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Member Since 05 Jan 2008
Offline Last Active Yesterday, 07:11 PM

#396998 Oly TG-5 Package Recommendations

Posted by tursiops on 03 July 2018 - 01:09 PM

The Olympus TG-5 in the Olympus housing is a awesome bargain, and a lot to learn if your spouse has not done much U.W photography. Some find the lack of manual settings a downer. Start adding a Nauticam housing and a wet WA lens, and it become less of a bargain and a LOT more to learn. 


My wife had an old Canon S110 in a Nauticam housing that she loved, but the flash stopped working, so she sent it in to Canon for a repair. They said they could not repair it so sent her a G7X Mark II as a replacement. Of course, that meant a different Nauticam housing, which we found used along with a dome port. She is a fairly accomplished photographer, but not a techie nerd, and the combined learning curve of the G7XII plus the new housing hit her limit. She took the dome on a single dive, then set it aside and hasn't touched it since.


i guess what I'm saying is (a) the TG-5 is great but limited, and too much camera/stuff can be inhibiting.

#396683 Need ID help

Posted by tursiops on 22 June 2018 - 01:11 PM

Could be anything.....a picture would help!

#394703 sharpnose puffer

Posted by tursiops on 24 April 2018 - 11:23 AM

i cropped it slightly, to move the little guy's eye away from the center of the photo.



#394056 Best backpaak or hard case suggestions

Posted by tursiops on 03 April 2018 - 04:38 PM

2 x sea and sea ys-d1 strobes

Nauticam housing with pro kit (handles) for a panasonic (compact) Lumix LX10
Nauticam wise lens IN CASE
Nauticam floatation ring for lens

I assume you mean the WWL-1 lens.

If you take out the molded foam from that case, the lens will fit inside already in its flotation collar, so you can leave the collar on and not have to keep mounting/unmounting it.

#393759 DIY Underwater Video Tripod

Posted by tursiops on 25 March 2018 - 05:50 AM

Cute bipod, not tripod.

#393687 What's wrong with my settings ? (Canon g7x mark II and Inon s2000)

Posted by tursiops on 22 March 2018 - 03:56 PM

Is the magnet perhaps removed from the s2000? You want the magnet switch installed, because the G7X II has no preflash.


"Basically, if your camera flash outputs a preflash, the  magnetic switch should be REMOVED. If your camera flash does not output a pre-flash, the magnetic switch should be INSTALLED.

Preflash – Magnet Switch Removed.

No Preflash – Magnet Switch Installed."

#392557 Wetpixel strobe review

Posted by tursiops on 20 February 2018 - 03:51 PM


From a purist point of view, f-stop does have units.  As an example, mm focal length/mm effective aperture diameter.  Since the 2 lengths are referring to different parameters, they do not cancel.  While I realize that ignoring the units greatly simplifies communications, as a chemist, I find that many professionals can't solve problems by simple unit conversions because they think things like vapor/liquid distribution constants (concentration vapor/concentration liquid) also have no units.  :)

LOL. I guess this is the difference between mathematics and chemistry. 

#392550 Wetpixel strobe review

Posted by tursiops on 20 February 2018 - 11:15 AM

and more:

The guide number has a unit of measurement: for distance. Feet or meter. Manufacturers do not even say it, but it's a mistake because it's not 33 feet or 33 meter. The guide numbers of the flashes in the article are given in feet.



Let me say this a little differently and in more detail, because I'm sure many people are confused about it.


The Guide Number (GN) is what you divide by the distance-to-subject to get an f-stop. The distance to subject can be in feet or meters. So, if you are 10 ft away with a GN of 33, you should use f/3.3. But, if you are a meters person, like most of the world (!), the GN should be given as 10, so when you divide by 3m (i.e, 10 ft) you still get an f-stop of 3.3.


Because f-stops are a ratio of lens focal length to lens opening, the f-stop has no units, it is a pure ratio of two lengths. So when you multiply distance x f-stop = GN, you still have units of distance, be they ft or meters. This means the GN MUST HAVE ITS UNITS ATTACHED -- feet or meters -- or it is incorrect and potentially will give you greatly underexposed pictures. .


Using the example of GN33 and assuming it works for meters, and you are 3m away, you will use f/11. But the correct f-stop is 3.3, because the GN is in feet. So you are underexposing by a factor of over eleven (11/3.3 squared).....good luck. 

#392470 How do you shoot a black hole?

Posted by tursiops on 18 February 2018 - 07:49 AM

Shoot from a lower angle...eliminate as much of the light-colored background as possible. Zoom in, eliminate as much of the light-colored background as possible. Use just enough light to keep the light-colored background from blowing out; the fish will be underexposed, but it is easier to bring up the underexposure in post-processing than to tone down a blown-out background.Light low and from the side, not the top, so you see both texture and can "skim" the light over the sand. Pray.

#392223 Olympus E-M1 MII Memory Cards

Posted by tursiops on 10 February 2018 - 11:17 AM

OK, now I understand. thanks. You want BOTH slots to be UHS-II. And, I had forgotten that the Mk II has two slots. Living in the past....

#392056 Olympus E-M1 MII Memory Cards

Posted by tursiops on 05 February 2018 - 01:21 PM

I'm using SanDisk Extreme PLUS U3 80 MB/s, 32 GB, without issues, E-M10.


I can't imagine using slower or smaller. 

What I have might be overkill.

I like overkill.


See the table in this link: https://havecamerawi...stest-sd-cards/

I also found this useful: https://en.wikipedia.../Secure_Digital


I think you want a UHS Class U3 to allow for burst RAW and 1080p/4k video.


The minimum write speed is the key. I think 64MB/s is a minimum, and 80-95 is better.

#391926 3D Printed Nauticam Float Arm Bayonet Holder

Posted by tursiops on 01 February 2018 - 03:32 PM


My float arm are not nauticam. They are Meikon brand.

LOL! Complete with blue o-rings!

#391776 Ambient Backscatter

Posted by tursiops on 27 January 2018 - 04:37 PM

Excellent point on trying to not shoot into the light, although it depends on the kind of scatterers. Here is an interesting plot of the angular "Mie" scattering of red light from a water droplet of size 10 micrometers. Zero angle corresponds to pure backscatter, which is what we get from our strobes. Each circle is a factor of 10 less than the next larger one. note that getting off-zero by only about 10-15 deg will drop the scattered intensity by a factor of well over 100, which is one reason we want to put our strobes off to the side! But there is still significant scattering in the forward direction, and 90 deg off zero is the least scattered intensity. the exact details of the plot depend on the relative wavelengths of the light and the particle/drop/bubble, but the general picture remains the same.


#391774 Ambient Backscatter

Posted by tursiops on 27 January 2018 - 02:45 PM

Some of that looks like near-surface bubbles (was it windy? were there people splashing around?), and some looks like "marine snow." It will mitigate a bit on cloudy, dull days, but I'm guessing from the shadows it was quite sunny. So you see "side-scatter" and "forward scatter" rather than just back-scatter. Solution? None I know of, except post-processing. A video can help you determine the source....easy to pick out bubbles vs sediment from their different dynamics.

#390768 INON Z-330 review/OlympusTG-5 with Ikelite housing review

Posted by tursiops on 02 January 2018 - 12:57 PM

Phil, I read both reviews. Very nicely written, very fair, very helpful. As always.