What is camera resolution

Another factor that affects camera resolution is known as Nyquist sampling, named after Swedish engineer Harry Nyquist. Essentially, imaging systems often match resolution to the size of a single pixel.

If two objects are next to each other, so are the pixels, as seen in Fig. This makes resolving these objects as separate much harder. In order to best separate adjacent features in a sample, there should be at least one pixel between them.

This means that the best resolutions require matching to two camera pixels instead of one. This means that the sampling rate is doubled, as there are twice the number of pixels and more fine details can be resolved. This doubled sampling rate is known as Nyquist sampling, and states that your max resolution should be twice as high as the smallest opject in your sample.

Operating below Nyquist sampling is known as undersampling , and operating above it is oversampling. Generally, it is best to image when optimised for Nyquist. Luckily, camera companies realise that most researchers image using standard magnifications: 20x, 40x, 60x and x are typically used within life sciences.

One of the reasons that camera pixel sizes are so specific is that they match up to certain magnifications:. So if you typically use a 60x magnification to best capture your samples, in order to get the best resolution this should be matched with a camera that features 6. This combination will be optimised for Nyquist and be able to resolve fine details. More resolution means better quality - up to a point!

Both optics and the quality of the image capture chip play a role too. The advantage of having a camera with a higher resolution is you have more pixels to work with. That's a big plus when getting prints made. Remember, you can produce a printout from just about any image, but the more you have to blow it up the more you degrade the quality. Computer monitors display images at 72 ppi pixels per inch , meaning that there are 72 pixels for every 1 inch of linear screen space you see on your screen.

This may look beautiful on the screen, but if you try to print this image on a printer at 72 dpi the result will look extremely choppy and jagged. This is what happens with light, too. At smaller apertures higher f-stops diffraction harms sharpness and resolution. Due to diffraction, there is a very measurable, physical limit on resolution.

Here, p is the smallest pixel that can receive pixel-level information from the lens. What this means is that the iPhone XR with its 1. This coincides with my experiences. Both shots are in perfect focus; the softening is due to diffraction. Sharpness is an important quality of a lens, but not a primary deciding factor, at least for me.

A great measurement of lens sharpness are MTF charts. They show you the resolution of a lens, irrespective of sensor size and pixel count. But you can check your lenses just in real-life usage, too. The upper limit of lens sharpness is pixel-level sharpness. It means that a lens is so sharp it can resolve image data to every single pixel, without affecting the neighbouring pixel.

And I love that lens anyway. You will only see it when you examine them zoomed-in. We all know that when light passes through glass, it refracts. But this is not a supernatural power of glass only. It becomes apparent when you shoot far-away subjects with a telephoto lens. Take a look at this photo. The closest buildings are 5km 3mi away, so everything is in focus. But notice the difference between the buildings in the foreground and the hills in the background. The foreground is nice and sharp.

The hills are more than three times further away from the camera. At this distance, the light starts to split. Different wavelengths are differently shifted. This shift causes blur. Megapixel and pixel count, as I mentioned earlier, mean nothing without the proper settings and technique to support them. Photography is not all about sharpness.

Or to please aesthetically. Still, there are applications where you want to highest resolution. Large prints also require highly detailed images. Know your lens. Examine what apertures it performs best at. Check if close-up focusing results in a blurrier image, this is often an issue. Check sharpness at different focal lengths throughout the zoom range. Know your camera. Know the ISO levels that you can dial in without affecting the image too much.

Shoot at proper shutter speed. Experiment with shutter speeds at all focal lengths. Unless I want a creative motion blur effect. Set it up properly. Set it to full aspect ratio, and best quality JPG.

Or, just set it to RAW, so you have more choices when post-processing. Also, check your in-camera sharpening settings. Oversharpening, however, can hurt detail in a photo. Clean your cameras and lens. If your lens has fungus, get it removed. Clean the sensor. Check your filters.