Anyone Use Shanghai GP3 Film in 4x5 and 8x10

[2014268]

Hi Boon,

That's very strange indeed! The film I received is a true negative film (i.e. one that develops as a negative when developed with developers like D-76). To make transparencies out of this film I had to reversal process it - a laborious multi-step process. I have not recently bought Shanghai GP3 from eBay sellers and I don't know if they are selling a different film now under the same label. It is possible that you might have got a direct positive film that develops into a positive when developed normally. If you can tell more about your film (notch code, thickness, halation dye color, etc), more knowledgeable folks in the forum might be able to help you identify the film. Also can you take a pic of the positive you got and share it here?

Hi Raghu,
I have attached a photo of the positive image
Thank you
Boon

[Raghu Kuvempunagar]

Hi Boon,
That's a nice one. I guess if this (direct positive?) film is developed in a paper strength developer like Ilford PQ Universal, the contrast will be better, highlights will be more clear and the transparency will overall look nicer.
Can you share the source of this film? I might want to give it a try myself.

[2014268]

Hi Boon,
That's a nice one. I guess if this (direct positive?) film is developed in a paper strength developer like Ilford PQ Universal, the contrast will be better, highlights will be more clear and the transparency will overall look nicer.
Can you share the source of this film? I might want to give it a try myself.

Hi Raghu,
This GP3 4x5 negative sheet film was bought in 2020 Expired but kept in fridge. When developed in DDX 10” it became positive and fogged. Took out some year 2016 FP4+, it developed into negative normally. I suspect the Shanghai GP3 is not usable once passed expiry date, even though the film is kept in fridge. What an experience! Maybe Ilford PQ developer may help.
Boon

[Tim Meisburger]

I ordered a box of 4x5. It came with no notches whatsoever. In the dark you can (kind of) tell which side is which by feel, but it didn't leave me totally confident about emulsion facing out. They replaced that box. The replacement box produced nice looking negatives, with low b+f, but:

1. You can fix the hell out of it and it will still retain a little pink tinge; and,

2. There were tiny holes in the emulsion. Lots of them, as in 20 or more per sheet. They are smaller than what I'd consider a "pin hole," so with modest enlargement perhaps they would be very hard to pick up.

With 4x5 Tri-x pushing $5 a sheet, I wanted a cheaper alternative. But with the expense and time of traveling around to make photos, the savings didn't seem worth it. I did get a box of 5x7 too, but haven't tried it yet.

Are you stopping with acid stop? I vaguely recall having problems with pinholes once when I was stopping with water and shifting to an acid stop fixed it. Just a thought.

[Vaughan]

Hi Raghu, I used 4x5" Shanghai GP3 negative at ISO 100 and the developed it with DDX ten minutes. The result: It is a positive image.
How come? can you enlighten me ? Thank you
Boon
Singapore

That's probably dichroic fog which can look like image reversal. Probably exhausted fixer, or used fix with dissolved metallic silver that's precipitating out (causing the dichroic fog). Try re-fixing in fresh fix.

[Raghu Kuvempunagar]

Hi Raghu,
This GP3 4x5 negative sheet film was bought in 2020 Expired but kept in fridge. When developed in DDX 10” it became positive and fogged. Took out some year 2016 FP4+, it developed into negative normally. I suspect the Shanghai GP3 is not usable once passed expiry date, even though the film is kept in fridge. What an experience! Maybe Ilford PQ developer may help.
Boon

Hi Boon,

I noticed that the current batches of Shanghai GP3 can be developed under deep red safelight according to the official GP3 store. As far as I remember, GP3 used to be a panchromatic film earlier and not an orthochromatic or blue sensitive film. Also, the film is now "high contrast" whereas earlier it wasn't so. This makes me suspect that a different film is probably now being sold under the same brand name.

[dave_whatever]

There is a UK retailer who imports GP3 into the UK. On their site they say:

"Shanghai GP3 Large Format Sheet Films are a truly lovely black and white film that come to us at a superb price these are a whole new film from the factory in China.

.....

The factory, now in private not state ownership has been getting some assitance from a quality European manufacturer and the new emulsion they are using is excellent…."

https://ntphotoworks.com/product/sha...e-format-film/

I asked them on a Facebook post how they compared this to Fomapan, and they said it was better (they do sell both, to be fair). However, I saw from another of their posts that due to "the ORWO situation" they suspect the Shanghai sheet films will no longer be available. I don't know what "the ORWO situation" is, so make of this what you will.



There is other mention online of Shanghai having some relationship with ORWO, and speculation that GP3 might be ORWO's UN54. The datasheet for UN54 says;

" UN 54 should be processed in total darkness. If absolutely necessary, a safe light using an indirect 15 watt lamp can be used while processing, having an ORWO safe light filter no. 108 (dark green), Kodak no. 3 or Ilford no. 908, but a distance of at least 75 cm should be maintained."

[Vaughan]

I noticed that the current batches of Shanghai GP3 can be developed under deep red safelight according to the official GP3 store.

They probably mean an infrared light source, or an extremely deep, barely-visible red. More likely it's a translation error.

Some panchromatic film data sheets allow for use under a deep green filter, but it's usually only safe if not directly shining on the film itself; typically the safelight is used to illuminate darkroom walkways for safety, and not intended to be used as a working light. Sometimes the light is directed onto the film surface briefly while it's moving for, say, visual detection of defects, but the brightness is low and time of exposure is brief.

[Tim Meisburger]

Interesting that they changed the emulsion, but not the name of the film. So is one expected to use the old development times for the new film? Any idea when they made the change? I have a box of that film I bought last year, and I found it funky, so maybe its the new emulsion? Ten years ago I used to get Shanghai for $13 a box in Asia, and I liked it, but then it seemed to change, so maybe they were fiddling with the emulsion the whole time?

Anyway, I'm going hand held in Africa this fall, so thinking of switching to HP5.

[John Layton]

Tim - by all means, switch to HP5…so that you don’t risk the photographic results from your upcoming Africa trip by courting (known or possible) inconsistencies in film stock!