Tag Archives: apr

Fixing Hot or Bright Pixels On the Sony FX3

The FX3’s larger brothers, the FX6 and FX9 have a function called “APR” that is used to periodically inspect every pixel on the sensor and normalise or map out any out of spec pixels. With modern 4K cameras having at least 8.8 million pixels the chances of a few going out of spec or being damaged by cosmic rays from time to time is quite high. So on the FX6 and FX9 you will get a reminder to perform the APR process around once a week.

From what I understand, the Alpha series cameras and FX3 also periodically perform a similar process automatically. Because these camera have a mechanical shutter to shut out any external light there is no need for any user intervention to perform this process so you will not be aware that it’s happening. On the FX6 and FX9 the user has to place a cap over the lens or sensor, hence why the camera asks you before it can happen.

But what if you find you have some bright or hot pixels with the FX3? Perhaps you have just travelled on a plane where the high altitude reduces the atmospheres damping effect of the high energy particles from space that can damage pixels. Well you can go into the camera’s menu system and force it to run its pixel mapping process which does the same thing as APR on the other cameras.

You need to go to:

MENU:  (Setup) ? [Setup Option] ? select [Pixel Mapping] and then select OK.  It doesn’t take long and I would recommend that you do this after flying on a plane or prior to any shoot where you will use large amounts of gain as this is when hot pixels are most likely to show up.

Hot Pixels and White Dots From My New Camcorder (FX9 and many others).

So you have just taken delivery of a brand new PXW-FX9. Turned it on and plugged it in to a 4K TV or monitor – and shock horror there are little bright dots in the image – hot pixels.

First of all, don’t be alarmed, this is not unusual, in fact I’d actually be surprised if there weren’t any, especially if the camera has travelled in any airfreight.

Video sensors have millions of pixels and they are prone to disturbance from cosmic rays. It’s not unusual for some to become out of spec. So all modern cameras incorporate various methods of recalibrating or re-mapping those pesky problem pixels. On the Sony professional cameras this is called APR. Owners of the Sony F5, F55, Venice and FX9 will see a “Perform APR” message every couple of weeks as this is a function that needs to be performed regularly to ensure you don’t get any problems.

You should always run the APR function after flying with the camera, especially on routes over the poles as cosmic rays are greater in these areas. Also if you intend to shoot at high gain levels it is worth performing an APR run before the shoot.

If your camera doesn’t have a dedicated APR function, typically found in the maintenance section of the the camera menu system, then often the black balance function will have a very similar effect. On some Sony cameras repeatedly performing a black balance will active the APR function.

If there are a lot of problem pixels then it can take several runs of the APR routine to sort them all out. But don’t worry, it is normal and it is expected. All cameras suffer from it. Even if you have 1000 dead pixels that’s still only a teeny tiny fraction of the 19 million pixels on the sensor.

APR just takes 30 seconds or so to complete. It’s also good practice to black balance at the beginning of each day to help minimise fixed pattern noise and set the cameras black level correctly. Just remember to ensure there is a cap on the lens or camera body to exclude all outside light when you do it!

SEE ALSO: http://www.xdcam-user.com/2011/02/are-cosmic-rays-damaging-my-camera-and-flash-memory/