Question about "Active D lighting"

[molested_cow]

To my understanding(pls correct me if I am wrong), active D lighting is an auto function that tries to bring up the exposure in the darker parts of the photo under high contrast lighting scenarios?

So if I shoot in RAW, does this actually matter? As in, shooting with or without Active D lighting shouldn't affect my RAW file right?

 

[Derrel]

My understanding is as follows: If you shoot with it on, the .NEF file will be tagged with appropriate information, so an As-Shot import profile will reflect the degree of Active D-Lighting used for the shot. So, in a way it will affect the .NEF file, by providing the needed infomation. But the way it affects the .NEF file is not a bad or deleterious way.

 

[Ysarex]

To my understanding(pls correct me if I am wrong), active D lighting is an auto function that tries to bring up the exposure in the darker parts of the photo under high contrast lighting scenarios?

So if I shoot in RAW, does this actually matter? As in, shooting with or without Active D lighting shouldn't affect my RAW file right?

Some variant of Active D-Lighting has become common place in modern cameras: Fuji DR expansion, Canon HTP, Sony DR, Pentax Highlight Correction, etc.

The problem is high contrast lighting, for example strong side or backlight. Without intervention and relying on the camera's metering system it's typical to get results in the camera JPEG where the highlights are clipped and the shadows are too dark. A lower contrast, brightening tone curve applied to the JPEGs will address the too-dark shadows, but not the clipped highlights -- blown highlights are forever. So to deal with the clipped highlights we need to reduce exposure. All of the above in camera functions do both in one form or another: 1. reduce exposure and 2. apply a modified tone curve.

The more common implementation used by Canon, Fuji and Pentax for example requires the camera ISO be raised (raising ISO causes the camera meter to reduce the exposure -- step 1.) and so avoid the highlight clipping. Nikon's Active D-Lighting takes a different approach and simply applies a -EC to the exposure. You don't see it on the EC scale but that's basically what the Active D-Lighting indicator means: you've set a negative exposure comp. to achieve step 1. and avoid highlight clipping. (At the lowest setting Active D-Lighting does not reduce exposure but with each additional AD step increase exposure reduction is increased).

This exposure reduction however achieved is a real exposure reduction for the raw file and so these functions are not exclusively JPEG process only. The reduced contrast tone curve and brightening (step 2.) only applies to the JPEG but the camera exposure reduction applies to the raw file.

So this begs the question, is step 1. appropriate for the raw file? In other words would the highlights have been clipped in the raw file otherwise and so the step 1. reduced exposure is a positive for both the JPEG and the raw file? I'll answer that with a very reserved yes. Take that answer and go and enjoy taking photos these functions definitely produce improved JPEGs without otherwise effecting the raw files -- it's all good. Don't read below the line.

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OK, this is below the line. The camera manufactures hedge their bet -- makes sense. Modern sensors even in tiny little compacts have amazing DR capacity and noise filtering is so good that there's ample room now to be very conservative with exposure. This mattered a whole lot more say 15 years ago but the principle hasn't changed: With a digital sensor the more you expose it the better it gets until of course it saturates and clips. If you're processing raw files and you want the very best end result possible you will incorporate into your practice the goal of a full sensor exposure -- the more you expose the sensor the better your image. This is a precise discipline because the more you expose the closer you get to crashed and burning highlights. Don't crash and burn.

So that 2nd sentence in the above paragraph; the manufacturers are hedging -- makes sense. They've adjusted their camera's metering systems and JPEG processors to deliver a well exposed JPEG from a slightly underexposed raw file. In other words when you nail the JPEG exposure in the camera and then examine the raw file you typically find that the raw file could have handled between .3 to as much as 1.5 stops more exposure and not clipped the highlights.

With today's modern sensors that's a no foul, don't worry be happy. Unless of course you're out walking the edge like trying to shoot very low light or trying to squeeze the max DR from your sensor etc., etc. Now then the exposure reduction that the above noted camera DR functions apply is going to be on top of the built-in hedge. So let's walk through a senario: You're shooting low light indoors and already working in the ISO 3200 range. Your camera's "hedge" is -.7 stop so you're always losing that up front. The lighting is high contrast and highlights in the JPEGs are clipping (but they're not clipped in the raw file because of the -.7 hedge). If you turn on Active D-Lighting and set it to high you're going to get a -1 stop EC applied on top of your ISO 3200 -- ouch! As an alternative test your camera. Find the "hedge" and shoot to it. Get as much raw file exposure as you can and process those raw files to best advantage. You lose out on the camera JPEGs this way but you get overall better end results. Is it worth it is up to you.

Joe

 

[molested_cow]

Thanks Joe and Derrel! Upon some reading on other websites, other users explained that Active D Lighting adjustment can only be read by Nikon RAW processing software, so I guess if I only use ACR, it won't make sense for me to turn it on? I understand the under exposed part of this function. I too manually under expose my photos when I am dealing with high contrast situations and pull the details back in ACR, so in another words, I do Active D lighting manually already. Should I just turn it off altogether?

When I was using the D700, I had absolutely no issue with the camera's handling of the exposure on any lens I put on it. I trusted it so much that I rarely had to look at the preview. Now I am with D750 and it's given me many weird results that I don't know if it's my lens or the camera, and it's making the experience of shooting less comfortable cus I don't trust it. I am trying all possibilities now to see how I can set it to be "trust worthy" again.

 

[Ysarex]

Thanks Joe and Derrel! Upon some reading on other websites, other users explained that Active D Lighting adjustment can only be read by Nikon RAW processing software, so I guess if I only use ACR, it won't make sense for me to turn it on? I understand the under exposed part of this function. I too manually under expose my photos when I am dealing with high contrast situations and pull the details back in ACR, so in another words, I do Active D lighting manually already. Should I just turn it off altogether?

I vote turn it off unless you want the JPEG output.

When I was using the D700, I had absolutely no issue with the camera's handling of the exposure on any lens I put on it. I trusted it so much that I rarely had to look at the preview. Now I am with D750 and it's given me many weird results that I don't know if it's my lens or the camera, and it's making the experience of shooting less comfortable cus I don't trust it. I am trying all possibilities now to see how I can set it to be "trust worthy" again.

Change in metering mode?

Joe

 

[Destin]

My understanding was always that it doesn't affect RAW files and therefore I just kept it off. Learned something new today.

That being said, I keep it off unless shooting .jpg (which is never)

In fact, I tend to keep all in camera image processing turned off. I'd rather take the pure raw file and perform the treatments how I feel best in post.

 

[astroNikon]

Thanks Joe and Derrel! Upon some reading on other websites, other users explained that Active D Lighting adjustment can only be read by Nikon RAW processing software, so I guess if I only use ACR, it won't make sense for me to turn it on? I understand the under exposed part of this function. I too manually under expose my photos when I am dealing with high contrast situations and pull the details back in ACR, so in another words, I do Active D lighting manually already. Should I just turn it off altogether?

When I was using the D700, I had absolutely no issue with the camera's handling of the exposure on any lens I put on it. I trusted it so much that I rarely had to look at the preview. Now I am with D750 and it's given me many weird results that I don't know if it's my lens or the camera, and it's making the experience of shooting less comfortable cus I don't trust it. I am trying all possibilities now to see how I can set it to be "trust worthy" again.

It's a learning curve. Even going from the D600 to D750 is a learning curve with specifics.
The D500 DX is driving me nuts with it's learning curve to getting accurate, detailed images in relation to how it handles contrast vs FF bodies.

 

[molested_cow]

Change in metering mode?

I am always on Matrix metering. If it doesn't work I will manually adjust exposure settings.