TriX vs HP5+

Lionel1972 said:

Yes you're right, it doesn"t seem that accurate doubling of time steps is very critical. So I don't think using 2.8, 5.6, 11, 22 for printing test strips has a real advange over strick doubling steps like 10, 20, 40. I tend to think it's more complicated and less accurate.

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Negative exposure at least can be pretty sloppy, so earlier cameras could happily get away with pretty coarse speed spacings. Especially when you consider that mechanical shutters can be off by quite a significant margin. However if you look at a modern(ish) electronic camera like my RZ, the shutter speeds are 8, 4, 2, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/400. Those values are nominal I suspect because no one really wants to see 1/32, 1/64, 1/128 and 1/256 on their dial; other than that the values are pretty much exactly powers of two. 1/400 is the odd duck just because the shutter physically can't do 1/500.

In terms of printing, there's absolutely no benefit to using the 2.8, 5.6, 11 sequence over the 2, 4, 8 sequence - both are spaced by factors of two (whole stops). I was suggesting you use 2.8, 4, 5.6, 8, 11, etc, which gives you half-stop steps. In my experience, half-stop steps are a good way to do a test strip at moderate (grade 2 or 3) contrasts. 8 steps of half stop covers a LOT of exposure range (e.g. 4s to 45s) to get you in the ballpark even with an uncertain negative. Once you get more confident, you'll find yourself doing 4-step strips at 1/4 stop intervals.

There is nothing special about the sequences I've illustrated, they're just (IMHO) the easiest ones because they're powers of two. You could just as reasonably use 5, 7, 10, 14, 20, 28, 40: still separated by a factor of sqrt(2) and therefore at half-stop spacing. You'll look at your strip, maybe you like one exposure, maybe want to go somewhere between two steps for a bit better rendition of subtle highlights. If so, you can so a second test-strip spanning the gap between two previous exposures. Say you like the look of the 11s and 16s exposures. You might want to try 1/8 stop steps: 11.3, 12.3, 13.5, 14.7, 16s. Yes, that's getting into finicky times but once you start doing fine prints at higher grades, you'll find that you need to be that finicky to ride the balance on highlights. With such fine exposure spacings though, there is very little benefit to doing exact logarithmic timing unless you're using an f/stop timer; you might as well use 11.5, 12.6, 13.7, 14.8, 15.9 or whatever.

Lionel1972 said:

I don't think using 2.8, 5.6, 11, 22 for printing test strips has a real advange over strick doubling steps like 10, 20, 40.

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There is no advantage as what you are doing is perfectly correct as far as f stop printing method is concerned. You are doubling the time for each step.

The traditional method of doing test strips is to increase by a fixed amount, usually 10 seconds, so the sequence would be 10, 20, 30, 40, 50, 60. In that case the difference between the first two exposures is 100% whereas the difference between the last two exposures is only 20%.

The further you go up just adding 10 seconds at a time, the less the difference compared to the previous exposure.

Photo-gear said:

A little word about this subject. I haved used both of them and both can give more or less contrast or grain, depending of the recipe used.

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Oh yes. This thread was about comparing Tri X with HP5+!


Steve.

As many have said before, you need to get the film developed to the same contrast as your Tri-X film before you can start comparing them.

The reason for this is that you cannot identify differences in tonality between the two films until your highlight and shadow points are in the same place. While films have an inherent level of contrast, how you develop your film determines what contrast your final negative will have (because the final result is more a function of how long you develop the film, developer dilution, agitation, and temperature). This is why coming up with developing times that work for your paper and paper developer is so utterly important. This takes observation in the area of contrast levels of the light you're photographing in, how to expose your film based on that, and finally how to process the film to compensate for BOTH. And never lose sight of the fact that you develop film to make sure the recorded tone scale fits the paper - that is how it's intended to work, not the other way around, (which is commonly seen), where printers try to wrestle the paper around the qualities of the negative.

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Now, about developer - I use replenished Xtol, and up until I tried HP5+ in earnest (about 20 rolls), I was under the impression I could make every film work in that developer. But I discovered that I don't like how the grain looks using Xtol, replenished or not. But I bought a bottle of Ilfotec DD-X, and all of a sudden I had negatives I liked again. Go figure.

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About f-stop printing. It is confusing to think of it in terms of f-stops. I prefer to think of it as doubling your exposure every time you expose a new area of your test strip. 2s, 4s, 8s, 16s, 32s, and longer if you like really dense negatives (I like really dense negatives).
The benefit is that in the lightest and darkest stripes of your test strip, you see things you wouldn't have come near with your regular approach. Highlights that sparkle, and really deep black shadows you otherwise would not have noticed - it makes you see a wider spectrum of versions of the same negative.

The recommendation is - try harder and you will find that HP5+ and Tri-X are a lot more similar than they are different.

Photo-gear said:

On the other hand, I prefer the no-curly hp5 film and its transparent base, while the trix is curly and has a purple base (anti-halo) that cannot be entirely removed even with a pre-wash.
It's only me.

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It's supposed to be clear? Cause my two rolls arent clear... By any stretch of the imagination.

HP5+ is faster and sharper. Your more dense negatives are the result of it being faster than Tri-X. A set of good tests will show it to be 2/3 to 1 stop faster than Tri-X dependent on choice of developer and processing method.

1/2 step test strip, works other values as well...


08|08|04|04|02|02|04 <- incremental exposure L-to-R
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32|24|16|12|08|06|04 <- resultant exposures

I don't know about you - I find the progression from f/stops on the camera to the f/stop timer much more easy. Or, if you want to make it cheaper, the f/stop table.

And I think you can bend Tri-X or HP5+ to whatever you want it to be (within reason - of course you can't make Delta 100 or Tmax 100!). The negative is just a start.

I've spent a whole chunk of my life using the 2.8, 4, 5.6, 8, 11, 16, 22, 32 progression on my camera (s).

I guess it just gives me comfort .

MattKing said:

I've spent a whole chunk of my life using the 2.8, 4, 5.6, 8, 11, 16, 22, 32 progression on my camera (s).

I guess it just gives me comfort .

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Comfort is good. I just want something I can keep track of with a metronome. Even seconds work best for me.

Thanks for all the great info, whether on topic or not! I've learned a few things that I hope to try soon.