Reciprocity Failure in B&W films

[Ethan Bickford]

I've been shooting 4x5 with Kodak Tri-X 400 and have recently moved to Ilford HP 5+ basically it's a lot cheaper and from what I can see, gives me similar resul ts. Now to the point. I shoot at night quite a lot, exposures after adjusting fo r resp. failure in the neighborhood of 8-15 minutes and sometimes an hour or mor e. So I'm looking for a film that has better resiprocity failure characteristics . I've heard that T Max 100 is good but finicky for developing. I've also heard rumor of some other films made by Agfa and Fuji but I'm under the impression tha t they are not widely available. Suggestions and personal experience would be gr eatly appreciated!

Thanks!

[John Kasaian]

Ethan, I've had pretty good results with T-max 400. The reciprocity tables in the Kodak B&W Data Guide( I think thats what its called) substantiates this. I really haven't shot enough T-max to comment on it being finicky to develop but I've heard the same, I think it was from a Shutterbug article by Roger Hicks. What I don't like about T- max is having to buy 50 sheets at a time(and all that stubborn pink stuff!)Good luck!

[joe freeman]

I don't remember having any problems developing tmax 100. I'm pretty sure John Sexton doesn't have all that many problems either. I think it is a great film. If you're interested, there is a thread somewhere in this forum with all the exact converted times for reciprocity.

[Matthew Runde]

Ethan,

Check out Fuji Acros. According to the spec. sheet on Fuji's web site, the film requires no compensation for exposures of up to two minutes, and then 1/2 stop extra up to about 16 minutes. I haven't used the film, but I'm certainly thinking about it.

[tedkaufman]

Acros has the best reciprocity characteristics of any b&w film. I've used it extensively for night photography with exposures up to 20 minutes. As previously mentioned, it requires no compensation up to 2 minutes, then only 1/2 stop for any length exposure, ad infinitum. I don't know where the other poster got the 16 minute barrier. My experience is the reciprocity claims by Fuji are exactly correct.

The only problem with Acros is cost. In 4x5 it's only available from Badger Graphics, and it costs nearly about twice as much as comparable films from Ilford or Kodak.

The next best film for lengthy exposures is TMX. It does require some exposure compensation, but considerably less that most films. Neither film, Acros or TMX, require development compensation for extended exposures.

[Matthew Runde]

Ted,

It's good to know that the 1/2-stop compensation extends beyond the 16 or so minutes that Fuji states. As I mentioned, I got the "16 minute barrier" (approx. 1000 seconds) from the spec. sheet on Fuji's web site.

[Brian Ellis]

I've never used Acros but T Max films (100 and 400) do have somewhat better reciprocity characteristics than other most other films. The tables that John Sexton hands out in his workshops show one time for T Max films, another (longer) time for other films. T Max films aren't difficult to develop, you just need to maintain very good consistency in your times, temperatures, agitation, etc.

[tedkaufman]

Matthew, my apology. Fuji has changed their spec sheet from what I originally read. It does say add 1/2 stop for exposurese from 120- 1000 seconds now. However, they don't offer any guideline beyond that.

[Matthew Runde]

Apology accepted, Ted. Have you seen Neil Folberg's web site?