Real world review of the AOI DLP-04 acrylic mini dome port with Olympus PT-EP10 housing

[TravelDave]

If you never plan on selling it, sometimes just using permanent marker is enough.

Could I not do the same thing with a $10 filter (as opposed to using permanent marker directly on a somewhat pricey lens)?

 

[Warmwater Wank]

I'd second C196's comment on the 9-18mm. I'm shooting one w/ a Zen semi-dome (using an EM-5) and the zoom aspect certainly is a major benefit. The other thing though is that the real difference between an 8mm FE and the 9mm end of the 9-18mm is not the 1mm of focal length.

On the 8mm FE the angle of view is almost double; 180 degrees on the 8mm FE vs 100 degrees at 9mm w/ the 9-18mm. So yeah,completely different animal. Good to know about the AOI acrylic dome though, just in case an 8mm FE ever drops out of the sky and lands safely nearby! // ww

 

[TravelDave]

I'd second C196's comment on the 9-18mm. I'm shooting one w/ a Zen semi-dome (using an EM-5) and the zoom aspect certainly is a major benefit. The other thing though is that the real difference between an 8mm FE and the 9mm end of the 9-18mm is not the 1mm of focal length.

On the 8mm FE the angle of view is almost double; 180 degrees on the 8mm FE vs 100 degrees at 9mm w/ the 9-18mm. So yeah,completely different animal. Good to know about the AOI acrylic dome though, just in case an 8mm FE ever drops out of the sky and lands safely nearby! // ww

Useful info. Thanks!

 

[TravelDave]

I also did some shooting with the 60mm macro lens. The difference in magnification was quite noticable when being used to the flat port, but I honestly felt it was an improvement for all but the tiniest subjects. The 60mm focal length on micro 4/3 is quite tight as is, and being able to move closer to fill the frame felt nice.

I ended up recently getting this port to work with my 9-18 lens. Also picked up a used 60mm lens for a good price. Do you need to use a shading ring with the 60mm lens, or is that only an issue with the 9-18. They seem expensive for what you are getting, but not sure I want to use tape or other measures on my pricey lenses.

 

[jgnu]

I ended up recently getting this port to work with my 9-18 lens. Also picked up a used 60mm lens for a good price. Do you need to use a shading ring with the 60mm lens, or is that only an issue with the 9-18. They seem expensive for what you are getting, but not sure I want to use tape or other measures on my pricey lenses.

I didn't use any shading ring or any other modifications with the 60mm. I didn't see any dome reflections from it.

I think dome reflections only happen when the subject is back-lit, and that pretty much never happens for me during macro with the way I usually position my strobes.

 

[Xscream100]

I have the acrylic version of the AOI DLP-04 on an Olympus PT-EP06 housing. Very happy with the port using the Olympus M.Zuiko 12-50mm lens and Athena ZG/12-50-NO-M1 zoom gear. For fisheye, I have the INON EP01, which is also a great port and cheap (check Divervision.com).

 

[Chris Ross]

Darn - looks like the anti-reflection ring is needed. Any thoughts of a middle ground between buying the ridiculously priced Olympus anti-reflection ring and using tape? I was thinking maybe a step-down ring (not sure what size I'd need for my 9-18). Amazon has a 52-49 and a 52-42 both very reasonably priced

The concern with the 9-18mm is vignetting, so you would not want to have it too small in ID, like if you just used one with the same ID as the front element diameter. If you did this with the 9-18 mm it would very likely vignette significantly.

What you could do is cut out an annular ring in black cardbaord that just covers the printing and goes all the way to the ID of the filter thread. Then you could use the step down ring as a kind of clamp to hold it in place, in which case the 52-49 would seem ideal as it would only be about 2-3 mm wide. As long as the threads are long enough to contact your masking ring it should hold it in place.

 

[Gdog]

Reading with interest....I also hate the thought of black marker on expensive lens.

 

[SCheckman]

Thanks for sharing this. I am looking at getting this port for my EP-13 housing for my OMD EM5 Mark II. I was wondering if I could use my 60mm in it as well as my 9-18mm. I think that you've convinced me! How easy is the port change if I wanted to switch to the flat pot to be able to use my wet macro diopter?

 

[Warmwater Wank]

Port changes on Oly EP housings are simple. Depress the release near the lower right front of the port lock ring and give the lock ring a twist. If you haven't done it before and have been diving in sand, muck etc. the ring may be a bit glommed on but persistence will win out. The port pulls out pretty easy if you've kept the O-rings lubed. The 9-18 really needs a dome.

There is an older thread about using a +4 diopter on the front of 9-18 (yes, inside the housing) to improve corner sharpness. You still get infinity focus but you also will see improved corner sharpness. To quote Storker:

I don't know about any of the Olympus ports, but the 9-18 has mushy corners behind the Nauticam 4" semidome. It can be fixed, though.

AFAIK, mushy corners is a quite common issue with many rectilinear (super)wides in a dome, since the dome projects a curved virtual image pretty close to the close focus limit of the lens. You can sort of hack that by using a dry diopter/closeup lens - preferably an achromat - on the lens. That brings the virtual image further from the close focus limit of the lens, and you'll get noticeably crisper corners. You'll lose a little FOV, though, but IMO it's not so much that it annoys me.

I use a 52mm Canon achromatic closeup lens on my 9-18 (behind a Nauticam 4" semidome) and I'm quite happy with the results. Noticeably better than before I got the closeup lens. Later, I've splurged on the 8/3.5 and a dome as well, but the 9-18 is a better allround lens for me, so I tend to use it just as much as the FE which is more of a specialized lens, IMO mostly suited for wreckscapes and CFWA.