PhotoShop-working with layers

[tgnych]

looking for expert advice on whether and how to use 'layers' to manipulate a pic with several different components, i.e. I would like to individually modify:
- the sky which is partly hidden by vegetation (trees, bushes). It occupies 1/3 of the pic & the hidden part is partly
visible throughout holes in the vegetation
- vegetation (trees, bushes) which occupy another 1/3 of the pic
- a skyscraper that extends into the sky and is partly hidden by the same vegetation.
- my family at the forefront.

I don't seem to be able to create 2 separate layers for the sky and the vegetation because of their overlap.

[john_houghton]

You need to create duplicate copies of the background layer and then apply layer masks to make various parts of the upper layers transparent. The idea is to end up with something akin to the transparent layers of film that Walt Disney used to create his cartoons. Each individual layer can then be separately adjusted for colour. You can paint on the masks with a black/white brush to create the transparent areas. Alternatively, you can make a selection in a variety of ways that can then be used to create the mask. You will find a description of the technique in this thread, which you can adapt for your purposes:

http://photography-on-the.net/forum/showthread.php?t=19958#112292

John

[shirbit]

Some good threads on this are available at:
www.photoshoptoday.com

do a search on 'masking'

this will get you up & running:

http://www.thinkdan.com/tutorials/photoshop/layermasks/

[tgnych]

thks for this lot of useful info.
being a novice to photoshop i am struggling to understand how to use it, i must admit.
e.g. i don't see how to apply a new colour (e.g. i ma selecting white as the colour but the colour appearing under the brush is grey!), i have difficulties identifying where (main picture, background pic, mask window, etc.) the changes will apply/be visible, i don't see how the results of the layer manipulation do combine to show the final result, etc.
anyone having resolved the same problems/challenges welcome to advise me.

[john_houghton]

When you have a stack of layers, each with a layer mask, what you see when all layers are visible is a composite image similar to a stack of cardboard cut-outs. By clicking on the eye symbol on the left of each layer (in the layers palette), you can switch off/on each image. In each layer, there are two thumbnails on the right: the first is the main layer image and the second is the mask.

When a layer is highlighted to make it the active layer, click on the mask thumbnail to enter mask editing mode. All painting operations will now be applied to the mask (a greyscale image). You won't see the mask itself in this mode, only the results of the masking of the main image. However, by pressing backslash, you can make the mask visible as a ruby overlay, and press it again to switch the ruby mask off.

Click on the main image thumbnail to enter normal image editing mode. All painting operations are now applied to the main image (though what you see will be a masked version, with some parts invisible). If you paint with the foreground colour set as white, you will get white, unless you set the opacity option of the paintbrush tool to something less than 100%. The white might be modified by the current state of the mask in that area, of course, to make it partially transparent. So it might not look "white".

Note that you can both view and edit the mask of the currently active layer by going to the channels palette. The mask will usually be the channel at the bottom, labelled: "layer name" mask.

I hope that helps a bit.

John

[Anonymous]

John - it definitely helped.
here is hopefully the last question: how can i colour the sky that appears in between the leaves of a tree that extends into the sky?
cutting/pasting the tree after colouring the sky obviously doesn't help and a selection is impossible given the complexity of the branches/leaves' shape.

[Anonymous]

a selection is impossible given the complexity of the branches/leaves' shape.

Making a selction of the sky that includes the bits between branches is, in principle, fairly easy. If it is practical to use the magic wand, you can select the non-contiguous option, which means that when you click in an area, it selects not only that area but also all the other areas that are of a similar colour (within the range of the tolerance specified).

Alternatively, you can create a selction from the blue channel, which is mostly white in the sky areas and largely dark elsewhere. So go to the channels palette and make a duplicate of the blue channel via right click or drag down onto the "make new channel" icon at the bottom. Then increase the contrast of the duplicate channel and use the paint can and paint brush to make the non-sky areas black and get the sky completely white. Then drag the duplicate channel down onto the "load channel as selection" icon and you will create a selection corresponding to the white parts in the duplicate channel, i.e. the sky. That selection can now be used to create a layer mask (in effect, a copy of the duplicate channel).

John

[CyberDyneSystems]

tgynch,

sometime working with selection tools is a real pain,. and it isn't worth it in the long run as there are other options...

Here's another way to handle it....

Make a buch of layers that are back ground copies,. and label them,."sky, people, skyscraper" etc...

Select one of the layers,. let's start with sky,. and make what ever changes you want to to get the sky how you want it, ignoring what these modofications do to the rest of the photo.

Once the sky is where you want it you can use either the history brush to erase these chnges to the parts of the image that you wnat to leave alone,. or you can use the eraser tool to actually erase the parts of the image other than the sky.... (but only working on the one layer!)

In then repeat the process for skyscraper,. people etc...

Then you can adjust the opacity of each altered layer untill you have the perfect blend....

I understand that in many cases,. this looks to be the long way to do it,. but in many it can be the easiest as well....

I use this in particular when I want to remove ISO noise or grain from a part of an image but not all of it.... I find it much faster to run a noise reduction filter on the entire image,. and then use the history brush to erase the filter from the parts I want to leave sharp and grainy... than to try and do this with selections that may result in unsightly halos etc...

[tgnych]

well! I feel frustrated after all the advisories I got because I am still unable to achieve what I am trying to do :cry:
Is there a way I could post the picture?

Basically I don't see how to work on the sky without impacting the tree that is within the same selection.
Magic wand didn't allow me to select the whole sky area and I couldn't therefore use the non contiguous option.

I worked w/ a manual selection instead.

Being the novice I am I feel like layers are not an easy feature and would appreciate any tutorial reference. I tried those from thinkdan.com but didn't find them particularly useful.

I am sure that once it will click it will look all so easy...

[tgnych]

One thing I noticed is that I have some way of resolving this by selecting both sky and vegetation, then match colour from a nicer sky, and then play with brightness/contrast/fade.
This changes the sky everywhere, including in vegetation holes but of course has a slight impact on the vegetation colour.
Maybe someone can advise what image adjustment parameter to use to make the vegetation greener? No colouring is possible.

[maderito]

I would like to individually modify:
- the sky which is partly hidden by vegetation (trees, bushes). It occupies 1/3 of the pic & the hidden part is partly visible throughout holes in the vegetation
- vegetation (trees, bushes) which occupy another 1/3 of the pic


Some of the tonal adjustment problems noted in this thread are better addressed by using a Hue/Saturation adjustment layer. It is an essential tool (along with curves/levels) in improving color and tonality.

With Hue/Saturation, you can adjust specific color ranges (reds, blues, greens, etc) via saturation, lightness, and color.

Hue/Saturation adjustment are best applied after you have color corrected neutrals (white, gray, black) in levels or curves. That's important since you don't want the adjustment of say "greens" during hue adjustments to also affect the whites and grays of the image.