Alpha Channel Progress and a Tip

[henryanthony]

Hi

I have been working on figuring out how to get Alpha Channels to do what I want and have been making good progress.

This morning, I decided to try to get the results I wanted using Photoshop 5. I was able to do that job in less than an hour. While I was almost going to give in and go the PS5 path, the fact that this job is so simple, I decided to beat myself over the head with Affinity Photo until I could get it to work.

I found out that, all along, I was approaching the Affinity solution in the right way. What I also discovered is a weakness in Affinity Photo.

The Alpha Channel I wanted to create is simply made up of 11 rectangular bands that go from, for the sake of discussion, a fill of 0 to 100 percent. This will vary depending on other factors.

Other than not understanding how anything works in this program, my main problem was, after selecting and filling a few rectangular bands using the Rectangular Marquee tool, I could no longer make any more selections. So, I automatically thought this was some how due to a user error. 

Through trial and error, I found out that, when the Marquee tool ceased to function, I could select the Crop Tool and then select the Marquee Tool and Marquee Tool function would be restored. My guess is that I could have selected any other tool but did not test that.

Came across a few more issues but those were easily solved and may have been a PEBCAK - Problem Exists Between Chair and Keyboard.

So now, I am in a happier place with Affinity Photo and will be moving on to get some actual work done.

Best regards,

Henry

[Ron P.]

I was trying to visualize what you're wanting to achieve. I done a quick screen video of what was in my mind and how I went about it.

• Instead of using the Marquee selection tool, I used the Rectangle Shape tool. Created a rectangle with a Gradient fill. The Gradient fill went from 100% opacity to 0%.
• Copied the Rectangle using CTL + J (CMD + J on Mac)
• Keeping the duplicated rectangle selected, hold down the SHIFT key and moved it down to keep it inline.
• That gives me 2 rectangles. Now just using the Power Duplicate  feature, CTL + J, duplicated to where I had 11.

Don't know if this is somehow what you're wanting to do with creating the 11 bands, but it's a lot easier and quicker then messing with the marquee selection tool.

[henryanthony]

Hi Ron P.

Thanks for your response and for taking the time to illustrate your method. Using some method of duplication is definitely a time saver. My project requires creating a lot of variations and your way certainly may help me avoid some tedious work. It also gives me some new ideas to try.

My first method involved setting up guides using the Guide Manager and its capability to set guides by numeric input and using the Marquee Tool to define and fill each rectangle. This method worked and resulted in finding the Marquee Tool would fail after drawing 2 or 3 rectangles and would need to be “reset”.  What I found worked better was to create a random rectangular selection and modify its position and size with the Transform pallet and then fill it. Then, increment the Y dimension of the selection position by 1”, fill and repeat.

I also need to duplicate and rotate the Alpha Channel by 90*. For some unknown reason, using my original method, I selected ALL and chose Rotate 90*. This would result in rotating an 11” x 10” high section instead of the full 11” x 11” image. I tried to find a reason for this and it may well have been an error on my part. However, this is super simple work I have done countless times using my prehistoric version of Photoshop that does it easily without errors.

But, enough complaining. I’ll be using what I develop in AP in Blender - another program new to me. Lots of fun to be had in the new year.

HAPPY NEW YEAR EVERYBODY!!!!!!!