Opaque Marks Around Edge of Dome

I've been servicing my Aquatica 5D MkII housing. When I started cleaning the Mega Dome Port and held it up to the light I can see opaque marks emanating from the outer edge. I tried rubbing it off thinking it could have been a water stain but it seems to be under the coating.

It's got me concerned as I have had the port for a couple of years now and have paid particular attention to looking after it.

Anyone know what it could be and what can be done about it??

I've tried emailing Aquatica but the email bounced back!!

Thanks,

Lance

My e-mail is jean@aquatica.ca, just shoot me a e-mail and i'll check on this tomorrow morning, I'm at home right now and a lot of the systems are down around here, we are going through a severe snow storm with over 45cm of snow, we actually beat a 40 years old record (which I am old enough to remember unfortunately, LOL)

My e-mail is jean@aquatica.ca, just shoot me a e-mail and i'll check on this tomorrow morning, I'm at home right now and a lot of the systems are down around here, we are going through a severe snow storm with over 45cm of snow, we actually beat a 40 years old record (which I am old enough to remember unfortunately, LOL)

Email sent...Thanks Jean

I would be very interested in seeing the outcome of this investigation on this port and whether or not there is a possibility for my 8" acrylic port to eventually have the same problem.

Stephen

The Mega Dome is a coated glass port....

The Mega Dome is a coated glass port....

Lancer,

Yep, I know that but I am not sure if your problem is with the coating wearing off or even perhaps a buildup of minerals. I have seen mineral deposits on my dinner glasses and have to use white vinegar to remove the mineral deposits.

My Aquatica macro port has the same coating as your 9" dome.

If the problem is the former, then my acrylic port should be okay since I don't have this coating but my macro port could be suseptable.

If it is a buildup of mineral deposits (e.g. hardwater) then I might be okay if it were to happen on my acrylic port since I can use an acrylic refurbishing kit. I would not know how to safely remove mineral deposits on my macro port.

I have not seen this issue with acrylic ports in any discussion boards so I am curious as to what the actual problem might be.

Stephen

I've seen this sort of coating loss happen on more than 4 Fathom lenses. I've sent them back and gotten loaners so I can work, However after so many attempts at resolving this problem it is still an issue and now a real struggle to get something done about this with Fathom.

The latest reason I've been told by the owners of Fathom is that it is an off gassing issue from the plastic lens cap.

So I would be very interested in seeing what the situation is here whilst I wait for my faulty lens to be sorted out.

Richard

As suggested by Jean, I rubbed a small area with the marks with some hard water stain remover and it made no difference. I'm now waiting to hear from him what to do next.........

Regards,

Lance

Just curious, how is the glass fastened to the aluminum? Could it be left over sealant from assembly that's stained with salt water? looking at your photo it seams to have a smeared look like that. Are you sure it's on the outside? I can't tell from the image.

Just curious, how is the glass fastened to the aluminum? Could it be left over sealant from assembly that's stained with salt water? looking at your photo it seams to have a smeared look like that. Are you sure it's on the outside? I can't tell from the image.

I'm not sure how it's sealed......The edge of the glass seems to have been ground to rough it where it's glued into a grove in the support plate. I have studied the marks and they are definitely only on the outside and go all the way around the port so it's not just in one place.

I hadn't noticed the marks before and it was only when I held it up to a light when I was cleaning it that I saw them for the first time.

Regards,

Lance

I would be interested also about the cure or cause.

I have a Mini Dome and wonder if and when that could happen to it. On close examination of my mini dome I see that it is held together by a combination of the built in dome shade and an oring.

My 8" dome, which is not made from glass appears to be held together with a silicone chalk looking and feeling substance. I wonder if yours is held in the same way and if some of the silicone looking stuff or whatever that might have been cleaned up with might have etched (or damaged)your coating.

You don't say if this goes all the way around or if it might be just in the areas covered by a dome shade.

My SWAG would be mineral deposit from hard water. It is in area not usually wiped, when done.

Question the out gassing from plastic cover. This type of deposit usually wipes off.

It will be interesting to get a qualified answer.

I'm not sold on the off-gassing explanation either. I was told by Dr. Paul Remijan from Fathom, before that explanation, that the reason was the coating on the outside of the dome is eroding away, because it is actually soluble in sea water, and he would be double coating some domes in the future as a precaution against this sort of thing. I haven't seen anything from him since (over a year ago now) on that despite me writing numerous emails to him.

I use the Fathom because it is a quality piece of glass (it should be at it's price) however this coating issue really lets down an otherwise outstanding product. The fogging is quite visible in a back-lit shot even underwater and many a good shot is rendered unsellable because of it.

I look after my lens diligently, only ever blowing rinsing fresh water off with a LP blower, never rubbing it with a cloth, so I am very disappointed that the issue has not been resolved and much of my hard work is being wasted because of it.

How many dives have you done with your Dome lance?

Cheers

Richard

The marks go all the way around the perimeter of the glass moving toward the center at varing amounts as per the pic and not restricted to any particular location. It's definitely on the outside so there is no chance of the lens cap off gassing. I tried a commercial grade water stain remover at 50/50 and then 100% (as per the instructions) and it made no difference which is how I came to arrive at the conclusion it's not a mineral buildup.

I have paid particular attention to looking after the housing and the port. It's a big investment and one I hope will last me a lot longer!!

I'd say it has done around 90 dives mostly in seawater and a few in freshwater and has always been rinsed and dried after.

Regards,

Lance

Lance,

I've got the Aquatica 8" acrylic dome with about 300 dives on it. No sign of the problem that you're experiencing.

Just FYI if that helps.

I'm following the thread for a resolution.

I'd consider sending the dome to Jean if all else fails.

Harry

I'm kind of getting the impression from reading the above entries that glass coatings and seawater don't mix and it doesn't look like it is manufacturer dependent. I am headed down to Grand Cayman in a couple of weeks and will check in with Cathy Church to see if she has any knowledge of this issue. I am sure that between her and her staff they have enough dives in to tell me if this is a common occurance or if it is appears to be an isolated incident amongst some owners with glass dome ports.

Has anyoneI heard of any issue withs coated macro ports?

Steve

Anyone got any development on this?

I do not know whether this is the case for the OP's port because its difficult to tell from the posted image, however....

I have come across a similar effect which is of a slight translucence which appears on all or pasrt of a glass dome's surface. It looks as though this may be down to slight oxidation of (some mineral) glasses such as those used in some dome ports and appears to happen when an uncoated mineral glass dome is left for a significant time with a damp or slightly damp neoprene cover in place. If the neoprene cover is at all damp, it seems that this can produce conditions which allow some sort of chemical reaction (oxidation?) to take place. I suspect that warmth is a culprit too. I've seen this on several domes (from different manufacturers I should add) and have had one or two cleaned/repolished, so it is possible to 'repair' them as the translucence appears to be very thin like a lens coating - and historically it was such an accidental (oxidisation) coating and the observation of increased light transmission due to the coating which led to coatings being applied to camera lenses originally. FWIW I suspect that it will have little effect on images unless it becomes really obvious.

The reason for my post is to suggest that anyone with a glass dome ensures that the neoprene cover is only fitted when it is needed for protection and that it is removed unless it is absolutely dry - I tend to store my dome ports without their neoprene covers in place as a precaution to prevent this being a problem.