Final render not the same detail as viewport render

Hello everybody,
I found a lot of solutions in all the topics, thanks for that. But now I have a problem with a difference in the viewport and the final rendering. Can you help me with that please ?

Final render

Sorry, but as new user, I can’t upload my Blend file and just one picture

Here is my Viewport render

In the viewport you can zoom in at camera infinitely as it is not rendered yet and with each close up the picture is generated from scratch.

After you render an image each pixel gets it’s own value, and the image has it’s finite resolution that can’t be enlarged.

If you want your render to be more detailed increase the resolution which will also increase the render time and the size of your image on the hard drive

Hello vicos, it looks to me as if you were accidentally zoomed into the render window. Try 1,2,4,8 on the numpad for different zoom levels or the mouseweel or view > zoom or the home key(100%)

How come you’re not using blender 2.82?

You know what ? I’m a happy man. The problem was just the camera placement and to work without zoom. First I tried to increase the resolution, but the render time was to long.
Thank you for the prompt feedback.

@Joel : I’m a beginner in Blender. Started in November 2019. Followed many tutorials and now started a project for the first time. Blender 2.8 is already ready on my PC but first I have to learn a lot in 2.79

Result :
Viewport :

Final Render:

@vicos good that it works. But now I’m wondering why you want to learn 2.79 if it’s not about the internal renderer? btw use @ instead of #