Dead pixels and what to do?

[Christoffer Glans]

I'm wondering about what dead pixel policy Red has? I tested some 1fps timelapse shots and ended up with a lot of dead pixels on my brand new Weapon 6K. Now some say that a black shade calibration will do the trick, but haven't Weapon been calibrated and should work with the auto-calibration it has? The "numbers" are all in the green. If I can do something about it I want to know what. If I cannot do anything about it, then this is pretty bad for a $29500 camera. I don't remember my Epic Dragon being like this.

Here's a R3D of a stopped down part of the shot.
Download

 

[Phil Holland]

I'm wondering about what dead pixel policy Red has? I tested some 1fps timelapse shots and ended up with a lot of dead pixels on my brand new Weapon 6K. Now some say that a black shade calibration will do the trick, but haven't Weapon been calibrated and should work with the auto-calibration it has? The "numbers" are all in the green. If I can do something about it I want to know what. If I cannot do anything about it, then this is pretty bad for a $29500 camera. I don't remember my Epic Dragon being like this.

Here's a R3D of a stopped down part of the shot.
Download

Sensor Calibration and when to perform a Black Shade is a fundamental part of using your camera. While it does leave the factory with a factory calibration you should really perform a your own Sensor Calibration.

Specifically in the case of your 1 second exposure time, you should create a a specific Manual Capture Sensor Calibration at that shutter speed.

While Auto Capture does indeed capture 16 different exposures to build it's calibration curve profile, that would be generally be considered for anything between 1/8th through 1/8000th filming (if I recall correctly). I imagine the camera applied it's best guess at a map for your super long exposure, but I'm fairly certain 1 second exposures are outside of it's Auto Capture range.

Do remember that ambient outside temperature ranges do indeed effect your Sensor Calibration. More or less one of the first things you should do once you receive your camera is perform at least an Auto Capture Sensor Calibration.

Also, just out of curiousity, next time post 5 frames up. Because you are doing longer exposures there's potential for other things to jump onto your sensor that may produce something similar to hot pixel, but actually being something else entirely.

And yes, at 1 second exposure Epic Dragon was exactly like this.

 

[Christoffer Glans]

Yeah, I figured as much. I did do a lot of cals on my old Epic, just thought it wasn't needed anymore. Can I create automatic cals for different temperatures? Like having one automation for interior and exterior summer and one for cold (Sweden you know :tongue_smilie
I can upload a few more frames, although those pixels in that frame are stuck throughout. Some also shift in color between red, green and blue, maybe because of the debayer process.

I'm gonna do a cal tonight and see if it gets better. I will return with the result.

 

[Marcus Friedlander]

We have been discussing a similar issue in the weapon sub-forum. Does this mean that manual calibration is still the preferred method for optimal image quality at a particular exposure time?

 

[Christoffer Glans]

We have been discussing a similar issue in the weapon sub-forum. Does this mean that manual calibration is still the preferred method for optimal image quality at a particular exposure time?

Yes, but you don't have to do it as much as on the Epic. Before you needed to do one per exposure (shutter) and temperature based on wether or not the numbers were in the green/yellow/red or not. Now you only need to do one auto-cal for a certain environmental temperature and then you will have all exposures for that... although it seems not for time lapse as slow as the one I did. If the shooting temp is the same in both studio/interior and exteriors then you only have to have one auto-cal for that. However if you do work in colder places where you shoot in cold weather and then interior warm temperatures you have to have one auto-cal for the outside cold temperature and one for the interior shooting in order to reach optimal quality.

But I've yet to tested out the auto-cal feature. Maybe Phil could weight in on this?

 

[David Battistella]

For any of that long exposure stuff you really need to do a calibration at exactly the settings on the camera preferably right before you start capturing in the temperature and circumstances of the situation. . I would not expect the auto calibration to cover this.

FWIW, in the file you provided. Regular Dragoncolor over DragonColor 2 helps your image a fair bit.

David

 

[Graeme Nattress]

Don't do 1 second exposures unless you can't avoid it. Use frame-averaging to average up to 16 smaller exposures to make one long one. Don't worry that you have to bump the ISO up to see the result as it will be as clean as a whistle.

Graeme

 

[Eric Santiago]

Don't do 1 second exposures unless you can't avoid it. Use frame-averaging to average up to 16 smaller exposures to make one long one. Don't worry that you have to bump the ISO up to see the result as it will be as clean as a whistle.

Graeme

Priceless

 

[Björn Benckert]

Don't do 1 second exposures unless you can't avoid it. Use frame-averaging to average up to 16 smaller exposures to make one long one. Don't worry that you have to bump the ISO up to see the result as it will be as clean as a whistle.

Graeme

Grame, Question can you not also make a function in the Record processing menu that allow us to skip every second or such.

For example so we can set it to frame average 10 and then skip odd... So it would record 10 frames average them, then record 10 frames and reject them, then record 10 frames and save them. etc...

If using 360 shutter that would give us frame sum 10 and equal to 180 deg shutter allready in camera. As it is now it has to be speeded up by 200% in post to get such result.

and it would be cool to to even have higher skip numbers, like skip 3 out of 4 or even higher.

 

[Christoffer Glans]

Don't do 1 second exposures unless you can't avoid it. Use frame-averaging to average up to 16 smaller exposures to make one long one. Don't worry that you have to bump the ISO up to see the result as it will be as clean as a whistle.

Graeme

But does that remove dead pixels? I don't have a problem with noise patterns and so on, but dead pixels are dead pixels, right? From my understanding, I'll get rid of them by letting the calibration map and "clonetool" them away in lack of better words, but they are still dead or stuck? And there's a lot of them as I can see.

 

[David Battistella]

What you are showing here is essentially the same as Bjorn's "macbook test" which I was able to duplicate. You might just be dealing with how the sensor is. Scroll through this thread to see that I was able to duplicate exactly what Bjorn was seeing.

http://www.reduser.net/forum/showth...e-stills-is-this-normal-for-dragon&highlight=

David

 

[Christoffer Glans]

What you are showing here is essentially the same as Bjorn's "macbook test" which I was able to duplicate. You might just be dealing with how the sensor is. Scroll through this thread to see that I was able to duplicate exactly what Bjorn was seeing.

http://www.reduser.net/forum/showth...e-stills-is-this-normal-for-dragon&highlight=

David

What I'm seeing is traditional dead pixels like I've encountered with my digital still cameras. But I dunno, it scares me a little that this seems to be common?

 

[Phil Holland]

What I'm seeing is traditional dead pixels like I've encountered with my digital still cameras. But I dunno, it scares me a little that this seems to be common?

Common at long exposure times such as what you are doing. Give 1/24th-1/8000th a go and tell us what you see.