View Full Version : Using Layers, masks and multiple exposures around difficult objects

12-04-2009, 9:12am
Hi folks, since writing my last tutorial (Using Layers, masks and multiple exposures to avoid blown highlights (http://www.ausphotography.net.au/forum/showthread.php?t=25151)), I've learned a liitle bit more so thought I would share. This follows on from the previous tutorial in that we are using two exposures of the same scene and a mask layer to blend them.

Here are our two exposures:

Image #1: exposed for the sky, causing the tree in the foreground to be underexposed and very black

Image #2: exposed for the tree, causing the sky to be overexposed.

The trouble this time is all those leaves and twigs! Masking every leaf and twig with the brush tool like we did in the previous tutorial is going to be a major headache and you'll probably end up with 'mouse induced carpal tunnel syndrome' :). How easy it would be if we were able to make a tree-shaped mask!

The first thing we need to do is get our images set up in layers and ready for masking using the same process we did for the previous turorial:

Ok, now that that's done, we can set it aside and make our tree-shaped mask using the following steps:
(I use Paintshop Pro. Adobe users, you will have similar features, just slightly different)

STEP 1. Open up a new copy of Image #2

STEP 2. Using the threshold tool, we need to adjust the image to a point where the background behind the tree is completely white and most of the finer branches are still intact. Don't worry too much about the really fine twiglets.


STEP 3. Next, we need to soften the edges of our image a little using the Gaussian Blur tool so that the final blend isn't so obvious.

This is your finished tree-shaped mask image!

Now that we have our tree-shaped mask image, the text step is to copy and paste this into the mask layer of our original layered image like so:
(Note the mask layer on the right is our tree-shaped mask)

and here's a 200% crop to show you what sort of job it does:

Using the brush tool, you can now go ahead and touch up and other parts of the mask you feel are in need of tweeking. Then, merge the layers and do the rest of your PP (level horizon, crop, sharpen, etc)!

Good luck and happy masking!

12-04-2009, 9:22am
terrific tutorial David, thanks for putting the effort in, I'm going to have to try this as your previous tutorial helped me greatly, and I can't see why this one shouldn't be any different.

12-04-2009, 9:30am
Well done David; that was not a 2 minute thread to write; I will have to book mark it to read later; thanks mate; appreciate the time you put in. :th3:


29-04-2009, 7:14pm
I love your work David. I got a lot out of your last tutorial and now I'm going to give this one a go.
About that carpet tunnel, I know what you mean. This way will save a lot of time.

01-05-2009, 6:05am
Thanks guys ... Anytime I learn some thing new, I don't mind sharing :)

27-09-2009, 12:54am
been looking for this for ages. thanks so much for sharing, David.