ND Filters for HV20? at DVinfo.net

Marty Hudzik · February 28th, 2007, 10:07 AM

In an effort to maximize the quality of the image recorded on the HV20, wouldn't you need to use an ND filter for bright outside shots? I realize the camera will try to adjust exposure by stopping down the iris and by upping the shutter speed, but these cause undesirable effects. I assume the HV20 will suffer form loss of sharpness when iris is closed significantly just as other HDV cameras do. Also, higher shutter speed are only going to exxagerate the "juddering" that we see with 24P material already.

So if I want to roll an HV20 for a backup to an A1 or an H1 that is running 24f and 1/48 shutter, I may need an external ND filter to match. At least in bright scenes. I don't mind letting a consumer cam handle some of the exposure automatically but I do not want the shutter speed to vary.

Currently the only auto exposure controls these small cameras have are the iris and shutter, right? No "psuedo" internal ND filters or anything?

Recently I shot some snow scenes with my H1 and found that I had to have both ND filters engaged, the gain at -3 and the iris was still at 8 or 9. I had to increase the shutter speed to 1/120 to get a decent exposure...and at this point the motion signature was different and I was still at a relatively high fstop still.

So how do we compensate for this? Are there ND filters for such small cameras such as the HV10/HV20?

Thanks!

Marty Hudzik · March 4th, 2007, 09:23 PM

Nobody can weigh in on this? There are no internal ND filters in this baby....right?

Rich Dykmans · March 4th, 2007, 09:42 PM

The HV10 has two internal ND's but they are not controllable. I bought an ND6 for my HV10. I'm sure the HV20 will be the same.

Marty Hudzik · March 4th, 2007, 09:48 PM

Can you point me to documentation of this? I have never heard of this in a "consumer" camera in this class. Is there a mechanism to engage them internally or are we talking about 2 "virtual" ND filters? Kinda like a negative gain in the DSP?

I have always seen this class of camera simply increase the shutter speed to compensate for too much light coming in when it cannot stop down the iris any further. If there is indeed some type of ND in the optical path that would be cool....but it seems unlikely.

Thanks.

Rich Dykmans · March 4th, 2007, 10:39 PM

Canon talks about the "ND gradation" feature of the HV10 on their website and in an earlier thread someone actually posted a link to a diagram showing them in the optical path. Evidently these are common in some of the earlier Canon DV consumer cams as well. I was surprised as well, but as they are not usable in the traditional sense, it still pays to add actual ND filters when shooting outdoors.

Rich Dykmans · March 4th, 2007, 10:49 PM

Marty, ck out this thread:

http://dvinfo.net/conf/archive/index.php/t-81516.html

Marty Hudzik · March 5th, 2007, 07:33 AM

Thanks for the link. I am hoping this helps with the image quality. As I said, recently I was shooting outside with my H1 and had both NDs engaged, -3 gain and iris in the 8 range and it was still over-exposed a little. This made me think of the HV10 that I had before and how would it handle this same scenario with only iris and shutter to compensate for the exposure.

Now it sounds more and more like there is an actual ND filter in the optical path....so I feel a little more assured that bright shots won't get too blown out or have to go to 1/500th shutter speed to expose properly.

Peace!

Ron Lemming · March 5th, 2007, 09:21 AM

And if that doesn't work, just buy an ND filter and screw it on. :)

Austin Meyers · March 19th, 2007, 01:00 AM

marty, you were talking about having to have both nd filters engaged shooting in the snow, have you used an polarizer? i've done a fair amount of shooting on water with a lot of reflection, and the polarizers help much more than cranking the nds up. just a thought...

Rich Dykmans · March 19th, 2007, 06:09 AM

I used an ND.6 onboard while doing a bunch of shooting in the snow. That worked out well along with shooting manual and using the zebras.

February 28th, 2007, 10:07 AM	#1
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	ND Filters for HV20? In an effort to maximize the quality of the image recorded on the HV20, wouldn't you need to use an ND filter for bright outside shots? I realize the camera will try to adjust exposure by stopping down the iris and by upping the shutter speed, but these cause undesirable effects. I assume the HV20 will suffer form loss of sharpness when iris is closed significantly just as other HDV cameras do. Also, higher shutter speed are only going to exxagerate the "juddering" that we see with 24P material already. So if I want to roll an HV20 for a backup to an A1 or an H1 that is running 24f and 1/48 shutter, I may need an external ND filter to match. At least in bright scenes. I don't mind letting a consumer cam handle some of the exposure automatically but I do not want the shutter speed to vary. Currently the only auto exposure controls these small cameras have are the iris and shutter, right? No "psuedo" internal ND filters or anything? Recently I shot some snow scenes with my H1 and found that I had to have both ND filters engaged, the gain at -3 and the iris was still at 8 or 9. I had to increase the shutter speed to 1/120 to get a decent exposure...and at this point the motion signature was different and I was still at a relatively high fstop still. So how do we compensate for this? Are there ND filters for such small cameras such as the HV10/HV20? Thanks!

March 19th, 2007, 01:00 AM	#9
Austin Meyers Contributor Join Date: Aug 2005 Location: austin, tx Posts: 300	nd filters vs polarizing filters marty, you were talking about having to have both nd filters engaged shooting in the snow, have you used an polarizer? i've done a fair amount of shooting on water with a lot of reflection, and the polarizers help much more than cranking the nds up. just a thought... __________________ Compositing is my life right now. IMDB page: http://www.imdb.com/name/nm3596782/

March 4th, 2007, 09:23 PM	#2
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Nobody can weigh in on this? There are no internal ND filters in this baby....right?

March 4th, 2007, 09:42 PM	#3
Rich Dykmans Regular Crew Join Date: Dec 2006 Location: Discovery Bay, CA Posts: 138	The HV10 has two internal ND's but they are not controllable. I bought an ND6 for my HV10. I'm sure the HV20 will be the same.

March 4th, 2007, 09:48 PM	#4
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Can you point me to documentation of this? I have never heard of this in a "consumer" camera in this class. Is there a mechanism to engage them internally or are we talking about 2 "virtual" ND filters? Kinda like a negative gain in the DSP? I have always seen this class of camera simply increase the shutter speed to compensate for too much light coming in when it cannot stop down the iris any further. If there is indeed some type of ND in the optical path that would be cool....but it seems unlikely. Thanks.

March 4th, 2007, 10:39 PM	#5
Rich Dykmans Regular Crew Join Date: Dec 2006 Location: Discovery Bay, CA Posts: 138	Canon talks about the "ND gradation" feature of the HV10 on their website and in an earlier thread someone actually posted a link to a diagram showing them in the optical path. Evidently these are common in some of the earlier Canon DV consumer cams as well. I was surprised as well, but as they are not usable in the traditional sense, it still pays to add actual ND filters when shooting outdoors.

March 4th, 2007, 10:49 PM	#6
Rich Dykmans Regular Crew Join Date: Dec 2006 Location: Discovery Bay, CA Posts: 138	Marty, ck out this thread: http://dvinfo.net/conf/archive/index.php/t-81516.html

March 5th, 2007, 07:33 AM	#7
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Thanks for the link. I am hoping this helps with the image quality. As I said, recently I was shooting outside with my H1 and had both NDs engaged, -3 gain and iris in the 8 range and it was still over-exposed a little. This made me think of the HV10 that I had before and how would it handle this same scenario with only iris and shutter to compensate for the exposure. Now it sounds more and more like there is an actual ND filter in the optical path....so I feel a little more assured that bright shots won't get too blown out or have to go to 1/500th shutter speed to expose properly. Peace!

March 5th, 2007, 09:21 AM	#8
Ron Lemming Regular Crew Join Date: Oct 2006 Location: Sweden Posts: 46	And if that doesn't work, just buy an ND filter and screw it on. :)

March 19th, 2007, 06:09 AM	#10
Rich Dykmans Regular Crew Join Date: Dec 2006 Location: Discovery Bay, CA Posts: 138	I used an ND.6 onboard while doing a bunch of shooting in the snow. That worked out well along with shooting manual and using the zebras.