Understanding Layers

[Brownbear]

I have given myself an exercise to try and understand layers.

I selected 5 images of birds that I am trying to combine into one one image.

I chose one image as the background layer, created an adjustment layer for each of the other images, and then I copied and pasted each adjustment layers that I created into the main background image. So all 5 birds should be in one image.

I can see that when I run the brush along the image it either brings out the subject behind or erases the subject totally.

For some reason I can't seem to grasp the concept of layers, and I think it is just the concept because I don't understand why the subject is
1. Hidden when I run the brush over it
2. Brought out when I run the brush over it.

Thank you.

[Andrew76]

Hey Christina, it's something I've struggled with myself. I've found this analogy helpful. Think of each layer as a transparency - like we used to use on an overhead projector in the 'old days'.

The transparency sheets are stacked in the same order as you have them in the 'layers' palette. So, you must decide which layer you'd like to select to work on, then what ever action you decide to take will effect that layer. For example, if you select the eraser tool, you'll start to reveal whatever is on the layer below the one you're working on.

A simple example would be to give you an easy way to make a colour appear in a B+W photo. I open the photo in colour in PS or Elements, or whatever you're using. I duplicate the layer, change it into B+W, then place the B+W layer on top. Take your eraser tool, and have at it! The colour image, which is below, starts to appear.

Does that help at all, or am I just muddying waters?

[Brownbear]

Hi Andrew,

Thank you so much. I've never used an overhead projector but I have seen them being used.

You have provided me with a great analogy which I have printed and that I will read a few times tonight. And first thing tomorrow morning I will try your colour exercise, and then have at it with my bird layers again.

Yes, very helpful indeed... Thanks a million.

[Andrew76]

No problemo - I hope it works out!

[dje]

Hi Christina

A couple of things to note about layers.

• Adjustment layers are different to other layers as they don't contain an image of any sort. All they contain are adjustment details to be applied to the layers below.
• If you have a stack of (non adjustment) layers, then the top layer will over-ride all those below it provided that it's Blending mode is set to Normal and it's Opacity is set to 100%.

To do what you want to do with the birds, you can

• Open all five images in PS
• Choose an image as the main background image.
• Go to another image and select the bird from it only using a selection tool
• Hit control c to copy this selection
• Go back to the main image and hit control v to copy this selection into the main image. It will appear as a new layer with just the bird in it.
• Select the new layer in the layer palette and with the Move tool, you can drag this bird around to where you want it. Notice that it covers anything beneath it on lower layers.
• Repeat the process for the other birds.

Dave

[bambleweeney]

The concept of layers has been nicely explained below. Personally though I would use layer masks to achieve what you're after. Basically a layer mask will hide or reveal the layer or parts of it that you choose, the advantage is that it is easier to return to your image later and by simple adjustment of the layer mask make any changes that you want. The disadvantage of using the selection tool and the copy/paste method is that you're kind of stuck with the selection you've made - if your selection isn't that good or needs adjustment then you really have to repeat it. With a layer mask you just redo or refine the mask itself to get what you want.
So, a quick intro to layer masks :-
at the bottom of the layers palette there is a square icon with a small circle inside it
clicking on this will give you a white layer mask next to the selected layer. Where a mask is white the layer contents will be visible. Painting over this with a black brush will hide some of the layer contents.
Back to that little icon - pressing the Alt key (on a PC - lord knows what it is on a Mac) and clicking on the mask icon will give you a black layer mask, effectively hiding all of the layer it's applied to. Painting over this black mask with a white brush will reveal the brushed parts of the layer.
Using a grey brush on the mask will partially reveal the brushed areas - kind of like a localised transparency.

In practice, open one of your bird images. This will become the base layer
Open another bird image as another layer.
Now make a selection of this second bird - don't worry too much about accuracy as we're going to make a mask of this selection which you can improve/redo later if you're not happy with it.
Select this second layer and click the mask icon at the bottom of the layers palette - a mask will always be a contain the current selection and you should now see next to this layer a mask that is black (opaque) apart from the area you selected. You can now with the move tool move this selected area round the screen to wherever you want.
Don't like your selection ? Click on the mask to select it and use a soft black brush on the mask with a lowish transparency to gently brush out the areas you don't like or a soft white brush to add areas you might have missed on your initial selection.
Honestly this is a lot easier to do than to describe !!!
Other things you can do with masks -
Sharpen them, blur them using the usual Photoshop tools.
Hide them by Shift clicking on the mask
Invert them by selecting the mask and using the Photoshop Invert command or by clicking Ctrl I
Look at your mask full screen by Alt clicking on the mask.
The whole concept of masks is fundamental in using Photoshop. Whenever you create an adjustment layer Photoshop will kindly give you a mask to work on and the principles for adjustment layers and 'ordinary' layers are just the same.

[Brownbear]

Thank you Dave and Paul for the detailed explanations and how to's of using layers and layer masks. I have read that layer masks are preferred because one can go back and undo things.

After I try Andrews exercise, I will try both of your suggestions and if I manage anything decent I'll post it.

Thanks again. Appreciated.

[bambleweeney]

No problem Christina. Masks really are a part of your basic Photoshop toolkit. Really useful stuff you can do with masks includes :-
Luminosity masking, saturation masking, vignettes, creation of realistic HDR images and I sharpen my images by using edge and colour edge masks allowing me to create really sharp images by only sharpening edge details without increaing noise.

[Brownbear]

I sharpen my images by using edge and colour edge masks allowing me to create really sharp images by only sharpening edge details without increasing noise.

Is a great motivator for me to learn about masks. Thank you for sharing.

[John 2]

The only thing I would add Christina is "one step at a time" otherwise you could end up with information overload. Andrew's excellent suggestion is a good starting point and once you have produced the two layers (mono base and colour top) you can use it in the way Dave suggests and move the top layer around with the move tool. It will mess up your image but it will give you an idea of what you can do. Playing can be worth a thousand words.

It is helpful if you open up your "Layers" pallet, usually on the right of the screen (Window then check Layers) so that you can see what layers you have created. Once it's visible, left clicking and lighting up a given layer in the Pallet makes it active i.e. any tool you use from then on will affect only that layer. Left clicking the "Eye" symbol on the left of any layer showing in the Layers palette will hide that layer or reveal it. As well as disappearing from the screen, a hidden layer is protected from any action you apply.

The only other thing I would suggest is that you always start by duplicating the original image layer (known as the Background Layer) and work from there. To do this right click the base layer and select "Duplicate Layer". That way the original image is preserved but in any case you will find that the Background Layer is locked and there are some things you can't do to it e.g. you can't move it from being the bottom layer in the stack. You can change the order for any other layer by simply dragging it up and down the stack. So for Andrew's exercise you would end up with a Background Layer and two duplicate layers. The second is the layer you would turn to mono. The top layer is the one you will erase so that the mono image shows through. Happy playtime.

[The Blue Boy]

Christina,

As with anything new, it's really important to get into some "good habits" at the early stage. And the only really good tip I can add to the excellent advice above is this; Name each layer as you go along.

You might think that sounds a bit daft at first, but if you're using multiple pics as layers it's a vital tip that can help you keep track of what's been going on if you're saving as PSD, and have to leave the editing for a while. Say to maybe to go to bed,

I'll give you an example. I had to do a really large group shot at a wedding and the whole day was not really going well. When doing these I'll always take about five or six as people will always close their eyes at the wrong moment. Long story short, I ended up with nine layers in all and had to come back to it at a later date. All the layers had their own little title, such as "2down3inR" which translates as "2nd row down, 3rd in from the right". If I hadn't have done that from the start, the whole thing would have been baffling.

[kurious]

hi , just found this ,,might help you. http://www.ps-elements.net/

[Brownbear]

Thank you Ralph. I will check out your link right after this. Appreciated and much needed as I appear to be quite dense.

I'm embarrassed to say that I am still on the colouring exercise, especially so because their have been 195 views so far and I still have nothing to show for my efforts.

While I understand Andrews concept of erasing a portion of the top layer, and I have progressed as far as to have copied and paste an adjustment layer on top of my main background image.. When I use the eraser tool the image either turns jet black or pure white (instead of revealing the b&w image below). When I run the brush over the black or white nothing happens.. it looks like my eraser tool is not working.

I have tried this once before with a head swap, so I shouldn't be having so much trouble doing this but the fact of the matter is that I am.

Here is what I have accomplished so far






Are their any clues in the images that point to something I am doing obviously wrong?

If not, no worries... I have enough information on hand, it just might take me a few days to figure out how to do this...

Thank you.

[pnodrog]

I assume if you are using layer masks that you are selecting the mask (righthand) part of the layer not the image (lefthand) part of the layer?

When working with layered images I very seldom work on the image part of the layer doing all my selection/masking using the mask portion of the layer and including (white) or excluding (black) with a suitable brush.

[Brownbear]

Hi L. Paul,

Yes I was using a layer mask but I'm not sure if I was working on the image or the mask. Fairly sure it was the mask... I will start over fresh and try again.

Thank you.

I assume if you are using layer masks that you are selecting the mask (righthand) part of the layer not the image (lefthand) part of the layer?

When working with layered images I very seldom work on the image part of the layer doing all my selection/masking using the mask portion of the layer and including (white) or excluding (black) with a suitable brush.

[Steve S]

Ok christina, lets go through this real slow.........................

Choose and image

Go to Image----Duplicate----click OK. Now you will have two images at the top of the paletts bar


Click on the second image---go to image---adjustment---hue and saturation---turn the saturation all the way down to make a simple black and white


Now click on the move tool


At the top of the photoshop page in the middle, you will see a square box that says arrange documents if you hold the curser over it. Click on that box and then click on the icon that looks like 2 squares side by side. Now your screen will show both images side by side.

Click and hold on the b&w image---hold down on the shift key (this will automatically align the two layers)---drag the b&w image over the color one and drop it. This will stack the two images together.


Now go back to the arrange documents square and click on it. Now choose the single square to make the view go back to one image. Now you should see the b&w image as a layer on top of the color one.


Now click on the eraser tool...........choose white color(when working with layers, white reveals and black hides) Paint over the black and white photo, where you want the color to show through. If you make a mistake, just switch to black and paint back over and the black and white will come back. Zooming into the image can make your edits more accurate.

Hope this wasn't too confusing.

[pnodrog]

Hi L. Paul,

Yes I was using a layer mask but I'm not sure if I was working on the image or the mask. Fairly sure it was the mask... I will start over fresh and try again.

Thank you.

Christina I nearly always use the paint brush not the eraser when modifying a mask and if you see either black or white being painted on the image you know you do not have the mask selected. The mask box in the layer display will have a white border when selected.

[Brownbear]

Hello all,

I'm happy to report that I managed to create a half B&W/half colour image using layers. My results do not look good but I will share just to show that I managed it. I will revisit the bird idea later next week, or earlier if I can find the time. This took me the entire day.

The first image is the original B&W just to show that the final version is indeed a mixed colour image... It was a strange image for me to choose for this project.

The 2nd image was created using Dave's copy and paste method.

The 3rd image was created using Johns adjustment layers method, which in the end I used to create my own method because John's explanation for some reason provided me with the best comprehension for what I was trying to do.

Steve, thank you so much for your step by step guide which I tried because of its simplicity but I struggled with doing it this way because my Elements menu is not the same as yours, so I was following it step by step but not understanding what I was doing, and when I came to the eraser black/white part I totally messed up the image because I didn't understand what I was doing.














Mark, thank you for sharing - I named all my layers and will continue this practice.

L. Paul - I was working on the image and not the layer, hence my frustration

Ralph - I viewed that video and although it didn't help me understand layers as I'm trying to use them here, it showed me the use of layers for selective adjustments which will serve me well in the future.

Thank you to everyone for your help with this. I now understand the concept of layers and I learned about the benefits of using adjustment layers to allow for changes anytime. I just have to figure out the white/black eraser bit (Which I find confusing) and it looks like it will take some practice to do be able to do it well.

I will try the combined bird shot when I have more time and post it here even though I know that is not going to look as I had imagined it could look, simply because of my post processing skills.

Andrew... Layers are like a pile of several sheets of paper. One cuts a hole (with an eraser) in a select portion to reveal a portion of the image below... So very much like a transparency place on an overhead projector... Thank you so much for helping me understand the concept...

[Brownbear]

Thank you L. Paul, truly appreciated as it was confusing, so I've made note of this.

Christina I nearly always use the paint brush not the eraser when modifying a mask and if you see either black or white being painted on the image you know you do not have the mask selected. The mask box in the layer display will have a white border when selected.

[pnodrog]

Christina if you have selected a layer with a mask you can always press the back slash key "\" to view the mask as a ruby coloured overlay. If you are working on the mask (using Blk or Wht painting) you will be able to observe the changes you are making to the mask by watching the addition or removal of the ruby colour. I don't use it very often but it can sometimes be helpful.