Catlabs X80 and Shanghai GP3- Same Film?

I have read in previous posts that suggest these two films are indeed the same film and not a different coated film on the same machinery as GP3. One giveaway was the 120 Catlabs X80 roll film comes with GP3 paper. Another used a densitometer to test both films and the results were very similar. Being one film is 100 ISO and the other 80 ISO, can one suggest they are the same? Anyone have any other proof to say they are the same film? I see on Ebay GP3 for sale in fresh boxes going up to 2022. I was wondering to buy it direct instead of going CatLabs route to basically buy a reboxed film? Has the imperfections in GP3 been resolved with current production, including the issue with pinholes in the sheet film? I know 120 has backing paper issues with the tape, but thats on both brands and current as well.

Some used to say GP3 was similar to Kodak Plus X, while Catlabs X80 would say its similar to Panatomic X. Those two films have quite a different look, especially in mid tones. If X80 and GP3 are said to be the same film, how could the comparison Kodak film be so different?

Being one film is 100 ISO and the other 80 ISO, can one suggest they are the same?

Hi, I'm not familiar with either film, but if the ISO speeds are that measurably different I don't see how they could be the same. But... that's assuming that the same developer was used to establish the speeds. Beyond maybe a dozen or fifteen years ago there was a certain specified developer for speed testing. But more recently it became permissible to use whatever developer was desired, WITH the condition that the developer also be identified.

If I wanted to know I'd check both film data sheets to see what developers were specified. IF it's the same developer, but with different ISO speeds, I'd presume that the films are different.

As a note, I don't see why they couldn't be slight variations of the same basic formulation. If a customer wants to buy enough material I imagine that the coating facility would be able to accommodate them.

ISO values are rounded to the nearest 1/3 stop. A film between 80 and 100 could easily

round one way or the other depending on some randomness in the process.

ISO values are rounded to the nearest 1/3 stop. A film between 80 and 100 could easily round one way or the other depending on some randomness in the process.

Could be, but very,very unlikely. Unless the manufacturer doesn't know what they're doing.

It would take an extraordinarily poor film manufacturing operation to have a film accidentally fall into another speed category than the design speed.

Could be, but very,very unlikely. Unless the manufacturer doesn't know what they're doing.

 

It would take an extraordinarily poor film manufacturing operation to have a film accidentally fall into another speed category than the design speed.

OK, but it also depends on the developer. I forget the details now on how developers are selected.

In theory the real speed is fundamental, independent of other things, but in practice it isn't quite that good.

If the change was bigger, I would wonder a lot more about it.