32bit TGA = no transparancy

This is not a problem and I'm not bothered, I'm just curious.

Now I save all my images from Photoshop (ready for upload) in 24-bit TGA format.

If I want to have transparacy I use PNG format.

I have tried saving as a 32-bit TGA (Photoshop pops up this box everytime you save a TGA) but if I do save as 32-bit I just get a solid white background and no transparency.

As I say, I'm not bothered as PNG is fine, I'm just curious.

sounds like you are using an old version of PS that has a bug in it.. download the patch from adobe or..


download gimp and make the 32 bit tga's there

It's CS4

When you save as PNG, Photoshop composites an alpha channel from layer and group masks plus transparency.

When you save as TGA, PS does it completely differently. It acts as though there is is always a solid background in place, and looks for a fourth user-created channel to use as the alpha instead.

So, to make each format do what you want, you have to alter the work flow to suit. To get the TGA you want, you have to create the extra channel so there is something to save into it (and you have to put something in there, PS won't try to do it for you with this format). To get an alpha onto a PNG that doesn't follow transparency, you have to use layer or group masks.

thanks.......

So, are you saying.................

All I need to do is to make a clean fully empty layer as well as my other layers (or the layer with the picture on it) and then it will work?

It will detect that there is an empty one and use it?

No, it's a fourth (alpha) channel, not a layer.

thanks for clearing that up.

In al my MANY years of using Photoshop, would you believe I've never had the need to use Channels

Also, if you us Gimp or an older version of PS and you will not have that issue.

The stickied thread at the top of this forum might have some useful information on this topic:
"Transparency and Alpha Channels: The Definitive Guide "
/109/32/80851/1.html

No offense, but if that's the case, then I would submit you've never REALLY used Photoshop. That channels palette is there for a reason. The ability to manipulate the primary color channels individually, and the ability to create and manipulate alpha channels at will, are two of Photoshop's most powerful features.

Alpha channels have literally thousands upon thousands of uses besides just serving as transparency maps for SL. To ignore the channels palette in PS would be like ignoring the quarterback on your football team. Until now, you've been trying to run every play on foot, without ever passing the ball. While it's certainly possible to play that way, and even conceivable that you might even win sometimes if you're tough enough, you're making things a whole lot harder on yourself than they should be, not to mention infinitely more time consuming.

If you're not going to use the channels palette, save yourself some money next time, and get Paintshop Pro instead of Photoshop. The channels palette is the single biggest difference between the two. Since you do have Photoshop, you spent several hundred dollars on that channels palette. Again, no offense, but it's pretty silly to dish out that kind of money for a tool and then not use it.




Actually, there was only ever one version of Photoshop that behaved any differently in this regard from how the current version behaves. That was version 7.0, which was deeply, deeply flawed. All versions of PS before and since 7.0 work exactly the same way as the current version.

Unfortunately, a lot of SL content creators who started in 2003-2004 tend to think the 7.0 behavior was normal, simply because that version happened to be current at the same time SL first came out. People who began using Photoshop at that time learned the bugged behavior first, and so tend to think the behavior of subsequent versions is abnormal, when in actuality, the difference is nothing more than a bug fix which restored the proper functionality. Even version 7 itself was fixed within three months of its release, with the free 7.0.1 patch.

As for GIMP, I consider it to be a tremendous weakness of the program that it doesn't allow for easy creation/manipulation of alpha channels via any other method than WYSIWYG transparency. Without that ability, it simply would not be possible to work the way I, and countless other artists, do. GIMP's a great program, but it's got its holes, and that's a rather gaping one.

Intersting post "Chosen"

As I say, I've used Photoshop very happily for, ohhhhhh, 10 to 15 years.

Quite happy with Layers and stuff.

Done all my photo editing on it, clening up pics etc etc........

Or course, like any package you don't generally use ALL the features.

If you can briefly explain to me in a paragraph just what I'd use Channels for then I'll happily take them on board and see if they can offer me any benefit in the future.

I'm not sure what putting my name in quotes is supposed to signify, but I'll assume it wasn't anything bad.

It's pretty tough to limit an explanation of channels to just one paragraph. You might as well ask a chef to explain in a single paragraph how a stove is beneficial for cooking, to someone who's only ever used a campfire. There are literally millions of possible answers, all of which are highly variable in accordance with what you're trying to make.

I could spend weeks assembling a proper list of uses, and that would still only scratch the surface. I'll try to limit this to a few that are immediately obvious for any texture artist, no particular order:

1. If you want to make a texture that grades evenly from opaque to transparent, you can do so in less than a second, simply by putting a black-white gradient on an alpha channel. To try to do it some other way could take hours, and there would be a huge margin for error.

2. For images with highly variable degrees of transparency, such as stained glass windows, proper alpha channel work flow can save countless hours per image, and is totally non-destructive. People who are new to the concept never believe me at first when I say that, since WYSIWYG seems so much more intuitive in the beginning. But every single person I've ever helped to learn the difference has been absolutely floored at how much time and energy they'd previously been wasting.

3. Channel-masking is an extremely fast and efficient means extracting image elements from backgrounds, especially for elements that have complex edging like human hair, furry animals, foliage, etc. Even the seemingly messiest and most chalenging extractions can be done in mere seconds, if you know your way around the channels palette, and have had some practice with applicable techniques. To attempt such extractions with any and all other methods I'm aware of typically will take considerably longer, and the results won't be nearly as clean. (Note, channel masking is slightly different from straight up layer masking, although they are closely related.)

4. Color balancing and adjustments can be done in seconds, simply by manipulating the levels of the primary color channels. This can be far more precise, and much faster than using tools such as the hue/saturation controls.

5. Alpha channels are the only fully controllable means of adding lighting, bumpiness, and other 3D-esque effects to your imagery.

6. The channel/masking mindset as a workflow is infinitely less destructive than typical WYSIWYG workflow. Changes can be applied, reapplied, undone, redone, etc., forever, without ever having to alter the original imagery.

7. Using channels as launching points for contrast masks can add a depth and dimension to photography that is almost unachievable any other way.

8. The effects of practical photographic darkroom filters can be simulated instantly, simply by controlling which channels do and don't receive the full weight of Photoshop filters and effects.

9. By having the transparency map be a separate element from the color maps, transparency values of one image can be applied to another, instantly. I'm not aware of any other method of doing this in any reasonable amount of time.

10. That same transparency map can be used to map any other effect in any capable 2D or 3D rendering program. So, for example, if you want that stained glass window to be shinier on the more opaque parts than the more transparent parts, or bumbier, or more specular, or more reflective, or whatever, all of that can be applied instantly, simply by assigning the alpha map to control those effects as well as just transparency. This is nearly impossible with WYSIWYG workflow, without an absolute ton of extra work.


That's 10 off the top of my head. As I said, I could go on for weeks listing more.

I used a football analogy earlier. Here's a better one I've used in the past. If your image were a football game, all your layers would be the players on the team. You as the coach wield a tremendous amount of power, as you can direct those players where to go and what to do at will. However, by ignoring the channels, you expose a fundamental weakness in your abilities. You see, the channels aren't merely additional players. They are the very field the players are playing playing on, they're the sun shining down on them, the temperature of the air they're breathing, the wind conditions on the field, etc. As a layer manipulator, you're a coach, but as a channel manipulator, you're a god.

Here's the bottom line. While I don't doubt for an instant that your 10-15 years of experience with Photoshop has taught you a considerable amount of expertise in what you've been doing with it, the fact is if you've been ignoring the channels palette all this time, you've only ever been playing half the game. No matter how good a coach you may be, and no matter what you instruct your players to do at that level, you'll never be able to make your team win every single game unless you also control all those overlying and underlying elements that are beyond the realm of what players on the ground can even comprehend. And that' something no mere coach can ever do. Unlock the power of channels, and become a god over your imagery. That's about the best way I know how to put it.

Nitpick: you could paint the selection mask with a gradient, and then cut. Or you could apply a transparency mask to a layer. Those don't actually LOOK like you're using channels.

I was hoping to beat Chosen with a long post of my own, but I didn't quite make it. Damn you, Chosen! Damn you!

Channels absolutely rock. They are old school, but you can't beat their simplicity and elegance. They really are the under-pinnings of how a lot of things work. Channels are the Axioms.

As far as photographic retouching goes, retouchers use Channels all the time. To create edge masks, lum masks, sat masks, and various other things.

In the Channels palette, ctrl + click loads greyscale as the selection. By using various combinations of ctrl, shift, alt + click, you can do some basic ChOps on the fly. Attempting to do these things in the Layers palette is a clunky nightmare.

If you are into retouching and want to know more about how Channels applies to these things, I highly recommend visiting the Retouch Pro forums.

Here is a snippet of what I was going to post:

----

Brief History

A long time ago, Photoshop did not have Layers. I know, hard to believe. But there was a Channels palette. Back then, not many people did much with Photoshop. It had some basic tools, but nothing quite like what we have today. In such early days, Photshop hadn't been around long enough for folks to figure out techniques for doing things.

Then along came this guy name Kai Kruse. He took the Channels palette and combined it with Apply Image to do some absolutely mind-blowing stuff. He was doing things that nobody had ever seen before - and they were cool things. He single-handedly pioneered many of the techniques that we see and use today - and he did it with naught but Apply Image and Channels.

Emboss? That was Kai.
Satin? That was Kai.
Drop Shadow? Again, Kai.

He also pioneered many other things. For example, using Gauss + Levels for rounded corners (we didn't have rounded corners back then unless you took the time to do it the long way). And he did absolutely amazing things with something he calls Domain Shifting. Almost everytime I think I've done something new, I go back to Kai and realize that he did it first.

ChOps, baby! ChOps!

Eventually Layers and Blending Modes showed up. And Calculations. Then Layer Effects. These were originally designed to replace ChOps, but I don't think that will ever happen.

----

And then I was going to go on about contemporary uses for Channels. But Chosen seems to have this covered.

I don't think it's nitpicking at all. It's a valid point. Allow me to treat it as such, and offer a proper response.

Sure, you COULD do those things. As we've said, there are lots and lots of different ways to approach any problem in Photoshop. But again, for that particular point, my emphasis was on speed. To apply a mask to a multilayer image first requires putting all the layers in a group, and then applying the mask to the group. That's a few extra steps.

Now, that in itself is obviously not all that significant. It's just a difference of a few seconds, or possibly no difference at all, depending on how the image was constructed in the first place. However, when you combine it with some of the other points on my list (and/or with countless others I didn't list), the difference can be huge.

If I understand your selection mask suggestion properly, it wouldn't be non-destructive. Big difference there.

The layer mask would be better, but it wouldn't necessarily be directly applicable to other purposes besides transparency. If you want to use it for a bump map or something, you'd have to first copy it to a channel, which is somewhat inconvenient, and can be very time consuming if you're doing it for more than one image at a time.








Sorry, Abu. I'll try to go slower next time.

Thanks for the history lesson, by the way. I didn't know most of that. Very interesting.

Which is why I said it was nitpicking.

Very cool, guys. I love threads like this.

Don't slow down on my account, Chosen. I do know a lot about a lot, but never telling when I'll actually speak-up. One of the things that I love about these forums is that the heavy-hitters were already here when I showed up, so I don't feel any real pressure to speak up very often to school. I love schooling, but it can wears me down.

On behalf of myself and countless un-spoken, many thanks for your efforts. That goes for the rest of you heavy-hitters (you know who you are). Y'all are truly appreciated.

----

Non-Destructive vs. Speed

Can be a touchy subject. I've seen some wars over this.

Personally, I go with the flow for what I have and what I'm after. If it's mission critical, I will probably take the time to build in extra non-destructive tweakage. If it's non-critical or I'm just goofing around, I'll go for speed and comfort.

Yep yep yep - Chosen, Abu and Chip... Y'all are rockstars! I couldn't agree more...

Coming from a print AND 3D background - Channels rock!

nuf said.

Oh, well that explains it Chosen.

After Photoshop started on the Mac and i had it there in the late 80's, i did not use it again until i came to SL and it was 7.0, which i still have and used until late 2008. Unfortunately it runs a little buggy on Windows 7x64 making it unreliable.

I hate the proper functionality

A lot of people say that at first, but really, it's just a matter of getting used to it. Alpha mapping is an extremely important skill to learn. It's applicable to sooooo many other things besides just SL transparency. Once you get into the logic of it, or more accurately, once its logic gets into you, you're 99.99% likely to find that you do like it better than the 7.0 methodology.

That said, if you'd rather stick with WYSIWYG, you certainly can. Just use PNG instead of TGA. Just try to keep in mind, you'll be missing out on an awful lot, and you'll continue to make things much harder on yourself than they should be, even if you don't quite see how that's possible from your current perspective.

After recovering for my (almost felt like) "Telling off" for having the dam cheek to not use Channels (despite me never being shown how, or knowing I even needed them in the 1st place)

I've dusted myself down, picked myself up and ready to go again

It's not that I've not wanted to use channels, it's that I have not read about them, been shown, seen tutorials, that explained when and where you use them, how you use them, and to what effect.

You weren't being told off. Sorry if it felt that way, but that certainly was not my intent. My purpose was just to try to open your eyes a bit to what channels are for, and why they're so important, not to scold you for not having been educated on them previously. You asked an important question, and I tried to provide you with a good answer. That's all.

Umm.. Abu, some of us were using drop shadows, emboss, etc. long before we ever heard of Kai.

There are tons of image retouching things that can be done with channels.

On the retouching side of things, I probably use the channels the most for masking. It can, literally, take moments to mask things using channels that would take hours, or be impossible, any other way.

You can see one technique for doing this at
http://graphicssoft.about.com/od/photoshop/l/blrbps_2fwks.htm

Don't forget, in PS channels aren't always about transparency! They are also where saved selections are stored, so you can use them to make selections.

And then there's all the stuff you can do with channel mixing...

Try Googling Photoshop Channel Tutorials. You'll get more than 2 million, that show you how to take advantage of this very under-utilized part of Photoshop.

(I think the only thing that's ignored more are the two extra Blending dialogs that you see when you double click on a layer; Advanced Blending and Blend If. Since I found out what those can do, I use them all the time. They are very, very powerful! Play with them, and you'll see what I mean!)

Love this thread! Thank you, I'm learning lots!

Z