14-42 mm & 9-18 mm in Olympus PT-EP10

[StefanKruse]

Hi all,

I have the Olympus PT-EP10 housing with the standard kit lense, but I am considering getting the 9-18mm lens. Without changing the flatport to the Zen Underwater WA-100 Dome Port, I will not be able to fully benefit from the FOV that the 9-18 mm offers, as I understand. But how about the 14-42mm is this lens also restricted by the flat port of the Olympus PT-EP10?


My worry is that the loss in FOV from the flat port only applies to the 9-18mm and thus in effect the FOV from the 9-18mm is approx the same as for the 14-42mm? and I have then bought a semi expensive lens which I will only benefit from when shouting above water.


Bonus question would the ZEN dome port also work with the 60mm macro lens?

Thanks,
Stefan

 

[Interceptor121]

It is not worth to get a lens with 18-36 mm field of view and put it behind a flat port as the water will provide a 1.33x zoom and the edges of the frame will suffer from pincushion distortion this is the reason why you need a spherical port
The 14-42 suffers the same problem but the pincushion distortion only affects the shorter focal lengths and come 17-18mm goes away the lens is in effect a 35-100 mm in water

If you want to shoot macro and avoid spending money for the port and 60mm lens you can try a wet diopter the quality is not the same but the cost is limited and it can be used with the equipment you already have

 

[Storker]

My worry is that the loss in FOV from the flat port only applies to the 9-18mm

Stefan, think for a few seconds: Are there any reasons whatsoever that the same image magnification/loss of FOV that you experience by looking through your mask should magically apply to only one lens and not another?

No matter what lens you put behind a flat port, you'll lose about 25% FOV. If you want to keep your lens' FOV, you need a dome port. OTOH, rectilinear WAs behind a dome port brings their own share of challenges. The most prominent one is that the curved virtual image from the dome port will give you poor corner sharpness. I've found that a +2 dry diopter screwed into the filter threads of the 9-18 helps quite a bit with corner sharpness.

 

[Furnari]

The 9-18 in the flat port isn't as bad as some people think- is it better than a dome? Of course not, but is better than the kit lens at the wide end. The 9-18 also suffers from distortion on land, but it's correctable in LR and not enough to make me stop using it. Same thing underwater.

 

[Texas Boy]

The 60mm lens also works in the Zen port. I have had very nice results.

 

[StefanKruse]

Thanks all,

Very helpful,

I realise that 9-18mm behind a flat port wont be the optimal solution, but as I also see the benefit of the lense topside, I am inclined to buy it, however if the 9-18mm lense does not add anything to the 14-42 mm kit lense, then 9-18mm would probably find its way to a lower ranking on my lens priority list (at the moment the lense tops my wishlist)

I already own the 60mm macro so not looking to add any wet diopters

Would I be right to conclude that:

9-18mmm in flat port beats 14-42mm in flat port
Both lenses benefit from a semi dome
60mm lens works in the Zen port

So questions is what would be a better match the flat port or the semidome if I would only travel with one and want to do both WA and macro photography. The all in one element is the main reason why I bought the Epl5 and olympus housing in the first place so I wnat to keep things as simple as possible for as long as posiible.

 

[nudibranco]

The zen port is fantastic and is the best for the 60mm, the 14-42mm and the 9-18mm.
I have used it as my only port with these lenses when I had the Olympus casing.
You can even adapt a macro adapter if you want.

 

[Storker]

I realise that 9-18mm behind a flat port wont be the optimal solution, but as I also see the benefit of the lense topside, I am inclined to buy it, however if the 9-18mm lense does not add anything to the 14-42 mm kit lense, then 9-18mm would probably find its way to a lower ranking on my lens priority list (at the moment the lense tops my wishlist)

Unless you choose to go full fisheye with a FE dome, I'd say you'll do well by buying the 9-18.

The 9-18 is a very nice compromise with pretty good (albeit not downright stellar) IQ. It's very useful topside as well, it's a part of my m43 topside travel kit (E-M5, 9-18, 20/1.7 and 40-150). The 7-14 is a little wider and is claimed to give better IQ, but it's big, and if I want a big camera setup I'll pull out my dSLR.

I'd say use it behind your flat port now, and find out if you want to go for a semidome in the future. In that case, I'd invest in a quality +2 closeup lens to put on it inside the port. You might decide to go for a fisheye instead of rectilinear WA, but be beware that there's a learning curve to using FE properly to get good compositions and you lose the flexibility of a zoom. In any case, you haven't wasted money on the 9-18, since it's so useful topside.

 

[ggibson]

I use the 9-18mm with just the flat port, and it is definitely a big improvement over the 14-42mm. Would it be better with a semi-dome? Of course. But using it with the standard flat port is still great. Here's an example for you:

 

[Interceptor121]

I use the 9-18mm with just the flat port, and it is definitely a big improvement over the 14-42mm. Would it be better with a semi-dome? Of course. But using it with the standard flat port is still great. Here's an example for you:

A shot with nothing in the corners is not a good representation anyway looking at the fish in the bottom right corner you can see a clear ring of purple fringing all around it and the diver in the chai suit is squashed like some gopro flat port clips