Redundancy in, or Extreme Similarity Between, Affinity Adjustments/Layer Operations

[GDPR-354025]

This past week, continuing to try to find answers to questions that arose from difficulties with lack of thumbnails for a certain Live Filter Layer, I read several articles that said there was no difference between Unsharp Mask and High Pass, and that Unsharp Mask was the "grampa" of photo-editing sharpening tools. ( I also arrived at this pretty hilarious and very helpful video about Radius, Factor, and Threshold I will call Grampa Unsharp because it uses PS terms.) After a week of trying to understand why Overlay and Soft Light blend modes are used with the specific Live Filter manipulation I posted here about last weekend--but still with no answer--I'd like to know which adjustments, filters, blend modes--any term regarding editing at all--can rightly be considered redundant, or at least so similar in their effects as to make them substantively redundant. 

Thank you. I'm making this post early on Sunday morning because I assume anyone who answers may be five or six hours ahead, so if I don't reply immediately, I will read all responses, as I always do.

 

[Alfred]

10 minutes ago, American said:

I assume anyone who answers may be five or six hours ahead

That’s an odd assumption! Users in Europe may be five or six hours ahead of you, but what about users in Texas or Hawaii, or Japan or Australia?

[GDPR-354025]

3 minutes ago, Alfred said:

That’s an odd assumption! Users in Europe may be five or six hours ahead of you, but what about users in Texas or Hawaii, or Japan or Australia?

Yes, of course you're right. 

[gdenby]

Hi, American,

I'm just a hobbyist when it comes to image processing, and after years of puttering around, I still have only the vaguest notions of how these things work. 

I think your perception of redundancy is because there can be a certain amount of overlap among filters and blend modes that are similar. But there are typically situations where one or another will give slightly better results.

An example. Up until recently, if I wanted a grey scale image, I simply used the HSL adjustment, and dropped the saturation to 0. (Note, in GIMP, desaturation can work on the color average, or its luminance. Slightly different implementation of the same thing.) But then I noticed the the B&W adjustment could produce a wider range of grays depending on the color component. W. some settings, it would be roughly the same as plain desaturation, in others, far more grey levels within specific colors were possible. So if I want to get a grey scale image from something like an old yellowed photo, desaturation works well enough. But if I have something w. lots of colors in it, B&W is the choice.

When I 1st started using Affinity, I noticed that it had more blend modes than photoshop. My daughter who uses PS extensively caught that right away. Affinity being relatively new at the time, had less documentation on the modes. I read a bunch of stuff about the PS ones, but then noticed a user here wondering what the exact numeric values for the modes were. That is, what range of hues or luminances, and what percentage of enhancement. From further reading, I found that individual developers implement the same notion is slightly different ways.

FWIW, there was a nice explanation about Affinity blend modes here.

My take on it is that there are certain filter, adjustments, etc that are most useful for specif images, or specific portions of images. Picking the right one is a matter of finesse.

[GDPR-354025]

@gdenby I wish I'd read what you wrote a few weeks ago! This past winter, I've had to make videos compiling old newspaper articles, some images of which were "cleaned up" before I stitched them together, some not. A few weeks ago, posting here on the forum because I was unable to get a color palette to open when I opened B&W images, a poster told me I had to change the Color Format from B&W to RGB. (I needed to highlight certain newspaper passages and gussy them up with colorful borders so the repetitive fine-print wouldn't put viewers to sleep... unlike my gripping posts here on the Affinity Forum... )

When I changed the Color Format to RGB, in addition to the highlighting and gussying, wow, did I discover the wonderful world of GRAY... 

I've just downloaded the PDF you linked to and will see if it tells me why Overlay and Soft Light are the blend modes necessary for the particular kind of sharpening last week's editing venture required. I suspect it may have something to do with wicked mathematics, the scourge of true genius.  A random video this past week talked about certain blend modes being able to do some kind of negative number operation that...that...produced something totally awesome. So maybe the PDF will help me figure out exactly why Overlay and Soft Light operate in the world of negative numbers.

Thank you for the response. I still feel as if the number of editing choices doubled in Affinity from "old" Serif days, and whether right or wrong, I am not convinced that all of these choices are necessary.