RAW nasuprot JPG:ispisni obračun

Prije mjesec dana pisao sam o nekim mitovima i zabludama o razlikama između RAW i JPG formata. I na kraju tog članka pitao sam RAW:"Je li kvaliteta stvarno bolja?" Nastavite čitati kako biste saznali što sam naučio. Odgovor bi vas mogao iznenaditi.

Htio sam vidjeti postoji li primjetno razlika u kvaliteti između RAW slike i JPG-a koje proizvodi fotoaparat. Postavio sam testnu scenu i snimio je dva puta sa stativa:jednom koristeći RAW format i jednom koristeći postavku JPG najviše kvalitete. Postavke obrade u fotoaparatu postavljene su na:Ton +1, Oštrina +1, Poboljšano zasićenje. RAW slika je obrađena pomoću Nikon Capture NX. Na slike nije primijenjeno dodatno izoštravanje ili smanjenje šuma.

Testna scena

Uvriježeno mišljenje kaže da otvaranje JPG-a i njegovo ponovno spremanje smanjuje kvalitetu. To je zato što JPG datoteke koriste oblik kompresije koji zapravo odbacuje dio slikovnih informacija (dakle kompresija "s gubitkom"). Zanimalo me koliko je zapravo loše u praksi. Dakle, kao treći test, otvorio sam i ponovno spremio JPG kamere deset puta koristeći postavku kompresije JPG najviše kvalitete.

Sve tri slike su zatim poslane u isti laboratorij (ezprints.com) koji je za mene proizveo tri mat otiska veličine 11×14. Svaka od slika u nastavku prikazuje skenirani uzorak pune rezolucije (300 ppi) iz svakog ispisa. “RAW” je slika u RAW formatu, “Camera” je JPG verzija u fotoaparatu, a “10-gen” je JPG otvoren i ponovno spremljen deset puta.

Vidite možete li uočiti razlike.

Conclusions

It’s clear from the examples that the RAW image provides superior sharpness and resolution. It’s most noticeable in areas of fine detail like the feathers but the RAW image also appeared to provide better definition and contrast, especially in darker areas of the photo.

But what’s it like looking at the actual print? When viewing these at a distance of about 5 feet they are completely identical . I think that’s important because it applies to how most people will view prints like this in real life. Most people aren’t going to get out loupes and examine them as closely as I have in this article (especially if they’re hanging on a wall).

At closer than five feet, I can spot the RAW print but I still can’t distinguish between the JPG prints. I have to bring the prints to within about 20 inches to distinguish between all three.

I asked a few non-photographers to look at all three prints as well. The first impression from everyone was that I was trying to trick them. They thought they were identical. I had to tell people exactly what to look for and let them examine all three prints side by side before they could find any noticeable difference.

It’s clear to me from this test that RAW does provide better sharpness and detail than an in-camera JPG. If you absolutely must have the best possible print then you must shoot in RAW. Most people, however, can happily shoot in JPG mode without worrying about any noticeable difference in print quality.

As an added bonus, I was pleasantly surprised to find that the lossy JPG problem isn’t nearly as bad as it sounds. Despite the compression, JPG files can tolerate a number of generations before any quality issues arise.