing campaign of Pawel is out of control and his system is not the only system that will produce results destin to make great images. This is always in the hands of the maker of those images first and foremost, and RED with land lens & dome port can produce beautiful HD images.

This grab has PLENTY of detail from middle to edges to reveal what this camera/lens/dome port combination can resolve--as well as anyone to scientifically diagnose. Yes, it becomes less sharp at the right corner....that starfish is closer the camera than the anemone that was focused on. Does it distract from the image? I don't think so...but this is up to the audience when viewing the MOVING image.

As one well known cinematographer told me recently..."if the audience is watching the edges of your images, then you've lost them in the story"
...this does not mean to say any of us "don't care" about image quality, but we work with the tools we have and make the best of them.

[/url] RED 18-50 PL by RedCineUnderwater, on Flickr[/IMG]

 

[Tom Hamilton]

As one well known cinematographer told me recently..."if the audience is watching the edges of your images, then you've lost them in the story"
...this does not mean to say any of us "don't care" about image quality, but we work with the tools we have and make the best of them.

Well said Johnny. I propose we hereby induct the phrase 'edge-peeper' into the lexicon of underwater imaging.

I do like the results of the Nikonos/Epic combination, a very valuable tool set for a specific range of shots.

But I don't think those images need push the rest of the bubble-blower community into abject states of sub SD-rez despair, as evidenced by the edge resolution of the Cineport. A little conflict of interest goes a long way at explaining recently entrenched attitudes.

Housing sales will go to the folks that support and encourage, without reservation of any kind, their operators, loyalty is a thing achieved by solid back-up and mutual trust.

Any lessons to be learned there, look to John Ellerbrock and his team.

 

[Tom Hamilton]

Great idea, however, their water tightness is far from a sure thing. I've had two of them drown on me on dives to 200 ft, well within their advertised range. I picked up four more for an expedition for which I am the diving consultant and they've had problems too. Basically, if I am on a wreck or somewhere else where there are surface, or shallow water, buoys where I can leave these suckers dangling, then I bring them with me. Otherwise, I don't bother, but then again, I've heard from many others who have taken them down without problems....

Speaking of safety, just had a near-miss in my aircraft today, windshield full of airliner Boeing 757, the only thing that prevented pretty white bits of aluminum and body parts strewn all over the Texas country-side was a little device called TCAS, installed as a precaution for just such an eventuality. The electronic alert of an impending mid-air collision enabled a last-second escape maneuver, that is how close it was, saved our very skins.

In looking at the average diver/cam-operator profile, and the safety profiles I have learned from aviation, I encourage all of you to adopt the Nautilus device; without it, you may find yourself regretfully surprised at the proximity of your demise.

 

[Mark_Thorpe]

"Housing sales will go to the folks that support and encourage, without reservation of any kind, their operators, loyalty is a thing achieved by solid back-up and mutual trust. Any lessons to be learned there, look to John Ellerbrock and his team".

Absolutely nailed it. I once had a dodgy monitor on Z1 Housing in Palau. John called me on my cell after my initial report of the problem and sent out a replacement before I even got mine sent back, talk about client care. That speaks mountains. Nice image Johnny, although color rendition on the red drops a tad on the PANTONE reference charts I guess most people will be able to put up with that.

Cheers,
Mark.
PS the quote reply option wasn't working so I used this way.

 

[Tom Hamilton]

although color rendition on the red drops a tad on the PANTONE reference charts

I'll go out on a limb here, my best guess is the CRI deficiencies of LED lighting, the pronounced peaks and valleys, never been a really big fan, reds and oranges don't 'pop' like they do with full-spectrum HID.

Artificially designed electronic lighting is something reserved for 9 to 5 office slave spaces, despite the salesmen out there trying to tell you different. Not something we want for u/w natural history imaging.

Just my opinion, always ready to stand corrected...

Which, I am sure, feckity feck's sake, will happen in the next couple of posts :auto:...

Tough crowd here, life's a bitch :violin:

 

[Pawel Achtel]

Here is yet another example of a frame grab underwater using a DOME port to dispel the fud that is being spread here in this forum: this from RED 1 with M sensor shot @ 4k using 18-50...original tiff is 57mb and this is merely a 5mb file. Further evidence of a land lens/dome port combination that can actually resolve better than 200 lines of resolution....

Johnny, your picture serves only as the evidence of your confusion and apparent ignorance on the subject: "Beautiful images" and "resolving 200 lines" are two different things. One is your personal opinion, the other is a fact.

Here are some MTF graphs showing sharpness and contrast measured away from the centre of the frame (not exactly on the edge, where the performance is even worse). You may ask your "well known cinematographer" what these are for, what they mean and why you should care.

...I post this because i think this marketing campaign of Pawel is out of control and his system is not the only system that will produce results destin to make great images...

Again, you are confusing opinions with factual information. I try to stick to facts and data, which can be verified, compared with and improved upon. I understand that it is difficult for you to deal with factual information mainly because you do not understand it and because you are unable to contribute any. If you have evidence showing MTF curves for your preferred underwater optics or otherwise able to measure resolution, please don't be shy to be a bright spark. Hopefully your dome or flat port will perform better than those that I measured and we may have something meaningful to debate. I'm not the subject here, so I would greatly appreciate if you could kindly refrain from making personal attacks.

You can either accept a fact (like a measurement of the MTF) or contradict it. In order to disprove it, you need to show factual evidence because beauty (opinion) is in the eye of the beholder. The only thing that your picture proves is your inability to properly quantify the optical performance of your underwater optics and evidences your apparent lack of skill in the fileld combined with strong opinion and antagonistic attitude.

Well said Johnny. I propose we hereby induct the phrase 'edge-peeper' into the lexicon of underwater imaging.

I'm not sure why I feel like responding to your trolling, but I do feel that it would serve you and Johnny better to refrain from personal remarks and learn the craft.

..But I don't think those images need push the rest of the bubble-blower community into abject states of sub SD-rez despair, as evidenced by the edge resolution of the Cineport. A little conflict of interest goes a long way at explaining recently entrenched attitudes.

As far as I know, CinePort was and still remains the sharpest dome port commercially available. I shot with it for many years and I'm happy with its performance. Due to its large 6" radius, aggressive light trapping and precision, I belive it is the best dome port available.

I personally chose Nikonos glass, because I believe it is better than any dome: smaller, simpler, sharper, higher contrast and free from distortions, astigmatism, image plane curvature and other optical defects associated with dome and flat ports. The reason I believe so is because I tested Nikonos lenses, dome and flat ports in controlled conditions on an optical bench. It is an educated choice that I made and I'm happy with it because I can back it up not only with beautiful images, but most importantly, the data showing that the underwater optics is not limiting my pictures (and creative choices).

It is all about choices. I give a choice between the best dome port available and the sharpest and the least distorting Nikonos underwater optics. You can, of course, chose something else, like the manufacturer that gives you the most flattery. It depends on what you are looking for.

I think it is great to have more choices and I'm delighted to be able to offer something different and something that was evidently not available in the industry: underwater optics that can out-resolve the Epic sensor in every point of the frame and optics that create flat, undistorted images.

I am also proud to offer an Epic housing that weighs 4.5kg (10 lbs) and 3D housing that weighs 14.5 kg (30 lbs). Again, maybe not for you, but another choice in the industry that, if not for my substantial effort and expense, would not have been available to the industry.

...Housing sales will go to the folks that support and encourage, without reservation of any kind, their operators, loyalty is a thing achieved by solid back-up and mutual trust.

Do you mean to the companies that produce no factual data of the optical performance of their products and give a pat on the back for mediocre results instead of educating their clients?

Or, do you mean those that do not respond to their customer's complaints and produce faulty products?

As far as I know there is only one manufacturer that meets and fully complies with ISO 9001 quality standard.

As far as I know there is only one manufacturer that actually cares about the image quality, measures it, publishes it and therefore is actually able to compare and improve upon it, You can only improve something that you can measure. You can not improve an opinion, although you can change it - hopefully after knowing and understanding the relevant facts.

I do not mislead customers by saying that our housing is the most compact in the industry, when it clearly isn't.

I do not say that our housings are bullet-proof, when they are clearly not (such claim taken literally is simply false and when interpreted as "reliable", it is nothing more than a FUD considering that it comes without quantifying MTBF or any other factual and recognised way to back it up).

When I say that Nikonos optics produces non-distorted and sharpest images underwater as compared to dome and flat ports it is because I know it from costly and time-consuming research, which I kindly share with the community. Other manufacturers don't do that. You prefer flattery instead, which is fine. Different people want different things and I respectfully acknowledge your needs and happily refer you elsewhere.

I strive to provide factual (measurable and objective) information. You can ignore it, if it is something you do not care about. You can contradict it with hard facts and data (an opinion saying that your picture looks beautiful to you doesn't cut it). Or, you can accept it based on the evidence how it was obtained.

If anyone is interested in measuring the optical performance of their housing (be it Gates, AV or home made), we can offer equipment, facility, IMATEST software and education. If image quality is important, you can learn, measure, compare and improve, which is what I stand for and this is how my company is different from others.

 

[Johnny Friday]

so I would greatly appreciate if you could kindly refrain from being a fuck stick making personal attacks.

You gotta be kidding me? Are you this delirious?

Pawel, you are obviously out of control. I beg you to tell me this to my face sir. You don't know me at all...and to suggest such garbage is just trashy and tell me this to my face and you would have another problem. I don't trash you personally or publicly here. I do question your constant barrage of marketing on top of other people's posts and merely add additional items as evidence to disprove your knocking of dome ports. You obviously lack social skills and i can not see how you will ever survive as a vendor with such a trashy mouth and one way attitude.

 

[Mark_Thorpe]

I'll go out on a limb here, my best guess is the CRI deficiencies of LED lighting, the pronounced peaks and valleys, never been a really big fan, reds and oranges don't 'pop' like they do with full-spectrum HID.

Artificially designed electronic lighting is something reserved for 9 to 5 office slave spaces, despite the salesmen out there trying to tell you different. Not something we want for u/w natural history imaging.

Just my opinion, always ready to stand corrected...

Which, I am sure, feckity feck's sake, will happen in the next couple of posts :auto:...

Tough crowd here, life's a bitch :violin:

Hey Tom,
I was taking the piss, awaiting, and not too long as can be seen, the impending techno blast from some little known boy scout badge winning world authority on sea dragons. As was expected a post full of innuendo and dismembering of market leading products and award winning camera operators.

I think I'm gonna commission a new men's fragrance and send some out to certain deserving individuals. 'Pont Brulant' pour Homme the cap would be a cleverly designed dome port replication of a Nikonos 15mm Fisheye. Ahhh the wafts of slowly roasting hardwoods with a cheeky nuance of lighter fluids. A welcomed break indeed from the slight aromatic suggestion of ruminant gastric acids and freshly laid fecal arrangements that seem to emanate so repetitively when certain keyboards are employed.

Some shout, some do. We all know the camps to which we belong.

Cheers mate, and congrats on not being a small red stain on a commercial jet liner!
Mark.

 

[Mark_Thorpe]

I'm not the subject here, so I would greatly appreciate if you could kindly refrain from being a fuck stick making personal attacks.

You're bang out of line with this. I hope you believe in Karma, the world of underwater cinematography is a very small one.

 

[Jannard]

Everyone needs to watch their mouth or be banned forever.

Jim

 

[Ron Lagerlof]

Thanks, Jim!

 

[Ron Lagerlof]

BTW - flying off to Cancun in the morning (yep, hurricane and all) to have a shot - pun intended - at the "big spotty fish" off of Isla Mujeres. I just hope the weather lies down in the next couple of days and the sharks are still hanging around.
Wish me luck on some "Epic" footage...
Peace
Ron

 

[Mark_Thorpe]

I guess we all get a tad excited every once in a while, but there are limits. Time for self restraint.

Cheers Jim.