Auto ND Filter

[Robert Young]

I did not really understand how the auto ND filter worked in the XA 10, and the XA 20 manual doesn't seem to explain it much better.
It says that the ND filter is available in any of the regular recording programs, and furthermore "when set to Automatic, ND filter settings will be available when the aperture setting is 4.0"
Does that mean that the camera will use the ND filter to keep the aperture at f 4??
If I set exposure for Auto with Shutter priority at 1/60th, will the camera dial in the ND on a bright day to keep aperture at f 4??
I would love it if someone could share some detail on this.
Thanks

[Don Palomaki]

That essentially corresponds to my understanding. No ND at f/4.0, ND1/8 in place by f /4.8

If you select Manual Exposure/Av and adjust the aperture you will see on the scale that between f/4.0 and f/4.8 there are marked three ND levels. Whether this is introduced as a uniform gradient or steps I do not know for sure.

[Robert Young]

So, basically if the ND filter is turned on in the menu, it will work in the background to keep the aperture in the "sweet" area around f 4.0 shooting in P and Tv as well, or only Av mode?
It sounds like pretty clever technology that I've not seen on the Sony cams.
It's both surprising and frustrating that they don't provide more detail in the manual

[Jody Arnott]

Originally Posted by Robert Young

So, basically if the ND filter is turned on in the menu, it will work in the background to keep the aperture in the "sweet" area around f 4.0 shooting in P and Tv as well, or only Av mode?
It sounds like pretty clever technology that I've not seen on the Sony cams.
It's both surprising and frustrating that they don't provide more detail in the manual

From what I've read, the XA10 doesn't have a physical ND filter in the traditional sense. It uses negative gain and other software tricks to emulate an ND filter. Someone please correct me if I'm wrong.. it's just what I've read online.

I've owned an XA10 for a couple of years and generally it does work pretty well. I've never felt the need for a screw-on ND filter.

Although I have noticed that if in P or Av mode, sometimes it selects a high shutter speed on very bright days that results in stuttery footage. Best to select the shutter speed manually.

This thread discusses it in detail:
http://www.dvinfo.net/forum/canon-xa...tion-xa10.html

[Don Palomaki]

From what I've read, the XA10 doesn't have a physical ND filter in the traditional sense. It uses negative gain and other software tricks to emulate an ND filter. Someone please correct me if I'm wrong.. it's just what I've read online.

Per my understanding that is incorrect. It is a physical ND filter. If it were just a manipulation of gain you would see sensor saturation effects in bright situations. However, it is controlled by the camcorder electronics (whether or not it is in the light path). If you change ND filter from "auto" to off, it no longer appears on the aperture scale.while the available gain range (0-24 dB) remains the same. The ND range (ND1/8) is equivalent to 3 stops or about 24 dB of gain

However, using external ND filters makes sense if you want to use wide open apertures in bright light situations.

[Jody Arnott]

Originally Posted by Don Palomaki

Per my understanding that is incorrect. It is a physical ND filter. If it were just a manipulation of gain you would see sensor saturation effects in bright situations. However, it is controlled by the camcorder electronics (whether or not it is in the light path). If you change ND filter from "auto" to off, it no longer appears on the aperture scale.while the available gain range (0-24 dB) remains the same. The ND range (ND1/8) is equivalent to 3 stops or about 24 dB of gain

However, using external ND filters makes sense if you want to use wide open apertures in bright light situations.

Hrm, you might be right:

Canon XA10 Internal ND Filter Test on Vimeo

There's a lot of talk online about it being a "digital" ND filter though. Who knows. Either way, whatever it is, it works well.

[Don Palomaki]

And I can say the ND filter on my XH A1 is digital - I use my finger to turn it on <g>.

One way to check would be to watch the video noise floor in manual mode as the aperture ND is changed with the lens on and a light-proof cap on. If the ND is implemented through gain the noise floor will change correspondingly. If it is a physical filter the noise floor should remain unchanged.