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Phil Rudin

Member Since 25 Jan 2005
Online Last Active Today, 01:45 PM

Posts I've Made

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

26 July 2014 - 06:40 AM

No filter required for the 9-18mm zoom and better overall performance than a 4" (100mm) port. The smaller port will obviously work better for confined spaces and at closest focus.

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

24 July 2014 - 10:52 AM

The 12-40mm F/2.8 gives you a little less magnification in auto focus than it does if you go to manual focus and crank the lens as far out as it will go, same same with all zoom lenses. So in practical terms using auto focus and the Zen DP-170 n85 II dome port you are looking at getting to around 1:1.5 in 35mm terms or about 55mm on the long side by 41.25mm. 

In Topic: Canon EF-S 10-18mm f/4.5-5.6 STM IS

24 July 2014 - 10:37 AM

Hi David,


Are these last set of photos from the Canon S1 in the Ikelite housing with the stock port? They look nice to me for such an inexpensive lens. I am over that nitpicking corner issues myself,  wide rectilinear lenses will always have some issues over fisheyes.

In Topic: OMD Flexi Tray vs Hand Strap

23 July 2014 - 12:04 PM

Regarding the EM5, the strap mounts to the little silver rod at the base of the housing and the rest of the hardware comes with the strap kit.

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

23 July 2014 - 08:27 AM

Hi Tom, Did you not look at the photos above, the starfish tip is full frame at close to maximum magnification and the 100% crop shows the detail at F/2.8. It is quite clear that in some cases the 170mm dome will be harder to get close with than say a 100mm or less flat port but that would not be comparing apples to apples. The lens that should be compared to the Olympus 12-40 is the Panasonic 12-35 zoom which works in the same port. Most will want to compare the 12-40 to the Olympus 12-50 using the flat port. The 12-40 is a much better lens than the 12-35 or the 12-50 in terms of image quality. If you can use the 12-50 with the DP-170 port the 12-40 wins hands down, it will focus much closer than the 50mm end of the 12-50 and has better image quality throughout the zoom and aperture range.


Attached are images with the 12-50 at 50mm max. magnification rendering about 1:5 in M43 or 1:2.5 in 35mm terms and the 12-40 at 40mm max. magnification rendering about 1:2.6 in M43 or about 1:1.3 in 35mm terms, Quite a difference in how close they will focus. You can argue the 43mm semi macro behind the Nauticam flat port which gets you to about 1:1 in 35mm terms v. 1:1.3 but then you don't get full use of the wide end of the lens.