Getting photoes from Camera to iPhone?

I upload the photos from my camera to my computer, and from there, I import these pictures to my iPhone, but they always come out somewhat blurry? I'm just wondering how the many photographers on Instagram have high quality photos? I've read on google and I'm doing exactly what they've said, but they're still blurry?

Post a sample. It could be that the photos are blurry due to camera shake or they're out of focus. These problems are not easily noticed on the 3-4" screens of a smartphone, but show up painfully clearly on a computer monitor.

Instagram resamples your images to make them smaller, because mobile devices which can run the Instagram app connect to the internet via your phone network, they need to be small so that uploading and downloading is fast.

Resampling images degrades their quality severely. It changes the pixel dimensions, and when scaling down removes pixels from the image.

There's nothing you can do to mitigate that degradation in quality, except keep a copy of your original images.

The samples you linked to are not the same size. Smaller images have less pixels, less pixels=less quality.