Tag Archives: Canon S120

Snell Windows with your compact camera

Snell’s window is a phenomenon by which an underwater viewer sees everything above the surface through a cone of light of width of about 96 degrees [From Martin Edge: Underwater Photography].

During my last Gapapagos Trip there was a bit of an issue in terms of photography subjects, in essence most of them were fairly big like sharks, turtles, eagle rays and of course divers.

After a while shooting or trying to shoot those uncooperative models I had the idea to try and do different things such as silhouettes and Snell windows. You can also combine both as we did in this case.

So what do you need to shoot image of a Snell window:

1. A lens that is wide enough, you need a bit more than 96º field of view to take the whole window

2. Something interesting on the surface (if you have calm water you can see right through)

3. An interesting subject as silhouette to contrast the clear water if there are waves and you can’t easily see through.

A normal flat wet wide angle lens for our compact camera is not sufficient to capture the snell’s windows as in this example

Safety Stop
Divers at Safety Stop – taken with Inon UWL-H100 at wide end

Take into account that even with a fisheye lens on an SLR you can’t capture the Snell’s window on the vertical axis as the field of view will fall short a few degrees.

With a compact camera a semifisheye lens will capture the edges of the window if correctly aimed on the diagonal and horizontal dimensions and will fall short on the vertical.

Snell to boat
Snell window divers exiting the water or ascending – UWL-04 semi fisheye lens Canon S95

I am reporting some of the calculated field of view for the most popular lenses at present for compact at 3:2 image format

Wet Lens Diag FOV Hor Fov Ver FOV Flare/Ghost
UWL-04 151.95 123.22 79.85 Ghost Possible
UWL-100 28AD 149.01 120.97 78.48 No
UWL-28 160.56 129.75 83.81 Both
UWL-H100 157.85 127.71 82.58 No

 

All those lenses will take a good Snell’s window I have not tried the UWL-28 and I have some concerns this lens may flare as it usually does but I do not know for sure.

Both the Inon lenses produce sharp images with no defect.

In general small sensor cameras like the Canon S series will work fine with the fix/idas lenses and should produce good results also of normal shots through the water.

Using the UWL-04 or UWL-28 with large sensor cameras like the RX100 there could be a sharpness issue a larger apertures so make sure you close that at f/8 or smaller instead of using the shutter speed to balance exposure if you want to go through the water.

Snell’s windows are uncommon with compact camera shooters as they are considered an advanced subject but they can be taken. I will be taking more in a next trip to Egypt I hope for calm surface conditions so I can go through the surface with the shots. Failing that this is very easy to practice in a swimming pool.

Have fun shooting snell’s windows!

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2014 Compact Camera for Underwater Photo & Video Round Up

After the various Backscatter, Bluewater photo, and other shops compact cameras reviews I thought of putting my 10 pence in as well.

Most of those reviews you find are written by people who shoot DSLR and then occasionally go and take a compact in water to see how it goes. For what concerns underwater use I only shoot compact and I believe I know how to navigate into features and limitations of compact camera quite well so here is my view on the subject.

The first hint when you look at a high-end compact camera is to check if Nauticam makes a housing for it. If not maybe your camera is not as good after all. There are some exceptions of course.

Categories

I have ranked compacts according to the following shooting categories:

  1. Movie
  2. Ambient Light
  3. Macro
  4. Portraits
  5. Close Focus Wide Angle
  6. All purpose cameras

When possible there will be a top 3 in each category.

The Compacts

I have considered only the following cameras

  1. Canon G16
  2. Canon S120
  3. Olympus XZ-2
  4. Panasonic LX7
  5. Sony RX100II

The Fuji X20 is a potential addition but I have not found anyone that actually shoots it underwater so I abstain from judging here.

Best Cameras for Movie

In order to score in this category the cameras need to have full manual exposure control in movie mode and be able to shoot double frame rates for the system of choice PAL or NTSC.

This is my appraisal:

  1. Sony RX100II
  2. Panasonic LX7
  3. N/A

Canon cameras do not offer exposure control in movie mode, Olympus video is pathetic. Not possible to even consider a number 3 here.

Best Cameras for Ambient Light

1st Cave@Jackfish Alley

Here I consider shots without strobes with a view angle of 100º diagonal you need a wet wide-angle lens to take those shots.

Here are the rankings:

  1. Sony RX100II
  2. Panasonic LX7
  3. Canon S120

Olympus lags behind in image quality and the Canon G16 does not have any wet lens that allows to take those shots without strobes.

Best Cameras for Macro

P1000463-.jpg

I am looking here at shots are real 1:1 reproduction ratio and how easy is to take those shots in terms of autofocus and depth of field. In order to achieve this level of magnification a close up wet lens is necessary for all cameras. No compact camera achieves real macro with the bare port underwater.

Here are the results:

  1. Canon G16
  2. Canon S120
  3. Panasonic LX7

The Canon G16 in virtue of a 140mm focal length at telephoto end gives the highest magnification ratio, the Canon S120 follows closely same image quality less magnification. The Panasonic LX7 has only a 90mm equivalent lens however the autofocus is incredible so you can use +10 diopters very easily and it is the only camera to really offer Bokeh.

The Olympus XZ-2 lags in terms of image quality, the RX100II has great image quality but little magnification, you need a +10 diopter to give a 1:1 reproduction ratio and focus is difficult because of shallow depth of field due to the large sensor.

Best Cameras for Portraits

Look Right in

Here we are considering shots with the bare port at 35mm focal length using strobes. Here is the ranking:

  1. Sony RX100II
  2. Panasonic LX7
  3. Canon S120 & Canon G16

Whilst the RX100II has the best image quality it comes a bit as a surprise why the LX7 gives better images than the Canon. The reason is that Canon tend to have a very unbalanced color range with over saturated red. This does not go away with RAW images as it affects the whole spectrum. It is possible to correct this using blue diffusers for strobe but this is just a patch, the LX7 tend to give much better balanced images.

Best Cameras for CFWA

Side Shot

Close focus wide-angle is shot with a fisheye like lens, using strobes typically at small apertures here are the rankings:

  1. Sony RX100II
  2. Canon G16
  3. Canon S120

It is quite clear that the RX100II with the widest choice of fisheye lens and the highest dynamic range is the best camera for the job, but the addition of the Inon Zoom lens helps getting the G16 in this category, the S120 follows with similar results. The LX7 does not offer a fisheye options sadly and the XZ-2 lags behind in image quality compared to the two canons.

Best Versatile Still Cameras

Here I look at cameras that can shoot all type of shots from macro to ambient light.

  1. Sony RX100II
  2. Canon S120
  3. Olympus XZ-2

The lack of fisheye options cuts out the LX7 and the poor performance of zoom wide-angle lens at wide end kicks the G16 out.

Best Overall Camera Still and Movie

Taking the previous list and eliminating the cameras that do not offer exposure control in movie mode this is the result

  1. Sony RX100II
  2. NA
  3. NA

So the Sony RX100II is the only real all round camera and this explains why it beats the other in terms of sales.