What exactly does "view at 100%" mean?

[Rod McD]

Hi,

Could somebody please help me out here? I'm a long time photographer and DPR member, but I'm struggling to nail exactly what "viewing at 100%" means.

Across the forums, we see common references to "viewing at 100%" when people are comparing image quality or referring to enlargement, etc. If I go into different apps, there are buttons and sliders which allow me to zoom in on an image to view at 100%, 200%, or whatever. There is a "View at 100%" in the DPR viewer. But when I use them, the image size actually displayed on my screen from the same original image is different sizes from different apps. Sometimes the difference in size is a very significant - like double.

What's going on? Is there a clear convention as to what "view at 100%" means? If I take an image of an object, and view the same image in various photo editing apps set to 100%, shouldn't the displayed size of the subject be the same actual size on screen in all the apps? Or not?

Is there an impact of the camera's sensor resolution and the screen's resolution on what "100%" means? If I take the same subject with the same lens with a 24mpx FF camera and a 48mpx FF camera, the image of the object on the sensor is the same size in both cameras. But is the "100% view" of the subject the same size on screen from both cameras when viewed at 100% (because the number of pixels differs?)

Many thanks, Rod

 

[J A C S]

100% view is a colloquial term for pixel to pixel rendering. To be more precise, the monitor RGB pixels, which consist of subpixels, are considered as pixels capable of displaying various colors.

With today’s high resolution screens, the OS and/or every specific app, may upscale the images. The default upscaling factor for my laptop, for example, is 200%. On the top of that, the browser may have its own zoom factor chosen by the user. Then 100% zooming could very well be 200% or higher.

Decent photo viewers or editors are smart enough to preserve the native resolution and to upscale the interface and the menus only. It was not always like this; a few years ago, LR looked really bad on Windows and very good on Mac.

Finally, on a high resolution screen, 100% looks like 50% or so on an older screen, not so pixelated, of course. If you really want to pixel peep, go to 200%.

 

[JimKasson]

Hi,

Could somebody please help me out here? I'm a long time photographer and DPR member, but I'm struggling to nail exactly what "viewing at 100%" means.

Across the forums, we see common references to "viewing at 100%" when people are comparing image quality or referring to enlargement, etc. If I go into different apps, there are buttons and sliders which allow me to zoom in on an image to view at 100%, 200%, or whatever. There is a "View at 100%" in the DPR viewer. But when I use them, the image size actually displayed on my screen from the same original image is different sizes from different apps. Sometimes the difference in size is a very significant - like double.

What's going on? Is there a clear convention as to what "view at 100%" means? If I take an image of an object, and view the same image in various photo editing apps set to 100%, shouldn't the displayed size of the subject be the same actual size on screen in all the apps? Or not?

Is there an impact of the camera's sensor resolution and the screen's resolution on what "100%" means? If I take the same subject with the same lens with a 24mpx FF camera and a 48mpx FF camera, the image of the object on the sensor is the same size in both cameras. But is the "100% view" of the subject the same size on screen from both cameras when viewed at 100% (because the number of pixels differs?)

Many thanks, Rod

Browser and OS scaling in Windows - the last word

When I post images from lens tests, I often encourage you to look at them at 1:1. I explain how to view them assuming that you're looking at them at 1:1. But I haven't explained the ins and outs of that. That was partially because I thought everybody understood them, and partly because I thought

blog.kasson.com

 

[Tom Axford]

To my mind, "view at 100%" simply means viewing the image sufficiently large that all the detail present in the image is visible.

As has already been explained, that does not necessarily equate to what a particular software application (or the computer operating system) labels as 100%.

 

[Dem Bell]

Hi,

Could somebody please help me out here? I'm a long time photographer and DPR member, but I'm struggling to nail exactly what "viewing at 100%" means.

100% or 1:1 means one pixel in the screen is showing one pixel in the image.

Across the forums, we see common references to "viewing at 100%" when people are comparing image quality or referring to enlargement, etc. If I go into different apps, there are buttons and sliders which allow me to zoom in on an image to view at 100%, 200%, or whatever. There is a "View at 100%" in the DPR viewer. But when I use them, the image size actually displayed on my screen from the same original image is different sizes from different apps. Sometimes the difference in size is a very significant - like double.

Because people upload cropped or full images. If I upload a 400px by 400px crop, it will already be displayed at 100%. If someone uploads a 60MPx image, it will have to be "fit" in the screen to be displayed fully. But then you press "view 100%" and it shows you the individual pixels.

What's going on? Is there a clear convention as to what "view at 100%" means?

I'd say, Yes. Take any image editing software, go to "View" and see what the options are.

If I take an image of an object, and view the same image in various photo editing apps set to 100%, shouldn't the displayed size of the subject be the same actual size on screen in all the apps? Or not?

Yes, the display size should be the same.

Is there an impact of the camera's sensor resolution and the screen's resolution on what "100%" means?

It means the same thing: pixel to pixel, therefore what you see on the screen might look different.

If I take the same subject with the same lens with a 24mpx FF camera and a 48mpx FF camera, the image of the object on the sensor is the same size in both cameras. But is the "100% view" of the subject the same size on screen from both cameras when viewed at 100% (because the number of pixels) differs?

Yes.

Many thanks, Rod

 

[Kenneth Morris Lee]

Another way to view at "100%" can be done in Photoshop (and other tools I presume). Perhaps it would be better to call it "actual size".

First, determine your monitor's dpi. You can use a free tool like DPI Love at https://dpi.lv/

For example, my MacBook Air has a 255 dpi screen.

In Photoshop, navigate to Image > Image Size

1) Select the units of measure, like inches, cm etc. (red arrow)

2) Specify the resolution of your monitor. (blue arrow)

3) De-select the Resample option. (yellow arrow)

4) Click OK

In Photoshop, navigate to View > 100%

Photoshop will now show the image in "actual size". If you bring a ruler up to the monitor and place it along the scale (purple arrow), the scale will match the ruler.

In this case, the image size on my monitor is exactly 2.824 x 6.725 inches.