View Full Version : Dots on the footage


Robert Bale
August 29th, 2015, 11:52 PM
Hi, can any one tell me where or why there are small purple dots at the top right of the screen.
dots_converted on Vimeo
Thanks.

Paul Hardy
August 30th, 2015, 12:31 AM
Damaged Sensor by the looks of it - If it's still under warranty, I'd send it back to Sony & get it replaced!

I had something similar on a previous NX70 camera & it was sensor damage caused by disco lasers - It required a new sensor & was covered by business insurance luckily. Don't know if you ever film discos??

Good Luck



edit:

Yes it's definitely damaged by lasers - the Purple is where there's damage to the green part of the Bayer filter - there's an article at http://www.laserist.org/camera-sensor-damage-thesis.htm

Robert Bale
August 30th, 2015, 04:36 AM
Oh Crap, yeah a few weeks back we were filming a concert and they were using 2 lasers, I did ask them to point them up so they did not point straight at the camera but it must of still hit the top of the sensor. It is under warranty, so I will send it in and see what happens.

Chris Harding
August 30th, 2015, 04:52 AM
Most definitely laser damage to the sensor ..we have seem this quite a few times on the forum and the venue always had lasers present..there has to be a lesson learned here. I wonder if that is classed as a warranty repair ...you might have to pay for a new sensor in this case and I bet you will make sure they are always behind you at the next event!

Maybe on paid events we need to start putting a laser damage clause as this is starting to happen more and more as DJ's get fancier lighting??

Lou Bruno
August 30th, 2015, 05:58 AM
Yep....lazer damage......replace sensor....expensive....

Noa Put
August 30th, 2015, 06:03 AM
A few weddings back lasers where used, I always shot with the camera pointed away from them, they where pointed toward the guests so I asked the dj if they where not dangerous since they could damage a sensor meaning an eye could suffer the same damage. He then adjusted the lasers to point higher because I pointed out there where children in the venue as well. :) But it certainly is something to avoid pointing your camera at at all times.

Robert Bale
August 30th, 2015, 10:52 PM
Maybe on paid events we need to start putting a laser damage clause as this is starting to happen more and more as DJ's get fancier lighting??
Yep Thats the plan, If there are Laser used my camera are going to be off.

Andrew Smith
August 31st, 2015, 05:16 AM
Actually, I'm wondering if it might be some kind of damaged lens element as there is movement on the whole field of dots from 0:03 to 0:04 and 0:06 to 0:07 when the lens (it seems) arrives at the end of its range. Or there is some sensor based image stabilisation at play in the clip.

Still, it's a bit of a bummer to have that happen.

Andrew

Paul R Johnson
August 31st, 2015, 07:01 AM
In the UK we have plenty of legislation on lasers for entertainment purposes and scanning the audience is an absolute no-no, but loads of dodgy dave double decks have no clue - and they just buy the kit and shine it on the audience. The impact on your retina would be equally destructive, and probably life changing.

Back in the tube days, we destroyed them when shooting videos of arc welding, and now that seems ok, but cheap lasers do more damage!


Out of interest, as it is just a few pixels is there a service routine to take them out of the scan on these cameras. Like the older dead pixel fix?

Paul Hardy
August 31st, 2015, 08:49 AM
Actually, I'm wondering if it might be some kind of damaged lens element as there is movement on the whole field of dots from 0:03 to 0:04 and 0:06 to 0:07 when the lens (it seems) arrives at the end of its range. Or there is some sensor based image stabilisation at play in the clip.

Still, it's a bit of a bummer to have that happen.

Andrew
No, the horizontal & vertical movement will be from the active stabilisation which uses a mix of digtal & optical stabilising methods. The zooming of the dots looks like it's due to using the clear image zoom feature.

Robert Bale
August 31st, 2015, 04:53 PM
So Sony Australia has replied to me, "yes this looks like laser damage, sensor replacement cost is $600 plus labour" well, well well, looks like it going to be expensive, i wonder if i could purchase the sensor and have a local camera tech fit it. hmmm,

Chris Harding
September 1st, 2015, 12:07 AM
Hi Rob

That is an expensive bummer but you have little choice! Problem is at a wedding it's not the bride's fault ..it's the DJ and the DJ doesn't book us or care!! So what do you do at an event ...Talk to the lighting guy and ask if they have lasers or who really books you? I think they need to be made aware that you will not film if lasers are used and at most concerts they are part of the show. Concerts would be a tricky situation to handle unless you make sure you only film where the lasers don't have the angle to damage your camera??? Were you at the back and the lasers up front?? Is it actually possible to get decent shots at a concert and have camera positions that cannot be in the line of fire??

I guess I would send it straight to Sony and bite the bullet and pay your money..It's gonna be close to $1000 in the end!!!

Dave Dyar
September 1st, 2015, 12:36 AM
Going forward, I wonder if some enterprising company could come up,with a filter that would prevent this kind of damage without screwing up the image too badly.

Andrew Smith
September 1st, 2015, 02:17 AM
It would have to be partially silvered like a one way mirror. You'd lose a bit of light coming in to the lens, but it could be enough to deflect enough of the laser light off the surface that it would save you from sensor damage.

Its a matter of what size the market for this would be, and if it did indeed work correctly.

Andrew

Craig Seeman
September 1st, 2015, 11:55 AM
If you're being hired to shot in environments which have (or may have unannounced) lasers, you may need to have a clause regarding sensor damage liability. How you handle may depend on the client and circumstances.

You may need to examine the possibility of insurance coverage and pass that cost on to the client, for example. A refundable deposit for potential sensor damage. Another may be to simply clarify your right to not shoot should a laser be turned on with no change in the fees for the job. Otherwise have an increase fee for jobs that include lasers to cover the potential cost.

Jeff Harper
September 1st, 2015, 12:28 PM
I appreciate this thread as a caution against lasers. I personally put fixed cameras next to DJ aiming away from lights, thereby avoiding most extraneous light, but when I'm wandering around handheld I will be extra careful.

Tom Grushka
September 2nd, 2015, 01:40 AM
Wow, thanks for this thread guys. Now I won't film anything with lasers with my X70 or my a6000. :(

Found this info on the polarization of laser light:

https://www.physicsforums.com/threads/is-laser-light-polarized-or-unpolarized.282195/

Maybe someone could come out with a set of specialized polarizer filters to filter out laser light, and they could be marked by the type of laser they filter, so people who need to film these shows could protect their cameras as much as possible?

EDIT: Would only really work if the laser light coming "directly" into the camera is attenuated but from the side, reflected off a mountainside or smoke in the sky, etc. is not.

Robert Bale
September 4th, 2015, 06:43 AM
Thanks all, yes its a good lesson for all, and expensive one for me, as the repair cost is going to be the same cost for the Job, what shits me is your right, the Laser guy said to me, you be right they are pointing up a bit, not at the camera, I didn't realise just how quick it can happen. I will get a screen shot from the footage and post it tomorrow.

Paul Anderegg
September 8th, 2015, 06:03 PM
OMG that sucks Robert! :(

I saw the exact same red dots on a Canon DSLR forum, a guy rented out his 5D and got it back with those!

I thought the days of tube camera burn in were long gone.

Paul