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#406162 Strobes

Posted by bvanant on 10 May 2019 - 03:39 PM

Here is some data from our local pool. Not quite the way the Backscatter boys did it. Put a bright white screen against the wall (about 11 feet deep). Put the strobe on a tripod parallel to the screen (PITA). Shot the strobe 20 times, averaged the shots using an image processing tool in Matlab. Also put a strip of photodiodes along the screen at the axis of the strobe light.  Here is data from the photodiodes. I can post the error bars, but all shots were within 5% or so except one shot with the S2000.  Note this is all from a single example of each strobe so YMMV.  The intensity scale is completely arbitrary, my waterproof flash meter was in fact not so waterproof so I have only intensity measurement.


Attached File  strobe.pdf   27.4KB   105 downloads

#405772 Our Strobe Problem

Posted by bvanant on 26 April 2019 - 06:06 PM

Correct on the physics until a better light source is developed, but is a distraction that misses the point.  


High voltages are part of electrical devices, such as televisions. Everybody who works with electricity knows how to handle voltages, low and  high.  Otherwise we would not live in an electrically powered world. To cry Wolf! about electrical hazards misses the real problems.


One strobe problem is reliability.  Current strobes much too often are not reliable.  For example, the YS-D1 and Chinese YS-D2 strobes were unreliable, with their multiple failures documented here in Wetpixel.


The other strobe problem is service, good repair service is mostly not available, or is unreasonably expensive.


It is true that everybody who works with capacitors knows how to discharge them, it is the people who don't know but try anyway (there are lots of them) that will get hurt. I think the issues are more complex than you are thinking about. Reliability is tough to gauge and the reporting is extremely biased since you only complain if your strobe breaks. I am currently using 3 Inon Z240 strobes that are more than 8 years old with about 200 dives per year on them meaning something like 20K flashes on them. The tubes are a bit discolored but their output measured with a good flash meter is still 90% as much as new. I also have a couple of 4 to 5 year old YS-D1s that are working fine (except they needed firmware updates). And yes I am very aware that the plural of anecdote is not data but in our lab xenon flash tubes have run hundreds of thousands of flashes with no issues. Getting stuff that is made in very low volume is always expensive to service, in the studio a Bowen flash head would cost 40% of its new value to get fixed (but you could replace a flash tube yourself.  If you want super reliability get a housing for your land strobe, and then you know you will have a strobe that is labelled for at least 100K flashes. Or you could go into business yourself fixing strobes if you think the profit margins that the strobe repair guys have is lucrative.  


Housed land strobes are still around (they are a bit big) and work well but I think the real problem is that underwater guys always think smaller is better and smaller sells so a lot of electronics gets put into very small cases and those need to be waterproof.  


I have had Ike strobes but my big issue with them is the proprietary battery and charger. Everyone knows that Ike service is good because everyone has had to send their strobes back more than once.






#405735 Our Strobe Problem

Posted by bvanant on 25 April 2019 - 09:07 AM

I agree with most of what you are saying, but I am quite sure that no strobe manufacturer would agree to supply repair or replacement parts to anyone other than an authorized repair facility. Strobes have big capacitors in them that can hurt you if you don't know what you are doing.  Not as bad as some scientific gear based on capacitors (we had a nitrogen laser in our lab that had a label that said "touching the capacitors when charged will lead to death with a high degree of certainty) but still bad enough. I am pretty sure it would be tough to get insurance to cover that kind of risk. For me, when I have a failed strobe I send it to Devin at Pacific Housing, he can get parts and is considerably faster than either S&S or Inon.





#404419 Video light advice...

Posted by bvanant on 18 March 2019 - 09:27 AM

Why do you need so much light? Were the Solas unusable? I guess if you are trying to light up wrecks you might need a lot of light, but for macro at least Sola 2500s would seem to be plenty.


#404207 macro lens

Posted by bvanant on 12 March 2019 - 07:21 AM

One interesting option is to use the 60 with a 1.4 teleconverter. A bit more magnification and a bit more working distance. On a cropped sensor this can be an amazing combo


#401515 Z330 flash duration

Posted by bvanant on 09 December 2018 - 11:19 AM


Now you have made me go back to the lab and get a notebook. Will post some numbers soon


#400795 Olympus 60mm and EM1Mk2 Strange Behavior

Posted by bvanant on 13 November 2018 - 09:22 AM

I have the same system and each my 60 macro lenses works as it should. I can not find a place in the menu to ignore it but I am only a third through them.


#400725 Smc 1 verses plus 10 macro lenses.

Posted by bvanant on 11 November 2018 - 05:41 PM

Well you are going to run into some laws of physics issues.  The SMC is stronger than +10, it is about a plus 12 or 12.5. The CMC is stronger, the SMC-2 is stronger still, BUT as you add diopter power working distance and DOF will both get smaller. With the 105 the +10 will give you about 2.2 magnification, while the SMC will give you about 2.5 x.  WIth the 60 the +10 will give you 1.5 x and the SMC will give you about 1.7 x.  



#400724 DIY fiber optic writeup with parts

Posted by bvanant on 11 November 2018 - 05:32 PM

I just ordered some of the same multi-fiber material that S&S and Nauticam use, I will see if it can be coiled. BUT using standard 1 mm fiber, my new coiled cables can trigger YS-D1 strobes from the Nauticam LED trigger.



#400692 DIY fiber optic writeup with parts

Posted by bvanant on 10 November 2018 - 05:03 PM

Coiling of fiber cables can be a pain in the butt. After many attempts (stubborn SOB), i found that if you take a piece of wooden dowel (about 8 or 9 mm or 5/16 inch in diameter) and drill two holes that are the diameter of your fiber through the dowel as far apart as you want your coil. I drilled them 90 degrees offset from each other but that doesn't matter.  Push about 25 mm or inch through the first hole, then wind the fiber tightly around the dowel til you get to the other hole then push another 25 mm through the second hole.  Place the dowel and fiber in a pan of cold water, then heat the water til just boiling, then turn off the heat. The important part is to now let the water sit til it cools.  Push the straight pieces back through the hole, and voila a perfectly coiled fiber optic cable. I had previously taken the coil out of the hot water and cooled it rapidly but letting it cool slowly is the magic.


Cheers and enjoy



#400574 DIY fiber optic writeup with parts

Posted by bvanant on 06 November 2018 - 10:01 AM

The fiber I use is from Industrial Fiber Optics, part number GH4001 1 mm fiber with PE jacket. It is $1.55 per meter. Works with both of the Inon plugs (the straight and the 90 degree) and with Inon strobes will easily trigger with the Nauticam LED trigger.  If you want to get really fancy, you can get from them the 217 core stuff for $6/meter. The 613 core (what Inon/S&S and others use) is $7.50 per meter. This will trigger the S&S strobes from the LED trigger. 


You can also get fc1.jpgthis from them for $25 or so. makes nicer cuts then doing it by hand.


#399799 Seeking underwater photos for science publication

Posted by bvanant on 02 October 2018 - 08:00 AM

I am pretty sure that the OP is not the owner of Current Biology so he is not asking for himself. As far as I know Current Biology is owned by the Cell group and there is likely a $5400 or so fee to get your paper published. This is not a dive magazine but rather a quite well respected science journal (Congratulations on getting published here) that happens to put pretty interesting photos on the cover. This is not the  case of a dive magazine wanting free stuff and also your photo will likely not be seen by most of your friends.



#396888 Inon Z240 Battery Compartment... Watertight?

Posted by bvanant on 29 June 2018 - 10:22 AM

Unlike Jeff, my flooded Z240 pushed water everywhere into the strobe. Not sure why, but this version was not sealed.


#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.