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bmorescuba

Member Since 12 Jun 2009
Offline Last Active Yesterday, 02:20 PM
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Topics I've Started

Ambient Backscatter

27 January 2018 - 01:42 PM

Recently, I spent a couple days in central Florida. We only had time for a few dives - one in Crystal River, one in Alexandria Springs, and one in Blue Grotto (plus a manatee snorkel). The first time I've done any of those locations. It was also the first time I've been able to take my new em1mkII underwater and I was pretty psyched. Since the average depth of most of the dives was <10ft., I thought I would keep things simple and just shoot with ambient light. This is not something I've done very much - I almost always shoot with strobes.

 

I was surprised by the amount of backscatter in most of my photos, especially given the generally clear conditions. It sure looks like backscatter to me at least. I hadn't really been worrying about it, since I always associated backscatter with strobes. Can others comment on backscatter occurring in ambient light and tips to minimize it? There was certainly particulate in the water, but it appeared generally clear with good viz.

 

Thanks!

 

Here's an unretouched example:

 

 

 

Attached File  P1130015.jpg   172.75KB   21 downloads


Port Glass "Cloudiness"

04 December 2017 - 08:23 PM

I'm guessing this is something very common. I've noticed my Nauticam flat port (which is fairly old at this point and has seen a lot of action) has a "cloudiness" when viewed at a certain angle. Cloudiness is not exactly the right term, but hopefully the attached image explains this better. This does not seem to affect image sharpness very much, but it does have me wondering. I'm pretty faithful about fresh water rinses, but this port has been through a lot, getting wet, drying, getting wet, etc. If you view the port glass head on, this is not visible. If you view it at an angle, it's quite apparent. I'd like to know what causes this, what it's called, prevention, fixes, inevitability - really any information would be helpful. One note - I have thoroughly cleaned both sides of the glass with a lens-safe cleaning cloth - whatever this is, it doesn't come off that way :)

 

Thanks!

 

port glass cloudiness not visible

Attached File  port1.jpg   159.55KB   17 downloads

 

sane port glass with reflected light, cloudiness visible

Attached File  port2.jpg   176.9KB   17 downloads


Shooting Experience - Oly 30mm vs. 60mm Macro Lenses

08 November 2017 - 01:37 PM

I have a lot of experience shooting with the Olympus 60mm macro on my EM10. I love the lens, but it does have some limitations for fish portraits and larger subjects. I was wondering if any seasoned users of the 60mm macro have tried the Olympus 30mm macro lens. If so - what are your thoughts? It seems like it could be better for fish portraits and larger subjects, and the > 1x is interesting as well. Does the 1.25x magnification require getting too close for anything but relatively static subjects? Does that make it hard to light? Is it good for medium sized fish portraits (like parrotfish-sized) and also for smaller stuff?

 

I use Nauticam and I see that the 30mm port chart calls for 36135 (macro port 45) whereas the 60mm port is 36163 (macro port 65). On a side note, has anyone found a port that could accommodate both? Right now, the 30mm macro is only $200, so I was thinking of playing around with it. Of course, the port is $300, so the total investment would be higher.

 

Thanks!


WTB: Olympus PT-056 Housing for TG3/4

24 May 2017 - 07:39 AM

Doesn't have to be pristine or anything, as long as it has the "Optical fiber cable adapter: PFCA-02" so that I can use my TG-4 with a strobe. Thanks!