disappearing hot pixels at DVinfo.net

Barry Goyette · October 29th, 2007, 10:11 AM

I went to a concert the other night which featured a great Tango Quartet and some professional Tango dancers. I brought along my XLH1 and shot some random stuff during a class before the show, and later the dancers performing before an audience. When I returned home to view the footage, I notice two hot pixels (one of which appeared to be a block of 2-4 pixels) on the footage taken earlier in the evening. Alarmed, as I've never seen this on any video camera I've owned...I forwarded through to the later stuff (during which the camera had been switched off, restarted and gain adjusted)...and walah...no hot pixels on the later footage..

Anyone else ever see this...?

Peter Ralph · October 29th, 2007, 11:26 AM

it is common for hot pixels only to be visible under high gain settings - hot pixels can be mapped out by Canon service

Barry Goyette · October 29th, 2007, 01:24 PM

What's interesting was that the later footage, in fact, had a higher gain setting than the earlier stuff...and both areas of hot pixel had completely disappeared...

Pete Bauer · October 29th, 2007, 01:59 PM

Could it have just been dust specks?

Anyway, clean the lens, put the lens cap on, crank the gain, and shoot a few seconds of behind-the-lens-cap-black video to see if it appears at max gain as P.R. alluded to.

Barry Goyette · October 29th, 2007, 02:31 PM

nah...they were bright white pixels in two spots...one was quite bright...looking like a block of 2 or 4...the other was small, probably just one pixel. and both were very sharp. (Dust would be dark...or if flared...light, but would change with any zooming..possibly sharp at widest settings, but would blur and then disappear when zoomed in). these were in the same position (and sharpness) at all zoom levels...hot pixels. and then...no hot pixels.

I will be checking everything again, I just was curious if anyone else had seen this before...

Barry

Marty Hudzik · October 29th, 2007, 02:55 PM

Barry, I have seen this with my H1. I see 2 hot pixels from time to time. It is more often with gain at +6 and a a slowere shutter speed but they appear from time to time. One is blue and one is red. I have been contemplating sending it in to have these pixels mapped out but do not know what the charge would be.

Anyone have a rough idea what Canon would charge for this service?

Barry Goyette · October 29th, 2007, 03:03 PM

Ha, Marty...I knew it would be you...

I think it's interesting....Mine popped up when my gain was at +6 as well...but when I increased it to +12 (after turning the camera off) they disappeared...which of course makes no sense...I'll report back if I see them again.

how sporadic has yours been?...I don't use my camera a lot...but I'm hoping this was just a one time event.BG

Marty Hudzik · October 29th, 2007, 03:22 PM

Off the top of my head I would say that I have seen it 3-4 times in the last year. I was testing a LetusXL the other day and it this adapter eats light for lunch. I was indoors so I stepped up the gain to +6 and I didn't see it. But when I pushed it to +12 they showed up. Then I stepped back down to +6 and they were visible still. All the way down to zero and I could barely make them out.

Later, when I started at 0 they were gone. Is is possible these things actually "heat" up when set to higher gain and then cool down? I wouldn't think so but I guess it is possible cause they aren't there, appear after gaining up and then linger.....hmmmm....

Barry Goyette · October 29th, 2007, 03:42 PM

I'm just thinking of something...we had a bit of rain and tropical humidity that day (which is unusual here in Southern California, especially after a week of wildfires)...the room we were in was heated, but this was after a long walk across campus to the auditorium...I'm wondering if humidity was the culprit...and after I'd been in the room for 45minutes with the heater on...things dried out....

hmmm.

Harry Bromley-Davenport · November 6th, 2007, 12:03 AM

I too have rashes of hot pixels which come and go.

Has anyone had any success in getting Canon to fix this in their service department?

Harry

Jon Bickford · November 9th, 2007, 03:44 AM

i took mine in to canon in irvine about a month ago for the exact same problem. it was $240 to map the pixels, they did a cleaning and firmware update. still pretty steep for something like that on a prosumer cam.

Harry Bromley-Davenport · November 9th, 2007, 06:27 AM

Thanks for the reply. I will send mine in to have the pixels mapped out. It's a pain in the neck. I have five scattered all over the screen which come and go, but I am supplying Canon with frame enlargements so, hopefully, they can locate them since, maddeningly, all pixels are working at the moment.

Harry.

Floris van Eck · February 16th, 2008, 12:41 PM

I also see one hot pixel now and then. So annoying. I might ship mine to Canon as well. What a waste of money. Shouldn't happen.

Marty Hudzik · February 16th, 2008, 02:39 PM

Has anyone found any pattern to this yet? I have 2 of them that come and go. They are really not noticable unless shooting with +3 gain and a slower shutter speed and in a dark setting. I shot in California for a week in January and didn't see a single sign of them. Then, first time I go to shoot back here in Ohio, they pop up. And I can only see them in the viewfinder when I have peaking turned on otherwise I wouldn't have seen them until post on this project.

Bummer.

Kevin Martorana · February 16th, 2008, 03:58 PM

Interesting,....I had just posted this in the P&S Technik forum...

I had seen this for the first time last summer...using a 35mm adapter...and now...once again...the same pixel...

"We used the adapter 400 series....last week.

After the camera was "warm"...the same pixel that showed up last summer...showed up again. But with the standard 20x lens on...it doesn't.

We were shooting at 0 db in the studio. So...as folks have said...is this just a "feature" of using the adapter...and having the image "smooth"...compaired to a sharper image with the standard lens ?

Or should I have the camera sent back to Canon...to have them map the pixel ?

Thanks....and BTW...I'll post some shots of this...and a small video clip...
Footage looks great...and I used a Cook 18-100 zoom lens."

Some folks suggest that with the use of the 35mm adapter and lens....the contrast ratio may allow the pixel to be "seen". I only have been seeing this pixel when using this adapter...AND....only at 0db...NOT at a higher db setting.

October 29th, 2007, 10:11 AM	#1
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	disappearing hot pixels I went to a concert the other night which featured a great Tango Quartet and some professional Tango dancers. I brought along my XLH1 and shot some random stuff during a class before the show, and later the dancers performing before an audience. When I returned home to view the footage, I notice two hot pixels (one of which appeared to be a block of 2-4 pixels) on the footage taken earlier in the evening. Alarmed, as I've never seen this on any video camera I've owned...I forwarded through to the later stuff (during which the camera had been switched off, restarted and gain adjusted)...and walah...no hot pixels on the later footage.. Anyone else ever see this...?

October 29th, 2007, 01:59 PM	#4
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	Could it have just been dust specks? Anyway, clean the lens, put the lens cap on, crank the gain, and shoot a few seconds of behind-the-lens-cap-black video to see if it appears at max gain as P.R. alluded to. __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

November 9th, 2007, 03:44 AM	#11
Jon Bickford Major Player Join Date: Nov 2004 Location: Las Vegas, NV., Los Angeles, CA, Posts: 220	i took mine in to canon in irvine about a month ago for the exact same problem. it was $240 to map the pixels, they did a cleaning and firmware update. still pretty steep for something like that on a prosumer cam. __________________ Jon Bickford, Trepany Films San Pedro, CA Trephine001@aol.com

February 16th, 2008, 03:58 PM	#15
Kevin Martorana Major Player Join Date: Mar 2007 Location: Lancaster, PA Posts: 250	Interesting,....I had just posted this in the P&S Technik forum... I had seen this for the first time last summer...using a 35mm adapter...and now...once again...the same pixel... "We used the adapter 400 series....last week. After the camera was "warm"...the same pixel that showed up last summer...showed up again. But with the standard 20x lens on...it doesn't. We were shooting at 0 db in the studio. So...as folks have said...is this just a "feature" of using the adapter...and having the image "smooth"...compaired to a sharper image with the standard lens ? Or should I have the camera sent back to Canon...to have them map the pixel ? Thanks....and BTW...I'll post some shots of this...and a small video clip... Footage looks great...and I used a Cook 18-100 zoom lens." Some folks suggest that with the use of the 35mm adapter and lens....the contrast ratio may allow the pixel to be "seen". I only have been seeing this pixel when using this adapter...AND....only at 0db...NOT at a higher db setting. __________________ Shooting Video since 1/2" EIAJ reel to reel and editing on 2" QUAD machines. http://www.takeoneprod.com

October 29th, 2007, 11:26 AM	#2
Peter Ralph Major Player Join Date: Feb 2007 Location: Denver/Vail Colorado Posts: 254	it is common for hot pixels only to be visible under high gain settings - hot pixels can be mapped out by Canon service

October 29th, 2007, 01:24 PM	#3
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	What's interesting was that the later footage, in fact, had a higher gain setting than the earlier stuff...and both areas of hot pixel had completely disappeared...

October 29th, 2007, 02:31 PM	#5
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	nah...they were bright white pixels in two spots...one was quite bright...looking like a block of 2 or 4...the other was small, probably just one pixel. and both were very sharp. (Dust would be dark...or if flared...light, but would change with any zooming..possibly sharp at widest settings, but would blur and then disappear when zoomed in). these were in the same position (and sharpness) at all zoom levels...hot pixels. and then...no hot pixels. I will be checking everything again, I just was curious if anyone else had seen this before... Barry

October 29th, 2007, 02:55 PM	#6
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Barry, I have seen this with my H1. I see 2 hot pixels from time to time. It is more often with gain at +6 and a a slowere shutter speed but they appear from time to time. One is blue and one is red. I have been contemplating sending it in to have these pixels mapped out but do not know what the charge would be. Anyone have a rough idea what Canon would charge for this service?

October 29th, 2007, 03:03 PM	#7
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	Ha, Marty...I knew it would be you... I think it's interesting....Mine popped up when my gain was at +6 as well...but when I increased it to +12 (after turning the camera off) they disappeared...which of course makes no sense...I'll report back if I see them again. how sporadic has yours been?...I don't use my camera a lot...but I'm hoping this was just a one time event.BG

October 29th, 2007, 03:22 PM	#8
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Off the top of my head I would say that I have seen it 3-4 times in the last year. I was testing a LetusXL the other day and it this adapter eats light for lunch. I was indoors so I stepped up the gain to +6 and I didn't see it. But when I pushed it to +12 they showed up. Then I stepped back down to +6 and they were visible still. All the way down to zero and I could barely make them out. Later, when I started at 0 they were gone. Is is possible these things actually "heat" up when set to higher gain and then cool down? I wouldn't think so but I guess it is possible cause they aren't there, appear after gaining up and then linger.....hmmmm....

October 29th, 2007, 03:42 PM	#9
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	I'm just thinking of something...we had a bit of rain and tropical humidity that day (which is unusual here in Southern California, especially after a week of wildfires)...the room we were in was heated, but this was after a long walk across campus to the auditorium...I'm wondering if humidity was the culprit...and after I'd been in the room for 45minutes with the heater on...things dried out.... hmmm.

November 6th, 2007, 12:03 AM	#10
Harry Bromley-Davenport Major Player Join Date: Dec 2004 Location: LA CA Posts: 317	I too have rashes of hot pixels which come and go. Has anyone had any success in getting Canon to fix this in their service department? Harry

November 9th, 2007, 06:27 AM	#12
Harry Bromley-Davenport Major Player Join Date: Dec 2004 Location: LA CA Posts: 317	Thanks for the reply. I will send mine in to have the pixels mapped out. It's a pain in the neck. I have five scattered all over the screen which come and go, but I am supplying Canon with frame enlargements so, hopefully, they can locate them since, maddeningly, all pixels are working at the moment. Harry.

February 16th, 2008, 12:41 PM	#13
Floris van Eck Major Player Join Date: Jan 2006 Location: The Netherlands Posts: 993	I also see one hot pixel now and then. So annoying. I might ship mine to Canon as well. What a waste of money. Shouldn't happen.

February 16th, 2008, 02:39 PM	#14
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Has anyone found any pattern to this yet? I have 2 of them that come and go. They are really not noticable unless shooting with +3 gain and a slower shutter speed and in a dark setting. I shot in California for a week in January and didn't see a single sign of them. Then, first time I go to shoot back here in Ohio, they pop up. And I can only see them in the viewfinder when I have peaking turned on otherwise I wouldn't have seen them until post on this project. Bummer.