How-to: Blending images in photoshop

[Steve Foss]

OK, there are several ways to blend images using Photoshop. Here is the simplest one I know. I use CS2. The technique works the same for several Photoshop versions, though I don't know if the commands are the same in Elements. This is a how-to on how to blend two images, one exposed for highlights, one for shadows.

First of all, when to blend.

Blending is most typically used by landscape or still life photographers challenged by a big dynamic range of exposure in a single image. A standard example is when a photographer doesn't have a graduated neutral density filter to even out a very bright sky and darker land in a landscape photo. So, using a tripod to make sure the images are identical (and on a calm day), a photographer will either use the camera's autobracket feature to make one exposure for the highlights and one for the shadows, or will make one exposure for either shadows or highlights and than use exposure compensation to correctly expose the second image. In either case, two images are produced and will be blended.

However, blending also can be used for a single frame, because more can be done by blending to get an evenly exposed final image than by trying to use curves/levels.

So the following example is of a single image that I've blended. The image on the left is the actual image I took, which was exposed for the highlights. Because the water is moving, I couldn't take a second image exposed for the shadows because the water would have moved too much, so I opted for opening the image twice.

My original image exposed for highlights on the left (no alterations), with second image of the same frame altered on the RAW preview screen to expose for the shadows. Virtually no noise is visible in shadows even though I raised them from underexposure because I shot at iso100, and the Canon sensor noise performance is the best in the industry.

For the technique, both images should be up on your screen. Choose the dark frame and hit Command-A to select the whole frame (Control-A with a PC). Hit Command or Control-C to copy it. Then close the dark frame because you won't need it any more.

Then select the light frame and hit Command or Control-V to paste the dark image into it.

Look at your "layers" palette and you will see the light image as the background and your dark image as layer 1.

Then, at the bottom left of the layers palette, select the icon that opens a layer mask. You will then see this white layer mask box next to the layer 1 image.

Now click on the background layer and hit Command or Control-A to select the whole image and press Command or Control-C to copy it. Then hold down the Option (Alt key on PC) and click on the white mask rectangle in layer 1.

That will turn the whole image white on your screen. Next, press Command or Control-V to paste onto the white mask. You will see the image as black and white on your screen. With the B&W image on your screen, go to the pulldown menu under Filter/Blur/Gaussian Blur. Set a radius of about 40 pixels when blending separate captures of the same scene (to help blur subtle differences between each frame) or 1 pixel when blending two versions of the same exact frame (like we're doing here).

Then, click on the background layer, and you're finished. You'll need to go back up to the pulldown menu and select Layer/flatten image, and then you can tone the photograph as you wish.

I used that technique to take a single frame shown above and render the one below.

It's a little hard to follow the tutorial without screen shots of the various moves, but if you go slow, read carefully and pay attention to what's on your screen, you can git 'er done. <img src="/forum/images/graemlins/grin.gif" alt="" />

[finnbay]

Steve,

Thanks for the post. I need to take some time to perfect this method. I know it works well. I'm at work and can't post in the regular manner because of filters, but have sent you an email with an alternative method. Let me know what you think.

Ken

[Steve Foss]

Ken, I'll take a look at it. I'm headed to the woods right now but will look later this afternoon or tonight. There are four methods I know of to blend. I chose this one because it's the simplest of them and still produces nice results.

[yakfisher]

Thanks for the post, it was going great until I found out that I can't create a layer mask in PS Elements 5.0. Does anyone know how to do this in Elements? I'll see what I can find out in the books.

[Steve Foss]

I've gotta think Elements will allow a layer mask. They're very commonly used in post processing these days.

[Dbl]

Elements DOES NOT allow layer masks. Do a google search there are a lot of tips on how to duplicate a layer mask in Elements.

[Steve Foss]

Cool info. Thanks Dan.

[finnbay]

Steve,

Got a chance to run a couple of images through this blending technique and it works well. Always good to have another weapon in the arsenal to get the most from an image. Again, thanks for posting it!

[Steve Foss]

No prob, Ken. It's what I'm here for.

[mmeyer]

Steve,

This is a great tutorial. Thanks for posting it. I hate to bother you about other PS things but whenever I open an image the background layer is locked. How can I unlock it without having to duplicate the layer and delete the original? If you can help, Thanks

Mike

[Steve Foss]

Mike, when I open an image in CS2 the background layer is locked, too. I have to open another layer or copy and paste one image onto another before an unlocked background layer is established. Not sure if that quite answers your question, and Dbl and Finn Bay have a lot of PS expertise, so they may want to weigh in, too.

[finnbay]

Yes, to my understanding the layer is locked. I know I've read the reasoning somewhere but like everything else, memory now fails me. In Ben Willmore's book on Photoshop cs studion techniques he says "Photoshop will not let you drag a layer below the background because it doesn't think of the background as a layer. If you liken it to a pad of tracing paper, then you would think of the pad's cardboard backing as the background layer." Hope this helps.

[Dbl]

To unlock a background layer, right-click it and choose "duplicate layer." This actually creates another layer called "background copy" above the background. You can now right click the locked background layer and "delete" it and you are left with an unlocked background. Wow, wasn't that fun! I usually just use "Ctrl J" to duplicate the locked background layer and go on from there and not worry about the locked background. There are many ways to make these things work.

[mmeyer]

Thanks everyone,

I am new to PS so I wanted to make sure I wasn't missing something. I'm glad I'm on the same page.

Thanks again for the help.

Mike

[finnbay]

Thanks Dbl. Have never done that before.

[Steve Foss]

Thanks, Dan. But help me out here. Why unlock it in the first place?

[Dbl]

I do a lot of poster work where you blend a couple of photos together with one photo as the background. In order to make some of the elements in these images line up it can require moving the background. The only way you can do that is with an unlocked background via the above method.

[Steve Foss]

This is a great discussion. I have done no poster work so far. So here I defer to Dbl (Dan) and Finn Bay (Ken), who both use almost exaclty the same equipment for exactly the same type of sports images/clients. Dan, won't blending two separate images via the tutorial that started this thread accomplish the same thing? Why or why not? Ken, I know you also do a ton of poster work. How do you blend images for that work?

[finnbay]

I always start with a solid or blank background (file, new, white, transparent or background color) and place layers on top of that, so I never have to fiddle with the background. All my work is done on top.

[finnbay]

I should add, I then mask and brush out on individual layers, use a lot of gradient layers and play a lot with opacities.

[Dbl]

Steve, here is my quick blending method. It is not great for detailed situations but in the case of skys and foregrounds it works well. This is not ground breaking stuff, I think it is used a fair amount. For these sunset or sunrise shots I usually take an exposure for the sky and one for the foreground and blend the two together to get the dynamic range I want.

Here are two throw away shots that I did not care for that should illustrate what I mean followed by the final result. Takes about 1 minute to do this.

1. Open both or more photos in PS. I usually take the light shot and using the move tool along with the shift key drag the dark photo on top of the light. Using the shift key until dropping will perfectly position them together.

2. Take the top layer and add a layer mask to it. Make sure that the foreground colors palete on the left is set to black and white and the selected color is black. Now using a broad brush, making sure you have the mask active, paint to reveal the layer underneath. Change brush sizes, the opacity of the brush and switch to white to undo what you have done.

This works well with sky and foreground that has reasonable lines to work with, the pier shot may not be the best to use. HDR in this case may be a better option. Give it a try.

#1 Sky is good, the rest is underexposed.

#2 Overexposed sky, foreground looks good.

#3 Result. Remember I did this in less than a minute. You could do some tweaking to certain areas. Just switch between black and white, size of brush, opacity of brush, opacity of layer. Many adjustments you can make. Pardon the dirty sensor. The restaurant on the left I used about 40% opacity because revealing the light under neath made it to bright. The building under the ferris wheel would benefit from the same treatment, just to lazy to work it.

[Dbl]

Quote:

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This is a great discussion. I have done no poster work so far. So here I defer to Dbl (Dan) and Finn Bay (Ken), who both use almost exaclty the same equipment for exactly the same type of sports images/clients. Dan, won't blending two separate images via the tutorial that started this thread accomplish the same thing? Why or why not? Ken, I know you also do a ton of poster work. How do you blend images for that work?

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Your tutorial really deals with blending lights and darks to obtain a more even exposure. Posters I think require a different approach, it might work but I use a different technique that is for me more effective. I start with a background PHOTO and add additional layers (more photos)and then add layer masks to each of those layers to erase away what I want. This gives me a nice way to blend the photos together. That is one time as I mentioned earlier that I unlock the background, so I can position it anywhere I want. You could do the same thing and start with a white, black or whatever color you wanted background and then just add photos (layers) and move them as you want (for the most part the same as Ken's method). I find that I sometimes have a hard time getting rid of the background color in spots when I do that.

This technique gives me so much more control over the blending that I now use this method nearly 100% of the time.

This is a quick poster showing four images blending onto one. The final image was improved upon around the mound to blend it better. These things printed at 24" x 30" really catch the eye.

And a handheld 8 image blend using the above technique, I may have shown this shot a while back. Can't wait to reshoot a better one this winter.

[finnbay]

Dbl,

Sounds like most of what we do involves the same techniques. I've looked at your web page and really like your work. It is obvious that the bottom layer as a photo is important to the effect you are achieving. I can see where a solid color background could cause some problems for you, especially if you drop the opacity down below 100%. You must have emailed your examples to Steve. I would like to see them if possible as well. I'm totally self taught, so when I can pick up an idea or technique from someone willing to share, I really appreciate it. I rely on a colored background (usually white or black) to get the effect I'm looking for. Great work and a good thread.

[MN Shutterbug]

Dan, that is some cool stuff. I would never have the patience.

[Dbl]

Quote:

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Dbl,

Sounds like most of what we do involves the same techniques. I've looked at your web page and really like your work. It is obvious that the bottom layer as a photo is important to the effect you are achieving. I can see where a solid color background could cause some problems for you, especially if you drop the opacity down below 100%. You must have emailed your examples to Steve. I would like to see them if possible as well. I'm totally self taught, so when I can pick up an idea or technique from someone willing to share, I really appreciate it. I rely on a colored background (usually white or black) to get the effect I'm looking for. Great work and a good thread.

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I am self taught as well but am always looking for a better way to get things done. You are right that the solid color background can cause issues in multiple blends with less than 100% opacity. I did not e-mail Steve but if you want examples just let me know what you would like to see and shoot me an e-mail. I would be more than willing to share what little knowledge I have. And X these once you have done a few they don't take all that much time to produce. I don't really have the patience for some of it either, I would rather spend time taking the photos.