Calculating Kodak Tri-X 400 pull development time

[MFstooges]

All, I accidentally shot Tri-X 400 at ISO64. Will it give good result if developed 5 minutes in HC-110 dilution E?
Any suggestions how to calculate development time?

[Sundowner]

Hmm...my normal development for 400TX is 5:30 @ 72 or 73 degrees, and that's at ISO 160. I've shot it at 100 accidentally and had a bit more density in the negatives, but it wasn't terribly much. I can't predict what the film will do in your camera, though.

I'd use your standard development formula and time and just cut it by a bit: if you've done a film speed test, check your negatives and see what your exposures were like and work from there. That's how I calculated my personal push and pull times, and it worked well.

You can always just go shoot a couple of throw-away rolls and test them out, should these particular negatives be valuable.

Edit: I seem to remember reading somewhere that you decreased development 1 minute for each stop of overexposure...which is 20 seconds for every 1/3 stop. I think that was roughly analogous to where I ended up after actually testing it all out.

[George Collier]

Normal ISO for me for Tri-x would be 250, so, for me, this is 2 stops over exposed. I would hold back development 20% - 30% to protect the highlights (more if contrasty subject, less if flat). The negs will be flat, but you can contrast up in printing. You'll have wonderful shadow detail.
If this puts your time too short for control, then the higher dilution might be necessary. You don't say what your normal dilution and time is, but if you post it, someone might be able to help you figure a dilution change equivalent to what I suggested above in time.

[MFstooges]

So here's the negative that I got from 5 minutes development in HC110. 5 seconds agitation at first and then 3 seconds every 30 seconds. Lack the contrast as expected but I don't know if this can be improved. Any suggestions?

[NB23]

To me it looks like it has very good contrast with some lack of detail in the deep shadows. All in all, I've seen worst from well exposed negs...

[Brandon D.]

Any suggestions how to calculate development time?

Grab a brand new roll of Tri-X 400, and shoot the whole roll at EI 64.

In total darkness, use sissors to cut that roll into three different segments.

Now, you have three chances to figure it out for sure. Trial-and-error is a great teacher!