graduated ND filter/lightroom

[Christof21]

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

 

[thegammaray]

Christof21 wrote:

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

It's certainly possible to brighten only the upper (or any other) part of the image in software. However, you'll never retrieve the information that the hardware filter (i.e. the one on the front of your camera) filtered out. If you had a perfect filter, then a bit of brightness would be the only thing missing, but you don't; there's always a quality loss, and it can be fairly large with cheaper filters.

Imagine you made tea, and then poured the tea through a filter into a new cup. The next cup would have a little less flavor and liquid. You can add water, but the flavor that you filtered out is lost forever.

In summary: Yeah, it's possible to do what you described, but why? Just take the picture without a filter. Then you won't need to fix it in software.

 

[Jeff]

Christof21 wrote:

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

In principle, yes, this would work.

Suppose you were shooting a scene with a bright sky and dark shadows in the foreground. Without the graduated ND filter, you would adjust the exposure to avoid clipping highlights in the sky and thereby limit the light captured from the foreground shadows. With a graduated ND filter you could increase exposure and capture more light from the shadows without clipping highlights. In post-processing, the Lightroom gradient filter could then be used to recover the dynamic range of the original scene.

In practice, however, the results may be disappointing. Modern sensors capture more dynamic range than can be displayed in prints or typical displays. So from a photographic perspective, the normal challenge is to compress the range from the brightest and darkest portions of the scene to fit within the dynamic range of the sensor at the time of exposure, and then in post-processing to fit the dynamic range of the captured image within the range of the display medium. The graduated ND filter helps with the former, and the LR gradient filter, tone curve, etc., help with the latter.

 

[Christof21]

Jeff wrote:

Christof21 wrote:

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

In principle, yes, this would work.

Suppose you were shooting a scene with a bright sky and dark shadows in the foreground. Without the graduated ND filter, you would adjust the exposure to avoid clipping highlights in the sky and thereby limit the light captured from the foreground shadows. With a graduated ND filter you could increase exposure and capture more light from the shadows without clipping highlights. In post-processing, the Lightroom gradient filter could then be used to recover the dynamic range of the original scene.

In practice, however, the results may be disappointing. Modern sensors capture more dynamic range than can be displayed in prints or typical displays. So from a photographic perspective, the normal challenge is to compress the range from the brightest and darkest portions of the scene to fit within the dynamic range of the sensor at the time of exposure, and then in post-processing to fit the dynamic range of the captured image within the range of the display medium. The graduated ND filter helps with the former, and the LR gradient filter, tone curve, etc., help with the latter.

--
Jeff
http://www.flickr.com/photos/jck_photos/sets/

Thanks for your answer. In fact, I wonder why they implemented the graduated filter in lightroom. I would use instead another tool to be more precise. This is very strange, other tools are much much better

In the opposite, It can have a real use when we used a graduated ND filter fixed on the lens. My question is : how do photographs post-process their images ?

When they use a ND filter, they will darken also parts that they would preferably not have darkened. That's why I think the first step may be to recover the original dynamic range and then to reduce it with the usual tools (tonal curve,..) This way, we have the more natural results.

I just try to find a use to this tool which seems really useless

 

[Jeff]

Christof21 wrote:

Jeff wrote:

Christof21 wrote:

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

In principle, yes, this would work.

Suppose you were shooting a scene with a bright sky and dark shadows in the foreground. Without the graduated ND filter, you would adjust the exposure to avoid clipping highlights in the sky and thereby limit the light captured from the foreground shadows. With a graduated ND filter you could increase exposure and capture more light from the shadows without clipping highlights. In post-processing, the Lightroom gradient filter could then be used to recover the dynamic range of the original scene.

In practice, however, the results may be disappointing. Modern sensors capture more dynamic range than can be displayed in prints or typical displays. So from a photographic perspective, the normal challenge is to compress the range from the brightest and darkest portions of the scene to fit within the dynamic range of the sensor at the time of exposure, and then in post-processing to fit the dynamic range of the captured image within the range of the display medium. The graduated ND filter helps with the former, and the LR gradient filter, tone curve, etc., help with the latter.

 

[Christof21]

Jeff wrote:

Christof21 wrote:

Jeff wrote:

Christof21 wrote:

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

In principle, yes, this would work.

Suppose you were shooting a scene with a bright sky and dark shadows in the foreground. Without the graduated ND filter, you would adjust the exposure to avoid clipping highlights in the sky and thereby limit the light captured from the foreground shadows. With a graduated ND filter you could increase exposure and capture more light from the shadows without clipping highlights. In post-processing, the Lightroom gradient filter could then be used to recover the dynamic range of the original scene.

In practice, however, the results may be disappointing. Modern sensors capture more dynamic range than can be displayed in prints or typical displays. So from a photographic perspective, the normal challenge is to compress the range from the brightest and darkest portions of the scene to fit within the dynamic range of the sensor at the time of exposure, and then in post-processing to fit the dynamic range of the captured image within the range of the display medium. The graduated ND filter helps with the former, and the LR gradient filter, tone curve, etc., help with the latter.

 

[Jeff]

Christof21 wrote:

Jeff wrote:

Christof21 wrote:

Jeff wrote:

Christof21 wrote:

Hi,

I've read that the graduated filter tool is used to simulated a graduated ND filter in lightroom.

I was wondering if it can be used when a picture is taken with a ND filter to annihilate its effect in post processing to retrieve the original dynamic range (but without clipping the highllights) by appying an opposite filter.

After this processing, I may modify the tonal curve (decrease the highlights), I thing the result may be more natural (without any border) ?

I do not have a graduated ND filter, I'm thinking about having one.

What is your opinion ?

Thanks,

Christophe

In principle, yes, this would work.

Suppose you were shooting a scene with a bright sky and dark shadows in the foreground. Without the graduated ND filter, you would adjust the exposure to avoid clipping highlights in the sky and thereby limit the light captured from the foreground shadows. With a graduated ND filter you could increase exposure and capture more light from the shadows without clipping highlights. In post-processing, the Lightroom gradient filter could then be used to recover the dynamic range of the original scene.

In practice, however, the results may be disappointing. Modern sensors capture more dynamic range than can be displayed in prints or typical displays. So from a photographic perspective, the normal challenge is to compress the range from the brightest and darkest portions of the scene to fit within the dynamic range of the sensor at the time of exposure, and then in post-processing to fit the dynamic range of the captured image within the range of the display medium. The graduated ND filter helps with the former, and the LR gradient filter, tone curve, etc., help with the latter.