Category Archives: White Balance

Sony RX100 – Tips for underwater video part 9 Wide Angle Shots and Lenses

During my last trip to Raja Ampat I had finally the opportunity to take the wide angle lenses in a real life situation and test that they were working to satisfaction. As some people know I really like my set of Inon AD lenses and although the RX100 has a 28mm equivalent lens I put together a bespoke adapter to reuse the lenses I already have. At the time of the trip I did not have the final prototype but only a pre-release which meant I could no use the fisheye as I had an alignment issue with the dome so I only used the flat UWL105AD.

There are two videos that are of interest one is the Raja Ampat North sites which is below.

In the north visibility was at best fair and I was struggling with the set up as I had not tested the push up filter. What happened is that the black ring created vignetting so I had to reverse the rubber ring on the lens until I could push the filter deeper. In the video you can see clearly a vignetting issue around 3:50 on the wobbegong approach where I had not yet resolved this problem. The video has no image stabilization nor cropping and it shows! There are also occasional soft corners as due to the low level of visibility and lack of light the camera was working around f1.8 or f2.0 aperture most of the time. This does create soft corners on the RX100 when you have something in close focus because I always shoot at the lowest ISO as I have found that increasing aperture and working with high ISO creates a mayhem of chromatic issues.

Anyway once I got a few dives and the problems were ironed out we also moved down to Misool where conditions where much better. This is the Misool video.

Here because of the increase of light and better conditions the image is sharper due to smaller aperture settings. I did not use the RX100 to take any stills as I wanted to focus entirely on video.

Once I got home I bought a fix M67-28AD adapter PRO, that allows you to adjust the AD lens so that the dome petals are in the right place. I tested it in the bathtub with the UFL165AD and the UWL105AD, in terms of vignetting as we shoot stills at 3:2 the working focal length is 34mm on the zoom or 12.8mm.

This is a shot of the bare lens

Bare Port

You can see the characteristic pincushion distortion that the bare port creates, this is the main reason together to demagnification to have a wet wide angle lens note the purple fringing is evident.

This is a shot at f5.6 with the UFL165AD.

UFL165AD 12.8mm

Despite the zoom the lens performs great and it is very wide. If we look at a 100% zoom of the corner

UFL165AD 100% crop

We can see that at this aperture the corners are sharp and there is a very small amount of red and blue fringing.

Let’s look at the Inon UWL105AD

UWL105AD 12.8mm

If we zoom into the corner this is what we get

UWL105AD 100% crop

Also here there is tiny blue and yellow fringing but the results are comparable to some shots I have been sent taken with the Inon UWLH-100 28LD.

Finally this is the UWL105AD with a 16:9 aspect ratio and 33mm equivalent zoom, this is interesting as it is the way the camera behaves in active steady shot without zoom.

UWL105AD 16-9 100 crop

As you can see even better performance in the corners as the port is closer to the back of the lens with the RX100 because of how zooming is implemented.

For who is interested I sell spacer rings and special screws that you can attach to the fix adapter at $45 get in touch if you have some old AD lenses and you want to reuse them with the RX100. Especially as the UFL165AD has incredible performance with stills and nothing can beat the flexibility of this lens and its very light weight in water let alone the speedy bayonet mount.

A final word about filters, in video filters are essential to restore colour however they also take away 1 1/2 f-stop of light so in low light the footage may get too grainy and it is actually better to work only with white balance.

I have heard many people commenting about the dreaded white balance error 9900K message of the RX100. So why is this happening?

It seems that the RX100 cannot white balance if the exposure is outside the -2 or +2 Ev range. If you do continue and ignore the error message you may end up with strange results.

So how to fix this? Contrary to what I said in my post about white balance I have worked out that it is best to set a custom white balance in P mode and not in M, this is because the camera will adjust exposure and never issue an error message. If you want to keep white balancing in M make sure you are within the allowed range of exposure.

Sony RX100 – Tips for UW Video Part 3 Setting Custom White Balance

In this third post we will look at setting custom white balance in our RX100.

The ability to change the color temperature and adjust it to the conditions is essential to take underwater video as the ability to correct white balance in post processing is nowhere near what you can achieve with RAW files in photography.

Unfortunately the RX100 does not allow to set a custom white balance in video mode, and actually does not allow setting it in many other modes either. So to achieve our objective we will need to use the mode dial.

Note that the RX100 has the ability to store custom setting in 3 memory recall modes however in this mode the set custom white balance option is not available.

As we don’t have a one push option we need to minimize key presses to build a reliable routine that we can recall underwater.

If we have a look at the mode dial we see that the Manual mode for stills M is the closest to the video position so our routine will be based on switching between M and Movie mode. Update The new recommendation is to set the dial to P see note at bottom

Preparation is important and the RX100 has two options when it comes to recalling functions from the menu as we can see from this picture.

It is essential for our purposes that in this screen we select Previous, this will position us on the last entry we used when we click on the menu button again. The other option Top does not recall what the last entry was and puts you back on the top of the relevant menu, and would mean more navigation for us, so make sure you are set on Previous.

Another important trick to remember is that through the Function button we can recall the various white balance settings. In my set up white balance is right in the center of the function option so that when the function button is pressed we are immediately there should we need to change it back to Auto when we use lights, so when we plan to custom white balance this should be left on the Custom position as in the main picture of this post.

The other preparation that we need to do is to go in Manual Program mode and navigate until we reach the entry that allows us to set custom white balance as shown in the picture.

Note that from here we still have to actually select and go into another menu to then finally navigate to the bottom where the set custom wb option is.

We now want to re-balance either on slate or some grey area or sand so how do we do it?

The starting point will be in Movie mode with the White Balance set to Custom (remember this is not to set a new WB but just to recall the last white point set).

This is the step by step routine:

  1. Move the dial to position P
  2. Press Menu – this will position us on the white balance entry in the menu
  3. Press Enter (central button) to access the options
  4. Scroll to Set Custom
  5. Press Enter
  6. Point at the slate and press the shutter
  7. Press Enter
  8. Turn mode dial to Movie – as we were set in function to Custom White point recall the setting we capture will be used

And we are done an 8 steps routine!

If you were used to a one push option this is a shocker!!!

For those on the more conventional option Menu-White Balance-Custom WB-Set-Menu this adds 3 more clicks.
Sony had made two very poor design decision for our underwater video purposes

  1. It has negated the option set custom white balance in video and now two turns of the Mode dial are necessary
  2. It has allowed to set a custom white balance only from the Menu but not from the White balance options that you can recall with the Function button, additional navigation is required because of this

I believe those issues can be fixed by a firmware update quite easily as they are clearly software issues the camera itself has got all the required capability.

That’s all for now if anybody has any alternative approaches that improve this routine I look forward to hearing what those are!

Meanwhile I recommend sending an email to Sony Support to ask for firmware changes…

Update 14 December 2012

Many people report a Custom WB error 9900K message. It turns out the RX100 fails to set custom white balance set up if the exposure is not within -2 to +2 range. So the new advice is to set custom white balance while in P mode