[juu]

I'm trying to process this picture:

as per the suggestions of this thread:
https://www.pentaxforums.com/forums/photo-critique/88333-landscape-silent-valley-3-a.html

I imported the DNG file in Photoshop CS4 as a smart object. Next I tried using magic wand and quick selection tool to select Foreground, Water, Sky and Mountains separately and "Layer via Copy", however because of imprecise selection I ended up with no-man's land areas between the different objects and perhaps overlapping selections too, which didn't look good.

Next I tried Layer via Copy of the whole image and then Layer via Cut of the different selections, thinking this would work. However it seems like a pixel deep portion of the selections just disappears and doesn't go to any of the layers.

Any advice?

Why are you bringing it in as a smart object? If your trying to bring out different effects to each of those things use layer masks. As for the pixel loss try defringe. Or extend your selection by 1 or 2 pixels. INHO you've gone about it in the wrong fashion. Depending of course on what your actual goal is.

[amoringello]

First; View at 100%. CS4 has a tendency to show splits between layers, especially if you use something the panorama stitching, each section has a pixel break between them until you zoom in close enough.

Next; Not sure of your exact steps, but if there is an actual break... try using a layer mask to hide the parts you do not want. If a line, gap or overlapping area appears, you can erase bits of the mask to reveal enough of the layer to cover the break or paint more mask to hide mre of the layer. This also allows you to smoothly blend from one section into another just by painting with shades of gray into the mask.

Dunno how proficient you are with PS. If this doesn't make sense I'm sure you'll ask, or someone else will fill in the terse bits. :-)

[juu]

Why are you bringing it in as a smart object?

It sounded like a smart choice. I'm not really sure, I thought this would be sure to preserve all the information in the RAW file.

If your trying to bring out different effects to each of those things use layer masks.

Yes, I was trying to lower the exposure of the sky while boosting the blues and contrast. Likewise boost the contrast of the foreground to make the diagonal feel stronger. I will read up on layer masks.

As for the pixel loss try defringe.

I will read up on defringe.

Or extend your selection by 1 or 2 pixels. INHO you've gone about it in the wrong fashion.

Probably.

Still I don't understand why the pixels are being lost.

I will tell you the exact steps:
a. Layer via Copy of the whole file (call that layer "All")
b. View only the "All" layer
c. Select any portion, let's say the sky
d. Layer via Cut (call that layer "Sky"; "All" layer no longer includes the sky)
e. Now view just the "Sky" and "All" layers
f. Add an adjustment to lower exposure by -10
g. Observe white thin line between the "Sky" and "All" layers
h. If I now merge the "Sky" and "All" layers the thin white line is still there - the merged layer no longer constitutes the whole picture

It seems as if when I did the "Layer via Cut" that it cut all the pixels including the selection line pixels, but it only put the pixels inside the selection (not including the selection line pixels) inside the new layer.

First; View at 100%.

Yes, I am doing that.

Next; Not sure of your exact steps, but if there is an actual break... try using a layer mask to hide the parts you do not want.

That sounds to me like working around the problem. I'm hoping it can be avoided in the first place.

Dunno how proficient you are with PS. If this doesn't make sense I'm sure you'll ask, or someone else will fill in the terse bits. :-)

Thanks. I'm not proficient at all.

I was just expecting that if I cut a layer out and then merge it back in I'd end up with what I had initially. Seems like that's not the case.

First; View at 100%. CS4 has a tendency to show splits between layers, especially if you use something the panorama stitching, each section has a pixel break between them until you zoom in close enough.

Next; Not sure of your exact steps, but if there is an actual break... try using a layer mask to hide the parts you do not want. If a line, gap or overlapping area appears, you can erase bits of the mask to reveal enough of the layer to cover the break or paint more mask to hide mre of the layer. This also allows you to smoothly blend from one section into another just by painting with shades of gray into the mask.

Dunno how proficient you are with PS. If this doesn't make sense I'm sure you'll ask, or someone else will fill in the terse bits. :-)

With the stitching it's all layer masks and can be adjusted to fit. I think the methodology for what he may be wanting to do is flawed.

OK you and I posted at the same time. After reading that last post your going about it wrong. What you want is double processing. It is opening the image in raw and adjusting for the foreground then opening from raw as a smart object. Now you have a great foreground but the sky is blown. Copy the layer as a smart object. This breaks the link between the two layers. Open the second layer and edit in camera raw. Create a layer mask Fill with white. (I think white hides, memory is failing.) Paint on the layer mask in black to reveal the parts of the sky you want. Pretty simple and you don't need to be as careful selecting. Use a soft brush around the areas where the foreground and sky meet to blend better. That's what I do.

Oh yeah, when you select something it does lose a pixel or two. Just the nature if the beast. Copy the layer but just a straight copy. On that layer select the white area. Inverse selection and either contract the selection or expand (depends on the selected area) go back to the first layer and delete. However for what you're doing you really wouldn't need to delete the copied area. The layer above will hide it and actually it would cover errors in your selection.