Nauticam 45 viewfinder.

Hi all, I have just installed my 45 viewfinder and I was a bit concerned that I was able to  twist it a little once the housing was vacuum sealed. I was also able to pull it out and break the vacuum seal ( although it wasn’t easy).

does this sound right? Or is it more a case of ‘there shouldn’t be any real way to physically be able to pull it out the break the seal’

just want to check the community before I either :

A) stop worrying

B) flood and destroy. 
 

I've got a Subal one - so not quite the same.

It might twist a little but if you can break the vacuum seal by moving it, that sounds a bit odd. I'm sure others with the same gear will chip-in. I'd suggest you're right to be cautious! 

Do be fair, I wouldn’t say ‘moving it’ more a case of ‘pulling and twisting’ it’s not ‘easy’ but I can break the seal if I pull hard enough not ‘gritted teeth hard’ 

just wondering if anyone can say that there is no way you should be able to break the seal.

im also thinking once I’m in the water, then the pressure will add to the vacuum..

I have followed the installation guide/watched the vids and backscatter have assured me it’s the correct viewfinder for my housing...

Hmmm, you're right, taking the v/f to depth will increase the pressure on it and increase the seal.

As I say, I've not used that combination but it just seems a little curious that you can break the vacuum seal. Can't say I have tried that with  my setup but I know for sure that there is no way of, say, breaking the seal on the main housing o-ring. That'd be definitely gritting teeth hard and, I suspect getting no-where.

Unlike the back door of your housing which would be very tough to pull open with the vacuum in place since it is quite large, the viewfinder has a very small surface area. If you had a perfect vacuum (you don't) then you would be pulling against 15 psi (more or less). If the viewfinder has a 1 square inch surface then 15 pounds of force will pull it out. Rotating it should be much easier, there is no force keeping it from rotating other than the friction of the o-rings.

Bill

I have the Nauticam 45o viewfinder: it is possible to rotate it, also UW (e.g. for changing from landscape to portrait format). I never have tried to pull it out under vacuum and will not do so for testing, I find this crude. There is, however a relatively thick O-ring that is mounted at the very end of viewfinder (close to the inner side of the back-door), after the insertion of the viewfinder. This O-ring is there in order to secure the viewfinder, not for sealing (as are the other, thinner, O-rings that are permanently on the tube of the viewfinder).

Maybe you did not mount this final O-ring?

see at approx. 1:55 of the installation video here: https://www.bluewaterphotostore.com/nauticam-viewfinder-mil-32205

Wolfgang

@Ministryofgiraffes
Rotating the 45 degree Nauticam viewfinder is actually a design point of the viewfinder. Without this capability it would be virtually impossible to shoot vertically on walls, etc. So having the viewfinder being able to rotate isn't an issue (it would be if it didn't rotate) - the viewfinder itself rotates between the eye piece and the mounting piece (not between the viewfinder and the housing).

However, pulling the viewfinder completely out seems like there may be something wrong. There is an O-ring that holds the viewfinder in place (seated at the end of the threads of either the standard viewfinder or the 45 degree viewfinder). You need to take this O-ring off before pushing the standard viewfinder out (to replace it with the 45 degree one), and then reseat this O-ring to hold in the 45 degree viewfinder.

For reference (not promoting Blue Water, however their "how to" videos are useful):
 

Yes, I have followed the instructional and the inside o ring is in place. It just seemed odd that nothing is actually holding the viewfinder into the housing other than the pressure from the vacuum and the 3 o rings. I.E with Lens ports  all have some form of locking mechanism, whereas the viewfinder appears to have nothing like this. It’s basically like a little Dutch boy sticking his finger into a leaking dam

How hard did you pull to get the viewfinder out? Mine would take significant force to both unseat the internal o-ring and then pull out the viewfinder. I did check mine, you cannot pull out the viewfinder without physically unseating the inner o-ring. The o-ring looks like it will unseat if the viewfinder is pulled hard enough.

I actually forget to seal my housing with a vacuum on a number of dives so it's just the o-rings protecting that particular seal. 

Having said this, I think the recommendation would be - don't pick up your rig by your viewfinder

Also worth mentioning - most of the controls that breach the housing (to connect to a control levers inside) are also only protected by 2 o-rings. 

I would think a little about what you've been doing.  the two sealing o-rings are very fractionally greater diameter than the opening for the viewfinder to allow them to compress and seal, the retaining o-ring is greater diameter than the opening so it won't go through the opening.  It will be sitting right on the edge of that opening so the viewfinder can't slide in and out.

You have been pulling on the viewfinder presumably straight out enough to move it the 6-8mm outwards to so it breaks the O-ring seal - or you could have been placing sidewards force on the viewfinder to break the seal that way.  That means you have forced the retaining o-ring to deform enough to jam it inside the viewfinder mounting port- potentially damaging it. 

I would suggest inspecting the o-rings for damage as particularly the retaining o-ring as it appears you have forced it to go where it's not designed to go.

I would suggest double checking the retaining O-ring is significantly larger in diameter (i.e. it's noticable to the eye) than the sealing o-rings.  Also confirming you have the right viewfinder for your housing , there are two models 33203 for DSLR and 33205 for mirrorless.  The manual has details of which viewfinder is compatible with which housing - the viewfinders actually lock in place so that the mounting tube does not rotate - the rotation is within the viewfinder assembly.  I'm assuming you probably can't fit the wrong one due to the differences in the mounting system the DSLR version has pins and the mirrorless has a cut out, but always pays to ask.

Certainly you can use one of the DSLR versions on the mirrorless housings, I have an older 45 finder from my DSLR days and am now using it in a Nauticam Oly housing. Seems to work OK. 

Bill

2 hours ago, bvanant said:

Certainly you can use one of the DSLR versions on the mirrorless housings, I have an older 45 finder from my DSLR days and am now using it in a Nauticam Oly housing. Seems to work OK. 

Bill

 

Interesting - if you look at the manual they show the two styles having different methods of keying the housing mounting hole.  The images Nauticam show of the two styles seem to show different spacing of the sealing o-rings to the retaining o-ring.

Mine does in fact not key the mounting hole in the EM1-II housing but has worked fine for the last 4 years (EM-1 I as well)

Bill