Underwater Bubble Blowin' Users Group

[David Nardini]

hotting up ... but interesting

hotting up ... but interesting

Good to see some new tupperware from Aquavideo.

Can 10-22 under Aquatica plastic-thingy resolve more than 1k underwater?

Aquatica dome is known to flare like kaleidospe, has massive CA and poor contrast. May as well put a VHS camera inside.

Can we see some charts shot underwater and topside to compare? 1:1 corner crops would be of particular interest.

I go on the road for a few weeks and return to see some interesting debates !
I do not know too much about Aquatica dome (plastic or not) but, Pawel, some of your comment are put across a tad (!) strongly ;-)

It's interesting to see on your web site that you are a dome man (all be it with 'astounding light transmission characteristics greater than 99.7%', coated, glass, etc) ... but, if your statement is correct (about the 1K resolution) the vast majority of the DSLR shooter out there are wasting their time shooting with their 6MP to 16MP cameras ;-) ... there being quite a few Aquatica shooters out there.

Personally, to date, I've used Seacam domes (glass and coated), perhaps not as good as your dome, but are you telling me I can SEE the difference between say 90-95% and 99.7% light transmission in an u/w shot ? I would argue that the dome correct placement and the controlling of internal reflections will have a greater impact on image quality (not to mention the massively variable water conditions we face, which is clearly not under our control).

The idea behind this kind of forum is to make contributions ... if your optics are so good, can you share your 'charts shot underwater and topside to compare & 1:1 corner crops' ? Will you be marketing your dome ? For what lenses (for use on RED) ? What is the expected price & delivery time ?

Cheers,

 

[David Nardini]

Birger and aperture control ...

Birger and aperture control ...

So ... having seen the Birger aperture control being operated by the 2 push buttons (NAB2008 YouTube clip), what happened to the pot-like-control ?

Unless I've missed a key post (somewhere) am I to understand that the only way it will operate it is now via the buttons ONLY ?

Cheers

 

[Pawel Achtel]

I do not know too much about Aquatica dome (plastic or not) but, Pawel, some of your comment are put across a tad (!) strongly ;-)

I guess I can't hide my strong views on the subject, can I? :tongue:

... but, if your statement is correct (about the 1K resolution) the vast majority of the DSLR shooter out there are wasting their time shooting with their 6MP to 16MP cameras ;-) ... there being quite a few Aquatica shooters out there.

Yes and No. Yes - I am not aware of any wide angle port commercially available which would reproduce more than 1k resolution beyond 70~85 degrees view on 35mm image plane.
No - you can still get "acceptable" sharpness in the middle 50 degree angle of view and you can still make nice images. Believe me or not, 1k underwater is a fair bit and (much) better than average. A lot of footage in the BBC's Blue Planet did not have more than 200 lines, some probably less than 100 lines in the centre!

Personally, to date, I've used Seacam domes (glass and coated), perhaps not as good as your dome, but are you telling me I can SEE the difference between say 90-95% and 99.7% light transmission in an u/w shot ? I would argue that the dome correct placement and the controlling of internal reflections will have a greater impact on image quality (not to mention the massively variable water conditions we face, which is clearly not under our control).

I used Seacam Superdome (three of them) for almost 6 years. It performes quite well and about 300% better on 2/3" image plane than it does on S35mm sensor in terms of image field flatness (mostly responsible for loss of contrast and sharpness away from centre). Superdome is the best commercially available wide-angle port. To answer your question: Yes, there is clear and visible difference between Superdome and CinePort. The main difference is that CinePort creates as "in air" look. You can only see it on a moving image. There are also significant differences in contrast, resolution, distortions, but also in flare and reflections. The last two are less prominent and harder to see on still images, but are quite problematic in motion picture. In moving image the difference is clear and a lame person can see it too, just may be not aware of the reason for it. I like Superdome but, it does not resolve more than 1k beyond ~80 degrees FOV, and this is with perfectly aligned entrance pupil, perfectly focused and stepped to the "sweetest spot" of the combined optics.

The idea behind this kind of forum is to make contributions ... if your optics are so good, can you share your 'charts shot underwater and topside to compare & 1:1 corner crops' ? Will you be marketing your dome ? For what lenses (for use on RED) ? What is the expected price & delivery time ?

I have four CinePorts which I use myself. The 5th one, and the only out there, is owned by Harald Hordosch - the owner and the CEO of Seacam. He bought it from me. You can only guess why.
Unfortunately CinePort is not available for sale or even for dry hire. The manufacturing cost, (excluding design, testing and development time) is higher than what Red One sells for. So, its performance is academic, really.

My statement was purely to lower people's expectations. The 10-22 zoom does not even resolve 10 megapixels in air, so expecting more from it underwater would be a bit ambitious, to say the least. Stephen Fink (and others) demonstrated limitations of various domes and this lens quite well in his pool tests. But then, it didn't stop me from taking thousands of topside pictures with the 10-22 - some even half-decent :biggrin:.

The best way you can get good sharpness underwater is to use lenses, which are designed for this purpose. Nikonos RS comes to mind.

You asked for a sample. I shot over 20 hours of footage with CinePort, but most is not available for preview (for various reasons). However, here is a frame grab from footage I took back in early 2002 with my HDCAM camera behind a different (let's call it "Mystery") port. The image is not colour corrected or sharpened in any way. These were the "early days" when even the BBC did not know what HDCAM was (I kid you not). Well, I did, but still had no idea what I was doing most of the time :clown2: . Ayway, the image resolves about 1.4k horizontally x about 700 lines (not line pairs!) vertically. 1:1 corner crop provided. The "better than average" contrast is mainly due to some luck and possibly the optics used. Whilst my optics, knowledge and skills improved somewhat since 2002, this shot remains my favourite to this day. You can compare it to any u/w frame grab from Red One.

Edit: I should add that the footage was taken in Sydney in 3-5 metre visibility.

 

[David Nardini]

Hi Pawel,

Concur that dedicated u/w glass is clearly the best (Nikonos & Nikonos RS glass); I've never matched the old Nik 15mm quality ... I got close with the Hassy SWC + dedicated Zeiss Ivanoff port. Since I've been using domes it's always been a BIG compromise.

The SuperDome is my 'standard' port ... controlling flare is a challenge ... (there are ways); best I've come across to date.

Shame the CinePort is not available, not even for hire (lucky Harald - I wonder if he's adapted one for use on a Seacam to try out ... I'll have ask him); perhaps a larger production batch ? or maybe you just want to keep the competitive advantage in house ;-)
Did you explore Ivanoff ports in the past (to produce flat depths of field and provide perfect water interface work / no magnification changes) ? At the unit costs you talking about I do wonder if there is some scope here ... (assuming non extreme wide angle work).

I'm very interested in your comment about the difference (perceived or measurable) 'behaviour' for moving images versus stills associated with domes ... I find this surprising ... then again, moving stuff is new territory for me, so I'll take that on-board.

At the end of the day, it's all about return on investment, and it would be good to see/gauge the benefits of CinePort versus correcting (hopefully) mild imperfections in post (for the rest of the commercially available domes).
Sounds like there are only 2 people in the world who can do a side by side comparison of CinePort vs 'the rest', so I guess it's a dead end road !

Thanks for the frame grabs ... I'll have a more careful look later.

Cheers

 

[Michael Hastings]

Birger has knobs and other updates

Birger has knobs and other updates

So ... having seen the Birger aperture control being operated by the 2 push buttons (NAB2008 YouTube clip), what happened to the pot-like-control ?

Unless I've missed a key post (somewhere) am I to understand that the only way it will operate it is now via the buttons ONLY ?

Cheers

David:

In the words of the Hitchikers guide DON'T PANIC, Birger will have knobs too. He added the buttons so that you could also change the iris without the knobs. You will have the ability to daisy chain the two knobs and the default will be first knob is focus and second is iris. Obviously the buttons would be a much harder way to set iris in the housing. Erik is making special encoders for use in the housing. Because of size and position constraints with the knob/control shaft method we are also looking into a simple remote for setting iris and focus via a small circuit board with simple iris up/down and focus near/far control which would use simple switches rather than the encoder knobs. This would open the possibility of putting the switches right at the handles.

Hi Pawel,

At the end of the day, it's all about return on investment,

Good points1) re: the cost and the possibility of the Ivanoff type correctors for that kind of money. 2) ROI. That is why domes are still virtually the only method used on high end motion picture projects S35, IMAX, etc. over the past 30 years.

However, besides the readily available Aquatica ports we are working on our own glass dome AND we have made our system very flexible, the large opening lets us use any of the existing ports, plus we have added an oring groove approx 6.25" diameter and the corresponding threaded screw holes to allow the use of simpler flat ports OR almost any type of port setup you would like to attach - that is if you or someone else wants to design another port system you already have an easy sealing surface and mount set up in place.

Hi Pawel

....
Sounds like there are only 2 people in the world who can do a side by side comparison of CinePort vs 'the rest', so I guess it's a dead end road !

Cheers

Another good point. I have a hard time with representations like "300 % better", since I don't know how that calculates in something like this. And things like 95% light transmission vs. 99% sound like a big thing until you realize that moving from F2.8 to F4 is 50% light transmission or the other way around F2.8 is 100% more light. So how much of an F-stop is 5% less light. Would it be like a tenth of a stop? - I don't know exactly, it didn't seem like enough to warrant the calculations. Better light transmission is part of it but the main reason to go to glass (other than scratch resistance during normal cleaning) is to try to reduce flare.

Optics are important - one of the biggest advantages of RED is that the simple single sensor (no prism!) allows the use extremely sharp lenses in the $700-$1800 range as opposed to the $20K or more you have to spend with a Varicam or HDCAM setup - but you can overthink this stuff too.

Hello to all!

New to the site and eager to learn more from the experiences within. Sounds like new depths are being charted daily.

AquaVideo, I may be interested in renting one of your housings and it looks like your webpage may be down. Any way to reach you?

PM me or call 954 937 6600

I just noticed the website being down - I was switching to another hosting company but I thought it stayed with yahoo (originally simplenet) until I canceled with them - will check tomorrow.

 

[Pawel Achtel]

Another good point. I have a hard time with representations like "300 % better", since I don't know how that calculates in something like this.

Assuming curvature of field is constant and relatively small on the image plane, the loss of resolution can be aproximated as linear function of the image plane size. Thus, as a ball-park figure, you would expect 300% more loss of resolution due to field curvature alone on an image plane that is 300% larger.

In lame terms and with some examples (Canon 14mm L f/2.8 on EOS 1Ds, 9" dome), Stephen Frink wrote about it here:

http://www.stephenfrink.com/sf-tips/200607-digital-wide-angle-dust/digital-wide-angle-dust.pdf

Even on the low-resolution PDF you can clearly see that Canon EF 14mm f/2.8behind 9" dome does not resolve even 1k away from the centre. The dome compromises its performance substantially.

And things like 95% light transmission vs. 99% sound like a big thing until you realize that moving from F2.8 to F4 is 50% light transmission or the other way around F2.8 is 100% more light. So how much of an F-stop is 5% less light. Would it be like a tenth of a stop? - I don't know exactly, it didn't seem like enough to matter.

No, you would not see 5% of light loss. However, what is not transmitted is generally reflected. 5% reflection of a dome surface (there are two) can show as much as 3 stops (5% of 100% is ~3.5 stops of 8-stop DR), of ghosting, glare and reflections. You would also see loss of contrast and detail due to reflected and dispersed light.

Even Seacam Superdome is capable of creating some terrible reflections, ghosting and flare if you are not careful. Just point it upwards on a sunny day and do some panning.

 

[David Nardini]

In the words of the Hitchikers guide DON'T PANIC, Birger will have knobs too. He added the buttons so that you could also change the iris without the knobs. You will have the ability to daisy chain the two knobs and the default will be first knob is focus and second is iris. Obviously the buttons would be a much harder way to set iris in the housing. Erik is making special encoders for use in the housing. Because of size and position constraints with the knob/control shaft method we are also looking into a simple remote for setting iris and focus via a small circuit board with simple iris up/down and focus near/far control which would use simple switches rather than the encoder knobs. This would open the possibility of putting the switches right at the handles.

Mike, thanks for the update. As for the Hitchikers guide reference, perhaps a 42" dome will fix all our problems

Cheers ....

 

[Pawel Achtel]

perhaps a 42" dome will fix all our problems

Howard Hall tried exactly that in order to overcome massive resolution loss on 65mm image plane....

 

[Michael Hastings]

RED housings and sharks in another thread.

RED housings and sharks in another thread.

Mark Thorpe/Camdiver (who started this thread) has a thread showing two of our housings shooting the sharks in Africa. Ken Corben and Johnny Friday are shooting with Mark this week.

http://www.reduser.net/forum/showthread.php?t=13740

 

[Pawel Achtel]

CinePort for Sale

CinePort for Sale

I have one new and unused CinePort for sale. Complete with SeaCam custom mounting. It will work best with Canon EF 14mm prime lens and covers the same field of view.

Pictures of the actual port for sale attached. The third picture shows CinePort next to Seacam Superdome.

Offers over $20k welcome. Only one is available for sale, so first in - the only dressed hmy:

Any questions, please ask. Some answers may be found here: http://achtel.com/News/CinePort.htm

Also available is a female bayonet mount that goes on the housing front plate, which will fit AquaVideo and many other housings.

This is quite unusual piece of glass, offering unmatched contrast and sharpness. Apart from me, the only other CinePort is owned by the CEO of Seacam.

You can contact me by email at: firstname.secondname@24x7.com.au

 

[Johnny Friday]

$20k usd?

$20k usd?

Hi Pawel,
Can you explain beyond what your website says about the glass. Basically where is the technology behind it? I see you have a coating on the glass and likely very nice glass, but what more goes into this glass for $20k ? I'm only curious to know more why this glass is so much better than say subal glass. I can get glass coated so that's not really a problem.

Am I missing something? You would have to explain to me in simple terms how the cineport is so much better. I've shot recently using standard acrylic ports and was quite impressed with the results. I will now try some glass ports to see what if any better quality I'll yield. I expect there to be better performance, but not substantially so.

Thanks

 

[Michael Hastings]

Hi Pawel,
Can you explain beyond what your website says about the glass. Basically where is the technology behind it? I see you have a coating on the glass and likely very nice glass, but what more goes into this glass for $20k ? I'm only curious to know more why this glass is so much better than say subal glass. I can get glass coated so that's not really a problem.

Am I missing something? You would have to explain to me in simple terms how the cineport is so much better. I've shot recently using standard acrylic ports and was quite impressed with the results. I will now try some glass ports to see what if any better quality I'll yield. I expect there to be better performance, but not substantially so.

Thanks

I am curious about the actual performance as well and would be willing to make a special frontplate for our housing incorporating the bayonet for the cineport so that the reduser/bubbleblower community could evaluate it among our other options. It would be simplest to do it in Ft. Lauderdale or possibly Key Largo. If there is a question of bias I could ask Stephen Frink to assist and oversee testing. I would also certainly invite any and all bubble blowers. Maybe we can organize an FLL underwater RED test weekend? Mid-July?

 

[Pawel Achtel]

I am curious about the actual performance as well and would be willing to make a special frontplate for our housing incorporating the bayonet for the cineport so that the reduser/bubbleblower community could evaluate it among our other options. It would be simplest to do it in Ft. Lauderdale or possibly Key Largo. If there is a question of bias I could ask Stephen Frink to assist and oversee testing. I would also certainly invite any and all bubble blowers. Maybe we can organize an FLL underwater RED test weekend? Mid-July?

I would be happier to let you or someone else test the dome rather than publically explain what it is that makes it the sharpest and clearest underwater port bar none.

The best would be to do a test with a still picture camera and Seacam housing because CinePort has the same position of the entrance pupil as the Superdome. If someone has a properly aligned 14mm Canon lens to the Superdome, it would be aligned with CinePort too. Just replace the port. One thing, though: it must be an S35 image size, not the 35mm still picture image size. The port covers just over 90 degree diagonal field of view.

CinePort didn't come to fruition overnight. It took many years of R&D. The process was a simple one: first try to quantify and identify the parameters responsible for contrast, flatness of field, sharpness, CA and flaring and then optimise them in a reasonable form factor. The starting point was the Superdome. There are numerous improvemnts that do not meet the eye, but rather than explaining them in detail, I would rather show the results, which speak for themselves.

The first obvious thing you notice with the CinePort is that it "can see" roughly twice or three times as far as you can through a dive mask. Number of times I filmed things I didn't and couldn't see myslef, but the camera could record a clear image of it. Filming in 3-5m viz produces very clear, high contrast image. I kid you not, the picture of the sea dragon a few pages back was shot in less than 5m viz and the image was not manipulated in any way.

The second thing you notice is that, when you move the camera, the rectiliner effect is preserved and the space feels like "in air" more than "in water". It is strange, but very natural feel when you see the footage on a large screen. It is non distorting and very flat. Hence, the name CinePort.

In terms of cost, there are very few optical workshops which can grind a cubic foot block of optical glass to micrometer precision and finish the surface exceeding that of HD glass. The coating is also unique and results in substantialy less flare and higher contrast underwater. The actual cost of CinePort would be much higher if R&D was included. The development requires trials and errors. The mount alone cost about $4k to make (I have another one spare, if anyone is interested). It uses about 3-4 times more material than Superdome and is incomparably more complex and harder to make. It is a 2-part design clamped with titanium bolts, so it is user-servicable (although not recommended if you don't know what you are doing).

Mike, to test the port you would first need to find out the entrance pupil of the EF 14mm f/2.8 II lens from Canon. I don't have the data. I can give you all the specifications for the front plate, which shouldn't take more than a couple of hours to make, but probably testing with still picture camera would be easier.

I am sure Stephen Frink would like to play with the dome and he has some good practical ideas too. You can certainly ask him. I don't mind or care whether the results are biased or not because I do not need convincing. I wouldn't have spent so much effort and money if there was little difference. Deep pockets are certainly not the area where I compete with the BBC and other usual suspects (some of which conceeded that they can not match or even come close to the resulting image quality at any cost). I also do not want to sell CinePorts.

In terms of timing, I will be going away to a remote location starting mid-June, so it would be best to plan it when I return around early July.

 

[conrad gaunt]

I don`t scuba dive, but I sometimes blow bubbles underwater

 

[Mark Thorpe]

I don`t scuba dive, but I sometimes blow bubbles underwater

Much to the chagrin of your little rubber ducks I bet .....

 

[Pawel Achtel]

I don`t scuba dive, but I sometimes blow bubbles underwater

You should try the opposite :usd:

 

[StephenFrink]

David - I noticed your comment about flare on the Seacam port. Some lenses are clearly more difficult to tame flare than others, however you may be interested to try the new Superdome AR (anti-reflective) that Harald created at my request. The interior flat surface of this dome is coated with the same black flocking as is used inside the housing, and is available only with coated mineral glass as well.

Hi Pawel,

Concur that dedicated u/w glass is clearly the best (Nikonos & Nikonos RS glass); I've never matched the old Nik 15mm quality ... I got close with the Hassy SWC + dedicated Zeiss Ivanoff port. Since I've been using domes it's always been a BIG compromise.

The SuperDome is my 'standard' port ... controlling flare is a challenge ... (there are ways); best I've come across to date.

Shame the CinePort is not available, not even for hire (lucky Harald - I wonder if he's adapted one for use on a Seacam to try out ... I'll have ask him); perhaps a larger production batch ? or maybe you just want to keep the competitive advantage in house ;-)
Did you explore Ivanoff ports in the past (to produce flat depths of field and provide perfect water interface work / no magnification changes) ? At the unit costs you talking about I do wonder if there is some scope here ... (assuming non extreme wide angle work).

I'm very interested in your comment about the difference (perceived or measurable) 'behaviour' for moving images versus stills associated with domes ... I find this surprising ... then again, moving stuff is new territory for me, so I'll take that on-board.

At the end of the day, it's all about return on investment, and it would be good to see/gauge the benefits of CinePort versus correcting (hopefully) mild imperfections in post (for the rest of the commercially available domes).
Sounds like there are only 2 people in the world who can do a side by side comparison of CinePort vs 'the rest', so I guess it's a dead end road !

Thanks for the frame grabs ... I'll have a more careful look later.

Cheers

 

[Bmoreshaun]

Epic housing

Epic housing

So I'm looking into an underwater housing for one of my REDs but I'm a bit concerned about compatibility if I switch to the new Epic. Although after reading a post it might serve myself and renters best if I just upgraded the chip on my REDs. Will the specs on the body size be the same?...Any thoughts???...

 

[Pawel Achtel]

David - I noticed your comment about flare on the Seacam port. Some lenses are clearly more difficult to tame flare than others, however you may be interested to try the new Superdome AR (anti-reflective) that Harald created at my request. The interior flat surface of this dome is coated with the same black flocking as is used inside the housing, and is available only with coated mineral glass as well.

Stephen, Welcome to the forum!

I had three specially made Superdomes AR and used them for many years - good glass, but still, under some conditions, hard to control flare and reflections. Certainly best dome comercially available.

If you like to test my CinePort I can make it available and see what you think :biggrin:

 

[Ken Corben]

So I'm looking into an underwater housing for one of my REDs but I'm a bit concerned about compatibility if I switch to the new Epic. Although after reading a post it might serve myself and renters best if I just upgraded the chip on my REDs. Will the specs on the body size be the same?...Any thoughts???...

It would be safe to assume that the RED team will surprise us all when Epic starts shipping and the upgrade may be a good choice for underwater work? I would also guess that the optical center from camera tray to dome port will not be plug and play between the two cameras in one housing. Possible yes - but likely?

If you are not planning on shooting full time between now and the release of Epic then renting a housing may be a solution. I do not see a disadvantage to owning a housing for both cameras either. The summary is that there is no way to make a decision on your question since the final specs on Epic are subject to change.