Final Cut Pro X turn my original videos and pictures in a lower quality

Hello, I am new here and I am desperate about my problem with FCPX I am doing a video with movies and pictures, all my movies and pictures in the Final Cut X Library  are in the same best quality as I have taken and exported from Photos, and when I select them from the library and watch them on the video window in FCPX they look the same with the best quality as I imported, the problem arrives when I watch them from the timeline and once exported the video, they are in lower quality, a bit blur and you can notice the difference of quality very well.

I normally export my files from photos to a folder and then I drag them in the timeline, I do not think it is the source of the problem because all the files are in the best quality once I watch them from the Final Cut Pro X library. The problem is not the BETTER QUALITY INSTED OF THE BETTER PERFORMANCE OR OPTIMISED/ORIGINAL instead of proxy, as I read in all the blogs, because I have tried them all and the quality is even worse.My original pictures are taken in 6016x4016 and the videos are pretty all in 4k ( iPhone and Nikon compact camera and Nikon D750) quality, I made the video in Final Cut Pro in 1080p HD  1920x1080, rendering standard as FCP choice: AppleProRes422, and I use MEDIA PLAYBACK : OPTIMISED/ORIGINAL, it is not normal that with these quality options all my pictures loose quality and videos too, so I tried also to change the quality of the FCPX video in 4k and the problem still there, when I see the picture or the video in the timeline with the preview and also once exported the images are in lower quality and a bit blur, and when I watch the same pictures and video trough my FCPX library are in perfect quality with the original quality.Could someone help me please? because I do not really know what to do and I am sure that there is a problem.thank you very muchPaolo

So you're shrinking 6K video down to 1080. I'd not think that was too much, but shrinking can degrade an image. Not as quickly as enlarging, but it can. I doubt the is what's happening. You can test it by putting that 6K video in a 6K timeline and exporting it.

FCP doesn't do anything to degrade image quality, something else is going on. Is your timeline the same frame rate as the original clips? What are you using to play these exported files back? And do not play them back full-screen, that enlarges them to larger than original, and will look blurry. Be sure you're playing back the exported clips at original size.

This will be your Export as properties.

1. Make sure the time line you are creating is the maximum size and resolution and yes frame rate as the materials. Remember there is a setting that says by default, make project the same as my first clip... if your first clip is rubbish, the whole time line will automatically be that.

2. Make sure when you click export / share "Master file" that the window that pops up has the right numbers in it. Sounds to me like you have a codec setting incorrect - the bottom right of that pop up will give you a file size which should be quite big if the quality is there.

3. Silly I know but I doubt you are exporting a proxy master or anything right?

Hello, Thank you very much for your answers,
I agree that it would be strange that my pictures loose quality when I decrease them from 6016x4016 to a 1080p 1920x1080 video, it would be natural the contrary... but I tried to double my video and make it at 4k at maximum resolution and now I can see on the timeline preview a much better quality, like the originals, but the file while exported is big 850 Gb!!!! how can I export a video lighter with the same quality? I export the master file, video codec Source-Apple ProRes 422, resolution 4096x3112, color space : Standard: Rec.709,

I have taken all my video at 60fps and 30fps with an iPhone and a little Nikon camera, all my pictures with a Nikon D750 at maximum resolution, and in the Final Cut timeline I sat the frame rate at 24fps, I still do not understand why they loose so much quality, I have always made videos in 1080HP with a bigger resolution pictures and I haven't had this problem before.

I do not export in proxy but in Optimized/Original and Better Quality

I have never noticed a loosing of quality of my pictures while decreasing from 6016x4016 to 1080p HD 1920x1080, because the original file is so big in quality that a more little file still have the same quality for the use I need, but instead not the contrary.

Where is the setting that says by default, make project the same as my first clip.. please?

Thank you very much