sharp photo looks blurred in photoshop cs6

[morpyre]

i have a query i am wondering if anyone can help me with.  when i bring a large photograph into photoshop cs6 that i took with my camera, it looks sharp as i captured it.  however, when i have had the photo open for a period of time, i notice that the photograph appears to have become blurred.  if i open the photo in a picture viewing program it looks its actual level of sharp.  if i duplicate the photo and reduce the dimensions to a smaller size, the photo looks sharp again.

i have a feeling it isn't lack of computer performance because all of the settings are set to more than enough memory & other requirements.

i appreciate any help because with this problem, while working on a photo in photoshop, i'm not sure if the blurryness is just in PS or actually the photo.

thank you in advance

peter turner

[JJMack · Accepted solution]

What zoom level are you viewing at and what is the DPI resolution of you display also remember you are only viewing your images actual pixels zoom to 100%.   At and other zoom percent you not viewing you image  you are viewing a quick scaled image.  The scaling was done quickly for good Photoshop performance not for the best image quality.  Do not judge you image zoomed to any percentage other than scaled 100% so you are viewing your actual image.  Your Display DPI resolution most likely is also not your Image Print DPI resolution.  You Print will most likely be smaller and sharper then the Image you see on your Display.   Displays have a single DPI resolution they can not change the size of their pixels to match you image's print resolution. The Pixels on your display will most likel be larger then the pixels  your image will be printed with.

[morpyre]

thank you for your reply.  yes reading that  makes a lot of sense and answers my query.  when i am looking at the photo it is at a zoom level such as "fit screen" so that i can see the whole image rather than zoomed in at actual zoom.

i appreciate your help and in future, when working on large photographs, i shall view at actual view.

thanks again

peter