12-40 Dome port possibility for OMD housings

[Furnari]

Like many people who tried the 9-18, I was never really happy with it underwater due to lousy corner performance in the small dome. In fact, I haven't dove with it since I started shooting the 12-40. The Pro lens works pretty well in the flat port, but as you can imagine a dome would be a lot nicer for dedicated wide angle dives. Unfortunately, in what is surely a surprise to many underwater photographers, domes are expensive. I'm cheap, so I ended up with the Inon dome intended for the Four Thirds e-volt cameras and 7-14 lens (the Oly PPO-E04 was designed for the same combination). This dome is currently listed on Divervision for $575. It took over a month to get it, so who knows if it's still available. If it is, it's probably the cheapest option for an OMD 170mm dome, and not a whole lot more than the flat port. It does need the Oly 2" port extension ring to work, so factor that into your budget as they can be spendy if you don't have one or can't find one on e-bay. You may already have the OMD port adapter, but I splurged and bought a second one for convenience. As I hadn't found anything online about this combination, I figured I'd be the guinea pig and report back; I'm also going to use it on an upcoming trip to the San Juan Islands so we'll see how it does in the real world.

I tested the combination in a tub yesterday, and corner performance is a lot better than the flat port, and significantly better than the 9-18 in the Zen dome. The test shots aren't the greatest, but they were enough for proof of concept. All three are compressed jpegs at 12mm- strobe positioning was a bit of a pain in the tub, so the exposure isn't perfect. The first shot is at the closest focusing distance I could get (F4.5), the second is probably a foot away (also F4.5), and the third is the same distance at F2.8. The lower left corner seems a little blurrier than the upper right on the two further shots, but if I had to guess I'd say it's because I wasn't holding the rig level. I also note a little more vignetting with the F2.8 shot, but it's not enough to hurt my feelings. 40mm performance was still sharp, so it'll work nicely for fish portraits and the like. I also tested the 60mm macro in the dome, and it works just fine. I didn't have the time or inclination to test it, but my guess is that the 9-18 will work in the dome if it's mounted with a 1" extension.

 

[EskilJ]

Thanks for sharing!

 

[Furnari]

Here's some examples of shots taken through the Inon dome with the 12-40. The single fish shot is of something called a Pacific Spiny Lumpsucker. They're kind of adorable as far as fish go, and this one was smaller than a golf ball. I cropped the original shot a fair amount and still ended up with lots of detail. The wide shot was at 12mm. At 12mm and f2.8, corner sharpness isn't the greatest, but that's going to be true for most lenses. Stopping down, as expected, helps.

I tried the Oly 8mm f1.8 fisheye in this port combination, but the 2" extension is too much and it vignettes a lot. I also have a 1" extension, and my guess is that combination would work fine. That said, I'm not sure I want to go through the hassle of switching extensions, so I may return the 8mm and get the 7-14 f2.8 instead, which should work in the same setup as the 12-40.

 

[vsc]

I seem to be heading down the same path where I have the PPO-E02 port, though I have yet to pick up the 12-40mm Olympus lens. Do you have any examples of the 12-40 with the flat port you can share?

 

[Furnari]

Here you go- the dive is at 12mm and f2.8, the clam siphon is at 40mm and f3.5. Both are OOC jpegs so you can get a since of what the corners look like. Viz when I took the clam shot was probably around 4', so you'll have to excuse the backscatter

 

[vsc]

View attachment 368351 View attachment 368352Here you go- the dive is at 12mm and f2.8, the clam siphon is at 40mm and f3.5. Both are OOC jpegs so you can get a since of what the corners look like. Viz when I took the clam shot was probably around 4', so you'll have to excuse the backscatter

Both look reasonable. The 12mm shot seems to have a little vignetting but the reviews show that the lens has this behavior, where it is easily fixed in camera raw (e.g. just tested that right now with your image).

 

[Furnari]

Yep- I agree that the vignetting is more of a lens characteristic than just the port.

 

[Furnari]

Thought I would update this post as I find out more about lens compatibility in the Inon dome port. As noted above, the 8mm f1.8 Pro fisheye lens vignettes strongly with the 2" extension; I suspect it will be ok with the 1" extension but haven't tried it yet (maybe this weekend- I've got to decide soon whether to keep it or send it back). I just received the 7-14 f2.8 Pro lens, and it does not vignette at 7mm in the same port/extension combination as the 12-40- that's good to know. I have a trip to Hood Canal and the San Juan's up in Washington in a couple of weeks so I'll try it out and see how it works underwater.

I knew it was big when I ordered it, but holy cow- the 7-14 weighs a ton compared to other M43 lenses.

 

[vsc]

I picked up the 8mm f1.8 fisheye and compatible dome port given the small minimum focus distance forgoing the 7-14mm. Also similar to your prior purchase a 12-40mm f2.8 and flat port.

 

[Wisnu]

here few shots and footage taken with 12-40mm with Nauticam 6"dome port

barracuda by Wisnu Purwanto, on Flickr

crowded by Wisnu Purwanto, on Flickr

Moray eel by Wisnu Purwanto, on Flickr

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