Jump to content


coroander

Member Since 10 Jun 2012
Offline Last Active Jul 15 2014 12:33 PM
-----

Posts I've Made

In Topic: Olympus 12-40 F/2.8 and the Zen Underwater DP 170 n85 port

05 July 2014 - 12:17 PM

Many thanks for posting these. I'm thinking about getting the DP-170 n85 version 1 and some extensions, for more versatility. I'm confused about all the different DP-170's though, there seems to be three?

1) DP-170 n85 version 1

2) DP-170 n85 version 2 (like version 1 with 25mm built-in extension)

3) DP-170 n120 (no idea what this is -- seems to be the same dome as the n85, but hard to tell, perhaps it's for DSLR housings?)

 

Presumably all use the same glass and same optical coatings?

 

Is it possible to attach the DP-170 n85 version 1 to the housing without using an extension?


In Topic: Nauticam 6" dome ports use with 9-18 mm Olympus

02 July 2014 - 05:34 PM

The Nauticam 6" dome and the 4" semi-dome have the same optical radius, i.e. the 4" semi-dome is just a piece of the larger 6" dome. All other things being equal (like the distance from the body to the front of the dome), the two domes will perform identically.


In Topic: oly em1 manual white balance issues

29 June 2014 - 03:13 PM

Manual balance is useful for video underwater. But for stills just shoot RAW and forget about trying to set the camera's white balance underwater.

If you feel the need to get a white balance, you can take a shot that includes something white and then use this to set the white balance for all other photos at around this distance/depth. When doing white balancing in this way you only need something white that occupies a dozen pixels in the image, and like manual white balance you don't need it in every image. I often just use some white bit of a logo on a buddy's gear to white balance at that distance for my current depth.


In Topic: Olympus OM-D E-M5

17 June 2014 - 03:46 PM

There's zero chance that good results will be obtained with the 9-18mm behind the 3.5" or 4.33" dome ports. These ports are far too curved to allow the corners to have any chance of ever being in focus.

The 9-18mm behind the 4" semi-dome (which has the same optical radius as the 6" semi-dome for the 7-14mm) with a +2 diopter looks excellent.

 

12mm test results behind the 4.33" dome:

http://wetpixel.com/...=51858&p=342712

 

Storker's 9-18mm test results behind the 4" semi-dome:

http://wetpixel.com/...=51969&p=343523


In Topic: GH4 lens recommandation

12 June 2014 - 12:52 PM

I'm an idiot.