Exporting Photo Error

[LeifJones]

I am a relatively new Affinity Photo user, and I have been having some exporting issues with the program.

For clarity, I am an Apple user using an iMac (Retina 4K, 21.5-inch, 2017) with operating system Mojave 10.14.1.

I have the exacting dimensions of a photo that I modified, edited, and completed in Affinity Photo as a saved .afphoto document, but upon exporting the image, either as a .JPEG, .PNG, or TIFF, the resulted image I receive is bigger than the dimensions I had saved it for. It appears stretched and pixelated as if I had manually blown-up/zoomed the image in Affinity Photo without preserving any of the pixels. It also appears more saturated than the screenshot I have.

Attached are two examples of the photo, and two reference screenshots of the settings I have on as well as the dimensions.

One is a screenshot of the same photo that is sized correctly in accordance to the dimensions I had, originally, saved and exported it for, and the listed file detail dimensions match the size I am viewing. The second is an exported version of the photo that under file details is listed as the dimensions I saved it for, but upon selecting and opening the file it opens as a largely blown-up image of the photo despite being listed under details as being the exacting dimensions I would expect it to be. It's as if the photo automatically forces my computer to blow-it-up to a larger, zoomed-in size that stretches and pixelates the image.

I'm sure there's an easy explanation for why this is occurring, but I have been unable to solve it on my own. May I have some assistance?

[firstdefence]

In the image that has more saturation the dimensions are 1920 x 1080 @ 72DPI and it displays correctly for me in Preview.

The screen shot is 1920 x 1078 @ 72DPI but I guess that due to cropping.

I have an app called xScope that can visually show dimensions using edge detection and this is what it reads in preview at 1:1 zoom, basically actual size.
 

[carl123]

When you open a document or image etc, Affinity automatically "resizes" it to fit your screen.  It does this by zooming in or out on the document/image by whatever amount is necessary. (different for each document/image size)

This zooming can make the document/image look pixelated or not what you were initially expecting to see.

To see the document at its exact size on screen you need to reset the zoom to 100%, either via the Navigator Panel or CTRL+1 on the keyboard.

It's annoying most of the time but you get used to it after a year or two.

Could the above be what you are experiencing?

[R C-R]

4 hours ago, carl123 said:

It's annoying most of the time but you get used to it after a year or two.

Why is this any more annoying than an image several times too large for all of it to fit in the workspace window at once defaulting to opening at 100% (so you could not see all of it without zooming out) or conversely a tiny image defaulting to a postage stamp 100% size in the middle of the window (so you would have to zoom in to do any detail work on it)?

[carl123]

I design for the web so all images I create are created at the size they will display on a web page and as such my screen is effectively my canvas size.

Reopening previously created images invariably enlarges them to fit my screen which is not what I want. 

Imaging a 100px x 50px button suddenly opening at a perceived 1000px x 500px size.  It means nothing to me and I have to adjust my zoom to 100% just to see the button at its correct size to determine if it will fit into my design.

Likewise, if someone sends me an image or I download one from the Internet I want it to immediately open at 100% so I can determine straight away if it will be too small/large for the design and what the quality is like at 100%

Also, APhoto files containing adjustments like sharpening/blurring etc will sometimes only give you a true representation of the effect when viewed at 100%.  If I open such a file and it automatically zooms to fit my working space I cant be sure what I am seeing is what will be exported.  So I have to waste time hitting CTRL+1 to make sure it is being displayed at 100%.

Like I said, it's annoying but I am used to it now

[R C-R]

1 hour ago, carl123 said:

I design for the web so all images I create are created at the size they will display on a web page and as such my screen is effectively my canvas size.

But images displayed on web pages can be & often are displayed at considerably different screen sizes, depending on the device, the OS, the "user agent" application (usually a browser) & its user settings or capabilities, & even the version of the image sent by the web server. In fact, to meet World Wide Web Consortium (W3C) standards, user agent apps are not required to display graphics in the same way on all devices (or even to display them at all).

For example, I am using the Mac Safari browser to view this page at "actual size," but I also have the option to zoom in or out, to change the text size without that affecting image size, to set up defaults for different web sites, & so on. The Mac OS also performs smoothing (interpolation) on graphic elements displayed at other than so-called "actual size," & if I change the browser window width the page reformats on the fly, affecting both displayed text & graphic element sizes. Other browsers I use have similar options & behaviors, & of course things often are displayed considerably differently on mobile & desktop devices.

IOW, web pages are not pre-formatted document "pages" at all. They are just a collection of tagged elements that a user agent app can format for display in many different ways.

So the bottom line is you cannot assume whatever image size you see on your screen is the same as I or anybody else would see on a web page that includes it.

[carl123]

Just leave these complexities to us web designers.  We've been doing this for years and we know how to design websites thanks.

[R C-R]

38 minutes ago, carl123 said:

Just leave these complexities to us web designers.  We've been doing this for years and we know how to design websites thanks.

For years web designers used to say things on web pages like "best viewed with Internet Explorer" or otherwise design for one specific user agent. That was completely at odds with what the W3C standards were intended to do, & for very good reasons something very few web designers would ignore these days.

[carl123]

4 minutes ago, R C-R said:

For years web designers used to say things on web pages like "best viewed with Internet Explorer" or otherwise design for one specific user agent. That was completely at odds with what the W3C standards were intended to do, & for very good reasons something very few web designers would ignore these days.

I would like to respond but my Grandmother promised to teach me how to suck eggs this afternoon so I have to go now.

[R C-R]

1 minute ago, carl123 said:

I would like to respond but ...

... you did anyway.