This summer during my photography workshops that I instruct I have been blessed with a lot of travel and photo opportunities
that have also given me the chance to try out some new techniques. The primary technique of interest has been image blending
and has also been one I have been apprehensive in giving a shot due to the inherent risk of messing up an opportunity. Should
you improperly expose, bump your tripod or a list of other mishaps you will have a very difficult time later in post, if you can even
salvage it at all. In this posting I wanted to focus on Image Blending which can help create an awesome and totally useable image
out of one that may have otherwise been thrown out. One afternoon while hiking the Narrows in Zion National Park with my
good friend, Dan Ballard, I decided this was as good of a time as any to try out the technique.
On this particular day the wind was terrible making any long exposure photograph useless. I wanted to soften the water and
create a smooth and silky effect to contrast with the hard rock and canyon walls in the scene. What made everything so
frustrating was the inability to simultaneously soften the water and capture the trees sharply due to wind. Every photo over two
seconds had terrible leaf and tree shake that ended up looking like a blur of green in the photo with the soft water effect I
envisioned. At a certain point I thought that it might be time to employ the technique of image blending to come away with even
something remotely useable and salvage the days photographic efforts.
Jumping into it, I would like to state that I had no prior experience with image blending. The only concepts I knew at the time
of capturing the images were: 1) Use a tripod and DO NOT adjust camera angle at all, 2) Keep ISO, White Balance and Focal
Length the same in every photo, 3) take a long exposure using my B+W 10x ND filter to soften the water, 4) a subsequent fast
shutter speed photo to freeze all motion in the trees and grass and 5) TAKE SEVERAL SHOTS OF EACH IMAGE. Ok, so
now that I have laid out the basic principles of image stacking and blending which apparently worked, let's jump in and see if we
can make sense of all of this.
The first image I took I shot at ISO 400, f/13 @ 30 seconds. I used f/13 for hyperfocal distance to keep everything in the shot
sharp from the log up close to the trees and waterfall in the distance. I chose ISO 400 because I prefer shooting in Aperture
Priority and 30 seconds is the longest exposure time without having to go into Bulb mode. I simply enhanced the camera’s
sensitivity to lightby increasing ISO. The image below is basically how it came looking out-of-camera. The only adjustments I
made were selecting Auto White Balance later in Lightroom as it was a little brown out-of-camera. Sometimes filters add a color
cast to your images which can be a nuisance though generally are not a deal breaker as long as you're sticking with a high-quality
filter. I love my B+W and use it all of the time as its color shift is so subtle and easy to later correct in post AND it's hundreds of
dollars less expensive and easier to get your hands on than a LEE Big Stopper. You can see from the histogram I am not clipping
on the shadows so I knew I could pull out any and all detail from the shadows in the image later in post process. Pay attention to
your histogram and don’t let it clip on either side and you can pull out shadows and control highlights to get your shot.
This is the same photo with nothing more than increasing my Exposure to +1.10 which you can see in the right-hand column in the Develop Module within Lightroom:
The next photo I removed my filter and shot at the same ISO and Aperture, though I increased my shutter speed to 1/20 second to freeze all motion within the frame and also increased my Exposure by +.75 later in post to get the two images to look similar:
We are now ready to take the two images from LR and import them into Photoshop. The two image files we will be working with are _DSC0367 and _DSC0368. What I should mention at this point is before opening them in Photoshop, make sure each image you are taking out of LR and into PS look as close to the same as possible with respect to Exposure and White Balance. We are trying to achieve a seamless look later down the line and that will be impossible if you have one image darker, bluer, etc. To open in PS simply right-click with your mouse over the image and select Edit In from the options and your installed version of Photoshop should be listed in the options available. If not, you will need to adjust your settings of external file handling programs. There are many resources on the internet that explain this and I prefer the Lightroom Queen. She has pretty much every topic covered and if not, send her an email and she typically responds in an incredibly timely manner.
This is the fast shutter speed image (0368) after opening in PS:
And here is the slower shutter-speed image (0367) with the soft and silky water:
Now that they are both open in PS we can overlay, or stack them, with a couple simple clicks of the mouse. What we need to do here is remember that the image we are looking to "keep" (0367) is the image with the soft water and only take the sharp leaves and grass from the other image (0368). So with that in mind, we will need to Duplicate a Layer on the Soft Water image by simply right-clicking with the mouse on the Background Layer:
This will pop-up the following window where you will now need to choose which image you want the image to be duplicated and applied to. Choose the image file of the other, or 0368 in this example, and click OK:
After clicking OK you will now go just above the images to where the tabs to your images are located and click on the secondary image that you applied the Duplicate layer to. This would be the fast shutter speed image in this case, or file number _DSC0368. The output will now be a layered composite of the two images with only the blur being visible. You can see in the right-hand column that you now have the Background layer and also the Background Copy. The Background Copy is the copy you sent over from your original image you "want" to keep:
We are now almost ready to begin the magic of making these two images come together to achieve the master image we envisioned in the first place. With your Background Layer still selected move over to the Tools column and choose your Eraser tool from the list. In the picture below it is almost exactly half-way down and is the one selected:
Here is a tighter crop so you can see what the tool looks like up close:
With the Eraser tool selected, move out to your image and now right-click anywhere in the frame and adjust the size of your Eraser and also its hardness. I wanted a larger eraser size so I chose one of 900 pixels with hardness set to zero. This will vary from photographer to photographer and situation. Perhaps you are wanting to image-blend 5 photos that you focused at various focal points throughout the frame and want to erase the soft areas away. In my case I simply wanted to eliminate the blurry leaves.
After applying your settings you are now ready to erase away the undesired part of the image. You can see that I have done just that when looking at the tree leaves in the following two images:
Now that we have removed the undesired portion of the image we are now ready to save the image back into Lightroom and make our edits there. On a Mac the keyboard shortcut is Command+S, on a PC: Control+S, and this will save the image in a .Tiff format back into your Lightroom Filmstrip:
Once the image is back in Lightroom this is where we want to make our adjustments to the saved file out of Photoshop. You can see many of the adjustments made in the right-hand adjustments panel are with Exposure, contrast, etc. One thing I would like to point out is at NO point in this workflow did we touch our Saturation slider. All of the color and depth comes from Dodging and Burning and working with our sliders in the Develop Module here in Lightroom.
This image below is the final product that I uploaded onto my Zenfolio site:
I hope this post has been helpful and has given some insight into how we can stack and blend in Photoshop and Lightroom. With a little trial and error you will be able to use this technique to make some great images out of a challenging situation and once you try it I think you will agree the results are worth the effort it takes.
Thanks for taking the time to read this post and I wish you luck out in the field when trying to employ this technique.