Category Archives: Stabilization

Underwater Video Tips: Best video settings for Panasonic LX7

I thought of doing a debrief of the settings I use as I see few people that have bought this camera and have few niggles to go through and the obvious learning curve of new equipment so here we go.

Which Video Setting

It is always possible to reduce detail if needed so always shoot in the highest mode AVCHD progressive that in the menu is called PSH this records at 28 Mbps.

Which Mode to Use for Video

The LX7 has a one touch video mode that is accessible in still mode. When you press this button, even if the camera is in Aperture or Shutter priority and even in Manual, the movie clip is recorded in Program mode.

It follows that the mode to use to have full control is the creative video mode accessible through the mode dial.

Standard Setting for Creative Video Mode

I use the Shutter priority setting submenu in this mode. This is because the LX7 does not follow the 180 degrees shutter rule in video program mode.

Set your shutter speed to 1/100 for PAL and 1/125 for NTSC so that your shutter speed is double of the frame rate (1/50 for PAL and 1/60 for NTSC).

Exposure Lock Button

I never use the manual or the aperture priority mode as I find the lens fairly sharp even in macro and very small subjects. When I have changing light I point the camera to the exposure I want and the click Exposure Lock. To disable focus lock you need to go into the menu and set the button to AE lock only.

Exposure Control

I personally find the standard exposure of the LX7 underwater far too bright. So using the exposure compensation dial found by pressing the shutter speed wheel I dial down to -2/3. This is personal sometimes I even go down to -1.

ISO and Max ISO

The LX7 has a very bright lens even at telephoto end and this lens produces also a very sharp image. In the worst case of deep water with low light I found that having an underexposed but cleaner picture at ISO400 is better than letting the camera go all the way to high ISO. So in the menu I set ISO MAX to 400 or in some cases I push this down to 800. I set the ISO to Auto as the camera generally keeps it very low anyway.

Autofocus

I leave autofocus for video mode to on and I ensure that the autofocus is set to single area. Be careful as the default setting is face detection and that does not work well underwater! Multi area and tracking are not available in video mode.

Zoom

In video you can extend the 90mm lens to 180 with the iZoom and to 360mm with digital zoom. I set iZoom to on and Digital zoom to off as I have seen that the iZoom is very useful in macro and the picture quality is not visibly affected.

Metering Mode

I use multi metering for landscapes and centred weighted for close ups and macro.

iDynamic

This is a tricky setting; generally I keep it off or on Low as the standard settings clip the highlights. In doubt turn it off.

Photo Style

This setting controls contrast, sharpness, saturation and noise reduction. I use the standard setting that is a little bit oversaturated. If you do a lot of colour corrections in post processing use the Natural setting. The footage will be less saturated and a bit less sharp with less noise reduction.

White Balance

I use two custom settings WB1 and WB2 one for shooting with ambient light and the other one with lights that I only use in special circumstances.

Stabiliser

I leave this on and it does not affect the field of view.

Zoom Resume

Zoom resume has to be left off as this delays the camera ready to shoot time and ends up with missed opportunities.

Menu Resume

It is useful to leave this on.

Custom Menus

I record all my settings for shooting in ambient light in the C1 mode this has all the settings are describes and recalls the Custom White Balance 1.

I then set another menu C2-1 with auto white balance for shooting with lights and menu C2-2 for shooting with lights and WB2.

This is an example video shot with those settings and no additional lenses this is with video lights and auto white balance little to no correction in post processing.

This other video is with some grading applied and ambient light for most

I hope you found this useful and happy shooting!

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Tips for Underwater Video – Tripods and Monopods

First of all I have to thank Mike on Scubaboard to get this in motion the original post is here

When you shoot macro and operate at high magnification even the smallest movement translates into shake, let’s think about it for one moment.

A macro image will have a frame size of 36×24 mm, this means that a move of half centimeter or 1/5 of an inch is equivalent to 20% vertical movement a considerable annoyance. When you shoot a picture this is not an issue because with a very high shutter speed you can freeze motion and there will be no blur like in this image.

Pygmy Seahorse 1.5 cm
Pygmy Seahorse 1.5 cm

Trying to take a video of a moving subject like this proves challenging, and you need to slow down the footage to avoid sea sickness like here

So how do we get outstanding macro footage? We need to be super stable and avoid any type of shake.

One possibility is a tripod. There are various examples of underwater tripods such those made by Ultralight example here

There are several inconveniences using a tripod first is that those are more suited to a camera than a tray that may have the tripod hole off centre, so if you use a tray for your set up and just want to occasionally put it on a tripod this gets complicated.

So that where Mike came into action and contacted ULCS to build a tripod out of a tray those are my results using the following parts:

Camera set up

  • TR-DM tray
  • TR-DUP Extention
  • 2x TR-DH handles
  • 2x 12 segments 12″ locline arms
  • 2x Sola 1200
  • Panasonic LX7 in Nauticam housing

Tripod set up (approx $310)

  • 3x 1420 ball base adapters
  • BA-FBd plate
  • 3x clamps
  • 3x 5″ arm segments

This gives something like this also called Ultimusmacro

UltimusMacro
UltimusMacro

I tried this set up and the key issue is that you are far away from the floor and end up with working distances of around 10-15 cm or 4-6″ those are suited to a +6 diopter but not more and best with camera with at least 105mm zoom.

This is a bit of an issue with my Panasonic LX7 as the max zoom is 90mm equivalent. So I came up with a mini-monopod that has several advantages:

  • Closer to sea floor
  • Less expensive
  • Lighter
  • More flexible

For the mini-monopod all you need is ($150)

  • 3x 1420 ball adapters (two female and one with screw or bolt) – alternatively 3x 3816 2x female and 1x 1420 with bolt if you use AC-AH handles with 3/8 hole
  • BA-FBd plate
  • 1 clamp
  • 1 8″ arm segment

This is the mini in action also called cyclop

Monopod
Monopod

In this configuration I also have a lens holder on the 8″ this gives even more stability
With a mini-monopod you can easily use +10 diopters as you are on the bottom. In my set up I have floats however the 3 1420 ball heads on the bottom are sufficient to have a stable platform that can be pointing down even more raising the arm segment.

In addition to this the monopod can be used to push the camera in remote places or approach critters in crevices or similar

I will be testing both in North Sulawesi starting next week I hope to come back with some great footage

For more pictures of the set up check the Panasonic LX7 link on the top of the page

Grenada Trip First LX7 release

I have just completed the first draft of the clips taken with the LX7 in my trip last week. Links are here:

Youtube may not work in some cases so use vimeo instead

For who wants to know the lens choice for wide angle was as follows

Wet mate: Molinere Sculpture Park, Purple Rain, Veronica L, Shark Reef

Inon UWL-H100: Bianca C (28-40 meters) , Northern Exposures, Southern Comfort, Quarter Wreck, Shake’em (20-32 meters)

You can see in the section of the Veronica L that missing those extra degrees field of view did not allow me to take the full wreck by side even if it was not that big. On couple of reef dives I already had the Inon on the previous wreck dive so I left it you can compare performance of the two lenses in terms of sharpness and flare. Generally I feel the wet mate has less flare and is sharper however it does have an issue of reflections as covered in the previous post.

As always I have used iMovie to edit the AVCHD progressive files that I converted to normal mp4 using the workflow in a previous post. There are no dramatic alterations of colour or exposure and no stabilization has been run in any part of the video (in some parts like the snake eel moving it shows) all was done with custom white balance using the camera functionality, considering how deep were some of the wrecks this is very good I believe.

I would love your comments this was mostly an exploration trip so it is interesting to compare to the RX100 Raja Ampat videos

Underwater Video Tips: Choosing a Close Up Lens for a Compact Camera

There is always a lot of confusion around macro photography and close up lenses. It is useful to set some definitions right before going into selecting the appropriate lens.

In traditional terms a macro photograph is one where the image of the subject on the sensor is the same size of the subject itself. As photography is based on 35mm film this means that a macro photograph is one where the vertical size of the frame measures 24mm. If we look at high-end compact cameras there are very few that are able to capture an area smaller than 35×24 mm, among those the Canon G15 or the Panasonic LX7. Majority of other cameras capture around 60-65mm wide and 40-42mm tall frames usually at the widest end with distances of 1-3 cm from the subject. As compact camera sensors are small strictly speaking there are no compact cameras on the market that can capture an object as small as their sensor.

So as far as we are concerned all that matters is that the height of the frame is same or smaller than 24mm as if we were shooting with a full frame DSLR.

Seems macro but it is not!
Seems macro but it is not! 1:1.2

For an SLR user the choice of a close up lens is quite straightforward as usually there will be a 100mm lens behind a flat port. This lens gives a magnification of 1:1 usually with a closest focus distance of 12” or 30cm. To achieve more with the same lens there is the need of a close up lens that works with a similar principle of a magnifying glass.

A close up lens will have a determined focal length or maximum working distance, beyond which it will not focus. If you hold a close up lens at the focus distance and look inside it you will notice that the object will appear larger as you step back from the lens and smaller as you get closer to it. The camera lens behaves in a similar way. Once you reach the working distance of the close up lens is the zoom that moves the lens forward or back and effectively provides the magnification. The close up lens only shorten the working distance allowing you to get closer.

Close up lens are measured in diopters this is the ratio between 100cm and the lens focal length. So a lens with a focal length of 20cm is a +5 diopter. A 100mm lens at 30cm once placed at 20cm from the object would achieve a 1.5:1 magnification. So with a 100mm lens in a flat port and a +5 diopter we are able to capture images larger than life-size with a DSLR full sensor. A +10 diopter would give a magnification of 2.1:1.

So how much power do we need to shoot macro with a compact camera? Is it the same than with a DSLR? Are there other considerations that apply?

The first issue is that because compact camera have fixed lens there is no way to predict at a given focal length if we will achieve macro or not. A compact camera zoomed to 100mm equivalent is not the same as a full sensor camera with a 100mm lens: in most cases the capture area is much larger. In fact there is no way to know if our lens will or not achieve our objective of taking a macro shot just looking at the camera specs. To make matters more complicated it is not always possible to get too close to our subject, this may be because there is no physical way to get closer or because we do not want to freak out the marine life that we want to capture. In general I like to leave some breathing space to subjects, as a minimum 3 inches or 7.5cm are needed and a bit more. This means that more than a lens with more than 12 power is generally a bit too close to the subject.

So how do we work out what diopters we need for our lens? Unfortunately we will only know after we have actually tested it, this is of course not very good!

Another possible approach is to define what is the working distance that we can realistically sustain with our equipment and the conditions we dive in.

Generally it is always possible to get between 20cm and 10cm and in some cases also under 10cm. This corresponds to 5 – 10 diopters and sometimes more for example 12. Considering that plenty of marine life is actually one inch or larger to capture a frame where the subject is filling it we do not actually need real life-size macro. In practical terms this means that for a compact with zoom of 100mm a lens with 6 diopters is fine with less or more depending on the camera zoom and focus ability. So for general purpose a close up lens between 5 and 7 is perfectly fine, this corresponds to working distances between 14 and 20 cm or a bit less from the back of the close up lens so actually closer from the front of the lens itself. For very small subjects around 1.5 cm like a pygmy seahorse we would be looking at 10 to 12 diopters, more is impossible as we would be crashing into the critter. This means a working distance between 8 and 10 cm or 3 to 4 inches from the front of the lens or 3 to 5 cm or 1 to 2 inches from the close-up lens that would still allow a small space for our lights.

Macro Shot 1:1
Macro Shot 1:1

Will we achieve real life size macro with this? It depends, to give some context my Panasonic LX7 that only has a 90mm zoom will capture a 32mm tall frame with 6 diopters power, strictly speaking this is not macro, and 20mm with two stacked 6 lenses achieving a 1,2:1 super-macro.

Super Macro 1.7:1
Super Macro 1.7:1

There are also other consideration that apply, if all we have is a +10 diopter we need to get very close to our subjects for our lens to start working, in all those situation where we cannot get close we would run into problems. If we look at a videographer with a 10x 400mm zoom camcorder they most likely only need a 2-3 diopter because with the range of zoom available they can comfortably achieve macro staying over a foot away from the subject. So the advice is to always have a 5-6 lens for general work and another 10-12 for smaller subject or if the lenses are stack-able two 5-6 this will cover all possible situations with a camera with a 90-140mm equivalent zoom.

I thought of concluding this blog with some recommendations so those are my recommended close up lenses based on personal use or looking at pictures of others:

  • DSLR: Reefnet Subsee both 5 and 10 with 100mm lens on full frame or 60mm on 1.5x cropped sensor. The new Inon UCL100 is also worth checking but it is more expensive.
  • Compact Camera: Inon UCL165 x2 or Dyron Double Macro lens x2

Note that the Inon UCL165 focal length of 165mm is from the back of the lens so the power is 6.06. Dyron lens are reported as 7 diopters however they are then declared 165mm underwater which is actually 6.06 exactly as the Inon.

Optical quality of both lenses is similar so I guess it depends on price what would be the choice. Inon is available with bayonet mount that maybe a big advantage for some cameras like the Sony RX100.

Whilst the Subsee give the best optical quality they are bulky and not flexible so I would not consider those for a compact rig. Inon and Dyron are lighter and more portable and can be stacked, a single diopter will be in most cases sufficient for good close up work with two required only for the smallest critters. It has also to be considered that at least for stills chromatic aberration can be removed in the editing phase, not so for video, but there generally goes unnoticed unless is really heavy. The Dyron and Inon lenses have the level of quality that the aberration cannot be noticed. This muck diving video has plenty of macro and close up with diopters note that no chromatic aberration is visible, shot with single or double Inon UCL165

There are other brands like FIT or époque but there seems to be quite some confusion as their specs are either air values or magnification that as we appreciate depends on the lens used. From tests I have seen the FIT 16 seems less powerful than an Inon 6 and same of a Subsee 5 and they are expensive so not an option for me.

What other tips are useful for shooting with close up lenses? The first is to make sure to use small apertures to have the maximum depth of field.

Contrary to what many believe the diopter itself does not create an issue of shallow depth of field is the size of the subject and the magnification that create the problem. With diopters most times we are at the maximum possible magnification with a total depth of field of few millimeters, it is important to operate at aperture values for a compact camera of f/8 and if available smaller.

For pictures is it also advised to use very fast shutter speed to avoid motion blur that the shake of the camera could create, usually 1/250 or faster unless using a tripod or a solid base. Video is not usually shot with high shutter speed, if available use double frame rate and shutter of 1/100 or 1/125 depending on the PAL or NTSC video system. This will allow half speed slow motion in editing that could prove useful.

Lights are also very important for close up, for still cameras they allow the camera to focus and for video they are needed to actually take the shot. For still cameras a strobe is essential, as video lights do not perform well at high shutter speed.

A final advice is to use the lowest ISO or gain available to ensure the quality of the picture or footage is the best possible, as we are close and have lights this should not be an issue at all. Most macro stills are shot in manual, for video if a manual mode is not available pumping the lights up results in the camera closing the aperture and reducing the ISO. If manual mode is available it is possible to set shutter, aperture and ISO and then measure the exposure that the light give until a satisfactory value is achieved.

Underwater Video Tips: Panasonic LX7 Settings and Features

My previous testing of underwater video with the Sony RX100 has been quite successful I was initially pretty hard on myself but I would say the performance was as good as it could have been taking into account the conditions

Most of my videos considering the conditions look better than dedicated single chip camcorders on the market and as good as some badly shot 3-chip camcorders

It is worth noting that a decent camera in a good housing like Gates or Light and Motion costs in excess of $3,000 without any lenses or lights, whilst with the same amount of money you can get a complete set up for a high end compact camera with included two sola 1200 and various lenses.

The restrictions of a still camera though still apply at least to the Sony RX100 and those are:

  • No use of zoom at wide angle with wet lenses (problem of set up not specific to RX100)
  • Clumsy operation of functions like white balance
  • having to change wet lenses multiple times in the same dive because close up performance is average

So is there something else out there that at similar or lower price point can get us high quality underwater video?

I believe there is and it is the Panasonic Lumix DMC-LX7, this camera has a bright f/1.4 lens with good sharpness, a 24mm lens and more effective ergonomics than the Sony.

Obviously I am talking about video here as I do believe the RX100 is the camera to beat in terms of compact for still pictures. For video especially at wide angle we are shooting mostly with ambient light and the corner softness of the RX100 does show with wide apertures. So whilst for your photos at close focus wide angle with a strobe the camera does an outstanding job for an HD video at 1080p the image does not look that crisp.

I am glad I got the RX100 as this is going to be the next camera for stills once I abandon the Canon S95.

Ok moving on to the Panasonic LX7 I did a little stress test pointing at the fireplace in low light to see how the two cameras respond, the clips are done 1 minute after the other so have similar ambient light available. It is clear that the LX7 is a winner in virtue of the brighter lens not only that the wider 24mm lens against the 28mm of the Sony shows a clear advantage.

Now what else is good about the LX7 the major feature are definitely the ergonomics, let’s have a look at the rear controls.

Panasonic LX7 rear buttons
Panasonic LX7 rear buttons

The first button of interest is the AF/AEL lock that you can configure to lock focus, exposure or both. Now having this with one touch means that any shot of moving fish in front of the camera or a dive into a cave will resist the camera hunting for focus or trying to change the exposure.

The other button of interest is the WB you can recall and set white balance in any non automatic mode including video, in addition there are two custom settings for white balance and you can alter the tint after setting that is great.

The ISO button is also very useful but mostly for picture and a half press will tell you what combination of aperture, shutter and ISO the camera would shoot at.

This also brings one of the weaknesses of the camera and is the camera’s video Program submode. For some reason this behaves like the still camera program mode so does not take into any account the 180 shutter rule, so be careful and never use the camera in Creative Video mode with the Program submode as results will not be good.

So how should you shoot video with your Panasonic LX7? Simple you should shoot in shutter speed priority or in specific cases in manual.

I think the shutter speed priority is the simplest starting point, so let’ assume you are in the PAL system where video is 25 frames per second you should set shutter priority and speed of 1/50 for wide angle with ISO in Auto. Depending on available light the LX7 will keep the lens at widest aperture and ISO until needed and then start closing the lens, this is fine for us as it is better to have lower noise image than huge depth of field.

If you want to influence depth of field for example in a macro situation when you are zooming in a lot you can take a half press and set the ISO manually until you have the aperture you like. The LX7 sets ISO in 1/3 of f-stop so the fine-tuning possible is incredible.

I would not trust the camera aperture priority mode as the LX7 will quite happily reduce the shutter speed all the way to 1/30 of a second before increasing the ISO and this would give blurred footage.

Shooting macro with the LX7 may require you to operate at double frame rate modes of 50 or 60 fps in that case again in shutter priority mode or manual start with a shutter of 1/100 or 1/125 and pump up your lights until you see the aperture closing. If the image is still soft increase the ISO manually to get where you want to be take into account that this camera has really a lot of corner sharpness so in general it is not needed to get to small aperture as much as it is with other cameras.

So which housing for the LX7? I have done a quick review of the Nauticam in the unboxing video here

This housing is really impressive and makes the camera actually even easier to operate when outside the housing!

Now with all those good things why is the LX7 not as good as the RX100 for still pictures:

  1. Too wide lens: 24mm makes it difficult to get wide angle lenses and impossible to use a fisheye
  2. Resolution is only 10MP in RAW pictures this shows, not in video though
  3. Smaller sensor again the performance at the same ISO is better with the RX100 when you have a strobe

For video some of those drawbacks become actually plus points:

  1. The 24mm lens when coupled with the Nauticam wet mate dome has 84° field of view in water that is good for most situations
  2. Smaller sensor means more depth of field at same aperture

Another factor to consider with regards to the LX7 is the 1cm minimum focus distance, this means that diopters are only needed for super macro very small subjects as the capture area of the camera is incredibly small less than half the RX100.

Other plus points of the LX7

  1. Neutral density filter, -3 f-stops means the camera will not jump to shutter speeds of 1/1000 in bright sunlight but stay at the normal speed with the lens wide open
  2. Stabiliser: the LX7 optical stabiliser is rock solid and gives the same performance of the RX100 active stabiliser without any cropping of reduction of the field of view
  3. A normal Mp4 1080p video mode at 20 Mb/s bitrate that is great for general purpose wide angle

In the next post we will have a look at the Nauticam Wet Mate and the diopter that I have chosen for the LX7

Sony RX100 – Tips for Underwater Video Part 7 – Macro Shots

Just came back from a 11 nights and 10 day diving on a liveaboard in Raja Ampat and I am in the process of putting together the summary videoclip for the trip. To have an idea of the kind of diving in this remote location you can have a look at the superb pictures that my buddy and fiance has taken on Raja Ampat 2012 Flickr Set

I had already gauged that the macro performance of the RX100 is far from outstanding and this trip just confirmed it.

To understand what I am talking about have a look at these two pictures both taken at 5 cm from the front port of the camera using a 3:2 format.

RX100Macro

The first image is shot with the RX100, note the shallow depth of field of the large sensor in P mode.

All looks good however if we take the same shot with a Canon S95 that has a 1/1.7″ sensor we get this result.

S95Macro

To make matters less complicated and don’t get too technical you can measure with a ruler the size of the memory card in the pictures. The S95 presents an image that is 26% longer than the RX100. It is like saying that compared to the RX100 the S95 has a 1.26x magnification.

In video diopters are not very popular because camcorders have small chips around 1/2.5″ and a 10x optical zoom and can focus at very short distance. So usually a no diopter is needed for regular macro work and a 4D is really only for pygmy seahorses.

With our RX100 however we need a 5D just to have a decent macro performance. Actually even a good size nudibranch looks small in the RX100 underwater without any lens. Moreover the RX100 has only a 3.6x zoom so even with a diopter that allows to focus a telephoto at closer distance things don’t really look that big so we are  looking at 5D for basic macro and 9D for super small critters.

The RX100 has a number of housing options with M67 thread as standard, this is the most popular format for diopters and there is ample choice there. If instead we want to use bayonet mounts we are pretty much limited to Inon or Seatool.

As discussed above we are  looking at a starting point of +5 diopter, this cuts immediately lenses like the Inon UCL330 out of the equation, if we look at the most popular and affordable lenses we are left with:

  1. Inon UCL165 6 diopters (1.5x) this lens is stackable
  2. Reefnet subsee 5 diopters (1.25x)
  3. Dyron +7 diopter (1.75x)
  4. FIT achromatic +8 (2x)
  5. Olympus +8 diopter (2x)
  6. Epoque DML-2 8.4 diopters (2.1x)
  7. Reefnet subsee 10 diopters (2.5x)

The first three options are adequate for most of the macro work with the RX100 and get you to fill the screen for almost all subjects except the smallest pygmy seahorses.

As we increase magnification we get the RX100 to a point where is very difficult to produce any decent footage. A 10+ diopter works very well for still pictures where you only have to take a single shot but for 10 seconds of decent footage is close to impossible to achieve focus without a tripod.

Looking at the featured image on this post this is a still picture with two Inon UCL165AD stacked at full telephoto. When I was in Raja Ampat I tried using two UCL165 it was very hard to get anything in focus however the performance is pretty good this is a snapshot taken from my footage.

Pygmy Snapshot

I posted all the pygmy footage on youtube

in this short clip I have a compilation of subjects, if you believed that an hippocampus bargibanti was tiny have a look at hippocampus denise, Pontohi and especially Satomi (1cm) in this clip to have an idea. All in all I am satisfied as I shot 12 minutes of seahorses and could use around 2 that were not too shaky. I do not use software stabilization as I don’t like the warping effect that CMOS sensor camera give so this is all done by hand. I did slow down some of the footage to half speed and this is were the 50 fps of the RX100 come really handy.

Other than Pygmy seahorses that are between 1.5 and 2.5 cm in size there is no need for such high magnification, in fact for the rest of the trip a single UCL165 has been more than adequate.

Looking at cost an Inon UCL165 costs less than a subsee 5  so that is the most cost effective option if you ever think you will need a very high magnification  and you are able to be super steady to avoid shake as it can be stacked with another UCL165 or an UCL330. Specifically having experienced the two UCL165 stacked I think that is probably too hard to handle so a combination UCl165+UCL330 should be the perfect choice for pygmy and similar at 9D alternatively a subsee 10seems the logical super macro choice.

A final tip is camera modes for macro, as discussed in a previous post aperture priority is the way to go and allows you to have enough depth of field so that you have sufficient part of the subject in focus. However this brings also the consideration about lighting. I took some shots in program mode with the RX100 and two Sola 1200, in some situations is quite hard to achieve f/8 or higher numbers with the two lights at the minimum power of 300 lumens with the lowest ISO. It follows that if you operate with a single light you need to have at least 800 lumens and put the light to the max, this may scare skittish critters and prevent you taking the footage you want. A possible solution is a red filter on the light followed by in camera white balance however a single light does produce harsh shadows and this needs to be taken into account.

In conclusion a diopter for macro work with the RX100 is a must so choose one that fits your needs and ensure you have sufficient lighting to support the small aperture required by the camera large sensor.

Sony RX100 – Tips for UW Video Part 5 – Video Modes

Yesterday I had the opportunity to take the rig in the pool and try the steadyshot in water. Clearly it is not really accurate to compare like I have done but it gives an idea you can check it out

This made me think about the video modes implemented in the RX100, as we know there are 4 surprisingly for a compact:

  1. Program
  2. Aperture Priority
  3. Shutter Speed Priority
  4. Manual

The manual option may sound very exciting to someone that comes from still photography but in the end is not that significant in video. Not sure how many have heard about the ‘180 degrees shutter rule’ anyway google it there is some good explanation there. In essence once you fix the frame rate you have pretty much fixed the shutter speed as well so this takes away one of the exposure variables, we are left with aperture and ISO.

Aperture is available in 1/3 of Ev however in wide angle shots with a wet lens most of the times with subjects 10 feet or 3 meters away the camera even with this size sensor has so much depth of field that there is no much point bothering.

ISO in video goes from 125 to the max in 1 f-stop increments so after 200 you have 400, 800 and higher values that are not good for video as the H264 compression makes the footage grainy. I would recommend limiting the max auto iso to 800 or maybe 1600.

So the manual mode allows you to set the exposure, now is that a good thing? As seen earlier on Part 2 this is indeed a good thing in specific situations such as wreck penetration, caves and the likes. It is not however that great for general wide angle and if you ever happen to do camera pan or change the angle of the camera. Panning is not that great in underwater video but sometimes you need it and fixing the exposure is not a good idea.

So the Manual mode is good to take control of the camera in specific situation but in most cases is an overkill as there are not many parameters you can really change independently.

Following on from the shutter speed 180 rule the shutter priority is also pretty useless as we should set the shutter value to a multiple of the frame rate to avoid stuttering.

Aperture priority is instead a great value add of the RX100. Diligently the camera will try and respect the 180 degree shutter rule but in specific cases, for example when doing macro with diopters or in close up, we want to really make sure we have the depth of field required. In that scenario I recommend leaving the ISO on Auto and not set it manually.

So why Auto ISO? Because changing ISO in a digital camera is done amplifying the signal, is not changing film, so in effect the ISO does not need to go in f-stop values at all. So leaving it on ISO the camera might as well apply values that you cannot choose manual.
This uneventful picture taken with the RX100 and an Inon UWL105AD shows a value of 320 in ISO as it has been shot in program mode.

We could not select this value if we were setting the ISO manually but would have needed to choose between 200 or 400.

Aperture priority is my favorite mode for those special situation where extra control is needed.

So what about the Program Mode? Actually that is not bad at all, especially for wide angle shots, as mentioned the shutter speed is pretty much set, in program the camera tries to keep the lowest ISO as possible and opens the aperture accordingly. This behavior may be acceptable with sufficient ambient light so I would not discount this mode at all.

Not bad for program mode with no lights…

A final note the camera uses a shutter speed of double the frame rate in Active Steadyshot and the same as frame rate in standard mode, also for this reason I do not recommend the standard steadyshot even if Active crops the picture in the 1080p50 mode

Sony RX100 – Tips for UW Video Part 4 – SteadyShot Modes

In this post we will look more closely to the image stabilizer options built into our RX100.

The RX100 is equipped with the Sony Steadyshot technology that has been around for quite a while however in this new camera we have a new additional feature that may as well worth exploring for our purposes, the Steadyshot active mode that was first introduced in the alpha series.

The active mode is only available for movies; for stills the choice is limited to the Standard mode, it is of course possible to switch off any type of stabilization, I do not recommend doing this for movies.

So how does the Steadyshot system work?

The standard mode is based on a gyroscope sensor present inside the camera that gives information to the microprocessor so that this can adjusts the relative position of the camera sensor with respect to the lens and compensate for the movement of the camera. More details are on the Sony website here.

There is no doubt that optical stabilization is a great help for still pictures however we have all experienced that this does not really lend a great help in situations where the camera moves quite a bit, for example if you walk with it taking footage, or in a dive when you have surge or uneasy conditions.

Usually in post processing we then add a software stabilizer that works out the camera’s pan and rebuilds the frame around it, this  comes at the expense of cropping.

Some cameras do not have an optical stabilizer but only an electronic system which is equivalent to the routines that editing program implement in post processing, Sony with the SteadyShot Active mode combines optical and software stabilization techniques.

I have put the RX1oo on an tripod fronting the window frame and set the camera in SteadyShot Standard mode, the diagonal field of view in this case is 73.44 degrees (it is actually 72.97 if we calculate accurately but let’s not worry for now).

You may wonder why this is not in excess of 75 degrees as the camera has a 28mm focal length at 35mm equivalent, this is because the camera sensor is 1″ wide with a 3:2 form factor, but in movie mode we are in 16:9 so part of the picture is lost and this makes the field of view smaller. In fact Sony declares the 35mm equivalent as 29mm in Movie mode, against a more accurate calculation of 29.25mm.

In this shot we see the camera in the same position but now in SteadyShot Active mode.

We see that we don’t have anymore any light on the sides of the window frame in fact right now this completely fills the camera frame.

Sony declares an equivalent 35mm focal length of 33mm in active mode that reduces the diagonal field of view to 66.5 degrees this corresponds approximately to a 10% reduction at field of view level. This crop is needed by the camera software in order to work out the camera pans and have sufficient margin of error for the calculations.

Now when it comes to underwater video should we be tempted by the SteadyShot active mode even if that means loosing some field of view? I guess it depends, most of compact camera users do not have underwater tripods, and the additional stabilization help is welcome especially when zooming in for example for macro or performing panning shots.

In this video you can compare the two steadyshot modes

This also brings another consideration in mind, there are many wide angle lenses designed for cameras with 35mm equivalent focal lengths, that could be suitable if we intend to keep the Steadyshot in Active mode.

A lens that immediately springs to mind is the Inon UWL-100, this is a lens with an M67 thread as natively supported by three of the housings currently available for the RX100, the Ikelite, the Nauticam and the Patima, an M67 mount adapter is also available for the Recsea housing.

The Inon UWL100 supports camera with focal lenght >31.5mm and would on paper be suited for video use with the RX100 with steady shot in active mode, this lens should not vignette at the widest setting due to the image crop and reduced field of view of the 16:9 frame in movie mode.

Another lens that come to mind similar to the Inon is the Epoque DCL-20 or Ikelite W20 those correspond to the Inon UWL-100 with mount type 2 and might not be suitable for the Ikelite housing. Ikelite tends to position the thread further away from the port so I invite you to test yourself before drawing conclusions as the increased distance lens to port generates soft corners.

Finally the Olympus PTWC-01 is also a potential candidate for testing for what concerns the M67 options.

If you happen to have any of those lenses with your current set up and are thinking of upgrading to the RX100 to use it for video you may well be able to use your lenses again and save yourself additional investment.