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#392992 Which Mirrorless Camera for 4k Video (Macro/Wide)

Posted by bvanant on 04 March 2018 - 12:52 PM

Yes indeed, if you take photos. But if you only do video, then I think a dedicated video camera is still superior, continuous auto focus for video is still not quite there yet.



#392797 Which Mirrorless Camera for 4k Video (Macro/Wide)

Posted by bvanant on 27 February 2018 - 04:45 PM

I think the recommendation for either the 30 or 45 macro for super macro is probably a stretch for micro 4/3. Neither plays particularly well with add on diopters; for that the 60 macro is the best thing I think. But only $3K for camera, lenses, housing, ports, and lights is going to be very tough unless you find someone wanting to get a rid of a used system for cheap. I would also probably stay away from the Meikon type housings, not much room for growing that type of system.



#391544 Can you use Nauticam silicone on Sea&Sea blue o-ring?

Posted by bvanant on 22 January 2018 - 05:18 PM

There is an old saying in organic chemistry that like dissolves like. For example salt is an inorganic compound that dissolves well in water while not so much in things like olive oil.  Similarly, olive oil floats on water but will dissolve very nicely in heptane or gasoline.  

For o-rings you don't have to worry about dissolving them (mostly) but you need to control swelling. For example many silicone rubber o-rings use fluorosilicone grease since silicone grease will dissolve into the o-ring and swell it perhaps leading to a leak.  Similarly some folks talk about using petroleum jelly (Vaseline). According to the o-ring kings (https://www.physics....ng_handbook.pdf) which comes from Harvard so it has to be right  :lightbulb: petroleum jelly is probably not so good for EPDM or Silicone but OK for nitrile and Viton.  

The reason to use Tribolube 71 (for sliding o-rings) is that it will not swell any type of rubber that I know about.  Similarly, Christolube is just as good as is Krytox (there are 745,000 types of Krytox, I think the scuba one is GPL 205 but others might work as well.  Krytox is ungodly expensive while Tribolube and Christolube are only ridiculously expensive but you don't really need much.  I store mine in contact lens cases that look like a dive mask (https://www.amazon.c...ge?ie=UTF8&th=1) and one side has lasted for at least two years. 

There are lots and lots of urban legends about o-rings and o-ring material compatibilities. Look at the table in the Harvard link and you will see that many o-rings are not so good in contact with common stuff.  




#391424 LED strobe trigger not enough power

Posted by bvanant on 19 January 2018 - 06:11 PM

Which fiber optic cable are you using? It makes a big difference. Try the Nauticam fibers or the S&S multi-fibers or make your own double fibers for cheap and see if that helps.

Does the LED trigger fire the strobe if you hold the LED up to the fiber port on the strobe directly?



#391354 Nauticam for Sony A6500 and strobes (help needed)

Posted by bvanant on 18 January 2018 - 05:17 PM

I am confused by the question. As I understand it (perhaps not very far) the IKE strobe has only an electrical sync cord connection. Adding the IKE fiber optic converter will allow for triggering by fiber optic but offers NO TTL ( This adapter is a manual exposure (non-TTL) trigger only.) so no TTL possible.  It will fire however from LED triggers assuming you can get one that fits in the housing. Hedwig's will fit and should work.

The fantasea version appears to be (40.5 x 45 x 20.5 mm) big so you can measure to see if you have that space above the hot shoe.

If you move to other strobes the cables will be the same.  


#390992 Triton Bay - trip report - December 2016 / January 2017

Posted by bvanant on 08 January 2018 - 09:21 AM

For a macro oriented video of Triton Bay (2016 and 2017) check out






#389966 DIY - Make your own fiber optic cable for your underwater flash - works with...

Posted by bvanant on 01 December 2017 - 05:40 PM

The advantage of the multiple fiber cable is not so much throughput (it has an NA of 0.5) but it has a really small minimum bend radius of like 2mm.  You can not get (or I couldn't find it) the 600 fiber in small lengths but you can get the 217 fiber stuff in meter quantities.


#388679 Triton Bay - trip report - December 2016 / January 2017

Posted by bvanant on 23 October 2017 - 03:30 PM

We agree, Triton Bay Divers is an excellent place to go diving. We spent a month there in Nov 16 and two weeks there in January 17 and are going back in January again for two weeks. The first month was with Graham Abbott (diving 4 images) and Lisa was there, the second trip Jimmy was there.  On the second trip, Conservation International was there tagging whale sharks which were able to observe.  Neat.  Here is a movie of the two trips kind of combined (the first part is on the Triton Bay website)



The only thing I would add was that the food when we were there was not terribly exciting (nor very good for the first trip) and they ran out of things like eggs and milk while we were there. That being said, the place itself is terrific and all of the staff were really amazing. I hope that the new dive masters (Andi is gone, married and off to Manado I think) are as good as last years.





#388662 ​​Is there a Smart Underwater LED Strobe in our future?

Posted by bvanant on 22 October 2017 - 01:49 PM

Well a GN of 4 isn't so interesting except for macro where it might be useful, but $1000 seems a bit pricey.


#388257 DIY - Make your own fiber optic cable for your underwater flash - works with...

Posted by bvanant on 09 October 2017 - 02:12 PM

Well, the 613 fiber cable by itself is quite expensive, in small quantities it is like $6/foot.  You can get it cheaper though if you need 500 meters worth. For me I make my own fiber cables because I like to mess around, not because of price so much.  In any case I buy the 2-hole bushings from Inon for $5 each (http://reefphoto.com...roducts_id=3932) and buy jacketed 1 mm fiber from Asahi for $1.25 per meter. If you use only one fiber then things don't work so well but if you use two fibers (one in each hole) you can get a 1 meter cable that works well with the Nauticam trigger and Inon or S&S strobes for less than $15.




#385685 Can you use Nauticam silicone on Sea&Sea blue o-ring?

Posted by bvanant on 08 July 2017 - 12:51 PM

Not so much. There are silicone greases and fluorosilicone greases and each has specific uses. For example Silicone grease (the stuff in the big trident tub) can swell silicone o-rings and lead to troubles.  That is why we keep recommending either the Tribolube or Christolube (or Krytox if you can find the right one) since they are good for all types of o-rings.



#383705 How to get sharper corners when using E-mount 12mm Zeiss in Ikelite housing a...

Posted by bvanant on 30 April 2017 - 09:20 PM

Firstly, why are you worried so much about the corners. Your photo looks fine to me and unless you are pixel peeping why worry. Secondly you can shoot at smaller apertures (like f:16) but most likely won't help too much. Getting a bigger dome will help but at a cost and pain for travel factor. Using a diopter on the lens can often help and is quite inexpensive compared to a new dome.  One thing to check on is the corner sharpness of the lens on land; test it in the garden; it can't be much better UW than it is on land.


#382052 Oops... Did I just mess up my kit?

Posted by bvanant on 07 March 2017 - 08:50 AM

No worries; think about what forces are on the o-rings and seals. All commercial planes run around the equivalent of 1800 meters (6K feet) or slightly higher than say Denver. Taking your housing to Denver is not such a worry.


#381149 And you think UW shooters are obsessed...

Posted by bvanant on 01 February 2017 - 05:16 PM

Sort of like the psychedelic frogfish in a sunball


#377775 TTL flash trigger for M43 Panasonic/Olympus cameras?

Posted by bvanant on 13 October 2016 - 02:18 PM

I don't think anyone has a TTL flash trigger for the u4/3 cameras and it is not clear that the Nauticam trigger will fit in your housing, check this carefully.  Getting an LED to drive TTL is not terribly simple for optically triggered strobes. As you know typically TTL is obtained by the internal strobe sending out a weak signal then measuring the resulting intensity then sending out the true strobe signal.  Neither Olympus nor anyone else has published the inner workings of their TTL (except in some difficult to understand patents) so this is tricky.