Olympus 7-14mm 2.8 pro vs 8mm FE, in a nauticam housing

I'm having a real doozie of a time trying to decide which wide angle option to go with on an OMD EM1 Mark 2 in a nauticam housing; any and all opinions are most welcome! I have a 60mm macro I'll be using for macro, but I do not own the 8mm or the 7-14 pro yet, so my decision includes topside factors to some degree, although I do own the M. Zuiko 12-100 Pro and it's good for most things. Not sure I like the barrel distortion of the FE, especially above water, but if there was a discernible advantage underwater, I might be swayed (and it's cheaper). I understand I would need to insert the lens through and attach the camera in the housing for the 7-14 2.8, which doesn't really bother me. Which do you think is a better option for over-unders--assuming the 8mm in a glass zen dome (4.33 in I think) and the 7-14 in a 180mm glass nauticam dome? How does the 7-14 perform in the glass 180 dome? I also shoot astrophotography a fair amount, and although I believe both of these lenses are capable in that department, does anyone have any hands on experience, or with defishing the FE? Thanks for any input to any of that disjointed paragraph above!

Cheers, Morgan

I have the 8mm, and used to own the 7-14 until I sold it in favor of the Panasonic 8-18. The zoom is a little more flexible (no kidding, right?), but if you plan on any astro work, you'll be better off with the 8mm. For over/unders, the 8mm also had the advantage when used in my 170mm dome. I can't speak from experience, but I'm guessing it would be a wash between the 8mm in a small dome and the 7-14 in a big dome. Someone on here (or maybe Scubaboard) was kind enough to share a Lightroom profile for underwater shots with the 8mm that works great. Otherwise, there's a lots of defishing options out there. For topside, I use the built in LR profile for a Nikon fisheye (can't remember which one off the top of my head), and that works well for most things.

I have the 8mm, and used to own the 7-14 until I sold it in favor of the Panasonic 8-18. The zoom is a little more flexible (no kidding, right?), but if you plan on any astro work, you'll be better off with the 8mm. For over/unders, the 8mm also had the advantage when used in my 170mm dome. I can't speak from experience, but I'm guessing it would be a wash between the 8mm in a small dome and the 7-14 in a big dome. Someone on here (or maybe Scubaboard) was kind enough to share a Lightroom profile for underwater shots with the 8mm that works great. Otherwise, there's a lots of defishing options out there. For topside, I use the built in LR profile for a Nikon fisheye (can't remember which one off the top of my head), and that works well for most things.

Thanks for the advice! What kind of housing do you have? Do you know anything about the 140mm nauticam glass dome that fits the 8mm?

I use the Olympus housing, so unfortunately I don't know much about the mini-dome; just thought I would chime in as someone who's played with both lenses...

I have the EM1 II in a nauticam housing, don't have the fisheye, Use the 7-14mm Pany in a Zen dome. You might want to also consider the Zen dome options:

http://www.jaredparsons.com/portchart/zen-only/by-combination-group/nauticam-n85/

You can use the Pany 7-14 in the same dome as the Olympus fisheye, but the Olympus and Pany 7-14 & 8-18 need the N120 dome due to the large diameter. This dome will also allow you use the Olympus 12-40 which is a nice mid range lens, I use it quite a bit in temperate waters around Sydney.

If you look at the port charts for Nauticam they say that the 140mm dome is the most optimised dome for either of the 8mm fisheyes.

https://drive.google.com/file/d/0BzggKvdoNvhkRlZhNTdLZzRIeXc/view

Ah. I've looked at the Zen ports, and I like the 170mm dome, but I have a question--for the Oly 7-14 2.8, the zen chart says I can use a 170mm dome, but I need the "Nauticam N85 to N120 60mm Port Adaptor"; so, the 170mm dome that is compatible with the 8mm FE is different from the 170mm dome that requires the port adaptor? Or does that just have to do with the size of the 7-14 fitting through the housing? This may be a stupid question...

No unfortunately they are different domes, a limitation of the diameter of the Oly 7-14. The N120 dome is for DSLRs and has no extension, the the N85 dome has 30mm of built in extension, the type II has 60mm extension built in. I seem to recall someone on this site was talking about having had someone make a custom 30mm N85-N120 adapter, but of course that can get expensive and you need to have someone with the skills available.

The 30mm N120-N85 adpater costs 390 Euro - not really expensive:

https://www.unterwasserkamera.at/shop/catalog/de/product_info.php?info=p6901_d-d-nauticam-n85---n120-portadapter-30mm.html

Wolfgang

Hi Morgan,

I have the EM5MII in Nauticam housing and use the Oly 8mm FE and the Pana 7-14mm with Zen-DP170-N120 with 60mm (7-14mm) and 30mm (8mm FE) extensions. I cannot say how the lenses would perform in different domeports, but can compare them in this situation.

Image quality is almost no comparison between the two - the 8mm FE is much better in sharpness, especially in the corners. In addition, when coming close to the subject, I prefer the FE distorsion to the distortion produced by the rectilinear lens (it is actually no distortion, but just an unusual perspective, resulting in e.g. "egghead" of a diver). Whenever possible I use the 8mm FE, its my favorite WA lens. Many creatures, however, do not allow to come so close that the FE is the right lens. There the 7-14mm is the lens of choice, although image quality is not so good…

• You see it is not a question of 8mm FE OR 7-14mm WA, the two lenses are complimentary and you will want both sooner or later...

• If I would now acquire a new WA, I would go for the Pana 8-18mm that Wapiti is using, no need really for 7mm (for such wide angels the FE is superior), but sometimes it is certainly good when you can zoom out to 18mm instead of 14mm…

The lensprofile for the Oly 8mm FE is here (there is also a profile for the Pana 7-14mm, but I use it seldom):

http://wetpixel.com/forums/index.php?showtopic=60426&do=findComment&comment=386534

Wolfgang

The 30mm N120-N85 adpater costs 390 Euro - not really expensive:

 

https://www.unterwasserkamera.at/shop/catalog/de/product_info.php?info=p6901_d-d-nauticam-n85---n120-portadapter-30mm.html

 

Wolfgang

I did not realise it was a commercial product I seemed to recall it was a custom item. Obviously this is a better way to go than a whole new dome.

Don't forget you can't directly compare focal lengths, and 8mm fisheye has a 180° filed of view and the 7-14 is 114° diagonal at 7mm and the 8-18, 107° at 8mm. Probably not a big deal in field of view difference between the Oly and Pany options.

 

Thanks for the advice! What kind of housing do you have? Do you know anything about the 140mm nauticam glass dome that fits the 8mm?

The Panasonic 8mm fisheye behind the Nauticam 140mm glass dome does slightly vignette, as indicated in the Nauticam port chart. I have the Olympus em1-mkii. Because vignetting only happens on certain shots I think it has to do with the in-body image stabilization. I noticed it was more visible when I moved the camera around quickly. Like in the un-cropped example below when I quickly looked up to and saw this pup with it's mouth open.

I recently upgraded to the Olympus 8mm Pro fisheye and added the 17mm extension ring. Based on only a few test shots in my living room, the only time that the dome shade was visible was when I very rapidly swing the camera up or down when taking the shot. It is much less visible than with the Panasonic 8mm.

Here are some thougths on the domeport to buy:

=> For the 8mm FE one needs theoretically a full hemisphere (or even a bit more of a full hemisphere) as the diagonal angle of few is 180^o. This is because the entrance pupil of the lens has to be put at the center of radius of curvature - this distance is:

r=50mm for the Zen DP-100

r=70mm for the Nauticam 140 port

r=110mm for the Zen DP170

r=110mm for the Nauticam 180

r=110mm for Zen DP200 (this domeport is no longer available)

The larger the radius, the further away from the camera and the bigger the virtual image produced by the domeport is and hence the better the image quality.

The saying is, however, that FE lenses tolerate much more malpositioning in this respect as rectilinear lenses do. I cannot directly compare, but I do not see a obviously worse image quality in my images (Oly 8mm FE with Zen DP170) than in e.g. in the image shown above by matrixed82. But of course who knows how the performance would be if compared in a rigorous test?

(such real test, by the way, are lacking - there are many reviews and the bottomline is always "gorgious (buy, buy, buy...")

=> What domeport now for a rectilinear WA lens?

As CrissCross points out, the angle of view of these lenses is considerable smaller when compared to FE:

7mm: 114,2^o

8mm: 107,0^o

^{9mm: 100,5o}

10mm: 94,5^o

The larger the radius, the better the image quality is finally. Therefore there exist relatively large domeports that are smaller sections of a sphere than a hemispehere, such as Zen DP170 or Nauticam 180. Depending on the diameter of the port, the largest angle of view that is possible without vignetting is:

Zen DP170(r=110mm; d (diameter of the port)=170mm): 101^o

Nauticam 180 (r=110; d=180): 109,8^o

Zen DP200 (r=110; d=200): 130,7

Of course I do not have vignetting at 7mm with the Zen DP170, but this means the positioning of the lens is not correct when using the 60mm extension (and if the correct extension would be used, there would be vignetting, of course).

=> Again I must say I have no idea how much this mispositioning (both for 8mm FE and Pana 7-14mm) worsenes the image quality in real life (as no real comparison tests on this issue are available).

=> In case I would buy lenses and domeports now (I started a year ago and did not know about these problems then), I would go for Oly 8mm FE (1st prioritity), Pana 8-18mm (2nd priority) and Nauticam 180 with appropriate extensions. Later I would add the Zen DP100 to my gear, because this port allows to get closer to the object than the larger diameter ports do (I will buy this smart little port sooner or later).

=> There is an additional problem: the companies do not say how much mispositioning is when using their recommended extensions (of course it is easy to calculate that correct positioning at 7mm is impossible with the DP170)

- therefore the larger diameter does not automatically lead to better results, it also depends on the extension...

=> A last word on image quality with rectilinear WA lenses: The differences in IQ are minimal between the Pana ad Oly 7-14mm (see e.g.: http://www.photozone.de/m43/961_olympus714f28proand http://www.photozone.de/olympus--four-thirds-lens-tests/530-pana_714_4). I could not find a real test of the Pana 8-18mm so far. The larger aperture of the Oly may be better for the AF, but one must close aperture to minimum 8.0 to get reasonable results.3

A fact is also, that UW the domports eats up so much of the IQ of a lens, that these parameters are probably not relevant for using the lens UW in domeports.

Wolfgang

To clarify further there are two problems.

First get the lens at the correct position with the entrance pupil at the centre of the radius of curvature. Sounds easy but where is the entrance pupil? I've seen references say it is where the iris diaphragm "appears to be" others that it is where the no parallax point is for the lens, the first one is a bit vague and the second a bit difficult to measure. This impacts on refraction, this link shows the problem: https://oceanity.com.au/tools/dome-port-positioning/

Second issue is the positioning has to be such that when condition 1 is met the metal frame of the dome does not appear in the image.

In practice port vendors do some guesstimating then try the lens with various configurations from their standard parts bin and make some recommendations and Nauticam often indicates the most optimal dome port.

Regarding Fisheyes I think Wolfgang is not quite clear on the issue. On a rectilinear wide angle the lens is projecting a flat surface onto a flat surface but is confronted with a curved virtual image in a dome port and you need to stop down to bring that edge into focus as it is significantly closer to the camera and the fact the virtual image is very close makes this harder. This is more sever for the wide end as you are trying to image a larger segment of the hemisherically shaped virtual image and the corners are progressively closer to the sensor as you go wider.

On the other hand a fisheye does not try to project a flat surface onto a flat surface , rather it uses a different projection to project a hemisphere onto a flat surface. In any case it does not make sense to consider projecting a flat surface that is 180° in extent onto anything as it is physically not feasible as the 180° surface would need to co-incide with the plane of the entrance pupil. Because the fisheye is designed to project a spherical image onto a flat surface it is effectively purpose designed to project the hemispherical virtual image of a small dome onto the flat sensor and the design also focuses very close which helps. Fisheyes will generally focus on the port surface. You still need to stop down to overcome other aberrations but in general it is a loss less troublesome. I believe it still needs to get good positioning under option 1 so you don't get refraction as the extreme corner rays pass the dome at something other than perpendicular to the surface if the positioning is not right. Bigger domes are a little better it seems but small domes are nowhere near the penalty they are in rectilinear.

I think what happens with the DP170 is in spite of being less than a 180° segment of sphere the positioning of the entrance pupil is such that even when it placed correctly it is far enough forward in the dome that vignetting does not occur.

Having said all that there is not choice other than to take the manufacturers recommendations, With the lenses I have they seem to work well. Getting back to the OP question:

It is probably not either or for the 8mm vs the 7-14mm, but for over-unders the bigger dome will be better. Whether you put the FE or wide angle in there really depends on what you are shooting UW. The FE is all about getting in close and shooting big reefscapes and probably very large animals like whale sharks as well, though the 7-14mm at 7mm was too wide for the 3-5m whale sharks at Ningaloo when you were at the regulation 3m distance and as noted above zooming in to 14mm is not a huge difference. Whatever you shoot with it would need to be quite tolerant or unable/unwilling to swim away. For example some people shoot weedy sea dragons with them, they are slow enough that you can get very close if you are patient.

The 7-14mm is more likely to work well for sharks, sea turtles and other things you can't get super close to, CFWA premise is you are mere inches away right on top of the reef you are shooting. If you want the flexibility to shoot both then the way to go is N120 dome with adapters including the custom 30mm adapter for the FE.

I'm a bit of a generalist and in Sydney's temperate waters I find the 12-40mm olympus most useful for shooting fish in the size range of 10mm to 1m or so as well as things like weedy sea dragons. I quite liked it at Ningaloo Reef as well. As luck would have the 12-40 works with the same dome and actually fits through the back of the housing.

Again very interesting what you say here, Chris.

I never measured the nodal point by myself as I prefer going diving, as most of us (but I may in case I order another coustom made extension in the future), but it does not seem to be very difficult. See e.g. this 3:30 video at youtube:

So there seems to be one opinion about the first choice recommendation for the domeport (questionmarks I put where I cannot tell from hands-on experience by myself):

Big, non-hemispherical port for both lenses: Good for over/under shots, only one port for both, (almost?) no loss in image quality for the FE. Later a small hemispherical port in addition for the FE (as Zen DP100), optimal for CFWA but not so good for over/under, same IQ as big port (?).

The bigger 180 Nauticam port may be the better choice to purchase, as the correct lens positioning (mostly important for rectilinear WA lens) is better possible, especially with the 8-18mm WA (who knows whether it is in fact with the recommended extensions from the companies?). At least Phil Rudin stated in a post monthes ago that he has recognizable better results with the DP200 compared to the DP170, when using one of the 7-14mm WA lenses.

As Chris is saying, one can even use the Oly 12-40mm with the same domeport, I also have it, IQ is outstanding, I personally use this lens regularily for night-dives...

Similar situation with the lens choice:

The question is not whether FE or rectilinear WA, as the angles of view are not even overlapping. Both are complementary to each other, usage depends on motifs and also on personal taste.

Question whether 7-14mm or 8-18mm remains, I tend towards the 8-18mm: one looses 1mm of wideangle (that gives the worst results in IQ, however), but gains 4mm to zoom out. Maybe one gains also some IQ, maybe Wapiti can say something about this, he was using both 7-14mm and 8-18mm with the same port (but only direct comparison at 8mm for both lenses is fair).

=> I personally will not change my gear according to the recommendations above for shure, as the differences are small and I invested a lot of money (and the IQ and the fotografic capabilities are outstanding). This is just what I would acquire now, at the moment in case I had to do...

Great forum here, I learned a lot since joining!

Wolfgang

Yes by difficult I mean I really don't want to do it!

Yes you will get some advantage with the bigger dome but it mostly confined to the corners when at 7mm and the corners improve as you zoom in. The small size of the dome and multi use for travel wins for me.

Per Wolfgang's mention above...

Image quality of the 8-18 is noticeably better in my Inon 170mm dome than the Oly 7-14 in the same port. To be honest, I haven't shot the Panasonic underwater as much as I would like; most of my shooting is in mediocre viz so the 12-40 is my go-to lens and the wide angle stuff only comes out for special occasions. That said, I have no reservations about recommending the 8-18 over the 7-14. Topside, the 7-14 is maybe a little sharper, but the ability to use filters makes the Panny an all around better choice (for me). I still have the Olympus 8mm FE, but will most likely not use it that much underwater as the 8-18 does everything I need.

Also, one other note is that Nauticam does have an adapter to use the old 4/3 ports with their M4/3 housings; the Inon dome is a lot cheaper than options from Zen or Nauticam, so this might be worth pursuing.

This shot is probably one of my favorites with the 8-18; it was taken at Clear Lake in Oregon.

The main attraction to Clear Lake (apart from the fact that it's clear) is the 3,000 yr old sunken forest created when a lava flow dammed the McKenzie River

This shot has no redeeming qualities except that that if you look close the sun isn't entirely round. Clear Lake was in the path of totality during the last eclipse so I set up my rig underwater on a tripod in an attempt to get a time lapse. It didn't turn out too great, but it was an amazing experience nonetheless.

Split in Clear Lake with the Oly 8mm FE. Viz was about a quarter of what it was during the eclipse weekend where I got the other shots, and I believe this was at f5- it would have been better stopped down a bit more. Also, if you're curious- water temp at Clear Lake is in the upper 30's year around. The snow on the ground didn't help...

Split with the 8-18 taken during our local dive community's breast cancer fund raising event. Viz was 4-6 feet, but it shows that splits are possible with this lens/port combo...