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View Full Version : PS CS Selective Processing Mini-Tutorial (56K Beware)


Scottes
24th of May 2004 (Mon), 18:56
Some time ago CDS had mentioned that noise removal plugins would remove detail, often undesirably from detailed subjects. He described using the History Brush to get those details back, and I was enlightened. I started to play with this last night and found it to be very useful for many processing tasks. Sharpening was one area that instantly came to mind.

First we start with an original image:
http://www.itsanadventure.com/postimages/5128_Org.jpg

Cropping and levels adjustment were already done. This obviously needs some sharpening. So I sharpened it:
http://www.itsanadventure.com/postimages/5128_AS.jpg

Well, that's OK, but those water drops don't look so great. In fact they're fairly distracting because they stand out so much. So I'm going to tone everything down, leaving just the sharpening on the osprey.


First take a look at the History Palette. (Click on Window, then History if it's not visible.) Note that I have two steps so far - I Duplicated the image (Image... Duplicate) so I wouldn't mess up the original. And then I Sharpened. I used the Intellisharpen plugin from Fred Miranda.

Notice the little box next to each step. Hover the mouse cursor over it like I did...
http://www.itsanadventure.com/postimages/5128_hp.jpg

Clicking in this box "sets the source for the history brush." That is, everywhere you paint with the History Brush will be "erased" back to that point in time. So I'm going back to a point before the sharpening. So everything the history brush touches will be "de-sharpened" - it will simply have the sharpening removed.

I going to choose the history brush. Click on it in the toolbox, or simply press the letter Y.
http://www.itsanadventure.com/postimages/5128_tb.jpg

I'm going to start with a large brush, and I'm going to set the hardness to 100%. The large brush will let me cover area quickly, and the hardness will completely "erase" the sharpening right up to the edge of the brush.

http://www.itsanadventure.com/postimages/5128_br.jpg

Setting the hardness lower would let you "unsharpen" a little at a time. With a very low hardness you'd erase just a bit every time you passed over an area - several passes will eventually get to a complete erase. This is great if you want some sharpening to remain, but it's a little trickier because you might pass over some areas once and other areas several times.

By the way, I use Brush-Size Cursors because I like to see exactly where I'm going to be working. If you don't have Brush-Size Cursors enabled, click on Edit... Preferences... Display and Cursors and check the box.


So you've got yourself set to a large brush, so just sweep around areas. Sometimes it's hard to see where you've been, so be sure to cover everywhere. Don't come too close to the subject - you'll switch to a smaller brush and get closer.
http://www.itsanadventure.com/postimages/5128_bb.jpg


Now make the brush smaller by pressing "[" a few times. That's a heck of a lot quicker than using the brush palette above. The "[" key goes smaller, and of course "]" makes the brush larger.

Since the brush is smaller you'll want to zoom in. You can click on the Zoom tool, or use the easier way by pressing the Z key. Even easier is Control+ (control-plus) to zoom in, or Control- (control-minus) to zoom out.
http://www.itsanadventure.com/postimages/5128_lb.jpg

Zoomed in with a small brush you can get closer to the subject to erase the sharpening. To move around you can use the scroll bars on the edge of the image, or click the Hand tool (or press H) and click, hold, and move the mouse. The fastest way is to hold down the spacebar - the mouse cursor will turn into a hand, and you can click and drag to move the image around. This spacebar trick works with almost every tool, so you don't have to switch to another tool just to move the image around.


So, that's it. Sharpen, set the history source to the step before the sharpening, grab the History Brush and de-sharpen away!


To re-cap for comparison, here's the sharpened version that didn't look so great:
http://www.itsanadventure.com/postimages/5128_AS2.jpg

When done with the History brush, the osprey is left sharpened while everything else has been de-sharpened:
http://www.itsanadventure.com/postimages/5128_SS.jpg

Now doesn't the osprey just pop a bit more?


You can use this trick for many things - sharpening and noise removal immediately come to mind.

But how about faking Depth of Focus? Take an image and do a light Gaussian Blur 4 or 5 times. It will look *way* too blurred. But set the History Source back before you started blurring. Use the History Brush and de-blur the closest subject. Now set the History Source forward one step (the first Guassian Blur), and de-blur the next-closest subject - it will still be a little blurred, but not as much as the rest of the image. Keep doing that until you've left the background completely blurred, but different subjects are slightly less blurred.


Finally, Photoshop lets you do things in many different ways. There's many ways to re-create this "selective sharpening" process. But maybe you learned a little about the History Brush, and maybe you learned a few quick key presses, too. Any way, I hope you enjoyed this.


Re-cap of quick keypresses used:
"Y" - History Brush
"Z" - Zoom Tool
"H" - Hand Tool
"Control+" - Zoom In
"Control-" - Zoom Out
"[" - Make Brush Smaller
"]" - Make Brush Larger
"Spacebar" - Press to change to Hand to move image around

Scottes
24th of May 2004 (Mon), 19:07
A little more pop:
http://www.itsanadventure.com/postimages/5128_SB.jpg

A bit of Gaussian Blur and then History Brush over the osprey to remove the blurring from the main subject.

cprevost
27th of May 2004 (Thu), 08:41
Awesome tips! Thanks for sharing.

slejhamer
27th of May 2004 (Thu), 09:18
Scottes, this is a great tutorial for anyone interested in getting good use of the history brush.

Personally I still prefer working with layer masks, but the history brush has its proponents.

Scottes
27th of May 2004 (Thu), 10:29
Slejhammer and cprevost: Thank You!

I spent a couple hours putting this together, watched and watched for days as people read it, and nobody said a thing! Not one comment until you two.

I was beginning to think that this sucked and that I had wasted my time. Thanks for breaking that thought. You two made the time worthwhile.

mapollo
27th of May 2004 (Thu), 11:48
I'll add my thanks too. I'd watched a tutorial on the history brush about a week previous but what I needed was a practical (usefull) example of how to use it.
The two hours worth of work you did really hit the spot. Consider me enlightened.. :)

Thanks David.....

LazyPhotographer
27th of May 2004 (Thu), 12:35
That's interesting and educational. I like these kinds of posts because the visual examples helps to get my head wrapped around the whole (and rather intimidating) concept of PS and manipulating images.

I don't use PS yet, but I do check out this forum about once a week or so. I've started to collect tips & links to posts like this one that may make more sense to me once I actually touch PS. Thanks!

quickben
28th of May 2004 (Fri), 10:32
This really has helped me, Scottes !!!

Even the shortcuts.

I think this is an underated part of the forum. I, personally, am a bit frightened of PS. I think it's way over my head, but posts like yours put it into Lament's terms so I can understand them.

Cheers, mate. :D :D

Gary.

tommykjensen
28th of May 2004 (Fri), 11:14
Slejhammer and cprevost: Thank You!

I spent a couple hours putting this together, watched and watched for days as people read it, and nobody said a thing! Not one comment until you two.

I was beginning to think that this sucked and that I had wasted my time. Thanks for breaking that thought. You two made the time worthwhile.

Thank You for taking the time to put this together, I'll have to try this some time.

Tutorials with photos of stages is always a lot better than a verbal description of how to do things. In fact not more than 1 hour ago I read a post on a danish forum about how to reduce noise with smart blur - I will try that too but it lacks photos of the steps.

So thank You. I hope You will create more tutorials either of subjects You think of Yourself or on request - obviously anybody else capable of doing this are most welcome to do this too :D :D

Scottes
28th of May 2004 (Fri), 15:12
More thanks to more people. I'm glad you enjoyed it, and I will try to put some things together as I think of them. I've got another brewing in the head now...

Quickben/Lazy - I don't blame you for being afraid of or intimidated by Photoshop. It's definitely one of the most complex programs I've ever used. It is also about the closest thing to perfect software that I've ever used.

There is one thing to realize about PS: it lets you perform almost anything in a number of ways. Learn the simple ways, and as you get more experienced or pick up more tips you'll get better and/or faster. Look at moving an image around in a window - first you use the scroll bars, then you learn to click on the Hand tool, then you learn that H switches to Hand, then you learn that simply pressing the space bar temporarily gives you the Hand tool.

Don't be daunted by Photoshop - in other words, stay away from those 1200-page Photoshop Everything books. Grab one of those small "Easy Visual Quick Start Guides For Dummy Digital Photographers" or something.


Again, thanks to all and I've glad you enjoyed and/or learned something.

tommykjensen
28th of May 2004 (Fri), 15:18
Don't be daunted by Photoshop - in other words, stay away from those 1200-page Photoshop Everything books. Grab one of those small "Easy Visual Quick Start Guides For Dummy Digital Photographers" or something.


I got the dummies books.

Photoshop Elements 2 for dummies
Photoshop CS for dummies


Guess I should use them more instead of asking questions :lol:

Scottes
28th of May 2004 (Fri), 15:53
Guess I should use them more instead of asking questions

I don't think that asking questions is a bad thing. One of those books is a great way to simplify a hugely complex program, and *get started* with PS. Once you are even somewhat comfortable, then find "tips and tricks" and ask questions.

I've got 9 Photoshops books not counting the manuals. 1 of them is one of those "All About" 1200-page monsters (From version 4 mind you), and the rest are specialized tips and tricks. (Web, type, photography, etc.)

In my opinion Photoshop is far too big to learn the whole thing. So get comfortable a bit and zoom into what you want to do.

CyberDyneSystems
28th of May 2004 (Fri), 16:27
Awesome tutorial Scott...

As you know I do this often.. and in fact I do it with Sharpening, noise removal. and even color/level adjustments where appropriate.

You can use the eraser tool on a second layer that the sharpening has been applied to as well.. in fact that can offer yet more flexibility.. but the technique is identical where the brush work is concerned.

By the way.. that is one of the best shots I've seen from the mill.. amazing!

jgjulio
21st of October 2006 (Sat), 11:25
I just found this post Scott. It is great. I learned a lot about the history brush. Nice thank you.

Scottes
21st of October 2006 (Sat), 12:32
Wow, what a blast from the past. This is the first tutorial I ever did, and I'd totally forgotten about it.

I'm glad you dug 2-1/2 years into the past, and glad you found it useful.