When compact cameras were designed for 35mm it was quite common to shoot just with a camera and strobe; this allowed the average user to take decent close up pictures as long as the camera was capable of focusing within a couple of inches from the subject.
Years later manufacturers started introducing wider lenses first came 28mm equivalent and most recently 24mm, these cameras give an increased field of view on land of 75 and 84 degrees diagonal.
There is a common misconception that as the camera has a wider lens you don’t need to buy a wet lens for underwater activities. This is also reported in otherwise good articles like this one: http://www.scubaboard.com/forums/tips-techniques/46508-getting-started-amateur-underwater-photography-buying-your-first-camera.html
So why is it a bad idea to shoot just with the bare camera and no add-on lenses?
Two key reasons:
- Once in water the 84 degrees diagonal of a 24mm equivalent camera reduce to 54 or less because of the water medium
- At focal lengths shorter than 35mm pincushion distortion becomes stronger to the point the pictures are awful.

So if you plan to use your wider compact camera underwater without lenses make sure you zoom to 35mm to avoid distortion.
This is the same picture at 35mm note how the image is now rectilinear.

At 35mm we are back were we were in the mid 2000 and all we can do is close-ups so there is no advantage having a wider lens for underwater use with a compact.
Another common misconception is that a compact camera takes great macro just with the internal flash. Firstly a macro picture has a 24mm height of the capture area, nearly no compacts on the market are capable of this: the Panasonic LX7 and the Canon G15 within the current range are the exceptions. However at 1cm distance the internal flash is completely obscured by the lens, which means there really is no macro without a strobe and a close up lens: all you can shoot are close-ups.

This explains the need for wet lenses in water, wide-angle lenses to increase the field of view and allow us to get closer and take advantage of artificial lighting, close up lenses that also allow us to get closer using the full zoom of the camera and shoot at increased magnification without being on top of our subject.
The needs of photography and video differ as lighting tools differ, photos require strobe to freeze motion, video instead uses fixed lights. Photos are also taken at much wider angle than videos and fisheye effect is accepted, an effect that in video is generally not welcome.
With this in mind what are the wet lens options for the Panasonic LX7?
It depends of course on the planned usage of the camera.
Underwater Photographers
The LX7 has extremely good close up capabilities out of the box, however the capture area is around 12×8 cm that is not exactly small. If we want our nudibranch of shrimp to fill more of the frame we need a close up lens.
From my tests the Inon UCL165 brings around 2.5x magnification with the LX7.

I have tried stacking two UCL165 but the amount of chromatic aberration is too much for my liking, I found that 9 diopters is the max before fringing becomes a real problem and I do not recommend stacking two of those lenses or two equivalent Dyron diopters. I think the most flexible set up is a UCL165 and UCL330, this covers all possible working distances. I do not have a UCL330 yet so I can confirm but I have taken shots with a very similar lens (Olympus PTMC-01) and the results are excellent with a capture area of 48×32 mm that is very close to real macro. The zoom of the LX7 is the real limit here as it maxes out at 90mm versus the 120 of a Canon S110 or 140 of the Canon G15.
For close focus and ambient light wide-angle the bad news is that there is no fisheye lens that works well with the LX7 this is due to the extremely large lens.
I have tested the Inon UWL-H100 and I had to wait for a new port to be delivered from Nauticam as their original one was too long and had vignetting even at 28mm. This lens yields more than 100 degrees diagonal and is my preferred choice for the LX7 for stills. There is however a good amount of blue and yellow fringing if I really have to be picky so the extended field of view comes at some price.

I use Inon lenses however a possible candidate is the Epoque DCL30, this lens is reported to work with 28mm equivalent cameras however the rear lens is smaller than the Inon so I believe this needs confirmation. There is a $70 difference in US and £70 here in UK between the two lenses and considering that a dome will not worth I encourage testing this lens as the results may be acceptable. I think bluewater photo markets this lens in US under their own brand.
Underwater Videographer
If you plan to use the LX7 for video the situation is different, as the camera close up performance is extremely good and usually macro video is very hard. Most time we shoot with ambient light and if visibility is acceptable getting that close is not so important considering the LX7 ability to manipulate white balance.
The first suggestion is to get a Nauticam Wet Mate, this is a sealed air dome that gives us back the air field of view and works extremely well without any chromatic aberration and extremely sharp corners. This lens keeps the image rectilinear that is also a good thing for video.

For majority of reef dives the wet mate is all is needed as this also allows the full use of the zoom without soft corners that occur if you zoom into a wet wide-angle lens. This lens is the most versatile for general video use and costs $250, great value from Nauticam.
There are however specific situations where the wet mate is not sufficient, as before close up performance with the bare port is good but not great for smaller critter, so a close up lens would be the next addition, again an Inon UCL165 or a Dyron Double Diopter would work just fine and have the same power.
When shooting at closer distance with lights, or when there is large fish or wrecks a wet lens is important as the 84 degrees diagonal of the LX7 are actually only 76 horizontal. Again the Inon UWL-H100 is my choice but would check again for the Epoque DCL-30. One characteristic of the LX7 that is interesting is that the diagonal field of view of the camera remains constant when picture format changes, this means the horizontal field of view is larger at 16:9 movie mode than it is at 3:2 for pictures.
Field of view with the LX7
Those are the maximum angles of coverage horizontal of the LX7 as I measured them at 3:2:
- Bare Port 24mm: 50°
- Wet mate 24mm: 71.5°
- Inon UWL-H100: 88°
At 16:9 there is a wider field of view of:
- Bare Port 24mm: 54°
- Wet mate 24mm: 76.2°
- Inon UWL-H100: 93°
In general terms with the wet mate we can cover 1.56x the horizontal field of view of the flat port and with the wide-angle 2.1x.
The wide-angle offers an additional 35% over the wet mate don’t be mislead by the apparent small difference between 84° and 100° as those are diagonal measures not horizontal and those few degrees more count.
At 1 meter distance the maximum subject size with the wet mate in movie mode is 1.56 meters and with the wide-angle this becomes 2.1, that confirms that the wet-mate is good for general use and the wide-angle is only required for close scenes of larger fish or wrecks.
Those are the three lenses I have used for those tests. A final consideration is about the lens mount. I will use the LX7 for video so my choice has been a 67mm mount, because this is the only format that the wet-mate offers.
If I was using the LX7 only for pictures I would prefer the flexibility of the Inon LD mount even if this costs a bit more as it makes it so much easier to swap lenses in water when you have a bayonet mount.
Thank You for this great information.
Mike Phillips
Thank you for your very informative blog. It has been pleasure reading it. I am really struggling with my choices and I would really appreciate some advice from you.
I have never done any underwater photography or videography. I have a Nikon D7000 which is great topside but it is too expensive to get the gear to bring it underwater. In addition, I am looking to do more video than stills and the D7000 is horrible. My shortlist has come down to:
1. Panasonic GH2 hacked – great value nowadays but I can’t find a housing (Nauticam stopped them). Do you know anywhere where I can find a housing?
2. Panasonic GH3 – seems great but very expensive to get the whole setup;
3. Sony RX100 – I was wowed by the quality of images and video seemed excellent too but many people complain that it is a pain to use and too complicated. I have noted your detailed analysis which highlights the critical drawbacks. I don’t know if for a newbie videographer like me, it would be too much to bear. On the other hand, it would be great to use for stills as well (unlike the GH2) so I was wondering how easy it is to deal with the issues?
Panasonic LX7 – so far it seems that you are veering towards it for video. Have you made any tests since your last blog? I am very curious and for the price it may well be the best option. I would really appreciate more info and advice on this camera.
I have also heard some good comments about the Nikon D5200 but it’s a bit too soon and I still think my dream to have the ultimate stills/video camera in one (you gathered I am a Nikon fan) is still some years away. Today at LIDS I had a chat with Ocean Leisure Cameras and Cameras Underwater and both recommended the Canon S110 as a simple to use with great results. For stills maybe but for video I’m not quite certain it has the results. What are your thoughts? Also what about the G15?
So, it looks like it’s narrowed down to either GH2 if I can find a housing or either RX100 or LX7. If I could afford it it would be GH3 but sadly it’s not an option at the moment and I think it’s wiser to get something cheaper and get some experience shooting video so that in a couple of years I can get a better setup.
Your advice would be most appreciated.
Many thanks.
Kind regards,
Peter
Peter
The cameras you are considering are very different and this requires some consideration.
First let me clear the issue of the Canon S110, this camera has no manual video control the quality is excellent however battery life will not allow for two dives. The limitations on exposure control are significant but can be partially overcome. It is an easy to use device however if video is your main focus not the best choice. The G series do not offer ambient light wide angle lenses so that is a no go for video too.
The other 3 cameras are different. The GH2 is a system camera with changeable lenses. If you are happy with that is the best in terms of optical quality and there are excellent examples of video. 10bar makes an housing for it, you can find it probably directly or via Germany. The rx100 is a compact with fixed lens probably the best compact for stills and takes terrific video. There are some annoyances but nothing that cannot be overcome. The lens support is great as it takes fisheye however it will require many lenses swaps in water as close range focus performance is not very good. The rx100 has also a large sensor and it is more difficult to use than a canon s series bit the video program mode is perfect easy to use with plenty of additional controls if you need manual exposure. The lx7 is a camera with a traditional 1/1.7″ sensor with a very bright lens and extremely sharp image. Works very well just with a mini dome and you can still add wide angle or diopters for specific needs. I have only tried it in the pool and it is obvious that it is the camera that is more oriented to video. I have compared shots with the rx100 and as in video you shoot only 2 megapixels resolution there are no benefits of the Sony larger sensor as the lx7 has 2/3 fstop brighter lens so can operate at lower ISO. I am now in grenada hopefully I will post some videos with this set up in the next weeks. So far I am impressed but the real proof is in the ocean dives
Thanks for your comments. I can’t wait to see your footage with the LX7. Regarding the GH2 I don’t know much about the 10bar housing. How would you rate it compared to Nauticam? I managed to find a US seller for the Nauticam housing but at $2100 it’s a bit steep. The LX7 looks like much more affordable option and I will wait to see your experience with it.
I suppose the RX100 could be OK but given that it struggles with macro, it’s a big negative for me. Great sensor but not so great lens. If only they combine the Sony sensor with the LX7 lens 🙂
The rx100 does some fine macro once you have the right close up lenses. I guess the issue is that you need a +6 for super close up work and another +6 for macro because the capture area is rather large. I also found myself working a lot with manual focus on the smallest subjects. With the LX7 a single +6 diopter is sufficient as the capture area is small and in video mode the intelligent zoom is effective with little artefacts. The camera also manages to work with autofocus very promptly. I am at day two of diving here in few days I will have a better impression so far the results are really promising
I was wondering if you have had the chance to look at the Nikon D5200. With the new Toshiba sensor it is getting some rave reviews. I saw a test against the GH3 and the Nikon was so much better.
http://www.eoshd.com/content/9653/nikon-d5200-review
What are your thoughts for underwater use if you have had a look at it? The rolling shutter skew worries me a bit.
The 5200 is DX SLR my whole setup is based on compacts so I don’t look at cameras with changeable lenses.
This is because am only focussed on video and I work trying to replicate a situation where you can do macro and wide on the same dive. Sure the quality of system or DSLR is superior but the flexibility is reduced so not for me really
I see. I can’t wait to see your comments on the LX7. One more question I have is regarding the lenses. Why should we get the Nauticam wet mate and the Inon UWL-H100 (which is needed for larger objects)? Surely if we buy only the Inon it’s going to do the job for wide angle.
Is there merit in spending money for both?
Also, what about the Inon UWL 105?
I am not suggesting to anyone to get both lenses. The wet mate has a narrower field of view however it allows zooming, essentially is like using the LX7 on land. For most people this single lens is sufficient for most cases. A close up lens is needed for smaller subjects. The Inon UWL-H100 is more challenging to use and does not allow zooming. I will cover the differences and drawback of both lenses in more detail when I am back from my trip. Some sample footage is here http://vimeo.com/62838598. The UWL105 does not work at all with the LX7 because the lens of the camera is too large. None of the AD lenses work with the LX7
Your extensive testing of these particular compacts has been of great help in deciding on a new camera setup, especially relating to the LX7 and lenses which is what I decided to get. Thank you.
Glad you find it useful
If you want to buy the inon lens I recommend the LD bayonet
I will post another blog soon to compare m67 vs bayonet for that specific lens
For now I just got the Nauticam wetmate and a UCL165 (M67) which were under $400 and as you say should cover the vast majority of video I will be using it for, reef dives and some close ups. Perhaps later I will look at spending another $1000 on the Inon WA + dome and going to bayonet mount.
That’s a good start and the wider lens is only needed for close encounters with sharks and for wrecks
Have fun and keep us posted look forward to some videos