The Gentleman's Underwater Bubble Blower Thread

[Graeme Nattress]

AFAIK there's no IR under-water. If anyone has any good references to the spectral nature of light at depth, I'd be keen to see them.

Graeme

 

[Johnny Friday]

Well, there may be little to none after going to certain depths....but most of the magenta cast i see is in very bright conditions and shallow depths where light is an issue and having to lower ISO as much as possible or even run overcranked. Others have said they see this at depth, but i mostly see it in clear, bright water. I know i'm in to my neck suggesting IR & UV, but i still ponder in this direction and see the water column acting like an ND 9 filter and allowing IR/UV to penetrate to a certain depth....then hitting RED's Red colored OLPF.....etc...etc...All observations and conclusions drawn from random shoots and understanding how IR/UV works on land.

 

[Greg F]

AFAIK there's no IR under-water. If anyone has any good references to the spectral nature of light at depth, I'd be keen to see them.

Graeme

I had thought about using IR to do some studies underwater but I quickly realized it would fail hard. IR Does not transmit anywhere near far enough.

http://www.academia.edu/1790553/Underwater_infrared_video_system_for_behavioural_studies_in_lakes

 

[Michael Hastings]

AFAIK there's no IR under-water. If anyone has any good references to the spectral nature of light at depth, I'd be keen to see them.

Graeme

I got jumped on when I posted the first quote, which was really just off the cuff to suggest that IR probably wasn't the issue and reflected the basic color absorption chart we have all seen since our basic scuba training (which appears like the first one I posted here which stops at the visible violet):

to quote an article on underwater optics:

"Ultraviolet rays reach farthest, whereas infrared ones are absorbed literally centimeters under the surface of the water."

Seems unlikely that IR would be the culprit.

#1119 5/29/2013

…snip The other part of the quote was just as interesting to me as it suggests that since we always have the reverse of that topside heavy ND scenario (i.e. water is fairly strongly and progressively filtering the overall light level - and more on the RED end) you might consider UV sensitivity or "contamination" as a possibility.

But the second two charts I have posted here after looking further suggest that the UV spectrum is also quickly absorbed so the chart is more of a bell curve peaking in the blue/green.

Not sure where that leaves us.

There's a fair amount of info out there if you google underwater color absorption but sorting the wheat from the chaff may take a while.

It's also worth noting the other point in the first chart - which is that the colors are absorbed additionally between the camera and subject which is one of the big reasons for using ultrawide lenses - reducing camera to subject distance even a little bit increases color saturation. (The other reason is simply improved overall clarity and contrast by shooting through less water).

The fact that filtration is progressive is really the weirdest part of dealing with underwater photography. Witness one of the comments about shooting upward - in the days before raw I used to caution people about setting white balance below 30 feet or so because if they shot pointing upward the streaks of sunlight near the surface will be quite reddish. Although that is accurate given the white balance at the depth of the camera, it is unnatural looking so in that case better to have a little deeper blue overall than the "unnatural" look.

 

[Graeme Nattress]

Thanks Michael - good info there. I saw too the diagrams showing the bell-curve on the absorption. I'd really like to know what's going on outside the visible range too. Either way, we can do a couple of experiments and start ruling things out.

Graeme

 

[Pawel Achtel]

It was Jarred who did not want this issue discussed or disclosed publically. He misunderstood my request thinking that I was going to.

Then he thought that I posted the information on Reduser, where all I have done was confirming the problem that everyone was talking about for months. Jarred got upset for completely wrong reason.

I offered to discuss the MX problem with RED but also requested the Dragon sensor to test, if possible. He again misinterpreted my request and thought I was demanding one (my clarification didn't change much) or else I would publically disclose the problem, which you all know was incorrect.

The reason we requested certain information from RED was to help us help them and the entire Red community. I haven't received such information. It wasn't shared with us. It was labeled confidential. We needed to go through a lot of trouble to measure it ourselves.

Despite all this, we offered to, without stings attached and in good faith, discuss the problem by email with RED. My emails are unanswered to this date.

All I can do is read your comments here and shake my head.

AFAIK there's no IR under-water. If anyone has any good references to the spectral nature of light at depth, I'd be keen to see them.

Graeme

We studied this area extensively in the past and run courses on this subject.

Good luck everyone with your joint research. Glad it is all going well.

 

[Jarred Land]

It was Jarred who did not want this issue discussed or disclosed publically. He misunderstood my request thinking that I was going to.

Then he thought that I posted the information on Reduser, where all I have done was confirming the problem that everyone was talking about for months. Jarred got upset for completely wrong reason.

I offered to discuss the MX problem with RED but also requested the Dragon sensor to test, if possible. He again misinterpreted my request and thought I was demanding one (my clarification didn't change much) or else I would publically disclose the problem, which you all know was incorrect.

The reason we requested certain information from RED was to help us help them and the entire Red community. I haven't received such information. It wasn't shared with us. It was labeled confidential. We needed to go through a lot of trouble to measure it ourselves.

Despite all this, we offered to, without stings attached and in good faith, discuss the problem by email with RED. My emails are unanswered to this date.

All I can do is read your comments here and shake my head.


We studied this area extensively in the past and run courses on this subject.

Good luck everyone with your joint research. Glad it is all going well.

You are completely off your rocker.

I have no problem discussing this in public.. take a look around, .. that is what we are doing here.

You say you want to just help us and everyone..... so why don't you tell everyone the problem and the solution?

Yeah.. didn't think so.

I think you are done here.

 

[Michael Hastings]

In a community where both RED and the users freely exchange information, I find Pawel's insistence on secrecy off-putting.

.................................. biting tongue .................. biting tongue .................. biting tongue .................. biting tongue ..................

Well, RED doesn't exchange as much info as they used to, but there's still a lot of open communication.

Niko: I'm posting this in part to explain myself and part as maybe a gentle admonishment to Pawel. First of all, the "biting tongue" had nothing to do with Red, it was a play on your "I find Pawel's insistence on secrecy off-putting" as many of us here (evidence in my PM mailbox) find A LOT of what Pawel says off-putting - particularly in tone. I know of several Redusers that I would consider very valuable artists and contributors that avoid this thread now because of the poisonous tone that Pawel's style creates.

Pawel: I don't doubt that there was some misunderstanding of what you were offering and asking of RED, but at some point it might be useful to take a look in the mirror and realize that your style is such that many people simply don't want to deal with it no matter how much you have to offer. You seem to be an intelligent guy that has access to significant research capabilities and an inclination to "dive" into these subjects deeply - which is admirable. But I think the "smartest guy in the room" attitude and the snide or sarcastic comments undermine any desire by others for your input.

There's nothing wrong with wanting to be compensated if you have gone to extraordinary lengths to figure something out but you have probably created so much alienation that you are going to have to proffer some pretty significant clarification of what you are offering before anyone is going to embrace it.

PS I see Jarred jumped in while I was writing this. (took a lunch break and didn't update the thread before I finished - but might as well leave it)

 

[Rudi Herbert]

Holy smoking mackerels.......and just like that, when it appeared there would be no end to the vitriol, he got banned!!! Anyway, let's hope we mere mortals can solve this issue once and for all. There's been an e-mail list correspondence with Graeme and we are moving forward though no smoking gun has been found as of yet.

 

[Graeme Nattress]

As mentioned in our email thread, the next stage is some experiments. I've been getting some good underwater spectral data too that should inform our deliberations.

Graeme

 

[Greg F]

Holy smoking mackerels.......and just like that, when it appeared there would be no end to the vitriol, he got banned!!!

Something about there will be peace in our time.

Anyway, let's hope we mere mortals can solve this issue once and for all. There's been an e-mail list correspondence with Graeme and we are moving forward though no smoking gun has been found as of yet.

If anybody wishes to be kept in the loop on this you can ask to be put on the list I am sure nobody on the list has a problem with anybody being added.

I will be dragging my camera down in test mode tomorrow. If the wall happens(Bottom to Surface filled with Hammerheads) I blame Graeme if the shot is ruined I suppose its best to test the camera where I dive all the time.

 

[Bill Anderson]

Greg:

Will there be other cameras around, ones that are known/claimed to not exhibit this "phenomenon" ? Stills cameras?

Is the phenomenon predictable and easily induced? Or is the issue intermittent: prone to being undermined by the many underwater variables?

 

[Dave Blackham]

We aim to be UW on the 20th in a controlled situation probably with 2 Epics, fresh water. Does anything need to be shot ? If so what would help ?

 

[Greg F]

Bill, I can drag my DSLR down that will be rough.. but I will do it.. I wish I had two of the same lens...

I will just throw my PL on my RED and then put the other lens on my DLSR and run them both 20mm for shots to remove vignetting.

 

[Russ Campbell]

You are completely off your rocker.

I have no problem discussing this in public.. take a look around, .. that is what we are doing here.

You say you want to just help us and everyone..... so why don't you tell everyone the problem and the solution?

Yeah.. didn't think so.

I think you are done here.

Thanks Jarred. This was way overdue and now I can enjoy participating in this thread again.

 

[Tom Hamilton]

3-Deeped - Banned to the Edge

Welcome back Russ, good to have you here.

Greg, can you put me on the list?

 

[Greg F]

Greg, can you put me on the list?

Yerp no problem Tom

 

[Dave Blackham]

Yerp no problem Tom

Greg, Please could you ad me to the list too.

thanks for this,

Dave

 

[Hugh Miller]

I dont think I have seen this problem yet, but I think its because I havent used the camera in those particular conditions (oddly enough, I've been thinking about my shoots over the last year and a bit and they've all been benthic or shallow open water). Whilst I dont pretend to understand what might be causing this issue I will say going back to my experiences with 2/3" broadcast cameras, I was taught to pull the IR filter out of them and replace with a clear version. It was pretty simple, it was held in a frame by some screws, just in front of the internal filter wheel and I would swap it for my clear version that I carried in my AC box on every shoot. Still have it, one of my most valuable possessions, till I got an Epic! The IR filter was very green so not only did you gain a stop overall you got at least a couple of stops on the red channel too. It made a huge difference. I remember being on a shoot with two cameras, one with a clear filter installed and one standard. The difference was hugely unfair to the operator without the clear filter. Everything was better with the IR filter removed and the reds just popped.
The only time I wouldn't do this was if I was doing any work at surface level for fear of colours going a bit odd with heavy IR contamination.

 

[Hugh Miller]

Would quite like to be added to that list too if possible. Many thanks.