Dragon Black Cal - strange noise pattern at 12800

[Ivan Kovax]

Hey Guys,

Just received my upgrade to dragon and have black calibrated the sensor. When putting it at 12800ISO to see if it was an even calibration i noticed that the noise was not even as it was on an epic MX, rather it flickeres across the LCD in a more sporadic pattern.Additionally the noise when viewed at this ISO is more reddish. The MX was different to this in that it was a more greyish noise and it didn't flicker with the lens cap on at 12800.

The calibration looked even, but this dancing noise thing worry's me a tad. Has anybody else noticed the same thing or can somebody help explain this to me?

Cheers in advance.

Ivan

 

[Medavoym]

With a Dragon I played with a few weeks ago, when I pushed the ISO to the max, I noticed to the left side of the image areas which were indeed more redish/magenta. Definitely not uniform across the image.

BUT - that was a Dragon with the old OLPF, old calibration, old color science etc

Can you post a reference image/picture?

 

[Ivan Kovax]

With a Dragon I played with a few weeks ago, when I pushed the ISO to the max, I noticed to the left side of the image areas which were indeed more redish/magenta. Definitely not uniform across the image.

BUT - that was a Dragon with the old OLPF, old calibration, old color science etc

Can you post a reference image/picture?

Mine is uniform across the image, however it simply flickers lightly... I guess I can make a video to show you?

 

[John Marchant]

Normal in my experience - the slight overall flicker at mega-ISO has been there from earliest version through to now. Nothing that hurts the end result as far as I can tell.

 

[Nick Fury]

Anyone successfully Black Shade with 5.1.47? Any failed calibrations?

Thank you very much

fury

 

[Mark L. Pederson]

When putting it at 12800ISO to see if it was an even calibration

Ivan (and fellow Redusers) I'm not sure who started this whole "crank up your ISO to check your black calibration" thing - but let me just say ... it's a HIGHLY flawed way to check your calibration based on my experience.

RED put the "CAL: T/E" meter on the UI for purpose. That meter is very accurate - you want green/green - I can assure you that the "crank up your ISO to check your black calibration" thing is NOT always an accurate indication of weather your CalMap is solid or not - so ... I hope people just STOP using this flawed method and focus on the "CAL: T/E" meter on the UI.

 

[luigivaltulini]

ciao Ivan,
ehehe this is my first blackshding with dragon, same to you :

http://www.reduser.net/forum/showthread.php?110711-DRagon-but-what-is

I've also noticed this thing, already from 3200 ISO up, especially if you are in need of light.
I sent an email to the bomb, and the answer is to be normal this is Dragon.

What can I say to help you ... for example, even if the wrong concept, I use a calibration at 1/200 also shoot 25 frames, I find it more quiet in terms of flickers in low light conditions, when they are in normal conditions use the 1/50.
Now you can take with dragon 4 calibrations in the drawer ))

You have to shoot at night without light?

Ivan can you still make some reduser tokyo night for us :drool5:

 

[ericyoung]

Ivan (and fellow Redusers) I'm not sure who started this whole "crank up your ISO to check your black calibration" thing - but let me just say ... it's a HIGHLY flawed way to check your calibration based on my experience.

RED put the "CAL: T/E" meter on the UI for purpose. That meter is very accurate - you want green/green - I can assure you that the "crank up your ISO to check your black calibration" thing is NOT always an accurate indication of weather your CalMap is solid or not - so ... I hope people just STOP using this flawed method and focus on the "CAL: T/E" meter on the UI.

I'm pretty sure it was a Red suggestion originally. Also I fail to see how it is a highly flawed method - ISO should be a uniform gain as we rely on that to be the case if we up the ISO when we shoot. In fact on the MX, at 12800, you can watch a cold MX warm up and see the noise get more uniform as it reaches the calibrated temperature.

OK, 12800 is extreme and probably never used for real shooting, but if we crank up ISO to 2000, we'd certainly want the noise map to be uniform!

[Edit: Did a brief search, and the earliest mention I found was 7th Nov 2011 suggested by Phil Holland, which while not directly from Red, seems like a solid source
http://www.reduser.net/forum/showthread.php?66210-Scarlet-X-Data-Sheet
and in all the two years it's been mentioned as a check, Red have never contradicted that advice]

 

[Patrick Tresch]

Ivan (and fellow Redusers) I'm not sure who started this whole "crank up your ISO to check your black calibration" thing - but let me just say ... it's a HIGHLY flawed way to check your calibration based on my experience.

RED put the "CAL: T/E" meter on the UI for purpose. That meter is very accurate - you want green/green - I can assure you that the "crank up your ISO to check your black calibration" thing is NOT always an accurate indication of weather your CalMap is solid or not - so ... I hope people just STOP using this flawed method and focus on the "CAL: T/E" meter on the UI.

I don't know if it's flawed but it's the only visible way of doing it and it's an easy way to see if you'r way off.
CAL : T/E is a good check if you often performed the BS callibratoin... But doesn't tell you if your map is wrong. It only says if you'r in the specs that maches the BlackShade map and not if your map is up to date.

Checking before cal and after cal pushing the iso to highest level shows howmuch emproovement there is in the noise floor with the new map. I don't see why this should be flawed?

Please explain?

Thanks

Patrick

 

[Mark L. Pederson]

I don't know if it's flawed but it's the only visible way of doing it and it's an easy way to see if you'r way off.
CAL : T/E is a good check if you often performed the BS callibratoin... But doesn't tell you if your map is wrong. It only says if you'r in the specs that maches the BlackShade map and not if your map is up to date.

Checking before cal and after cal pushing the iso to highest level shows howmuch emproovement there is in the noise floor with the new map. I don't see why this should be flawed?

Please explain?

Thanks

Patrick

First of all .... you are looking at a SCALED image from the sensor on a low resolution display. So, sure ... SOMETIMES it will show you - sometimes you won't see it. Further, on some firmware builds I have seen some funky-ness on "extreme" high ISOs.

CAL : T/E is a good check if you often performed the BS callibratoin... But doesn't tell you if your map is wrong.

I disagree. By the very nature of how the CAL: T/E meter works - it's is, based on all my tests, the BEST way to know if your map is wrong - more accurate than cranking the ISO.

The CalMap cares about only two things - sensor temp and exposure time. The camera can 100% check those values against the values used to create the currently loaded CalMap - and that is all that matters.

So ... I fail to see WHY you would even bother to crank up the ISO for visual check - unless your CAL: T/E was showing you a YELLOW indicator - that is the ONLY time I ever do it. Because if you are GREEN/GREEN you are good to go.

 

[Patrick Tresch]

So ... I fail to see WHY you would even bother to crank up the ISO for visual check - unless your CAL: T/E was showing you a YELLOW indicator - that is the ONLY time I ever do it. Because if you are GREEN/GREEN you are good to go.

On my understanding, a CalMap is not set one for all, other wise it could have been implemented for all shutter speeds in the manufacturing process. This means it has to be done depending on various factors : days/weeks passing, variation of external heat, humidity, travelling in airplanes, electronic variations, all what could make a CalMap go out of specs.

T/E is telling you if you'r in the same specs as when the current callibration was made, and in my understanding not if it is still up to date for current sensor status.

Pat

 

[Mark L. Pederson]

On my understanding, a CalMap is not set one for all, other wise it could have been implemented for all shutter speeds in the manufacturing process. This means it has to be done depending on various factors : days/weeks passing, variation of external heat, humidity, travelling in airplanes, electronic variations, all what could make a CalMap go out of specs.

Pat - days/week passing & humidity are not going to make a CalMap "go out of spec." It doesn't ever go out of spec - it's spec is based on sensor temp and exposure time for that specific sensor (and sometimes changes/advances in firmware)

It IS possible to effect a sensor in air travel, but I think it depends if how high you fly and for how long. As a "best practice" - you should always re-black shade after flying your camera.

T/E is telling you if you'r in the same specs as when the current callibration was made, and in my understanding not if it is still up to date for current sensor status.

Pat

Well ... "current sensor status" is the current SENSOR TEMP and EXPOSURE TIME! And that is what T/E is monitoring - by comparing that to the currently loaded CalMap.

Variation of external heat, humidity, days/weeks passing do not change your "sensor status". I'll give you the one exception of air travel / gamma rays - but other than that - it's temp of the sensor and exposure time. And like I said - cranking up the ISO is not ALWAYS going to show you if you are getting issues. I have never seen an issue without the CAL: T/E meter warning me.

 

[John Marchant]

The exception IMHO is when you have a camera which has been reset to factory settings without your knowledge. Factory cal can be off for the sensor but still show you green cal.

 

[Mark L. Pederson]

The exception IMHO is when you have a camera which has been reset to factory settings without your knowledge. Factory cal can be off for the sensor but still show you green cal.

Very good point John. In another thread I suggested that factory CalMap should be buried since the it is of no use to the user.

 

[TheBied]

Anyone successfully Black Shade with 5.1.47? Any failed calibrations?

Thank you very much

fury

Nick -- We've taken a look at your log and will have a fix for you to try shortly.

 

[TheBied]

Very good point John. In another thread I suggested that factory CalMap should be buried since the it is of no use to the user.

5.2.x and up will store the user cal map across upgrades and resets.

 

[John Marchant]

5.2.x and up will store the user cal map across upgrades and resets.

Nice, hadn't spotted that

 

[Mark L. Pederson]

5.2.x and up will store the user cal map across upgrades and resets.

On MX as well? Or only Dragon?

 

[TheBied]

On MX as well? Or only Dragon?

MX too

 

[Nick Fury]

Nick -- We've taken a look at your log and will have a fix for you to try shortly.

Hi Matt,

You guys are the best!

I was thinking that the info I requested, from the community, might be useful, to expedite the fix. Glad you guys are on it, as usual.

Thank you very much

Fury