1Dx ISO100 high DR shadows SNR improvement

[Neutral]

One of the weak sides of the 1Dx is noise   in deep shadows at base ISO.
It seems that nobody is arguing about that any more.
 DXO 1Dx measurement results also show that very clearly on their measurement curves.
And I believe that nobody would be arguing that performance in this area is very critical for not just few people but for many people  - for landscape photography, evening/night  city shots and other sort of photography.
Though it is easy to argue that that Nikon D800 would be the better choice BUT why not to see how we could get better deep shadow SNR from 1Dx.
In one of my posts I mentioned that 1Dx has a very nice feature that could be used for that.
I will not name it now (will do at SOME next post) but here is some magic - example how it works (snapshots from LR screen - noise reduction is totally disabled  )
1.  First image shows 1dX  shot at IS100  with EV=(-3)   the Data Color noise calibration chart  which was  used  for Noise Ninja NR S/W and PS plug-in. Shot  with  manual Out of Focus  to blur target texture so it would not interfere with noise
2. Second one is the same with Exposure slider in LR set to +3  - looks the same as normal shot with EV=0
3. Third  image is 200% crop  of shot with EV=0 showing normal 1Dx ISO shadow noise
4. Fourth one is 200% crop of the EV=-3 shot with LR exposure set to +3 to raise shadows to normal level.
     Level of 1Dx noise at ISO100 at  -3 EV shadows is very clearly seen
 
 And next post is  little bit of magic  - the similar EV=(-3) shoot from 1Dx  recovered in LR - 200% crop  to see the difference  in SNR for random nose with the previous shot.
 

[Neutral]

OK, now is 200% crop of the similar EV=(-3) shoot from 1Dx  using some  special shooting  method  with 1Dx . 
Shadows are recovered in LR with Exposure slider set to +3 to compensate for in camera EV =(-3) . No noise reduction in LR.
Note how SNR for random noise was improved.

 So we have almost two stops  improvement here  for random noise SNR.
This means that with normal exposure it is possible to successfully recover details in very deep shadows at ISO100.
We still  see some slight pattern noise on the image but I believe that there is some NR software that doing very well with reducing pattern  noise - might be Topaz  De-noise  but not very sure  as I do not have that.
  If all combined together with some special shooting method with 1Dx  it  is possible to get shadow SNR  on par with Nikon D800.
So now quiz - how this was done?

[victorwol]

No clue, but would be nice if you can share it. It's very interesting for sure.

[neuroanatomist]

The suspense isn't killing me.     But feel free to share, when you're ready...

[Viggo]

Bring it on! 

[nightbreath]

Resizing down to 8Mpx file dimensions? 

[Neutral]

Resizing down to 8Mpx file dimensions? 

No, full sensor resolution )))

[Neutral]

OK, no magic - just "feeling" what is behind numbers )))

But seriously  this method used for decades for filtering noise out in different applications.
This is use of simple math in real life use.
Noise is random - image is fixed.
So what is required is just to integrate information element for a longer time and random noise would be filtered out.
  I believe that  this is something that  also was being used in astronomy to separate low level image details that could be even below random noise level.  Also used in communication systems.
=========
So how this is done with 1Dx
------
1Dx has one feature which is  intended for some artistic work but it could be used for something completely different.
This feature is multi-exposure – in one of the posts I mentioned about this for filtering out noise.
You can take up to 9 shots and 1Dx will average these shots into one.
 As each shot has it's own random noise distribution then averaging 9 shots into one would  essentially suppress noise - only fixed elements will  be kept - so random electronic noise is significantly reduced but fixed patterns - real image or sensor defects are kept and cleared out of noise. This is equivalent  to 9 times of longer integration time of the information element in the image detector.

How to  do this in 1Dx:
Enable  multi-exposure continuous shooting, number of exposures to 9, multi-exposure control to  Average (to integrate over 9 images) , put mirror lock up with the set button release  to reduce camera vibration (will be returned back by set button) , put camera in high speed continuous shooting mode, press shutter - mirror will be locked, press shutter again and keep it pressed - camera will take quickly 9 images in less than 1 sec , stops and then merge it ( integrate)  into one image.
And you are done.
Now press set button to return mirror back and then you could see the result.
So nothing special - just to see things a bit deeper)))
Method is suitable for only still images .
In normal conditions such kind of shot will take about 0.75 sec with FPS =12
And of course could be only shot using strong stable tripod for camera.

[nightbreath]

Could you do one thing just to test another approach? Please export the RAW file to TIFF and push the shadows in the resulted file. I saw very good results someone shared here using this method.

[neuroanatomist]

Thought that might be the 'trick'. I use it all the time in photomicroscopy.  Works great for test charts and fixed tissue.  Not so well with anything that moves, which limits its utility for >95% of what I shoot...

[tron]

This is routinely applied in astrophotograpy if combined with precision German Equatorial Mounts. It is also used when combining many video frames into one photo (see registax). But I doubt it can be used elsewhere. You have to exclude leaves, people, water, clouds maybe and I am sure I haven't thought of everything...

[pj1974]

Hi Neutral, thanks for sharing the technique and outcomes.... interesting (& understandable).

The only thing is, that the final output file you show, has significantly more noise and vertical banding than the base file "1DX_ISO100_EV0-Crop200%.JPG".

The file 1DX_ISO100_EV0-Crop200%.JPG is the cleanest for me... in fact very good for a 200% crop.

At least, that is what displays on my PC & Monitor.  Anyone else?

Paul

[PVS]

@OP - if you're that desperate to pull +3EV in shadows you could use split-toning action in PShop with (obviously) using blurred layer to pull those shadows up.

here's a dload link> http://www.mediafire.com/?po4x8dcgg5msr6a for that action, let me know if it works for ya.

[RLPhoto]

The d800 currently has the best 35mm sensor ever made. We all know this.

The 1Dx currently the best professional camera ever made. We all know this.

Two tools for two uses.

Canon could use some newer tech on the sensor base, and Nikon currently could use a newer AF system from the 3500 series. If you nail your exposures on either camera, only good photos will result.

[Tammy]

it's also the same method used in the "handheld night shooting" mode in the latest compact cameras, first introduced by Sony..