How do you get the best possible quality ?

[fab19]

I've been asking myself the question for a long time, how do you get the best possible quality, are there parameters or settings to be made to optimize it as well as possible?

[NotMyFault]

Welcome to the forum.

Can you tell us a bit more what specific quality do you intend to optimize?
Can you upload an example image?
 

There are countless quality parameters, some conflicting targets:

• reality / realism 
• Smoothness
• sharpness
• color rendition (color gamut, bit depth)
• Size / dimension / resolution
• dynamic range (contrast)
• file size
• Compatibility of files to other apps

There are complex relations between quality (both measurable and subjective), source images, and parameters and settings in Affinity.

Most work done in Affinity is intended to be consumed (viewed) by humans. Human perception is highly subjective, and could differ for every viewer depending on physical/ medical condition, personal taste and preferences, and viewing conditions (paper printout, laser cut, led display large or small, dark room or sunny beach / alpine sun).

The result you are producing in Photo is always optimal only to certain target groups anf viewing conditions, either intentionally or by chance.

There is no „global“ optimum. You can only try to achieve an optimum for specific cases, considering your limited resources in form of source images, time, available tools, artistic and technical capabilities. 
 

The first question to be answered: how do you define and measure quality. In essence, quality is the degree of compliance of your product / resulting file to the specifications defined before. So please state

• What quality parameters are relevant
• how can these parameters be measured 
• what values would be rated as good / optimal

Example:

• The image should contain smooth gradients of colors, banding should be unnoticeable for a average human when viewing on a led display (27“ 4K display at 80cm distance, in a room with average ambient lighting)
• average humans can perceive banding if color bit depth is below 12
• The document must be exported as RGB/16
• The display must support 12 bit color depth

If you use a paper printout by inkjet printer, RGB/8 (or CMYK) might be sufficient as this printing technology inherently smoothes the gradient, as the individual color dots combine in a smooth way.

In case you design vector documents used in laser cutters, a complete different set of quality parameters becomes relevant.

[Designer1]

Unfortunately, even free Inkscape can export better PNG, JPG than Affinity Designer. I would like to refer to this discussion:

[RichardMH]

Which program are you asking about?

[PaulEC]

4 hours ago, fab19 said:

how do you get the best possible quality,

The problem is that "best quality" means different things to different people; what is "best"? Is it sharpness, colour balance, using anti-aliasing or not etc etc? (Assuming we are talking about images rather than text layout or something else!) Often it is a matter of compromise to get what someone thinks of as "best". There can be no fixed formulas to get "best quality" as the concept is completely subjective. For example, you can get discussions in this forum, running for many pages, where one person insists that an image exported from an Affinity app is lower quality than the same image exported from another app. That may be their opinion, but that is all it is, just an opinion, which many other people may disagree with!

[Pšenda]

3 hours ago, fab19 said:

how do you get the best possible quality

The best quality of what? Bitmap images (photos) or vector images (graphics and drawings)?

What application do you use (APhoto, ADesigner, APublisher)?

What OS do you have? (for example, quite important for the quality of RAW file development), etc. 

Edited April 2, 2022 by Pšenda