I was wondering why the image quality of EoE is subpar compared to the episodes? And is the new blu ray supposed te be remastered?

It is remastered, but the issue might stem from how EoE was originally photographed and formatted for theatrical release.

The TV series OP was filmed in 35mm film, which is standard for theatrical production and presentation. Gainax probably did not have the means for 35mm film photography in their studio, so that entire process might have been farmed out to a different photography agency. The TV episodes themselves were photographed in 16mm film on a system Gainax had access to (most likely within the studio itself), which is standard for television production and presentation. All of these formats are natively 4:3. One would have to deploy either anamorphic lenses during photography or crop the image after photography in order to create a 16:9 image from the 4:3 film. So the TV episodes on Blu-ray are scanned from 16mm film camera negatives in most cases, with the exception of Episode 16, which had to use a film positive dub to the original negative being forever lost.

Anywho, since the staff were photographing everything in-house on 16mm film, then the EoE production was probably on a 16mm work flow as well. But Anno and his storyboard artist Shinji Higuchi had intended the movie to be framed in a theatrical aspect ratio, similar to 16:9. (It's very likely that it was framed for 1.85:1 aspect ratio, which is only slightly wider than 16:9. Most viewers can't tell the difference, and the released DVDs and Blu-rays are all in 16:9.) But, since they were using the exact same workflow as before, they couldn't utilize cinema-quality 35mm film, and didn't have access to any anamorphic lenses. So EoE was most likely shot in 16mm film, then the image was cropped to 16:9 to fit Anno's and Higuchi's original vision, and blown up to fill the entire 16:9 frame. So, what we're seeing when we watch EoE is probably a cropped version of TV-quality film blown up to the size of a theatrical presentation. And no matter how much you touch up and restore the scanned film, there's no getting around the quality of the original photography of the film itself. What we have with EoE is the best possible quality of the movie given its original work flow.

We kinda forget how cheap and rag-tag Gainax actually was as a studio until something like this comes along. Then we remember "Oh yeah! They didn't even pay their artists the industry standard, so there's no way they would pay for better equipment for their second theatrical presentation." (The movie for Nadia was their first theatrically released film, I believe.)

Ok, very insteresting, where did you get these informations? Thanks for the answer

This EvaWiki article mentions in the "Notes" section at the bottom the 16mm film negatives that were photographed during production of the TV series and were later on the source for the Renewal of Eva restoration in 2003. Film negatives are the most original form of film after photography. Everything else is either a film positive or an interpositive, both of which would be derived from the original film negative. While animation was certainly outsourced on several occasions to other studios, all of the animation cels would be collected and photographed at Gainax. There's no evidence of that workflow changing for EoE.

Another way to tell what exactly's going on with EoE's quality is that it matches the quality of Evangelion: Death, which is compiled of scenes from the TV show photographed in 16mm film, cropped to 16:9, and blown up to a theatrical resolution. If Death's quality looks the way it does due to the usage and cropping of 16mm film, and EoE's quality matches Death's, then it's relatively safe to assume that both films used the same methods of photography and cropping. EoE is framed a little better than Death because the production was planned to be in widescreen from the very beginning, but the methods of getting a widescreen image were still the same.