Kodak Black&White 400 -- the finest grain of any Kodak C41 film?

According to Kodak's technical publication for Kodak Black&White 400

film (code name "BWC") (which is alleged to be the consumer version of

Portra 400BW), the film has a PGI rating of "less than" 25. If that's

true, it means that B&W 400 (and Portra 400BW) have the finest grain

of any C41 film currently being manufactured by Kodak.

 

In comparison, Portra 160NC, which has a PGI rating of 36, is

currently the least grainy color print film that Kodak makes. Supra

100, which was discontinued, had a PGI of 28.

 

Here is where the typical Kodak confusion comes into play: Kodak uses

RMS, rather than PGI, to measure the grain of its traditional

(non-C41) black & white films. TMax 100 and 400 have an RMS rating of

8 and 10, respectively. Unfortunately that makes it very difficult to

compare to their C41 black & white film.

 

Upon further digging, I found tech pubs for Portra 400BW and T400CN,

and oddly enough, Kodak used RMS to measure the grain of those films.

Both received an RMS rating of 9.

 

If we are to believe Kodak's tech pubs, this means that their ISO 400

C41 black & white films are only slightly grainier than Tmax 100, and

are less grainy than TMax 400 -- and, perhaps, less grainy than any of

Kodak's color print films.

 

I guess maybe that gives me a reason to continue to use the

chromogenic B&W films after all. Not an incredibly compelling reason,

but a reason nevertheless.

You can believe those marketing based specs if you want, but I'll believe my high rez scans. Plus, if Portra B/W had such an amazing grain structure Kodak could simply split the dye coupled layers and easily make it a color emulsion with little effort without investing so much R&D into other c-41 films.

 

I've got Base72 Kodak PhotoCD scans from T400CN and *no way* does this film touch RG-100 or Portra UC. I have less experience with Portra B/W, but what I have used tells me it's not much sharper than T400CN, if at all. It's smooth, which lends a very fine interpretation of grain, but I don't find it 'eyelash' sharp like Portra UC is.

Royal Supra 200 has a PGI of 32 for an image size of 4x6 inches, so that's better than Portra 160.

 

If you print one of the Kodak colour negative films as a monochrome image, and compare it with a Portra 400BW image, the latter blows the former away in both sharpness and lack of grain. I prefer the image quality of DSLRs over iso 400 colour neg (35 mm), but P400BW is in a different class altogether in image quality - in my opinion.

Kodak's Print Grain Index is a psychological field-test measurement. Without different coloured grain, the brain does not have such an outstanding visual cue to notice the grain precipitating out of the picture. The C41 dye cloud type grain is softer than silver grains.

I've always wondered about this film, seeing it sitting on shelves

year after year, never being purchased. Who buys it? Maybe it sells

in Paris, Rochester, and other gray-based locations. Anyway, other

amateur films that Kodak misrates are Max 800 (PGI 48 my a**), HD 200

(PGI 32 but about as grainy as 400UC), and HD 400 (PGI 39 but grainier

than 400UC). Also the grain difference between Gold 100 and 200 is

more than 45 - 47 if you ask me.

Notice that Kodak defines the print grain index using a diffuse enlarger, so the numbers don't apply to scanned film.

Nonetheless there is a strong correlation between diffuse-enlarger

prints and scanned grain. Old NPH is the foremost example of a film

that printed better than it scanned. R.T: have you heard that BW400CN

replaces T400CN and P400BW?