Discrepancy between camera resolution and PC resolution
Do you know lots of images are shown condensed on the monitor?
Images consists of dots (called pixels). Combine pixels to get an image.
The above is an image of “P8”. It is a combination of pixels.
There are various ways of generating images, but one way is to take pictures with a camera. Cameras generate images with different number of pixels according to the camera. Expensive ones might have more pixels than cheap ones.
There are also various ways of displaying the images, but one way is to display them on a monitor. Different monitors have different number of pixels. Expensive monitors have more pixels than cheap ones.
Reason some camera images are shown condensed on the PC monitor
Images are shown condensed on the monitor because the number of pixels generated by a camera might be greater than the number of pixels in a monitor. If a monitor can only display 2 Megapixels but the camera generated image has 20 Megapixels, you have to condense or reduce the camera image to 2 Megapixels in order for it to show on the monitor. That’s reducing pixel count by a factor of ten. This is basically what is happening.
Go to http://gs.statcounter.com/screen-resolution-stats/desktop/. That’s a site that shows trends in PC desktop monitor resolution (that’s a different way of describing the number of pixels). As of October 2018, 25% of desktop monitors have 1366*768 pixel resolution, 20% have 1920*1080 pixel resolution 1366*768 is about 1 Megapixels and 1920*1080 is about 2 Megapixels. Other resolutions with lower percentage exist but are mostly in the 1 to 2 Megapixel range. In contrast camera generated images tend to have higher resolutions.
Let us look at camera generated images. A famous camera company called NIKON sells digital cameras which cost about $500 and has 20 Megapixels resolution. There are less expensive cameras with comparable resolution out there. An iPhone X which costs maybe $700 to $1000 has a camera with 12 Megapixels resolution. It’s possible to buy high end cameras with 50 Megapixels resolution. Sony has announced plans to market a smart phone with a 48 Megapixels camera in 2019. So there are a lot of camera generated images out there with maybe 20 to 50 Megapixels resolution.
Area possible to view at different pixel resolutions
The figure above shows the area possible to view at 50 Megapixels (50M) resolution, 20 Megapixels (20M) resolution and 2 Megapixels (2M) resolution.
Condensing camera images to display on PC monitors
The picture above shows a 50x pixel image condensed or reduced to 20x pixel, then to 2x pixel. The pixels (dots) in the image are reduced and the picture becomes smaller and smaller. The 20x image size is 40% of the original and the 2x image is just 4% of the original. What happens when shown on a monitor? Well some monitors have 50x pixel resolution while some have 20x or 2x pixel resolution. However the size of the monitor does not change. Just the resolution.
Details are lost when image is condensed
The above show 50x, 20x and 2x images. The 20x image has been expanded 250%, the 2x image has been expanded 2500% so that they are the same size. The 2x pixel image is fuzzy. Detail information is lost. Look at the 20x pixel image. If you look carefully you will see that it is better than the 2x image but still fuzzier than the 50x image. This is what happens when high resolution images are shown on low resolution (low pixel count) monitors. Image details are lost.
How to see image details
Of course, photographers would like viewers to see the original high pixel count, high resolution images. So how to see details in high resolution images? One answer is cropping and scrolling. You can select the area you want to view closely, crop that area and view. If the cropped area is still bigger than the monitor you can show portions of the image and see the rest by scrolling the image automatically. This is what the Vertical Scroller and Cropper is doing.