Hi Doremus, Where did you get your table? Did you make your own? I am seeing conflicting information. This site shows something different from the app:
http://www.huecandela.com/hue-x/pin-pdf/PinPLUS_Rfail.pdf
Ariston,
First, a correction. My personal table for reciprocity failure for 320Tri-X (TXP) says that for a metered time of 1 minute, 3 minutes should be given (I inadvertently read the wrong column). Still that's a long way from 26 minutes mentioned above or even the 9+ minutes that the table you linked to indicates (and which agrees with the Kodak official tech sheet).
Matt is right that I've tested times and arrived at my own adjustment tables, but I didn't do that in a vacuum. There's a couple of things going on which I'll attempt to explain.
First, if you get the Kodak data sheet for new 320TXP, you'll see a table that suggests the adjustment for an indicated 1 minute time should be about 9 minutes. The problem here is that Kodak, when the reformulated Tri-X in the early 2000s, didn't change the reciprocity table from the older version, which needed significantly more exposure. Howard Bond wrote an excellent article for Photo Techniques magazine in 2003 called "Black and White Reciprocity Departure Revisited" that used to available from their website as a pdf. I can't seem to find it quickly any more and the Photo Techniques website appears to be gone.
In any case, Bond found that the reciprocity characteristics of several Kodak films in their new versions were markedly better than the older versions. He also indicates 3 minutes adjusted exposure for 320Tri-X at a metered exposure of one minute. Ralph Lambrecht in
Way Beyond Monochrome also has a lot of reciprocity information, which seems to corroborate Bond's findings. In other words, the published Kodak adjustment times for Tri-X at least is likely wrong. My own experience bears this out.
Early on, I made reciprocity correction tables bases on the manufacturers' graphs, often extending them out to several hours, since I do enough work in low-light situations to often need a couple of hours or more exposure. When the new versions of the Kodak films came out, I immediately noticed a discrepancy. Bond's article confirmed this and gave me a better baseline to start testing on. Since then, I've been using tables based on work and infor from Bond, Lambrecht and Patrick Gainer and tested and verified by my own work in the field for some years now with good success.
There are still a lot of sources on the web that give times based on Kodak's information (understandably, even though it's likely wrong) and many that pre-date the reformulation of the films. All these give way more correction that I (and Bond, et.al.) find necessary. Still, I believe you can find some reciprocity tables on the web based on Bond's findings. Google is your friend here.
At any rate, your film is likely just a stop or a bit more underexposed, and that just in the shadows. I'd develop normally and go from there.
If you're interested in a copy of the Bond article, pm me. I can send you a pdf.
Best,
Doremus