Blending Help Needed

PHOTOempt

So assignment #2 was to blend: (Assignment #1 - Stitch done - OK stitch - somewhat boring image - can show later, but...) - nice sky here and foreground of iris patch, trying to blend together and then will decrease exposure of foreground so less surreal. Have ended up with a white line that I have cleverly substituted with a black line!! I guess I can blow it up to 3200% and fix it pixel by pixel. Ross swears there must be another way, but hasn't quite sussed it out, and of course, I am clueless.....Everyone to the rescue please!! Sarah

DavidTO

Sarah, you are going to be best off making a post in Finishing School, where we discuss post-processing.

pathfinder

Hi Sarah,

I greatly enjoyed meeting you in Mull, and Nightingale says 'hi' also.

Using masks can be very simple or rather complex.

I, typically, use the Quick Selection tool ( hit the 'W" key - and use the Shift key if necessary to deselect the Magic Wand ). I make my selection by painting over the area desired, and then going back and looking at the selection indicated by the 'marching ants' carefully, and painting over the area not wanted by holding down the Alt ( option ) Key while painting with the mouse in the Quick Selection mode. I then switch to the Select>Refine Edges, and typically use a radius of about 2, contrast about 10, smooth about 10, feather 1.5 to 3, and the Contract/Expand slider to adjust the mask. You can see the pink mask by clicking on the pink "knot" at the bottom of the drop down box. Once you have a selection in 'marching ants', you can hit the Q key and go into the Quick Mask mode and actually see the pink mask of the selected area. You can then paint on this mask with the Brush tool in Normal blending mode with Black ink as the foreground color, to smooth out edges of the mask that might otherwise be sharp. Once you are satisfied with your mask, hitting the Q key again, returns you to the Marching ants selection view. If you have spent some time getting your mask selected, this is a good time to save it as an 'alpha channel' by Select>Save Selection and filling in the drop down box with a name for your selection. You can see this mask in the bottom level in the Channels palette. You can then reload this mask later by Select>Load Selection. Saving the file as a .psd retains this saved mask for later use. Saving as a jpg discards it.

If you create your mask carefully, you should not have a white border left in your image - but I do occasionally too. Sometimes you just need to go back and touch up your mask. Sometimes it is easier to examine the image at 200% or 300% and clone in a gray area to hide the white selection line. Not an elegant choice, but one we have all used at least once in our lives.

Sometimes just enlarging the mask 1 or 2 pixels is all that is needed - Select>Modify> Expand or Contract. The Select>Modify>Border command allows you to specify a border thickness in pixels , but I rarely use that, preferring to just eyeball the mask from Refine Edges and then looking at the mask in Quick Mask mode.

It sounds complicated in text, but flows pretty easily at the keyboard, and once you combine Quick Mask mode with using selection tools as well as the Quick Selection tool, neat things begin to happen.

I saw this statue in Bath, but did not like the color nor the mid-day lighting, but I was not going to be there at any other time of day.



Selecting this type of image used to be rather tedious, because you could not use just color or shape, but with the Quick Selection tool in CS3, using the alt key to remove selected area, and the shift key to add selected area it went pretty quickly. Typing Q to go into Quick Mask then should give an image like this... Notice the absence of a white border.



And this allowed me to create this image.......which I think is an improvement - you may or may not agree





Sarah, you got to star in several of my images I shot in Mull.

Here is a pano with you in the right lower corner



Here you are with David and Schmoo



Good luck to you in Italy. Kathy and I truly enjoyed your company.

DavidTO

pathfinder wrote:

Ha!

That was the night I was the windbreak. It was cold.

Richard

I don't see the white (or black) line you are talking about, so it can't be that bad.

I have had better results blending exposures by using channel masks than selection-based ones. As long as the versions are perfectly aligned, the transitions are usually unnoticeable. It looks like the blue channel of the bright version would give the best separation in this case, though the red one also has possibilities.

Since you haven't posted separate images, it's hard for me to experiment, so here's what I think would work here. Put the bright layer over the dark one. Add an empty mask to the bright layer and use Apply Image to copy the inverted blue channel of the bright layer to the bright layer mask. That should brighten the foreground without affecting the water or sky much. You can fine tune the result by changing the opacity of the top layer, changing its blending mode and changing its Blend If sliders. Finally, you can paint directly on the mask to correct local problems.

If you post the light and dark versions as separate images, I'd be glad to play around with them.

Hope this helps.

PHOTOempt

Thank you Richard and Jim

Richard wrote:

I don't see the white (or black) line you are talking about, so it can't be that bad.

I have had better results blending exposures by using channel masks than selection-based ones. As long as the versions are perfectly aligned, the transitions are usually unnoticeable. It looks like the blue channel of the bright version would give the best separation in this case, though the red one also has possibilities.

Since you haven't posted separate images, it's hard for me to experiment, so here's what I think would work here. Put the bright layer over the dark one. Add an empty mask to the bright layer and use Apply Image to copy the inverted blue channel of the bright layer to the bright layer mask. That should brighten the foreground without affecting the water or sky much. You can fine tune the result by changing the opacity of the top layer, changing its blending mode and changing its Blend If sliders. Finally, you can paint directly on the mask to correct local problems.

If you post the light and dark versions as separate images, I'd be glad to play around with them.

Hope this helps.

Thank you both. What I finally did was to use the gradient tool and do a grad ND effect, which seemed to be a short cut, but I want to play around with both your suggestions. Richard - I will post the separate images as you suggest. Jim, I really like your statue. I also like the calm expression on the "wind barrier", but neither Schmoo nor I were caught at our best...! Back to sorting and processing, and I will post again after a bit more experimenting. Thanks again, Sarah