Hi, PGH. First off, thank you for the compliment. In all reality, since I push my exposures as much as each camera will allow, I get a lot of 'red' areas and warnings when I first open a photo in ACR. If I didn't, I'd be surprised.

To quote Scott Kelby, "Another cause of clipping is when you’re editing the photo in Camera Raw. You could have increased the Exposure amount (or Whites or Highlights sliders) enough to create clipping that wasn’t in the photo. Hey, it happens. If you know what you’re doing, it might be okay. More on that later."

The warning areas fall along those lines. I'm not as familiar with the internal workings of ACR but know how to use it effectively. It's similar to not knowing the intimate chemical processes involved in developing film but being able to control tonal qualities of a negative to produce the densities desired.
--Bob

I'm not sure that this is the best place to post this but the only other which I could consider is Post Processing. This requires processing but most are done prior to taking the photograph.

As many of you know, I believe in two photographic techniques The Zone System (TZS) and the use of ETTR and EBTR to do the vast majority of my digital photographs. Similar to, but opposite, the way The Zone System, as used with film, these techniques allow for better control in placing selected exposure values in an appropriate Zone. With film one meters the shadow (dark) area of the scene and then exposes to place that area in the appropriate Zone, as the photographer chooses. In processing the film, the highlight areas of the scene are controlled by the processing.

In digital photography, when using TZS and ETTR/EBTR, things work the opposite. The metering is done on the brightest parts of the scene and exposing in such a manner as to place those highlights in the appropriate Zone. That is, the brightest areas of the scene are exposed in such a manner as to place them just shy of the sensor overexposing. The dark areas of the scene are controlled by processing in an appropriate software package. My preference is Photoshop.

Recently, I purchased a digital back for my Hasselblad 500c/cm. As with any new film, camera, lens or sensor, I tested it. These are structured lab tests, not just a few random photos taken around the neighborhood. This testing would determine how much additional exposure I could apply before the image of a test chart was not capable of being adjusted to its original appearance. After determining the capabilities of the sensor, it was time to take the camera out and do a few photographs with it. The Grand Canyon was a planned trip. So, it was as good a place as any to put the experimental data to use.

Here's where the luck figured in. The manufacturers of the back include, in the kit, a mask that shows the portion of the viewfinder that is going to be captured by the smaller sensor. (see image 1) There were several included in the "kit". One of them was made of transparent gray plastic. Now, the metering viewfinder I use reads the entire focusing screen area. Thus, the transparent gray mask is going to reduce the amount of light the meter actually sees.

As such, the meter will indicate a setting which is more exposure than if the mask weren't there. By luck, the exposure reading is the same as the additional amount of exposure I'd have needed to "calculate" to produce an ideally exposed image for processing. Thus, I can simply meter the scene, set the exposure to what the meter indicates and I have a sufficient amount of additional exposure to push the image the appropriate amount to the right.

So, now to the Grand Canyon photograph.

The first image shows the viewfinder with the mask in place.

The second image shows a screenshot of ACR prior to adjustments.

The third shows the SOOC image.

The fourth image shows the image in PS after my usual adjustments are made in ACR.

The fourth shows the black and white conversion and finished "print".

One of the added benefits of Exposing To The Right and Exposing Beyond The Right is that the inherent noise within each photosite of the sensor is masked by the additional light allowed to reach each photosite.
--Bob

I'm not sure that this is the best place to post this but the only other which I could consider is Post Processing. This requires processing but most are done prior to taking the photograph.

As many of you know, I believe in two photographic techniques The Zone System (TZS) and the use of ETTR and EBTR to do the vast majority of my digital photographs. Similar to, but opposite, the way The Zone System, as used with film, these techniques allow for better control in placing selected exposure values in an appropriate Zone. With film one meters the shadow (dark) area of the scene and then exposes to place that area in the appropriate Zone, as the photographer chooses. In processing the film, the highlight areas of the scene are controlled by the processing.

In digital photography, when using TZS and ETTR/EBTR, things work the opposite. The metering is done on the brightest parts of the scene and exposing in such a manner as to place those highlights in the appropriate Zone. That is, the brightest areas of the scene are exposed in such a manner as to place them just shy of the sensor overexposing. The dark areas of the scene are controlled by processing in an appropriate software package. My preference is Photoshop.

Recently, I purchased a digital back for my Hasselblad 500c/cm. As with any new film, camera, lens or sensor, I tested it. These are structured lab tests, not just a few random photos taken around the neighborhood. This testing would determine how much additional exposure I could apply before the image of a test chart was not capable of being adjusted to its original appearance. After determining the capabilities of the sensor, it was time to take the camera out and do a few photographs with it. The Grand Canyon was a planned trip. So, it was as good a place as any to put the experimental data to use.

Here's where the luck figured in. The manufacturers of the back include, in the kit, a mask that shows the portion of the viewfinder that is going to be captured by the smaller sensor. (see image 1) There were several included in the "kit". One of them was made of transparent gray plastic. Now, the metering viewfinder I use reads the entire focusing screen area. Thus, the transparent gray mask is going to reduce the amount of light the meter actually sees.

As such, the meter will indicate a setting which is more exposure than if the mask weren't there. By luck, the exposure reading is the same as the additional amount of exposure I'd have needed to "calculate" to produce an ideally exposed image for processing. Thus, I can simply meter the scene, set the exposure to what the meter indicates and I have a sufficient amount of additional exposure to push the image the appropriate amount to the right.

So, now to the Grand Canyon photograph.

The first image shows the viewfinder with the mask in place.

The second image shows a screenshot of ACR prior to adjustments.

The third shows the SOOC image.

The fourth image shows the image in PS after my usual adjustments are made in ACR.

The fourth shows the black and white conversion and finished "print".

One of the added benefits of Exposing To The Right and Exposing Beyond The Right is that the inherent noise within each photosite of the sensor is masked by the additional light allowed to reach each photosite.
--Bob

I'm not sure that this is the best place to post this but the only other which I could consider is Post Processing. This requires processing but most are done prior to taking the photograph.

As many of you know, I believe in two photographic techniques The Zone System (TZS) and the use of ETTR and EBTR to do the vast majority of my digital photographs. Similar to, but opposite, the way The Zone System, as used with film, these techniques allow for better control in placing selected exposure values in an appropriate Zone. With film one meters the shadow (dark) area of the scene and then exposes to place that area in the appropriate Zone, as the photographer chooses. In processing the film, the highlight areas of the scene are controlled by the processing.

In digital photography, when using TZS and ETTR/EBTR, things work the opposite. The metering is done on the brightest parts of the scene and exposing in such a manner as to place those highlights in the appropriate Zone. That is, the brightest areas of the scene are exposed in such a manner as to place them just shy of the sensor overexposing. The dark areas of the scene are controlled by processing in an appropriate software package. My preference is Photoshop.

Recently, I purchased a digital back for my Hasselblad 500c/cm. As with any new film, camera, lens or sensor, I tested it. These are structured lab tests, not just a few random photos taken around the neighborhood. This testing would determine how much additional exposure I could apply before the image of a test chart was not capable of being adjusted to its original appearance. After determining the capabilities of the sensor, it was time to take the camera out and do a few photographs with it. The Grand Canyon was a planned trip. So, it was as good a place as any to put the experimental data to use.

Here's where the luck figured in. The manufacturers of the back include, in the kit, a mask that shows the portion of the viewfinder that is going to be captured by the smaller sensor. (see image 1) There were several included in the "kit". One of them was made of transparent gray plastic. Now, the metering viewfinder I use reads the entire focusing screen area. Thus, the transparent gray mask is going to reduce the amount of light the meter actually sees.

As such, the meter will indicate a setting which is more exposure than if the mask weren't there. By luck, the exposure reading is the same as the additional amount of exposure I'd have needed to "calculate" to produce an ideally exposed image for processing. Thus, I can simply meter the scene, set the exposure to what the meter indicates and I have a sufficient amount of additional exposure to push the image the appropriate amount to the right.

So, now to the Grand Canyon photograph.

The first image shows the viewfinder with the mask in place.

The second image shows a screenshot of ACR prior to adjustments.

The third shows the SOOC image.

The fourth image shows the image in PS after my usual adjustments are made in ACR.

The fourth shows the black and white conversion and finished "print".

One of the added benefits of Exposing To The Right and Exposing Beyond The Right is that the inherent noise within each photosite of the sensor is masked by the additional light allowed to reach each photosite.
--Bob