Vertical flaring of bright light sources at DVinfo.net

Bruce Simpson · April 23rd, 2004, 10:10 PM

I was filming some video the other night with my MX500 and discovered that it really doesn't like bright light sources against a dark background.

As you'll see in this framegrab there's a noticeable vertical artifact which appears under such conditions.

There were much worse examples of this but this was the only frame-capture I have at hand.

Is this normal and does it simply indicate that the camera is built to a price.

Other than a few niggly little things, I'm quite happy with my MX500 and have taken some (for me) really good footage with it over the past 12 months.

Frank Granovski · April 24th, 2004, 12:06 AM

Quote:

I was filming some video the other night with my MX500 and discovered that it really doesn't like bright light sources against a dark background.

Actually, no video cam or still cam "likes" this, unless the light is positioned correctly, and the exposure is correct and locked.

Dave Largent · April 24th, 2004, 12:53 AM

Bruce, that's mild compared to the Sony VX.

Frank Granovski · April 24th, 2004, 02:20 AM

For a full list of miniDV cam faults, check this out:

http://www.ferrario.com/ruether/vid_pict_characts.htm

For more informative links, see my list here:

http://www.dvfreak.com/links.htm

Bruce Simpson · April 24th, 2004, 02:43 AM

Thanks Frank, that was interesting reading.

Andre De Clercq · April 24th, 2004, 04:28 AM

Allways set no higher than 1/60(1/50) if you want to avoid vertical streaks in critical situations. If e.g. 1/10000 is chosen, just remember that the effective light captured by the fotodiodes on the CCD corresponds with 1/10000 sec, but the high amount of light, (needed because of the short shutter setting) "shines" on yr CCD during the full 1/60(1/50), all the time generating leakage photons, which are further being transferred and generate the vertical streaks. For the same scene at 1/60(1/50) you will have to set for a higher f-number and/or use ND filters. Both reduce the amount of light (and the leakage!)on the CCD

Wayne Orr · April 24th, 2004, 02:26 PM

I hope you don't hate me for saying this, Bruce, but even without the vertical streaks, that is a dreadful picture. Way underexposed. I am amazed at the number of examples of "camera error" we see that are from stills that exhibit "pilot error." I am reminded of the recent wedding photo that was terribly exposed, but the young lady who took the picture was concerned about the "blue spill," that was barely visible.

Before we start knocking our tools, perhaps we should work on our skills.

Bruce Simpson · April 24th, 2004, 02:35 PM

<<<-- Originally posted by Wayne Orr : I hope you don't hate me for saying this, Bruce, but even without the vertical streaks, that is a dreadful picture. -->>>

I don't mind you saying it -- because I'm the one *in* the picture, not the one taking it :-)

Everything was left on automatic for the person using the camera and it was almost pitch-black at the time so I wasn't expecting anything special -- but was interested to see the amount of flare/bleed produced.

Guy Bruner · April 24th, 2004, 03:26 PM

Bruce,
I'd love to see a short clip of that video...in spite of the *weak skills* exhibited. It seems to me to be an excellent depiction of the low light, auto mode ability of the MX500/DV953 as well as an interesting scene. Man! That looks like fun! If you need bandwidth, put it in the Members Album on my website.

Frank Granovski · April 24th, 2004, 03:43 PM

Bruce, one more thing. It's really difficult to get half decent video when one shoots in the dork. In fact, it's difficult taking stills too, in the dark. Man, I'm a bad speller. :-))

Rob Belics · April 24th, 2004, 05:12 PM

Do you mean shooting in the dork or shooting a dork?

Frank Granovski · April 24th, 2004, 05:30 PM

In the dark. :-))

Bruce Simpson · April 24th, 2004, 10:17 PM

Quote:

Originally posted by Guy Bruner : Bruce,
I'd love to see a short clip of that video...in spite of the *weak skills* exhibited. It seems to me to be an excellent depiction of the low light, auto mode ability of the MX500/DV953 as well as an interesting scene. Man! That looks like fun!

I've put up a 3.5MB MPEG1 file at: www.interestingprojects.com/jknightrun1.mpg

It's only rendered at a fairly low bitrate (750Kbps) but will give you some idea.

There's some daytime footage of the same activities at: www.interestingprojects.com/jkdayrun1.mpg

Guy Bruner · April 25th, 2004, 07:15 AM

Bruce,
I get an error on attempt to download...is the server offline? Ah, I see now. Your URL is wrong...leaves off the .COM.

Wayne Orr · April 25th, 2004, 11:17 AM

Now that I have seen the footage of your "rocket," I can say that what you are seeing is very common to chip cameras. They don't like hot sources of light, and you will often see this streaking in footage with headlights, or other bright lights in dark backgrounds. Not a problem exclusive to your camera.

For the technical explanation, read Andre De Clercq's post.

BTW, can I have your camera after you blow up? ;-}

Wayne

April 23rd, 2004, 10:10 PM	#1
Bruce Simpson Regular Crew Join Date: Apr 2004 Location: New Zealand Posts: 34	Vertical flaring of bright light sources I was filming some video the other night with my MX500 and discovered that it really doesn't like bright light sources against a dark background. As you'll see in this framegrab there's a noticeable vertical artifact which appears under such conditions. There were much worse examples of this but this was the only frame-capture I have at hand. Is this normal and does it simply indicate that the camera is built to a price. Other than a few niggly little things, I'm quite happy with my MX500 and have taken some (for me) really good footage with it over the past 12 months. __________________ ----- No problem too small to baffle this expert

April 24th, 2004, 02:43 AM	#5
Bruce Simpson Regular Crew Join Date: Apr 2004 Location: New Zealand Posts: 34	Thanks Frank, that was interesting reading. __________________ ----- No problem too small to baffle this expert

April 24th, 2004, 02:26 PM	#7
Wayne Orr Major Player Join Date: Dec 2002 Location: Northridge Ca Posts: 734	I hope you don't hate me for saying this, Bruce, but even without the vertical streaks, that is a dreadful picture. Way underexposed. I am amazed at the number of examples of "camera error" we see that are from stills that exhibit "pilot error." I am reminded of the recent wedding photo that was terribly exposed, but the young lady who took the picture was concerned about the "blue spill," that was barely visible. Before we start knocking our tools, perhaps we should work on our skills. __________________ Wayne If it was easy, they'd get a relative to do it.

April 24th, 2004, 02:35 PM	#8
Bruce Simpson Regular Crew Join Date: Apr 2004 Location: New Zealand Posts: 34	<<<-- Originally posted by Wayne Orr : I hope you don't hate me for saying this, Bruce, but even without the vertical streaks, that is a dreadful picture. -->>> I don't mind you saying it -- because I'm the one in the picture, not the one taking it :-) Everything was left on automatic for the person using the camera and it was almost pitch-black at the time so I wasn't expecting anything special -- but was interested to see the amount of flare/bleed produced. __________________ ----- No problem too small to baffle this expert

April 24th, 2004, 12:53 AM	#3
Dave Largent Trustee Join Date: Aug 2003 Posts: 1,483	Bruce, that's mild compared to the Sony VX.

April 24th, 2004, 02:20 AM	#4
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	For a full list of miniDV cam faults, check this out: http://www.ferrario.com/ruether/vid_pict_characts.htm For more informative links, see my list here: http://www.dvfreak.com/links.htm

April 24th, 2004, 04:28 AM	#6
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	Allways set no higher than 1/60(1/50) if you want to avoid vertical streaks in critical situations. If e.g. 1/10000 is chosen, just remember that the effective light captured by the fotodiodes on the CCD corresponds with 1/10000 sec, but the high amount of light, (needed because of the short shutter setting) "shines" on yr CCD during the full 1/60(1/50), all the time generating leakage photons, which are further being transferred and generate the vertical streaks. For the same scene at 1/60(1/50) you will have to set for a higher f-number and/or use ND filters. Both reduce the amount of light (and the leakage!)on the CCD

April 24th, 2004, 03:26 PM	#9
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	Bruce, I'd love to see a short clip of that video...in spite of the weak skills exhibited. It seems to me to be an excellent depiction of the low light, auto mode ability of the MX500/DV953 as well as an interesting scene. Man! That looks like fun! If you need bandwidth, put it in the Members Album on my website.

April 24th, 2004, 03:43 PM	#10
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Bruce, one more thing. It's really difficult to get half decent video when one shoots in the dork. In fact, it's difficult taking stills too, in the dark. Man, I'm a bad speller. :-))

April 24th, 2004, 05:12 PM	#11
Rob Belics Major Player Join Date: Apr 2003 Location: St. Louis, MO Posts: 581	Do you mean shooting in the dork or shooting a dork?

April 24th, 2004, 05:30 PM	#12
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	In the dark. :-))

April 25th, 2004, 07:15 AM	#14
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	Bruce, I get an error on attempt to download...is the server offline? Ah, I see now. Your URL is wrong...leaves off the .COM.

April 25th, 2004, 11:17 AM	#15
Wayne Orr Major Player Join Date: Dec 2002 Location: Northridge Ca Posts: 734	Now that I have seen the footage of your "rocket," I can say that what you are seeing is very common to chip cameras. They don't like hot sources of light, and you will often see this streaking in footage with headlights, or other bright lights in dark backgrounds. Not a problem exclusive to your camera. For the technical explanation, read Andre De Clercq's post. BTW, can I have your camera after you blow up? ;-} Wayne