In-camera noise reduction

[Harv]

This question is directed to the technically knowledgeable out there and has to do with in-camera noise reduction settings. Although I'm shooting with a 1D4, I would guess the same would apply to all models. In a nutshell, is in-camera noise reduction (assuming it's enabled) applied to RAW files or just to JPEGs? If it's applied to RAW files (which is all I shoot), have any of you shot RAW with noise reduction disabled, and if so, how were the results? I tried to do a search here on this topic but was unable to find any information. Thanks.

[Skirball]

I'm no expert, but I'm sure that someone will correct me if I'm wrong:

I was told that only the long exposure NR is "destructively" applied to the RAW files.  All the others, like High ISO NR, are non-destructive.  If your editing software is able to read the Canon settings it will apply these, but you could jsut move the setting back to zero.  If the software doesn't recognize them it simply won't have any NR.

[Harv]

Thanks a lot. Much appreciated.

[HDCamTeam]

Hi,

Skirball is right. Only "Long Exposure NR" is permanently applied to RAW files. The rest NR options can be turned on or off on your RAW processing software. But 3rd party software will not apply NR in the exact same way than Canon DPP (or won't have some options).

Regards

[hsbn]

But in camera Long Exposure NR will make it worst if you're using ISO 1600 or higher (also says so in the manual).

[HDCamTeam]

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@hsbn wrote:
But in camera Long Exposure NR will make it worst if you're using ISO 1600 or higher (also says so in the manual).

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l think you got confussed.

What you say (and the manual tells about it) is in-camera High ISO Noise Reduction, not Long Exposure NR.

Regards

[hsbn]

No, with all due respects, it is Long Exposure NR. Why would it make it worst with High ISO if it is "High ISO Noise Reduction".

6D Manual page: 128 - 129
5D Mark III manual page 144-145

"Images taken at ISO 1600 or higher may look grainier with the [Enable] setting than with the [Disable] and [Auto] setting"

With Auto setting, camera will not do LENR if the ISO is higher than 1600.
I've tested this and it's give many kind of artifact with high ISO from time to time. Others it just gives more noise.

[Skirball]

l looked at my 6D manual yesterday after HSBN mentioned it, and sure enough, 1600 or higher.  I'm surprised that the auto feature doesn't incorporate this and only turn on for long exposures under 1600 ISO, but as far as I can tell it doesn't.

[HDCamTeam]

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@hsbn wrote:

No, with all due respects, it is Long Exposure NR. Why would it make it worst with High ISO if it is "High ISO Noise Reduction".

6D Manual page: 128 - 129
5D Mark III manual page 144-145

"Images taken at ISO 1600 or higher may look grainier with the [Enable] setting than with the [Disable] and [Auto] setting"

With Auto setting, camera will not do LENR if the ISO is higher than 1600.
I've tested this and it's give many kind of artifact with high ISO from time to time. Others it just gives more noise.

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Hi,

- Great to know, thanks! It's very surprising indeed.

LENR is supposed to remove hot pixels and noise due to long exposure. It's (sadly) surprising the in-cameras LENR may be worse than in post...

We'll take a review about it , since shooting long exposure at higher than ISO 1600 is not uncommon for astro photography.

I think 5D Mark 2 didn't have this "problem". Will check that too.

- The manual tells that in-camera High ISO NR applied is lower at high ISO than the NR that can be applied in post, not "worse", sorry, my mistake.

Thanks once again.

EDIT: The User manual of 5D Mark 2 doesn't tell anything about this matter. The manual of 7D does, as well as 6D and 5D3 as you mentioned.

Since I used to work with 5D2 I didn't realize the 5D3 could be different. Or at least the manual of 5D2 doesn't say the final result of LENR at 1600 or higher could be worse. Good thing to keep in mind.

Sitll doesn't understand why the result "may" be worse, the 5D3 has enormous computing potential with the Digic 5+

This seems to only affect if  LENR is set to "ON" / "Enabled", not to "Auto". Very likely a more agressive NR is applied in such case.

We'll carry some test indeed.

EDIT 2:

In just brief tests with the 5D Mark 3 we found some inconsistency on the results between setting Long Exposure NR to "OFF", "Auto" & "On".

We set High ISO NR, Peripheral Illumination Correction and Chromatic Aberrations to OFF, to see only the effect of LENR in JPG (not RAW yet).

This camera (5D3) applies High ISO NR even when you set it to OFF (very noticeable in video mode).

At ISO 6400 we didn't see a hot /stuck pixel (even when LENR set to "OFF") that appears at ISO 3200 when setting LENR to OFF or Auto. Of course "ON" deletes all hot /stuck pixels, but also increaed grain.

We all already know that the more the sensor heats up (shooting and shooting long exposure stills - or using Live View for stills or video), the more noise we'll get in the pictures (and video).

So far we couldn't get a "rule". Sometimes the "Auto" works better than "ON", it seems it depends on the selected ISO value and how hot is the sensor too.

I pesonally don't understand WHY the LENR delivers more grainy images when set to "ON", if the NR is more agressive the grain should be finer than in "OFF" or "Auto", so it doesn't make sense...

 We'll test the 5D Mark 2 to compare with 5D3 in this regard