Was looking for a dome to go with my new Nauticam housing and decided on the Zen 100mm dome.

Anyone have any experience with this dome or the similar Nexus?

Dr. Mustard, I thought I saw somewhere that you took one out to test?...

My thought process was this, and I hope I made a good decision...

Dome is glass... so I would assume good optics and scratch resistance.
Dome is TINY... so great for travel. I can now fit my entire rig macro/wide and all items necessary to shoot in my carry on.
I don't plan to shoot any thing wide that would NEED a lens other than the 10-17 - sure a bigger dome can accept other lenses... but I don't particularly care about taking a 17-70 or 18-55 underwater (although they are fine lenses and can take fine photos) for example.

I've just received my Zen-100 (for Subal) but have yet to get it in the water... From what I understand, the dome works well with both the 10-17 or 10-17 + 1.4TC.

Alex is out testing the dome and I understand he is planning on writing up a review.

ps. I'm also based in Bangkok so PM me if you want to take a look at the dome.

I'm also interested in this port and am deciding between this and an 8" dome for my Tokina 10-17. There seems to be a lot of favorable reasons to going with this dome, except making it harder to take over/unders. But the small size and weight are definitely great for traveling! I would love to hear how you guys like it after getting it in the water and also hopefully have you post some pics for us!

Adam Hanlon was kind enough to lend me his (fortuitously he also has a Subal), which I have had a chance to try a little here in Cayman. I hope to get a review together over the coming week, although have plenty of other writing to do first.

These are with the 10-17mm on D2x, no teleconverter, uncropped.

Urchin at 10mm:
Click to view attachment

queen conch at 14mm:
Click to view attachment

In the meantime here is a copy and paste from a Facebook discussion, that has a few thoughts:

Alex Mustard: Luis, my opinion is complicated. Small domes have negatives and positives compared to large domes. Also with wrong lens (e.g. Nikon 16mm) you loose all the positives!
Wed at 21:54 ·

Colin Lee: I just received my Zen 100mm - it looks super sweet! Looking forward to more feedback from your tests...
Wed at 22:16 ·

Steve Williams: Alex, what are the negatives of this little beauty besides the problem with over/unders. I'm thinking about using it with the 10-17 on the 7D.
Yesterday at 04:49 ·

Alex Mustard: I had wanted to wait for the review - as its a complex issue that needs more words. As I have said it works well with the 10-17mm, Steve.
Hadn't really considered over-unders as dome is unsuitable. Optically a small, highly curved dome is inferior to a large dome because it creates a virtual image (underwater) that is closer to the camera and more curved. At each aperture the corners will be less sharp than with a large FE dome. The curvature of the virtual image is parallel to the dome - with infinity being 4x the radius (check this as I have not) of the dome from the lens. This should allow you to visualise the virtual image. Subjects closer than infinity are even closer to the camera.

The very close virtual image created by this dome causes problems for lenses than cannot focus super close. My 16mm FE (I am on full frame), for example achieves significantly better subject magnification behind a big fisheye dome, than this dome, because the virtual image is further away from the camera (it cannot focus on the foreground of the virtual image of such a small dome).

The Sigma 15mm (which focuses closer) would be better, but while it fits in the dome at infinity focus it does not fit as the lens barrel extends as it focus closer!

This dome fits my 10-17mm well and this setup allows you to reap some of the benefits of a small dome, particularly the ability to position strobes very close to get a better quality of lighting.
Yesterday at 12:14 ·

Steve Williams: Thanks Alex, I understand the optics better now. I'm thinking that the smaller dome would be a little harder to use for over unders in rough seas than the large ones, probably not unsuitable just tougher. Really appreciate your work and info on this. ;-)
Yesterday at 14:55 ·

Alex Mustard: Steve, I would think split levels are probably the least suited application for this dome. The small size makes the meniscus harder to control. Depth of field is always a limiting factor in splits - made worse by the more curved field and closer virtual image of this dome in the UW section.

I have just done a dive with it and 10-17mm. I love this dome. I took photos I could never get with my standard FE dome. But it is very important if you are thinking of buying it that you understand the strengths and weaknesses of small domes. It is in no way a replacement for a big dome, rather a different tool for a different job.
Yesterday at 16:27 ·

Colin Lee: Alex - was that dive with the 10-17 alone or with a TC? DX or FX?
Yesterday at 16:35 ·

Alex Mustard: 10-17mm, no TC, DX = excellent. Use the smallest strobes you have. Z240s are too big!


ADDITIONAL:
Should add corner sharpness issue for standard CFWA is not a problem above F13 on DX, there is a need to keep lens stopped down though.

Those are beautiful Alex and make a case for this lens. I agree with your sentiment that it's not a replacement for a large dome but is a different tool. Could you ever see yourself traveling with just this dome or would you always take both?

Definitely some pros and cons..however as a shooter who rarely shoots anything other than a 10-17 for wide angle, I love the compact nature and ease of traveling. That in my opinion far outweighs the difficulty in shooting over/unders.

Really, it just comes down to two things. 1. Are you just shooting a 10-17, or do you want a versatile port. 2. What are you primarily shooting.

Traveling with 8 and 9 inch domes really can be a PIA. The small 4inch makes it very easy to carry on the entire SLR system.

I understand (somewhat) the optics of a large dome versus this small dome...

And I can see how it would be a great option on DX for the 10-17 and CFWA...

But what about general wide angle work, reef scenics, pelagics, etc...? If your only planning on shooting with the 10-17, would this dome and its potential benefits (size, travel, etc.) make it a suitable choice or would you go with the 8" still?

I know its been mentioned that this is not a replacement for a big dome but a compliment, but as someone who cannot currently justify the cost of two domes...!

For general wide angle work the Zen dome works perfect (big animals, reef scenes, etc). For only shooting with the 10-17, and if over/unders were not a priority to you, then I would definitely go for the Zen 100mm.

I think that it is very important for anyone considering this dome to be aware that small domes are not all positives and no negatives.

Corner sharpness of any small FE dome is inferior to a big FE dome. What matters is how much.

I have found that on a DX/APS-C camera, it is fine for wide angle work, where you have lots of light at can stop down to F11-F16. But for shots that must be taken at wider apertures (where light is limiting, or aperture must be opened up to get strobe to carry - e.g. big animals, large reef scenes, wrecks) a bigger dome, for example the Zen 200mm, will give superior results.

This dome is cheaper, lighter and smaller than a big FE dome. It also enables closer focusing (with the right lens) and thus a larger subject size in the frame. Furthermore the small physical size improves lighting on shots very close to the camera (with the right strobes). Importantly, both factors will get you shots you could not before.

But small domes have the optical problems highlighted in the chat above. You don't get something for nothing.

For me the main uses of this dome is for CFWA and WAM shooting - as it allows you to get shots you could not before. Also for travel on trips with tight luggage restrictions and mainly a macro bias. I see it as something you buy in addition to your main dome port, rather than instead of. It could also be a first purchase, perhaps when starting with wide angle and wanting to save a few $$$.

The bottom line is that all the early dome ports were small. It was the only size people could make them. The quest for better quality led to people making more expensive, bigger domes. The current 8-9 inch (200-225mm) are a good compromise between cost, performance, portability and practicality. Small domes offer some advantages over big domes, but to make light of their optical compromises resulting from their size and curvature in misleading.

Alex

p.s. I have shot a review of this dome with a variety of test shots, that show these factors. I hope to be able to get it up on WP in the next few weeks so people can judge the significance of various factors.

Over the last week I've done four dives with the Zen 4" and Tokina 10-17 (with and without a teleconverter) and can only say "What Alex said!".

Amen to that! I can see a second Inon S2000 in my future.

As quite a few have been messaging & emailing me about this dome I thought I would add another post. I have several other tests to share, but I will pull them all together is a full review, which now will probably be in a couple of weeks.

As I have said above, small FE domes have advantages and disadvantages compared to larger FE domes. If you already have a large dome and are buying a mini-dome to extend the types of pictures you can take, you can reap the advantages of both and insulate yourself from the disadvantages. If you are planning on buying a mini-dome as your only dome port for all your wide angle photography it is important to understand potential negatives and if they will be significant or not to your underwater photography.

Again, as I have said above, small, highly curved dome ports existed long before the big dome ports we have today. People went to the effort of producing the big domes to overcome some of the disadvantages of small domes. That said, small domes are a very valuable tool, particularly for CFWA and WAM, and can get you shots that are impossible with a big dome. I have regularly used a small dome for some of my images over the last 5 years or so, and many of my popular images are taken with it.

In recent years most small domes have been produced in small numbers and not widely available. The Zen 100 is very exciting as it makes small dome wide angle accessible to many more underwater photographers. It is a powerful tool, but one that should be understood a bit to get the most out of it.

One of the big negatives associated with small, highly curved domes is that virtual image, which is created by all domes in water, is closer to the camera and more curved than with a large dome. One of the main consequence of the curved field is corner sharpness. This can be overcome by stopping the lens down a bit (when possible). It is also much less of an issue on an APS-C or DX camera than on FF/FX. How much you need to stop down depends on a few factors, not least of which is your sensitivity/standards when it comes to corner sharpness.

Here are two test shots to show the corner sharpness issues associated with a small dome. These two images of the same subject are taken with D2X + 10-17mm @ 11mm (meant to use 10mm, but just did not wind it all the way), one at F7.1, one at F14 (this is a 2 stop difference).
Click to view attachment

Here are corner enlargements to 100%, screen grabbed from Lightroom.
Click to view attachment

At F7.1 corner sharpness is not acceptable to me. But stop down two stops (F14) and it is much improved, and while still not perfect is acceptable IMO.

Of course at medium resolutions the F7.1. example looks fine and many may be content with this. After all soft corners to focus the attention on the subject.

I also did pool tests, where I was able to compare the small and "normal" FE dome. From these I concluded that the corner sharpness difference between a big dome and small dome is about 1-2 stops (i.e. for the same corner sharpness as F8 on a large dome, you need to be at F13/F14 on the small dome). I much prefer real world tests, the flat tiles of pools are a bit artificial for evaluating what we might deem acceptable in a real shot, but I did not have the opportunity to repeat these in the field.

A small dome, like the Zen 100mm, will allow you to take photos you cannot with a larger dome - the urchin shot above is good example - with the small urchin being the whole width of the frame even at 10mm. It is cheaper, lighter and easy to travel with. But it has some limitations, which are not specific to this dome, just a consequence of its shape.

I really like this dome and would certainly buy one in the future if I go back to shooting a DX Nikon as my main camera.

I hope that this helps.

Alex

<<Use the smallest strobes you have. Z240s are too big!>>

The 240's are too big in size? Can't get them where you want? Or too powerful? Too close and can't turn them down a bit?

Sorry, trying to follow this.

Bob

Maybe an over reaction on my behalf bought on by excitement and touch of frustration. I didn't have any real problems with lighting my shots with Z240's (it's certainly easier than with an 8" dome). Realising the potential of the small dome I found myself thinking "I wish I could get these strobes in even closer" a lot and this got me thinking that I could do better with even smaller strobes. I already have an S2000 and might try this in place of one of the Z240s next time I get out.

Hmm... all good advice.

As someone who wants to buy the best dome possible but only has the budget for one... maybe I should just go with a 8" acrylic dome? But then maybe some of the soft corners on the 4" would be equal to the 8" acrylic (vs. glass)?

Anyone know if there's a 4" dome available for Aquatica housings?

Reef Photo only have them listed for Subal, Nauticam and Sea&Sea with "Other mounts are in development".

I emailed them a while ago, the response I got was "Unfortunately, the Zen DP-100 is not currently offered in an Aquatica mount, and to my knowledge that option is not planned."

If anyone knows anything different I'd love to know though!

Disclosure, Zen Underwater is a manufacturing arm owned by the same owners as Reef Photo. This isn't stated in my signature currently, but will be.

Alex, thanks for the examples. We have have a narrative in the works describing much of what has been said above for the web, and some grid chart comparisons between our upcoming 230mm dome v. the current 200mm dome for superwide rect. lenses, and some fisheye comparisons.

Personally, I'd only recommend the DP-100 dome with Tokina 10-17 or Nikon 10.5mm at this time. There is some promise for Canon 15, but there are reproduction ratio disadvantages that Alex mentions above, and the corner sharpness isn't as good. We are also working on a gizmo that would allow Nikon 16mm /2.8D to be used, but lens design doesn't happen quickly.

Like so many things in life, this is a compromise. Personally, I'll travel with the 200mm dome on a trip where I want to use superwide rectilinear lenses like 10-24 or 17-35, but on trips where I don't need that focal length I'll only travel with the small dome. I don't love those focal lengths, and am happy that in most situations 10-17 fits the bill.

Corner sharpness is a funny thing... After using 17-35 on full frame, I'm pretty thrilled with what I see with 10-17 on DX in the 100mm dome. Given the impact photographs that are possible with better foreground reproduction, I'm willing to accept some small amount of corner smudging.



This was incorrect, or a miscommunication, and I'm sorry. We are not planning to offer our 230mm dome in the Aquatica mount in the immediate future, but both the 200 and 100mm domes are in stock for Aquatica. I have not published the 100mm dome for Aquatica on our web site as I have not had time to determine the best extension ring to use.

For a novice to the D-SLR world (I used to shoot Oly 5050 with Oly housing) with grand plans to finally house my D90 in a Nauticam housing, I am very intrigued by this compact dome.
I understand (sort of) the limitations of the smaller dome, but I'm only shooting for fun/ hobby, and do not plan on trying to market my images, nor do I currently plan on trying over/under shots.

Couple of questions arise:
- How is this dome for general WA shots? (Big critters/ wrecks/ walls, etc)
- People keep referring to a Tokina 10-17 but I have a Tokina ATX PRO 11-16 f2.8 - is it usable?
- (The following is directed to Ryan): What port base, gearing, extension rings, etc is/ are needed to attach to the Nauticam with the above lens?

Thanks in advance!

Hi!,



Quite good. The corner softness diminish as subject distance increases, so for more normal shots it isn't apparent.



No. That 11-16 needs a big dome...



We do manufacture the dome in a Nauticam Mount, and 10-17 is used with Extension Ring 20. If you want to zoom the lens, you'll need a zoom gear too.

Ryan - Thanks for the prompt, albiet unfortunate, answer!
I guess I'll be contacting you soon about a 6" or 8" dome then...

Thanks Alex, for these test images, and thanks Ryan for the additional information on mounts offered. This dome has generated a lot of excitement in the current travel environment! It's great to have some firsthand info on its pros and cons. Alex, I look forward to your full review.

I was out last Friday off Jupiter. Conditions could have been better - 40 to 50 foot vis with a lot of fine particulate in the water. overcast skies made made available light look pretty flat.

Here are two samples shot with the Tokina 10-17 behind the Zen 100 in a general WA situation showing that in a pinch it can do the job should you be shooting something like a Super close WA of a clownfish and a manta shows up.

The first is at 17mm @ 125sec/f8
Click to view attachment


with the second at full 10mm @ 200sec/f11
Click to view attachment

Thanks for all the great info!

I decided to not go with the Zen 100mm and instead picked up a S&S Optical Dome. A bit more money but I think it will serve my needs better and hopefully (with some care) last a long time. The S&S is a bit smaller than typical 8/8.5" in. domes, so still packable in my current setup for travel.

I can't post them here from my .mac gallery, but some shots I took with the Zen 100 from the Blue Heron Bridge can be found here: Blue Heron Bridge - January 18

Using a Nikon D200 with Sea & Sea YS 110a

Wow, that is a small urchin!
Looking forward to your report. I hope that it will include shots of your strobe set-ups.
Using the Seacam 6" dome (effectively an intermediate size between 4 and 8 inch FE domes) I try to use the dome's shade to minimize flare while using mainly one WA strobe centered over the port. I posted a set-up shot in your slave thread.

Hi all,

I received my Zen dome last week (Thanks again Alex!) and have been playing with it a bit.

I got it for close focus wide angle (CFWA) and wide angle macro (WAM) to get round the problems of trying to light things that are very close to the dome port. I'm shooting DX with my D2Xs in a subal Housing and have been using a Tokina 10-17 for some time. I've set the dome up with a 30mm extender, which seems OK, but this may well need additional adjustment.

My first impression of the dome was quite how small it is! When compared with an 8" dome it seems really tiny! It also seems very well made and finished.

In use, for CFWA, with a Kenko 1.4x converter, you can really feel the magnification working! You can get the front of the dome so close to the subject that you really can feel the magnification "pulling" the subject in:



Practically, this means as long as you can physically get the strobes in close enough, that lighting is fairly easy! With dry gloves, the strobes want to be where my hands are! The reduction in distance between the front of the dome and the subject helps with colour and sharpness.

For more general wide angle, I took the following series of shots. These were all shot at 1/60th which may be a bit slow, and I am getting used to the set up-so please don't take them as anything like definitive! The full image looks like this:



I've then taken crops of the left hand bottom corner, and zoomed them to 100%

1/60th at f5



1/60th at f6.3



1/60th at f7.1



1/60th at f8



1/60th at f9



1/60th at f10



Corner sharpness seems to suffer at large apertures!

I'll do some more playing-please note that these aren't definitive.

Hope this is of interest

Adam

I used this dome port for the first time Sunday. Very poor water conditions so couldn't eliminate backscatter. This shot was at F8 with a D300 and the Tokina 10-17

Click to view attachment

Reading another tread reminded me of something. I was going to test this dome as a macro lens. Perhaps with a ext. ring.

Has anyone tried this 100 dome with a macro lens?

Hi Dave,

There is an interesting post from Steven Frink about using small domes (in this case a seacam one) with the Nikkor 60mm one in this post

I've got acold, but as soon a sit clears, Im going to have a play with the Zen one

Adam

Yes, I read that thread. Reminded me that I wanted to try this dome for wide angle. I've used domes for macro before. It would be nice to have such a small dome that could serve dual purposes.

After reading Stephen Frink post, on using a small dome with macro lenses, I thought I'd give it a try! I used it with a Nikon 60mm f2.8, on a very dark and gloomy day. I used a 33mm extension on my Subal housing. For reference purposes, the water temp was 4 degrees, and I lost all sensation in my hands for most of the dive (despite dry gloves!)

The port gives really nice results-sharp and it corrects the parallax that you get with conventional flat ports. I will definitely try it some more

Great shots Adam! I've just ordered some 100mm Zen ports for the Nauticam housing to supply in the UK.

Excellent news. That means that it could be a great port for travelling- both the 10-17mm and a 60mm macro all with one port. I love it!
Nice photos too. Especially like the first one. You're a brave man with those temperatures.

Did you use an extension ring with the dome when shooting the 60 mm lens.

Hi Dave,

Yes on my ND2, I added a 33mm one.

Adam

Hi Adam,

With your 60mm and the 100mm dome / 33mm ext is the 1:1 focus point of the lens inside the dome ?

If so are you going to be concerned of getting too close to a hard object & trashing the expensive dome (or indeed subject) ?

Paul C

kudos for you going in at 4C BTW

Hi Paul,

I haven't experimented per se!

Ken Rockwell gives the minimum focus distance (1:1) as 48mm for this lens. From the front of lens to subject.

With the Zen port and the 33mm extension, the lens does protrude into the port say 10mm. Given that the corners are less of a problem with a macro lens, getting the nodal point perfectly in line is not as much of an issue.

The port itself is also very shallow so the lens only has about 20-25mm in front of it.

So it is just about OK! Given that though-I don't see this as a replacement for a conventional flat port (or dome port for that matter!). I see it as an alternative, that is great for fish portraits etc, but would stick to a flat port for "true" macro. I think it gives a subtly different look to some types of picture, and that is exactly what I am after!

Adam

OK thanks for that Adam - To be honest myself I can't justify the price tag for CFWA - just have to hope someone else is around at the time for a loaner!!

I know I have hit the front of my flat port a couple of times and would just cry if it were a $900 dome....

Paul C

Alex,

Did you try the set up with a 10-17 and 1.4TC on the D700?

Julian

No, I tried the 15mm & TC on D700. I don't have a zoom gear that works with the 10-17mm and TC. Also you would need exactly the right sized port extention to make sure you don't hit the inside of the dome/or get cut off.

Also I used the Zen Dome in Cayman, which does not really have the most suitable subjects for WAM. And since it was Adam's dome I didn't want to risk dinking it against something. So only did a couple of dives + the pool tests.

Alex

Can I go back to the strobe positioning question? I'd like to understand the issues with using large strobes to light the subjects using the little dome. Is the problem that wide strobe pattern blows light into the dome or that it's just tough to get them close enough or .......? I'm wondering if a large dia. snoot would help (if it's a pattern issue) almost a barn door type effect? I have the Ys 250's or the 110's if smaller is better but their really isn't that much difference in the diameter.
My shiny new Zen 100mm showed up yesterday so I'm itching to give it a try. The pool is still a little cool but the hot tub is ready. Just waiting for the duck.

Any thoughts appreciated,
Steve

I used the small Zen dome on a couple of dives in Lembeh together with Seaflash 150's (similar size to ike DS-125/160) and found it quite difficult sometimes to get them close enough to the dome. I didn't have any issues with the strobe flaring into the dome.

Can imagine smaller strobes (e.g. Inon Z240) being much easier to position. Maybe the 'baby' Inons (S2000) are sufficient...

Hi Steve,

I've found the issue is getting my Z220's in close enough to the port, and still being able to hold the housing handles!

I think it is a physical size issue-you want the strobes in close and behind the port-but that's where your hands are!

Adam

Hot tub......???

Come on Mr Williams get in the pool and do some more of your testing. It cant be as cold as diving in murky UK waters. ( not that I do that ) Mine is now ordered and will be heading to Lembeh in may. Then up for sale when I return.

A quick question for 5D MK2 owners: Has anyone succesfully used a Zen mini dome on a Sea and Sea housing in combination with the 1.4 TC and 10-17mm and obviously an extension ring. If this is a possibilty then i might not have to get rid of the Zen.

Stew

Yep, Hot tub....




My wife took this and mentioned something about evidence to use at the hearing. The good news is the new Nauticam rig has been underwater (a nice toasty 102 degrees F) if not officially baptized in saltwater yet. The great news is no red lights or large bubbles. This is the Zen 100mm setup on the Nauticam 7D with electrically fired YS-250's. I put one of those fuzzy car wash mitts in the spa to play with strobe position. I thought the long yarns would sort of replicate anemone arms or I could at least see some shadows to understand how the light was acting. I shot everything at 10mm, zoom ring is back ordered.

I quickly understood what you were trying to tell me about getting close enough to light the front of the subject. My normal macro strobe position started to go bad with the subject about 6 in. away. After some trial and error I was able to work out a couple positions that allowed me to get a reasonable exposure with the subject actually touching the dome. You can tell from the shot above that it was a very bright day in Arizona today. Ambient exposure was about f/8.0 at 1/250 Iso 100. So I was shooting my mini test, manual f/14 at 1/250 with the strobes around 1/4 power, diffusers on. I was playing with strobe angle, position for and aft, up and down, and power. Four variables will keep you in the water a while. I started off shooting my 13" x 19" lens chart and you can really see how the corners roll away optically. It's pretty clear why you can lose corner sharpness as you open up the lens. You can also see how the normal strobe position would cause problems. It's made worse by the reflective plastic but you get the idea. This is at 10mm f/14 1/250 about 1/4 power on both strobes.



This is the mitt I used about six inches from the dome. The shadow on the right is all from the sun.




Here is a shot with the fuzzy things touching the dome with the strobes positioned beside and behind the dome, angled in toward the subject, right strobe higher than left, 1 notch under 1/4 power.



After a little practice I think the issue is not so much the size of the strobe as it is how sensitive a great exposure is going to be to position and angle. Very minor changes give very different results. The good news is after playing around I'm confident I can get reasonable results with the big YS 250's.


The Nauticam is really feeling nice, everything comes to hand almost instinctively. It loaded up without a problem. I don't have a manual yet so I just screwed on the tray, stuck it in the housing and everything worked. My old S&S ports with Nauticam adapter ring look like they were made for it. If you look close at the top shot you can see I have both the handle and housing arm balls mounted so I could try out different arm mounting positions. I definitely prefer the arms mounted on the housing. I also figured out that when I'm doing this type shot for real I'll only need to use the shorter 5 in arm on each side. Unless I trying to use Martin's inward lighting technique, but that's for next time. I feel a good hot soak coming on.

Happiness is a new rig, a dry camera, warm water and more to learn.

Cheers,
Steve

Um, I would remind you that O-rings are designed for a normal temperature range. Remember what happened to the Space Shuttle when it's O-rings got below 32 degrees?

It is not recommended to take housings in a hot tub. Still, they were pretty cool shots.

Thanks Dave,
Good point partner, I was thinking about that. Of course normal around here in the summer is way above 102 air temp so I was comfortable it would be OK based on past history. And you don't have to worry about the rig being in anything close to 32. Heck the pool is at 70 and I wimped out.

Edit- I did some checking and the lowest high temp range for elastomeric material I can find is around 180F. The old Nikonos rings would fail about 220F. Some of the silicones are good to 450F. Not sure what the Nauticam o-rings are made of but I'm feeling pretty good about getting back in the warm water.

Steve

Steve - you will lobster thermadore yourself before you cook a nitrile o ring,

Some of the pool chemistry might get at nitrile after a few years immersion I suppose.

Dont forget these o ring things are fuel rated - and some of the stuff in diesel is just nasty - even with coke and ice.

Thanks for the test shots.

Paul C

Too funny Steve!

Great info-thanks for sharing.

Adam