Wide angle dome port options for Olympus E-M1

[Bogdan]

I travel with an OMD E-M1 and the Nauticam housing and plan on using the 9-18 mm Olympus. I'm trying to decide between the Nauticam 4 inch dome port for this lens and the larger Zen 170 mm dome port. The price difference seems substantial as the Zen is about $1100 and the Nauticam is $480. Does anyone have any thoughts in regard to image quality with this setup or other advantages/disadvantages of the larger Zen port to justify the price difference? Thanks in advance!

 

[Wisnu]

9-18mm is not the best lens for UW. Later, you may want to have better and wider lens for WA.
If I'm in your position; I'll get the 4" semi dome, not as good as zen 170mm, but you can also use for 60mm and 12-50mm.

 

[JackConnick]

The Zen MIR Dome Mk II is glass, more durable and fits a very wide array of lenses including the fast Oly f1.8 12mm, 9-18, Panny 7-14, 12-35 and others. It doesn't fit the Panny 8mm. It may be a better option for video shooters for some of those lenses, but it is quite a bit more versatile.

 

[Storker]

9-18mm is not the best lens for UW.

It gets quite a bit better with a 52mm +2 dry diopter (preferably an achromat).


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[PHIL RUDIN]

While I have heard this pitch for using a +2/+3 closeup lens on the 9mm end of the 9-18 in the past it has never made much sense to me. I understand that you get better corner sharpness at 9mm and I realize this was a way to get better corners brought forward from the film days. The difference is that during the film days the ports were smaller which is the case here but the lenses were fixed focal length lenses. A closeup lens works the same on a wide lens like the 9-18 as it does on a macro lens. So your are magnifying the image which reduces the distance to the subject and therefore reduces the AOV of the lens at 9mm. If I am not mistaken you can does the same thing by zooming the lens from say 9mm to say 11mm and as a result you will have better corner sharpness with the four inch dome. If I am missing something please let me know because ALL of the wide angle zoom lenses I have tested have varying degrees of better corner sharpness if you just zoom the lens a bit which is what the low power +2 C/U lens is doing, that is why +5,+10 and so on are not recommended like they are for macro.

I agree with Jack that if you intend to use any of the lenses he has listed or a few more like the seller Olympus 12-40 F/2.8 or the coming Olympus 7-14 F/2.8 you will wish you had bit the bullet and gone with the more expensive Zen 170mm port. Sharp corners is in part the result of the size of the dome when it comes to rectilinear lenses that is why you see full frame guys using 230mm ports for lenses with the same AOV as the 9-18 and 7-14.

Another issue is that the C/U lens was never a part of the original lens design and will by itself reduce the quality of the lens. I you chose to skimp by buying a cheep +2 C/U lens it gets even worse.

 

[Bogdan]

Thanks for the comments Jack. I noticed that the Zen comes with a built in extender. Would these different lenses require different extenders to the port?

---------- Post added February 28th, 2015 at 05:51 PM ----------

Thank you Phil! I hadn't heard anything about the Olympus 7-14 yet, but that is the lens that I am waiting for and I would be thrilled if it fits inside this Zen dome port. I already use the 12-40 f2.8 for topside photography and I just love that lens! The only trouble is that I have a nice trip to the Socorros coming up and the Olympus 7-14 won't be out in time.
In any case, I may be able to borrow a friend's Panasonic 7-14 for the Socorros (though I only have the zoom gear for the Olympus 9-18). Do you think it may be worthwhile to bring the 7-14 along and use it at say 8 mm without the zoom gear in this Zen port? Or just stick with the extra zoom versatility of the 9-18?

 

[JackConnick]

No extensions are necessary with the Zen MIR Dome II right now, it's built into the mount. But, that could change with the Oly 7-14, nobody knows, my guess is that it will be close in size to the 12-40mm.

Jack

 

[PHIL RUDIN]

I use the 12-40 F/2.8 with this port and it is outstanding for a number of subjects. The lens is a very tight fit with the gear and the lens needs to be installed from the front of the housing before the port is mounted. My guess is that you will need to do the same thing with the new Olympus 7-14 or we may need to move to the Nauticam 85 to 100 extension adapter with the 180mm Nauticam optical glass port to make it fit. I would also expect to see ZEN have an answer for the lens if the current port will not work.