Fujifilm X10 'Orbs' Investigated. Does the Firmware Fix Work?
Barney Britton, Kelcey Smith | Product Reviews & Previews | Published Feb 25, 2012
It didn't take long once samples of the Fujifilm X10 were out in the wild for reports to start surfacing of a strange and unwelcome phenomenon in images taken in certain conditions. Colloquially known as 'white orbs' or 'white discs' the problem describes the peculiar circular, hard-edged appearance of clipped specular highlights in images taken on the X10. The effect is unpredictable, but virtually unavoidable in some situations (low light cityscapes for example) and impossible to ignore once you notice it. The table below shows what we're talking about - this is the same scene, shot at identical settings. The Fujifilm X10 is on the left, and the Panasonic Lumix DMC-LX5 (one of many examples we could have used here) is on the right.
|Fujifilm X10, ISO 100, f/5 0.8sec||Panasonic LX5, ISO 100, f/5 0.8sec|
We mentioned this issue when we included the X10 in our pre-Christmas roundup of high-end enthusiast compact cameras, and have since reported on Fujifilm's announcement of an upcoming firmware release to address the problem. In the meantime we had no option but to put our in-depth review of the X10 on hold until the new firmware was available in case it made a significant difference to image quality.
As soon as the new firmware (version 1.03) became available a couple of weeks ago we loaded it up on our test camera and started shooting. Here's what we found.
In our shooting with the X10, we had already established that white orbs aren't a problem in every single exposure. Far from it. In fact, depending on the sort of photography that you do, you may encounter the problem rarely, if ever. This is important to bear in mind, especially since the images you're about to see were shot in conditions specifically designed to highlight the issue. As such, these samples should not be regarded as representative of the X10's image quality in day-to-day use.
For the purposes of this exercise - to see whether firmware version 1.03 reduces or solves the orbs issue - we set up a controlled studio test.
Studio Scene: ISO Sensitivity
|There are two light sources in this scene - a pen-light, to provide a point reflection on the metal frame and balls in the Newton's cradle on the left, and a low-intensity tungsten bulb on the right, for light relief.
We used one camera, and shot one set of images using firmware version 1.02 and then updated to firmware 1.03 and took another set. The camera was tripod-mounted, and white balance was set manually to 2800K.
The first set of images is a simple run up the X10's ISO sensitivity settings, from ISO 100-3200, at its full resolution of 12MP. DR was set to 100%. Images taken with the older firmware version 1.02 are on the left, and the new firmware is on the right. All other settings are identical.
As you can see, white discs are very obvious around point highlights in images shot with both the new and old firmware at ISO 100 and 200. As we move higher up the ISO scale the effect is reduced until by ISO 800 we wouldn't really consider it to be problematic. Highlights are blown, but lack the unpleasant hard edge which looks so artificial in lower ISO images. The new firmware appears to have little or no material effect on the appearance of the 'orbs' in this scene.
Studio Scene: EXR 'DR' Mode
Something that we have noticed after extended use of the X10 is that the appearance of the white discs/orbs differs depending on the 'DR' dynamic range setting. In full-resolution 12MP mode the reason for this is obvious if you know how the camera works - increasing the DR setting from 100% to 200% and up to 400% increases the base ISO sensitivity from 100 to 200, to 400, and as we've already seen, increasing ISO sensitivity reduces the intensity of the white discs effect.
But what about EXR mode? In 'DR' EXR mode the X10's 'DR' dynamic range setting can be extended up to 1600% using a combination of exposure and tone curve adjustment, and EXR technology. These images were shot in identical conditions to the samples on the previous page, but ISO was set to automatic (400) and because exposure cannot be manually adjusted, exposure compensation was used to match the brightness.
As you can see, the white discs decrease in size as you go up the DR scale, but they retain their artificial-looking, hard-edged appearance. Again though, there is no noticeable improvement between firmware versions 1.02 and 1.03. We also tried shooting side-by-side comparisons in EXR 'SN' mode, which is designed to deliver lower noise at 6MP, but with identical results - no improvement with firmware 1.03.
One curious thing that we've noticed while working through this issue is that not all X10's display the dreaded 'white orbs' to the same extent. We've used two cameras from different production runs, and while both produce images that show the effect, one displays more severe 'orbing' than the other. We've used images from the better of the two cameras in the rest of this article, so you can judge for yourself the severity of the issue, but for the sake of completeness here's an example of the difference between the two models that we've used, at base ISO and full-resolution (12MP).
|Camera A||Camera B|
|Camera A||Camera B|
We would hope that Camera B, in the table above, (from an earlier production run) is the exception, and that more of the X10s on the market behave like Camera A in our example. Even if this is true though, the key point is that the 'white discs' effect is visible in images from both cameras that we have used, and in neither case does updating to firmware 1.03 make a difference. We have asked Fujifilm whether or not changes have been made to the X10's manufacture since production began and we will update this article with a response as soon as possible.
We're still working through our testing, but for now it seems clear that firmware version 1.03 does not appear to have a significant impact on the appearance of 'orbs' and certainly isn't the silver-bullet solution that a lot of users had hoped for.
We have been unable to observe a meaningful improvement in either studio or real world testing which strongly reinforces our suspicion that the problem is hardware-related, and cannot be solved by an adjustment to the camera's firmware. The issue is caused by uncontrolled sensor blooming, where signal spills out from photodiodes radially, onto their neighbors, which creates an artificial-looking white disc around blown-out point highlights. Blooming isn't unique to the X10, but this effect - the distinctive 'orbs' - is unlike anything we've seen before from a modern camera.
After drawing a blank in all of our image quality testing we had thought that perhaps the new firmware adjusted the camera's program line in Automatic ISO mode. As we've seen, the appearance of the white discs is less severe at higher ISO sensitivity settings, so perhaps the new firmware biases automatic ISO to use these high settings more frequently? We have seen reports that this is the case in EXR Auto mode and we will continue to work through the issue, but so far we have not been able to consistently demonstrate any clear bias towards higher ISOs with the new firmware.
So after all this, what have we learned? Here are our findings, summarized.
- 'Orbs' are real, but some cameras may be more prone than others due (presumably) to hardware variation.
- The appearance of the orbs changes as you increase ISO sensitivity, and they become softer.
- By increasing the DR '%' settings you can reduce the size of the orbs, but they remain unattractive unless you increase ISO sensitivity.
- In itself, firmware version 1.03 appears to have no noticeable intrinsic effect on the appearance or intensity of the orbs.
- However, some reports suggest that auto ISO performance in EXR Auto mode is tweaked in FW 1.03 to select higher ISO settings (where orbing is less noticeable). We cannot consistently demonstrate any high ISO bias in FW 1.03 compared to 1.02 (but we'll keep on looking).
UPDATE March 5th 2012: Following the publication of this article Fujifilm has promised us a 'definitive solution' to the so-called 'white orbs' problem, which will be announced on the 12th March. We will report full details when we have them.
We would like to thank Glazers Camera of Seattle for the loan of equipment used in this article.