Preserved Topic: Calculations (Page 1 of 1)

I was wanting to expand my horizons more with calculations and wondered if anybody had any good links to info or tutorials on different ways to use calculations. This is the only one that I have.
Thanks in advance all.

Just a side note...

Element K provides the courseware that we teach from at New Horizons. That stuff is good shit.

Yeah, I've been a pretty happy camper since I've found that site...Although I did get one free issue of their journal and for the price, I wasn't impressed. It's really small.

Vogonpoet might have some input - he frequently makes reference to a book - maye David Biedney's??

Once upon a time, when the world was a simpler place and photoshop versions were still in the 2's, there were no layers.

~collective gasp~

But there were channels, just like today. Compositing one image into another was one thing that could be done very effectively with calculations. Also very elaborate channel blending for special effects. I have one of the first "Photoshop WOW!" books, and there is a fantastic, unbelieveable sequence creating glassy and metallic effects on type using calculations with blurred or offset channels blended. We called them "chops" - channel operations. The required experience and the ability to look at a channel not for what it looked like but rather what you could do with it. What could it select? What could it mask?

Now we have layers. Together with blend modes, much of what calculations can do can be done with layers, and with the added advantage of being able to diddle with the effect. Do I want screen or hard light? Do I want 80% or 60% opacity? Calculations only let you change your mind with "undo".

A good resource to learn about the power of calculations, "chops", would be Kai Krause's groundbreaking Power Tips, still available from many sources on the internet. Many of his tips involve chops, and even today the effects and the potentials are breathtaking. Good stuff to absorb even now.

Calculations still exist in Photoshop 6, pretty much identical to what it looked like in version 2.5, but they aren't as commonly used today I don't think. However - there is a new tool that is very useful indeed for channel blending of the sort your link demonstrates. It's a simplified Calculations - "Apply Image". Dan Margulis teaches channel blending with Apply Image very effectively in his book "Professional Photoshop 6", and he's about the only one I know who does. Briefly ... let's say you have a CMYK file of a portrait that isn't making it. You examine the channels and find plenty of detail in Yellow and Magenta, but Cyan is flat and featureless. Bringing detail into Cyan is going to have a strong effect on a face - it's the "unwanted" color. Do you have any idea how to get some of Yellow's detail into Cyan? Curves won't work, because there's no detail there to begin with. Select the Cyan channel. Image>Apply Image. Select Yellow from the pop-up menu. Default is 100%, which would replace Cyan with Yellow completely, not what you want. But set opacity of the blend to maybe 30%, blend mode maybe to darken, maybe to hard light, and Cyan starts to perk up. You can even use the Yellow channel to mask itself as it blends into Cyan by checking "mask..." and choosing Yellow - composite Yellow into Cyan just in the lighter areas! Check "invert" and composit just into the darker areas!!!!

Wow. I could go on and on, but I'll restrain myself! But mess around with it. Please. This is a power tool. I mean it. Wear your safety goggles and steel toed boots, and watch out where your fingers are!

I remember that there were some really great calculations tutorials Kai Krause which were origionally intended for ps3 but I cant seem to find them out there anymore. A lot of the really great practical tools seem to get avoided by the "Filterrific" crowds of web geeks. Photoshop is such a complete tool, I laugh when I encounter people who feel they have totally mastered it.

One source for the archive: http://shiva.snu.ac.kr/KPT/Tips/

Oh my goodness. Read Tip 1 and thank God and Adobe everytime you click on the layer effects button to get a drop shadow!

But I can tell you from first hand experience - the old way worked. You just really needed to want a drop shadow, cause as you can see it involved a fair bit of work!

[This message has been edited by Steve (edited 09-15-2001).]

Steve... This version of PS didn't have layers, I guess? Ouch time. I read it through... for some reason I'm quite shy when it's about layer effects. I do my drop shadows still as

a)copy layer
b)check [preserve transparency]
c)set to default colors (press D)
d)exchange colors (press X)
e)fill (press CTRL-Delete)

takes me 1.25 secs now... Using keyboard for PS is fun once you know the shortcuts.

I usually just select layer + fill + gaussian blur, takes less time than it does just to load the layer effects box :P

Thanks for that link Steve. I read Kai's Chops quite awhile ago and it's about time I go through it again....Time hasn't permitted for quite awhile. Always good to get back to your roots. Thanks again