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troporobo

Member Since 23 Jul 2010
Offline Last Active Mar 27 2015 05:50 AM
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Posts I've Made

In Topic: Second thoughts about vacuum systems

26 March 2015 - 09:11 PM

I'm with both of you - if the light stays green for a half hour or so before the dive, then the housing is sealed and the o-rings are safe unless something fails, which is of course impossible to predict or protect against.  All in all, the vacuum system gives me much greater peace of mind


In Topic: Second thoughts about vacuum systems

26 March 2015 - 08:35 PM

I think you are onto it.  If the gland failure happened once already under water, then no additional air could get into the housing, thus not raise the pressure (decrease the vacuum) enough to trigger the alarm.  

 

But another interesting issue raised above by junior5  - once sealed, how is it possible for the pressure inside a rigid housing to significantly change at depth?  That would seem to violate the laws of physics. Not counting temperature effects of course.  


In Topic: Second thoughts about vacuum systems

26 March 2015 - 04:04 PM

If in fact the leak was caused by the shutter gland, are you saying that you suspect the vacuum system contributed to its failure?  It's not obvious to me how the two could be correlated.

 

BTW I've been using the same Leak Sentinel for over a year on a Nauticam housing without issue. 


In Topic: OM-D with +5 or +10 diopter for 12-50mm Olympus?

21 March 2015 - 05:17 PM

OK, so I found a local dealer willing to let me test with my setup (Olympus m.Zuiko 12-50 lens in Nauticam flat port).  I tried the SubSee +10 in the Nauticam flip adapter.  My objective was maximum magnification (we consistently find pygmy seahorses on our local dives) so I did not test permutations at constant distance.  As luck would have it I forgot to check my camera battery and it started flashing red on the first test shot so I had to rush, hand-holding a heavy housing over a poorly lit sales counter, hence these images are not very good, but they show the most important parameter which is maximum image size.  

 

First, the lens at 43mm macro mode, no diopter.  Closest focus is about 50mm from the front of the port. Horizontal image size is about 35mm:

 

16680592137_dcc2a3a39b_o.jpg

 

Then, same 43mm macro mode with the Subsee +10.  Closest focus is actually touching the lens, resting the front of the Subsee on the edge of the ruler.  Horizontal image size is about 28.5mm:

 

16700296528_622a855d1c_o.jpg

 

Finally, for those without the Nauticam gear for this lens, I tried The Subsee +10 at 50mm (normal not macro mode).  Closest focus was about 50mm from the port and horizontal image size is about 32mm 

 

16700296348_2db56cc218_o.jpg

 

 

I conclude that this combination doesn't do what I was hoping, as the relatively small increases in magnification (about 25%) is offset by the loss of working distance, which would make approaching and lighting anything animate just about impossible.  

 

Also for those hoping to save on the cost of the expensive Nauticam zoom port and gear for the 12-50 lens, it seems you can save $400 by buying the macro port and Austrian zoom gear, but end up at nearly the same image size as the 43mm macro mode, and need to spend about an extra $400 or so for the Subsee and flip adapter.  

 

So for now I am going to stay happy with the versatility of the zoom lens, and buy the 60mm macro.  Once I have that lens, then maybe the Subsee will produce the results I am after.  


In Topic: Hey Guys I need a recent honest input review on Beqa Lagoon Resort

20 March 2015 - 06:31 AM

You won't be bored there, the reefs are productive and there are lots of pelagics. Something for everyone!