Designing T-Max Films: TMX speed; In response to David Williams' request

[David R Williams]

Ok, so confession time...my acutance issues may be due to an oversight on my part due to my much (un)loved Omega C760's negative stage and my ageing eyes.

When all fails, check everything....and maybe some other stuff too...

My C760 is bolted to the wall using a wall support base on the bottom of the column and top mount for the column head which together rigidly attaches the column to the wall.

However, that wall is subject to load from above and unfortunately part of that load is a torture test: our washer and dryer are on the floor above the basement darkroom and that wall is hung from the joists of the floor above.

So, the wall is subject to periodic vibration which shouldn't be a problem as long as I'm not printing while laundry is in-process, but it seems that the highly "adjustable" negative stage in the C760 shifts it's negative stage alignment as the result of it's less than optimal engineering.

Specifically, the negative stage is designed with a sprung base under the negative carrier and relies upon the lamphouse positioning to hold the negative holder in alignment using 4 adjustment screws at the back of the lamphouse. These screws are quite difficult to use to align the lamphouse and negative carrier (even with a laser alignment tool) and quite apparently, and I've now determined will shifting due to vibration.

After checking and re-aligning the enlarger last night and reprinting a 120 TMX neg developed in Perceptol 1:3, the 16x20 test size enlargement is crisp, sharp, smooth and detailed everywhere, especially in off-centre parts of the image that are best to evaluate acutance.

Lesson learned - I'll confirm alignment before any meaningful printing session.

 

[MTGseattle]

I just tried to google the date of transition from old tmax to TMY-II and I do not trust the results I am seeing. I have a chance to get some 2008 confirmed frozen Tmax 400 in 4x5 for a really attractive price compared to current retail.

 

[Milpool]

TMY-2 was released Oct 2007

I just tried to google the date of transition from old tmax to TMY-II and I do not trust the results I am seeing. I have a chance to get some 2008 confirmed frozen Tmax 400 in 4x5 for a really attractive price compared to current retail.

 

[David R Williams]

I just tried to google the date of transition from old tmax to TMY-II and I do not trust the results I am seeing. I have a chance to get some 2008 confirmed frozen Tmax 400 in 4x5 for a really attractive price compared to current retail.

Do you have an image of the packaging available?

 

[Milpool]

Here is the tech doc which also shows the packaging revision related to the reformulation.

https://125px.com/docs/film/kodak/f4043-TMAX_400-2007.pdf

I just tried to google the date of transition from old tmax to TMY-II and I do not trust the results I am seeing. I have a chance to get some 2008 confirmed frozen Tmax 400 in 4x5 for a really attractive price compared to current retail.

 

[David R Williams]

Here is the tech doc which also shows the packaging revision related to the reformulation.

https://125px.com/docs/film/kodak/f4043-TMAX_400-2007.pdf

That's exactly what I was thinking - great reference document that I couldn't put my hand on.

 

[Milpool]

125px is a pretty good archive.

That's exactly what I was thinking - great reference document that I couldn't put my hand on.

 

[chuckroast]

DK50 was called the poor man's HC-110, and in fact preceded HC-110 in certain graphics applications. I doubt you'll get the same effect without added salt. But might as well try just as long as they're not valuable shots.

Pan-F has such a miserably exaggerated S-curve, with such a brief straight line, that I only got a modicum of cooperation from it using a modified version of PMK pyro. It's really suited more for lower contrast scenes having a dynamic range equivalent to what's best for color transparencies too. But I have gotten lovely Pan F shots in misty conditions, and coastal fog, and mountain falling snow. TMax is just so so so much more versatile.... Speaking of fog, it's starting to lift, along with its chill, so I need to think about heading outdoors soon.

I have found DK-50 to give very low fog but tending toward more grain for a given film than, say, HC-110 or D-76. For MF and larger, it was never much of an issue, though.

 

[Augustus Caesar]

I have found DK-50 to give very low fog but tending toward more grain for a given film than, say, HC-110 or D-76. For MF and larger, it was never much of an issue, though.

Slow films have inherently lower latitude.

 

[John Wiegerink]

I have found DK-50 to give very low fog but tending toward more grain for a given film than, say, HC-110 or D-76. For MF and larger, it was never much of an issue, though.

I remember using DK-50 with some old Ultrafine Extreme 100 film in 120 and it worked very nicely. I figure that with 120 Tmax and its fine grain DK-50 might just be the cat meow.

 

[djdister]

I remember using DK-50 with some old Ultrafine Extreme 100 film in 120 and it worked very nicely. I figure that with 120 Tmax and its fine grain DK-50 might just be the cat meow.

I recall using DK-50 for 4x5 and 5x7 Ektapan and Tri-X many years back - it was an easy developer to work with and clean working.

 

[mshchem]

Grain helps with the mostly subjective phenomena of apparent sharpness because it contributes some edges.
Acutance - observable edge contrast - is a major component of what we perceive as sharpness.
Resolution contributes to perceived sharpness, but they are not the same.

This is too technical for my feeble mind.

I just go back to 1940's Kodak "brilliant negatives" "fine grain" "snappy" or good old Ilford Hypersensitive Panchromatic. That's proper film speak.