Difference Between Fuji Super HR-T and HR-U Radiographic Film

[Alwelch1]

I've been shooting xray film in my 8x10 for years (100% cost saving measure), mainly AGFA G-Plus and Fuji HR-U. I'm was shopping for some 11x14 for my upcoming camera and stumbled across a box of cold stored Fuji HR-T.

The only information I can find is that HR-U is simply the replacement for the discontinued HR-T with the majority of example photos I've found looking more or less consistent between the two stocks.

Does anyone here know if there is a functional difference between HR-U and HR-T? Speed, emulsion, ect.? Or is it just a name change?

Thanks
-Adam

 

[koraks]

I haven't used either, but I did have a quick glance at the datasheets for both:
Super HR-T30: https://asset.fujifilm.com/www/uk/files/2021-05/5ab45153071d63774da94736378573d7/SuperHR-T30.pdf
Super HR-U: http://www.fujifilm.gr/src/Fujifilm/Downloads/SHR-U.pdf

The characteristic curves tell at least part of the story of the differences:

HR-T is higher contrast; its curve is steeper and it also shoulders off at a significantly higher density. The latter isn't very relevant for most pictorial photography where you'd probably be working at densities lower than 2.0 for the most part. For alt. process printing and in particular processes like carbon transfer, salted paper and new cyanotype, the HR-T might be preferable, but the HR-U will work (almost) just as well.

If you scan and/or print on enlarged silver gelatin, I'd expect you could produce comparable results from both films, but with slight adjustments in exposure and processing. You might have to give the HR-U slightly more exposure and development to obtain identical negatives.

 

[Alwelch1]

Thanks a lot for that, Koraks. I tried looking for the actual charts but somehow managed to never find them. Of course these are for actual radiation/screen derived exposures so I wonder how different it might be given use photographically? Honestly I think it would likely be the same.

Something interesting is that I noticed the "30" was absent from the pack I had referenced. It turns out Fuji has switched to a "super thin grain" emulsion, hence the 30 designation. I've also found some packs of HR-U which are also marked as be 30-grain. So there appears to be some HR-U and HR-T floating around without the newer 30-grain emulsion. I'm assuming this is a similar situation as when Kodak switched to "T-Grain."

Thanks again for the information. And as an aside actually went ahead and purchased some 11x14 HR-U as that is what I have formulated my developer for currently.

 

[koraks]

Of course these are for actual radiation/screen derived exposures so I wonder how different it might be given use photographically? Honestly I think it would likely be the same.

I don't think there will be any differences in curve shape depending on what actual wavelength of visible light you expose the film to, as long as it's within the sensitivity band of the film of course. There will be differences in absolute density in response to different wavelengths in accordance with the spectral sensitivity of the emulsion.

I'm assuming this is a similar situation as when Kodak switched to "T-Grain."

This might be the case, indeed. For mammography I think Fuji has been producing tabular grain emulsion films for many years. They may not have extended their use to other x-ray films for practical/economic reasons.

 

[Alwelch1]

I don't think there will be any differences in curve shape depending on what actual wavelength of visible light you expose the film to, as long as it's within the sensitivity band of the film of course. There will be differences in absolute density in response to different wavelengths in accordance with the spectral sensitivity of the emulsion.



This might be the case, indeed. For mammography I think Fuji has been producing tabular grain emulsion films for many years. They may not have extended their use to other x-ray films for practical/economic reasons.

Thanks again for your help!

 

[koraks]

You're welcome; very much looking forward to seeing more of your work - especially on x-ray film! I'm sure you get far superior results from it than I ever did. I never quite liked how the highlights rendered.

 

[wiltw]

Are you aware of the fact that the mentioned X-ray films are orthochromatic, and how photos generally look with that type of film?

 

[koraks]

Given the first sentence of this thread, I suspect he might have noticed this. I do know for sure, and it's indeed one of the reasons I don't prefer this film for my own photography (and envy those who get good mileage from it!)

 

[DWThomas]

(I may have posted this in another thread sometime ago.) I have been working my way through a hundred sheets of HR-T in 8x10, shot in my pinhole camera. In 2022 I shot a steam locomotive with a greenish blue paint scheme and yellowish lettering. When I went to print the shot, the lettering was barely visible:

What it looked like in digits:

That is the first time I can recall seeing such an obvious difference. It was no big deal, but I could imagine attempting portraits or the like could get "interesting!" I mean it is green sensitive film so I suppose it makes sense.

 

[wiltw]

Given the first sentence of this thread, I suspect he might have noticed this. I do know for sure, and it's indeed one of the reasons I don't prefer this film for my own photography (and envy those who get good mileage from it!)

given the fact that radiographic film emulsions are one of three types

TYPES OF RADIOGRAPHIC FILMS

• Blue light-sensitive emulsion coating.
• Green light-sensitive emulsion coating (Orthochromatic)
• Red light-sensitive emulsion coating (Panchromatic)

I would not assume he is familiar with orthochromatic X-ray emulsion response when used for general photography...why I asked.

 

[koraks]

I would not assume he is familiar with orthochromatic X-ray emulsion response when used for general photography...

I would, since he's been shooting lots of it and the red-sensitive stuff is basically nonexistent in the market. Besides, the specific film he's used and inquires into is green sensitive. Since he's used it, I figure he noticed it's not panchromatic, which is also explainer on the hundreds of websites that deal with x-ray film for still photography. It's relevant information, and quite well disseminated.

 

[Bronson Dugnutt]

(I may have posted this in another thread sometime ago.)

This is a consequence of over-exposure, the double-sided emulsion, and halation effects rather than any particular spectral sensitivity IMO. Flowers are usually excellent subjects for exploring the response of less-than-panchromatic films.

FujiFilm, maligned as they seem to be these days (RIP Velvia), have to have been one of the biggest drivers of large format photography in recent years. I started into large format solely to pursue x-ray (HR-U, cheap!) and it still accounts for 90% of my film use in 4x5 and 100% in 8x10. It can be fickle but is capable of excellent results with some practice.

 

[koraks]

FujiFilm, maligned as they seem to be these days

I wouldn't call them that. They're just focusing on many markets with strategic potential. Analog photography evidently is not one of those. It's a bit of a miracle they've kept up the E6 ball for this long.