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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Underwater Bubble Blowin' Users Group

Aymen said:
Mike,

Do you have a practical solution for controlling the Birger through the housing? Is there an external housing available for the Empiro or similar?

Amund
Click to expand...

Amund:

About another week, (an AquaVideo week not a birger week, which means if things go well I can make the waterproof switches next wednesday, but if I get too jammed up it might be 2.5 weeks because I will be shooting the sinking of the Vandenburg the following week. Nobody knows how long a birger week is.:biggrin: PS I kid...)

The circuit board is done and operational, I just need a few free hours to get some switches done. First few will be a bit primitive with the switches but also working with some Japanese guys on a fairly slick handle with Amphibico type switches.

I should be able to make a basic housing for the impero very quickly once I get one from Erik (he says he should have it monday and I should have one wednesday. I think even with impero there may be a good use for our board so you can use impero just for focus and ours for iris and trigger, Image stabilization on, lens initializing etc. as well as backup for focus. Ours has focus near focus far like a prosumer housing while the impero would give you knob-style focus.
 
Matt Uhry said:
Wide is Better. We fitted the PL mount Tokina 11-16 2.8 to Sharky's housing - he has yet to take it under.

tok-housed.jpg


Matt Uhry
www.mattuhry.com
Click to expand...

Thanks for the second opinion matt, I have been saying this for many moons.

If people read the Friday/Thorpe .pdf report - I had too much going on to respond in the amount of time given, But the biggest thing I wanted to say was that the AquaVideo housing with the simple bent shaft controls was never meant to be used as they had it set up with the 18-50 on an ocean shoot. Those simple controls would only be reasonable with something like your 11mm or 10mm zeiss where you really can shoot hyperfocal if you don't need a lot of iris changes, and of course even then gears/motors would be better.

You might have a problem on Ken's housing with vignetting because the camera is set back farther than the normal housing since it was set up specifically for the 8r.

But your 11-16 actually should set up very well in the stock housing (I think Johnny's is the standard depth) and I think it is the perfect low cost solution for those that don't want to go the Birger route. It could be used reasonably with the free bent shaft controls we include or we could set it up with the ET style gears for a few thousand extra or they could use motors as some of my customers have done.

What are the gear diameters and distance from the sensor plane? With those I could set some simple controls and I do have an LA customer with the stock type housing that you may want to get with for some testing as well (he is also a likely customer) and he has the glass dome which would probably work okay on Ken's housing and may not vignette since it is a larger hole. That way you could play with both versions.

BTW I love the machinist in the background - shorts and sandals - my standard shop uniform.

PS Is the gear an add-on, and could we use an aquatica gear? - I have a stack of Aquatica gear mechanisms here but they don't use cine gear pitch. If it is easily swappable it might also be a good low cost alternative gearing. I think amund has set some things up with the Aquatica gears.
 
AquaVideoRed206 said:
If people read the Friday/Thorpe .pdf report - I had too much going on to respond in the amount of time given, But the biggest thing I wanted to say was that the AquaVideo housing with the simple bent shaft controls was never meant to be used as they had it set up with the 18-50 on an ocean shoot.......
Click to expand...
Every manufacturer was supplied with a copy of the final report prior to its public release. After two reminders and a three week wait we had only heard from one of the housing manufacturers. Given this weak show of responsiveness by companies who allude to a certain professional standard was quite disappointing. Everybody had more than enough time to work with us if they required to defend a product or application of said product. The fact that they chose to take a silent approach should negate their need to make public excuses for the points raised in the report. They had every chance to do that prior to its public release. We were, after all, testing underwater housings for what they are supposed to be used for, underwater applications.

Regards,
Mark.
 
Second part of response to Thorpe/Friday report.

Second part of response to Thorpe/Friday report.

10K character limit- 1st part is in next post.

I still don't have time to give an in-depth well thought out response but let me throw out a few points:

1) Focus/Iris has been beat around quite a bit already - see my other posts or call me for more explanation. But I would like to talk about "hyperfocal". The RED 18-50 really doesn't have a hyperfocal setting like we normally think about for underwater. Even at its angle of view the DOF is much shallower than you are probably familiar with on 2/3" or 1/3" video cameras like a Z1. According to iSee4K, on the RED an 18 mm at f2.8 has DOF from just 2.5 feet to 3.7 feet and even at f8 it is only 2.5 to 15 feet. On the other hand a 10mm at f8 is from less than a foot to infinity and even at 2.8 it has DOF from less than 2 feet to 26 feet - so would be quite feasible to preset and forget focus in many or maybe most common situations.

So clearly, as you said "The housing as featured is really setup for a shooter to set a hyper-focal setting on the focus ring and then manipulate Iris only when necessary." And yet you were using it with an inappropriate lens even though you had an 8R available and other housings with gears that possibly could have made decent use of the 18-50. I fully understand and appreciate that either you wanted to play mostly with the new toy OR that one of you (Johnny?) was the primary contracted shooter and therefore needed to have best lens/housing combination you had available to you even if the other was short-shrifted because you are the one getting paid or at least the lead. In that case I also would have made the same choice given the Gates/External LCD/14mm was the most complete package BUT at that point it isn't really fair to talk much in a public "report" about a system (the AquaVideo) that was setup in the worst possible way on that particular shoot.

2) LCD. The fact that you can use the LCD at the back of the housing is not a negative it is a BONUS/major positive. You have also had the option of an external LCD case ($1499) for almost a year - with the same easier-to-use user set buttons as on the Gates version. We also make a ProLCD external housing ($2099) and as you may or may not know the ProLCD has a much greater viewing angle than the REDLcd (Viewing angle: 130 degreesH, 110 degreesV, vs 60 degrees H, 50 degrees V) which is a huge improvement. Although virtually everyone I know also wants to have the external LCD for most shoots it has been pointed out by several whale shooters and others that it is REALLY nice to be able to just have the internal LCD and therefore the GREATLY reduced drag. Nothing like that is really possible with the DeepRED.

I suspect the reason that Johnny hasn't purchased an external LCD is that, as you mentioned previously, you guys were getting an external LCD case made by someone out there (ET?) and he figured with the internal LCD and external EVF he was covered. Which is fine, but to make multiple mention of the difficulty and lack of an LCD when it is readily available seems to be "ACCENTUATING THE NEGATIVE".

BTW the reason we didn't have an external EVF almost a year ago is part of that other backstory. But making an underwater case for the RED EVF is actually pretty easy since its tubular style is virtually the same as what we have made for many of the modified viewfinders for VARICAM, BETACAMs, etc. over the years (at least 6 different versions). In fact the LCDs aren't very difficult either - the only hard part of RED monitoring is the cables - which brings us to the next point.

3) You both talked about how "Also as Mark mentioned, a bulkhead connector for an external LCD would greatly improve the ease of use and basic handling of the (AquaVideo) housing" but also went on to talk about a problem with the Gates LCD "whereby on occasion the LCD would show us a pixilated yet viewable screen. ... that seems to stem from the cables or LEMO connectors from a third party vendor."

Well we knew about this issue early last summer. Jarred told me that the DVI-type signal used was very sensitive and that we should definitely NOT cut the cables or redo connectors as we might experience exactly that problem AND that it could/would (I don't remember the exact wording) void the camera warranty. And since I actually know quite a bit about digital video technology, unlike I think some of the other players, I thought that he probably wasn't exaggerating the issue.

So we came up with a seal that does not require cutting or reconnecting and lets us use the RED cables (with some external sheathing for toughness). And I think the guys at ASL knew this as well since they came up with a similar cable seal on their Red LCD case (which BTW is an alternative LCD case that could be used with our housing as well.) In other words, I believe that seaconn/subconn type underwater bulkhead connectors for either the LCD or EVFs are likely to cause problems and that we are not ALLOWED to use them within RED warranty terms.

4) You also made specific mention of a Gates having a Schrader valve vacuum port. Well, we have always had that option and maybe I am thinking of someone else but I am almost certain I put one of those in Ken's "hybrid" housing and I think maybe Johnny's as well.

5) Ports: You both made several mentions of the danger of us using an Aquatica port that is no longer made. Well, again you espoused something that is only half true and turned something I consider a bonus/benefit into a supposed negative.

It is true that Aquatica no longer manufactures the A80 housing or the ring portion of the dome ports (although they told me at DEMA that they thought they might still have some full parts and components still in the warehouse) BUT

a) the dome that they use is still the same and can be replaced fairly inexpensively by them as they do with current housings. So yes I do recommend that if you buy our housing and plan on using the acrylic domes that you order an extra. That way if I have a stroke or get hit by a bus you can always swap it out with them and you won't be without a port in the meantime. and b) once you have one it really isn't that hard for any competent machine shop to make one or many of the rings that the dome gets glued into at a fairly inexpensive price.

c) I made quite a few of the front plates with the threading in it; I bought over 60 of the new domes, as well as many of the extension rings, long macro ports, etc. and since day one have had stock for all of those ports available for overnight shipment. I did not buy a lot of the 8" acrylic domes as I knew we were making an 8" glass (which has been available since DEMA in October). But in fact, I was able to ship an 8" acrylic overnight to Johnny. I did tell him that day that I only had one to ship because others were committed to orders. I didn't see enough in the normal spot we kept them and couldn't remember how many we originally had or had shipped out over the year - but in fact found 5 more a few days later. But I would suggest you ask Pace, Hydroflex, Gates and others how many units of a broadcast or cine housing they have sold and how many finished ports they keep on the shelf for them. I doubt if anyone has large JIT inventory sitting there since most of these systems are somewhat custom. How many do Gates (or ET/SLcine) have on hand? Not to mention ANY long lens macro ports, short lens flat ports, Glass domes, etc. all of which we have and have had.

Also I have over 20 units with this port system in the field, so it is a fairly full boat that you are in with to be able to combine to have them made, if or when I should disappear. The reason I chose those ports is because no one knew how many REDs or housings would get out there so it would be nice (for the customer! not me.) to use an existing SLR dome, but all of the current housings use bayonet style that are too small for the cine lenses like the 8r, 14mm 12mm, etc. The hole on the A80 IS large enough AND the A80 (for the Nikon N8008) was one of the most popular Aquaticas ever (it was distributed by Nikon) AND the same dome and ring were used on the AquaLens that was made for the Nikonos - so there are a lot of them around to be used or refurbished.

And finally, if you read my literature - or simply looked somewhat closely at the frontplate on those housings you will see that there is also an o-ring groove with 8 concentric tapped holes out around it. Anyone with a black and decker drill and a clear piece of plexiglas bigger than 7.5 diameter could easily make a usable port out in the field in a matter of minutes, and of course with a little better tooling you could make and easily attach/seal all kinds of custom ports.

For you to somehow turn all of that into a negative seems to just show a great ignorance of how small the high end professional underwater camera market is. I have, as a favor, made replacement ports for Rick Frehsee's SLR housings and McGillivray-Freeman's Imax housing because they could no longer get them from the original maker. So I know from 25 years in this business and from personal experience that you can't expect that stuff necessarily to be sitting on the shelf even a week after you get it much less long term. You don't know how long the principals of Amphibico, or Gates, or PACE, or Hydroflex or Subal, or Seacam, or Nexus or anyone else is going to be around at all (they are all small shops) - much less in business and supporting their products. When it comes to high end underwater systems, I don't see anyone that is or has been better positioned to provide rapid support of ports. Nor do I see any of those that have provided something like the universal mount seal setup that we have (try to get someone to make you an inexpensive extension port for that DeepRED housing.)

Anyway, enough time and enough rant. But I would like you and anyone that reads the report (and it is worth reading) to consider my thoughts as well.
 
1st part of response to Thorpe/Friday "report"

1st part of response to Thorpe/Friday "report"

1st part of response to Thorpe/Friday "report" second part is in previous post:

Mark Thorpe said:
Every manufacturer was supplied with a copy of the final report prior to its public release. After two reminders and a three week wait we had only heard from one of the housing manufacturers. Given this weak show of responsiveness by companies who allude to a certain professional standard was quite disappointing. Everybody had more than enough time to work with us if they required to defend a product or application of said product. The fact that they chose to take a silent approach should negate their need to make public excuses for the points raised in the report. They had every chance to do that prior to its public release. We were, after all, testing underwater housings for what they are supposed to be used for, underwater applications.

Regards,
Mark.
Click to expand...


Mark:

I have tried to take a high road approach to this, and would like to keep it reasonably so, but there is so much wrong with that statement that I have to take exception.

In order of appearance: (and this first is a nitpick) I received your initial report on May 1 and it was publicly released may 11, so NOT 3 weeks. And in fact May 1 was a Friday and by the time I checked mail on Monday it had slipped down two pages in the list and I missed it until I got your reminder on the 7th. So my real response window was 4 days and over a weekend. And you know through our private correspondence that my stepson was killed at the end of March so in addition to dealing with that, playing catch up with orders, dealing with suppliers, trying to finalize the Canon smart mount control, etc., I have also tried to devote a little more time to family stuff. So you might have considered that your report wasn't my highest priority and if you were so antsy to get it published, you or Johnny (who I have talked to many times) could have picked up the phone - number is below on all my posts - and said "hey, what did you think" and we could have quickly covered the main points.

Second and more importantly, whether is true or not that I took a "silent approach" it IS NOT TRUE that it should negate the need for public "excuses". Your "report" was released publicly therefore responses both private AND PUBLIC are completely appropriate. As I get time over the next days/weeks to be more articulate I will post responses, partly to set the record straight AND also because I think they are educational. If a significant majority of bubble blowers think that my posts have been less than fair or informative then I will consider refraining but so far I have been told that they were appreciated.

My post was an EXPLANATION not an "excuse" because an excuse implies that there was something wrong - which there isn't with that control setup. I was just explaining to those that might not be aware that you were using it in a way it was never intended. The points about the limitations of bent shaft controls and particularly with the 18-50 have been covered with EVERY customer (including Johnny) - and virtually everyone that has inquired directly about our housing. It is also covered in the download .pdf file that has been on our website for a year:

http://www.aquavideo.com/pdfs/RED1HousingBrochure309.pdf

not to mention that it has been thoroughly covered on multiple occasions in this thread.

(Also far as I know, through several discussions with Johnny Friday, he has just been vacillating over whether to spend the money with ET for their gears; OR to have the people he knows in Mexico City do his gears - that seem to have a nicer, more flexible gear system which is already in use on another of our housings and was to be here at the Underwater Boot Camp before it got canceled. That is an option that you may not know about or simply chose not to mention in the report; OR to use servo motors like most B4 and modern film based systems use; OR to go with the Birger solution OR maybe to just get the Gates.)

And this is the same situation with more than half of the current owners - they knew that there were several immediate gear or motor solutions in the 3-8K range (that required a $6K - $20K PL lens to be purchased or rented) but also knew that there are several better and less expensive options on the horizon so were waiting to see what shakes out while getting by with the simple setup. Typically that would be through rental of an 8R or 12mm (about $300/week almost anywhere in the world) which work acceptably with the bent shafts - but NOT expecting that to be the case with the 18-50 except a few VERY simple controlled situations (not open water). But even an AquaVideo with a super slick setup like Heden motors or similar would be $8K to $10K less than the Gates setup with gears - that still can't provide the flexibility of Cine motors or a Canon smart mount.

Maybe John at Gates was more responsive but remember I have had a year and a half of both personal use and feedback so I am pretty well aware of our limitations and strengths. And it also may be more critical to him as yours was a very early use of the housing (albeit it had a year plus of development) and seemed to be the focal point of your trip.

But regardless of that, my biggest gripe is I just don't feel you did due diligence. Most of your comments/criticisms had to do with the fact that they simply didn't purchase the options that have been readily available for over a year, and that are covered in the brochure and have been talked about several times on this thread. The other thing that made it hard to comment is the somewhat effusive praise of whole ET lens gear/hybrid housing thing. While I don't hesitate to admit that Joe Ortega and Hector are far better machinists than I will ever be and do great work, there is a whole backstory to that that I don't want to get into publicly. (But I think it may be time to share my feelings more thoroughly with you, Ken, and a few others).

(continued in previous post....)
 
Mike,
You had every possibility to address the report out of the public gaze, you chose not to. I am not going to get caught up in your feet stamping mate. We used your housing, which has positives and minuses the same as every system out there, to get a job done. It stood up to the mark and performed well. There were issues we had in the field as with every system. It really appears that after all of this time you have only just read the paper now and are reacting to that.

We tried to be as even minded with this as possible mate, take it at that, or leave it, simple.

I will not respond to further posts or emails on this topic.

Cheers,
Mark.
 
Fair enough Mark, I don't want to get it overblown or develop any bad blood with you or Johnny. (JF, I got your email and you were right I just needed to calm down...). So please take it all with a grain of salt or (spoonful of sugar.)

The basic design philosophy was to keep the base unit as compact/minimal drag as possible with the greatest port optics and lens flexibility. And to give the user options for external viewing, lens control, etc. that they can add immediately or as their needs or budget develops. I guess I just wanted to make sure people didn't get the wrong impression and think that those things weren't readily available.
 
Housing Report

Housing Report

I think if anyone reads the housing report, you'll find an honest evaluation of each and every housing used on our shoot. And there is no attack upon any housing manufacturer as i think you'll see if you read carefully each evaluation. In fact there is nothing more than constructive recommendations for each housing that we used and what would make it better. What you will see with Mike's 'Aquavideo' housing under recommendations that we thought would make it better are:
1. external housing option (which Mike states is available)
2. gearing solution for lens control (which is an option with either ET or other skilled machinists)

*what we endeavored to accomplish that i think everyone will (after reading the report) is a fair evaluation of each housing as we had it delivered to us. Mike makes a point that he has additional options available that answer our "what would make it better" section so therefore those points have been dealt with at 'Aquavideo'.

We all know that Mike has been hard at work on his housing and has been open about what he thinks will make it better as well and I salute him for his honesty. Additionally Mike has always come through for me with any and all of my requests to get me any additional items such as dome ports and glandular fittings for controls.

Finally, not to beat a horse here, you will find surmised our first hand evaluations of the housings and each has its respective strong and weak points that differ for each user. In fact, Mark and I have disagreed upon some points with 'certain' housing 'strong/weak' points. But it is all a matter of our personal opinions and needs.
 
Where I hear some consternation in the last few posts is that it appears this was not an apples to apples comparison.

So a car with a v8 is compared with a competitors V6 powered car (which, incidentally, also comes with a v8) and then noted negatively for not having a V8. The maker of the second car will surely feel slighted and wonder--why did the reviewer not compare the V8 version???? That's the tone I hear in Mike--and I can see why he'll want people to be aware he's got the V8 version for sale too.

I'm sure its impossible to have a perfect apples to apples comparison--but I can see where manufactures would feel slighted when the test appears unfair.
 
AquaVideoRed206 said:
On the other hand a 10mm at f8 is from less than a foot to infinity and even at 2.8 it has DOF from less than 2 feet to 26 feet - so would be quite feasible to preset and forget focus in many or maybe most common situations.
Click to expand...

This may be true in air, but not quite so behind a dome port underwater. When using dome, one needs to focus on the virtual image, which is often closer than 1 foot with the real subject being some distance away.
 
paul engstrom said:
Where I hear some consternation in the last few posts is that it appears this was not an apples to apples comparison.

So a car with a v8 is compared with a competitors V6 powered car (which, incidentally, also comes with a v8) and then noted negatively for not having a V8. The maker of the second car will surely feel slighted and wonder--why did the reviewer not compare the V8 version????
Click to expand...
Well IF the v8 was on the starting grid it would have been addressed. Simple.

I find the negative reception of this act of wanting to basically share our experiences with the equipment at hand, not what is available, but what was at hand is pretty sad in a way.

I'm outta here.
 
Mark Thorpe said:
Well IF the v8 was on the starting grid it would have been addressed. Simple.

I find the negative reception of this act of wanting to basically share our experiences with the equipment at hand, not what is available, but what was at hand is pretty sad in a way.

I'm outta here.
Click to expand...

Sorry Mark--these forums are so difficult to convey the correct tone and clarify one's meaning; I'm glad you guys gave your feedback as its very helpful.

With car reviews there's plenty of money & magazine sales to accomplish apples to apples testing--not so in the high-end bubble blowers camera housing market. Reviewers have difficulty getting the gear to review and manufacturers have difficulty sending the gear to review. Its such a niche business. And so we're thankful with what we get--even if we can't get perfect apples to apples comparisons.

Cheers,
P
 
I think that if anyone 'ACTUALLY' reads the housing report, then they will understand that there is no attack on any manufacturer and any of our recommendations are just that 'OUR' recommendations. You as a user may feel different and Mark and i differ on our opinions on the same housings as a fact.

But read it and you'll get our 'tone' and understand that we have given our recommendations based our our personal needs and desires and what we think an end user may need/want as well. Again, go read it first. There in fact is (in my opinion), no apples to apples comparrison. the prices differ as well as options for what you get and that is also taken into account. One housing costs sub $9,000 the other over $25k and yet another around $15k so forget apples to apples. that was not intended.
 
Johnny, I have spoken to you a number of times and you have always been the voice of reason and calm even when others (including myself) were not, so I don't think you and I have any significant misunderstanding and I know you were not trying to attack me or the housing - because you just wouldn't do that.

But as you can see below, I basically made a one sentence reference to the report - in the middle of a longer post saying nice things about Matt Uhry's 11-16; providing some insight on how it might be used; offering to help him get a housing setup to test it; talking about the possibility of lower cost gears; etc.

Yet, Mark took that one reference and got a bit strong in his post and basically called me and whoever else out - implying a lack of professionalism because we didn't drop everything and respond. And yes I got a little annoyed, especially when he said that since we didn't respond when he wanted it, that I don't have the right to correct what I thought might be misimpressions. And none of that seemed to be very fair or to make much sense.

I'm sure Mark is a good guy to work with, have a beer with, etc. and we'd get along just fine - so as I said I don't want any of this personality stuff to get overblown.

I took the time to write that long post mainly because I thought that maybe there is some confusion out there (not because of the report) and it was important for people to understand that there is an underlying philosophy and plan with my version. It is modular (like the new Epic) so you can set it up as your needs or budget dictate, and I think that whether you go with a base unit, or one with full lens controls, external LCD, cheeseplates, Glass domes, macro ports, video out cables, etc. etc. - it hits the sweet spot in terms of being compact, capable, and like the RED, an excellent value in terms of price.

So everyone should use this stuff as a positive. Read the report - it brings up valid points that people should consider as far as the equipment that was there and how they were setup. Then I suggest they take a look at my post, ignore any personal stuff and just see what we have to offer as alternatives, improvements, or whatever.

AquaVideoRed206 said:
If people read the Friday/Thorpe .pdf report - I had too much going on to respond in the amount of time given, but the biggest thing I wanted to say was that the AquaVideo housing with the simple bent shaft controls was never meant to be used as they had it set up with the 18-50 on an ocean shoot. Those simple controls would only be reasonable with something like your 11mm or 10mm zeiss where you really can shoot hyperfocal if you don't need a lot of iris changes, and of course even then gears/motors would be better.
Click to expand...

Mark Thorpe said:
Every manufacturer was supplied with a copy of the final report prior to its public release. After two reminders and a three week wait we had only heard from one of the housing manufacturers. Given this weak show of responsiveness by companies who allude to a certain professional standard was quite disappointing. Everybody had more than enough time to work with us if they required to defend a product or application of said product. The fact that they chose to take a silent approach should negate their need to make public excuses for the points raised in the report. They had every chance to do that prior to its public release. We were, after all, testing underwater housings for what they are supposed to be used for, underwater applications.

Regards,
Mark.
Click to expand...
 
No offense either side of the fence Mike. As many know i started with an AV housing for Red a long time ago. Ken and myself got base units 1 and 2 and have since tricked them out to the gills with gearing, dual batteries, LCD's and more. So there is and never was a reference to AV housing as anything but an underwater housing like the others out there....just different features and options and price points. I'd continue, but the report says it all...

Thanks to all that made it happen,
ps....a big one to Mark for actually initiating and writing the report.

**Yeah, Mark's all right to have a beer with, but don't get him anywhere near a karoke bar....
 
BajaProductions said:
... but don't get him anywhere near a karoke bar....
Click to expand...

... so that may be the ticket, get him on video and I can blackmail him to say whatever I want... :cool::thumbsup::) But seriously, I know it takes a lot of time and effort to write a report like that, so I do thank Mark and yourself for doing it - the more experience and discussion the better.


Pawel Achtel said:
This may be true in air, but not quite so behind a dome port underwater. When using dome, one needs to focus on the virtual image, which is often closer than 1 foot with the real subject being some distance away.
Click to expand...

Of course that is true - for a six inch dome a true 2 foot subject distance becomes 6" in front of the dome and infinity becomes 9" in front of the dome. You get that close focus on the virtual image either with lenses that can focus that close, or with diopters. (and remember you add in the distance behind the dome and to the sensor plane so that 6" actually becomes more like 13" or so.) But it is basically proportional so for the most part the DOF works same way - wider lenses provide greater DOF.

In some ways "virtual" image is a confusing misnomer. In actuality it just means that the physical distance to the "in focus" image is no longer in the same place - so the scale markings on the lens don't match the measured distance to the subject. The thing to remember is that EVERY lens element creates a so called virtual image that the rest of the lens elements behind it have to focus on. Underwater we have just added another element(s) - the air/port/water interface.

Basically an underwater lens like the Nikonos 15 is just a normal lens (20mm, but that's another story) where the gearing has been adjusted and the scale remarked to take into account the glass/water interface.
 
BajaProductions said:
Red in the Arctic....
Click to expand...

Back to something interesting.:):thumbsup:

My third video dive with the first AquaVideo (1981) housing was an ice dive, but freshwater could only get to 32F - what's the water temp there?
 
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