TMX vs Acros

[john_hicks___]

I had to keep myself out of mischief but inspiration was MIA, so here's yet another film/developer test.

 

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The test was simply "which shows finer detail, Acros or TMX in Rodinal 1:100 w/ascorbate or Beutler 105?"

 

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I used 35mm for the test, and the target was a sticker on an air-conditioner compressor (not running of course) around 25 feet away. The test camera was carefully focused, and the apertures used were halfway between f4 and f5.6 to f5.6 to accomodate the slightly different film speeds. I did all the usual stuff for high-resolution photography but didn't go to extremes, but I'm satisfied that the film and/or developer was the main factor in the image-quality chain.

 

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The little sticker itself has lines of type across it in varying sizes.

 

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Anyway....no significant differences were observed between the films developed in Rodinal 1:100 w/ascorbate and the classic high-definition developer Beutler 105.

 

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For TMX at 30x I could make out lettering in the lines of type and felt that with more magnfication I could probably read them, while in the Acros negs I could see only jaggedy lines that were apparently type but I wouldn't have been able to say for certain whether the original was lines of type of just jaggedy lines. There was no feeling that more magnification would've helped.

 

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So it appears that TMX wins this round.

 

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The two TMX strips were interesting; sometimes a frame from Rodinal was sharper and sometimes a frame from 105 was sharper. I think what caused the variations was either the film slopping around in its channel, the vibrations that occur no matter how vibration-free the camera and its mount are, or both.

 

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This is of course extreme nit-picking. For an encore I'm going to inspect pinheads for angels.

 

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Actually there was a point; I wanted to see if there was any good reason to buy Acros in Quickloads at roughly three times the price of TMX in Readyloads. So far I don't see any reason at all to use it rather than TMX.

[ryuji_suzuki]

John, do you ever make 30x enlargement out of your large format

negative? I wonder if the biggest you make is something like 4x or 6x

then why bother? If that resolution goes away when you stop down to

f/11 or f/16, then again, why bother? So far, only the advantage I can

think of of Acros is less departure from the reciprocity law. You

also mentioned increasing contrast in highlight areas, which may or

may not be advantageous.

 

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Off topic: for 120 size HP5+, Delta 400 and TMY have negligible price

difference. However, in 35mm (36exp) the price for Delta 400 is almost

double that of TMY (international packaging). Do you think it's really

worth it? (Or is it just a matter of finding the right developer for

TMY??)

 

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PS. I think I found a PostScript file to print a resolution test

target chart somewhere before. I have my copy (file and printed one on

my wall) but I can't remember where I got it from...

[ted_kaufman]

My results with Acros support John's findings. I give the sharpness

edge to TMX as well as an advantage in grain structure--TMX has

better defined and sharper grain structure. With that said, however,

I do find Acros' tonality very appealing. Acros definitely has an

advantage in highlight separation; midrange separation is very close,

but I'd give a very slight nod to TMX. But the most appealing

characterist of Acros is its reciprocity characteristics. I shoot a

lot of long exposures, mostly night scenes in NYC, and I find that

not having to adjust for time and contrast is a great benefit.

 

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Ryuji, I was a dedicated user of HP5+, but I've since switched to

Delta 400 (new). And it's not because of sharpness or grain. HP5+

has at least as fine grain and resolves as fine detail. And TMY

beats all the 400 speed films in those respects. HOWEVER, Delta 400

has tonal characteristics that lend a 3-dimensional look to images

I've never seen with another film. I don't really know how to

quantify it, but it is simply beautiful film. Is it worth 50% more

than the others? To me it is. I bulkload 35mm which somewhat

mitigates the cost.

[conrad_hoffman]

Ryuji, good test target info here-

http://www.efg2.com/Lab/ImageProcessing/TestTargets/ and I think the

downloadable target is somewhere right here on this site, but I'll

have to search.

[john_hicks___]

> 30x enlargement out of your large format negative?

 

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No, the max is 11x from 35mm sometimes but that's usually because I should've brought along a larger camera but didn't.

 

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> just a matter of finding the right developer for TMY??)

 

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That's probably what's needed. The last time I experimented with TMY I found that it had an upswept curve shape (similar to Acros) which was the opposite of what I wanted but I didn't pursue it very far.

 

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The biggest difference I see between HP5+ and Delta 400 is that Delta 400 has a bit of a built-in S-shaped curve with a little more low and midrange contrast and less highlight contrast; usually straight prints can print with a hint of highlight detail that's absent with HP5+.

 

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I find it interesting that Ilford's moving away from the "modern" straight-line curve shape that began with TMX. Although the straight-line response may be more technically "correct" I prefer the old-style look.

[conrad_hoffman]

Actually, straight line response is not "technically correct". Kodak

and RIT did studies years ago to find the most pleasing transfer

curve. It turns out that it's S shaped, with the midtones at a slope

of just under 1, and reduced separation in the shadows and

highlights. Also critical was shadow detail- it had to be there for

prints to be considered high quality. The info is from Photographic

Sensitometry by Hollis N. Todd & Richard D. Zakia. I suspect Kodak

has long forgotten those studies...

[ryuji_suzuki]

Conrad, is that study based on current line of papers?

 

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General trend in exposure-density curves of enlarging papers also

changed over years, and this affects that kind of consideration a lot.

[conrad_hoffman]

Probably not, since the studies were several decades ago. OTOH paper

curves haven't changed all that much, so I doubt straight line film

developer combinations (TMX & T-Max dev fer instance) are compensated

for by even todays papers.

[ryuji_suzuki]

Conard, do you know the difference between current and previous

versions of Ilford Multigrade papers? Same for EKC paper? (AGFA,

on the other hand, seems to ignore these new trends and go with

their tradition.) In short, newer multigrade papers lowered

highlight contrasts to compensate for increased highlight contrast in

film. This combination is user-friendly because you can still get a

lot of highlight details from overexposed negatives by printing with

longer exposure. Tastes differ, and I have a different approach :-)

[conrad_hoffman]

Alas, I can measure anything now, but wasn't so well equipped years

ago. I'd love to know the curves for some of the old graded papers I

used to get from Luminos and Prinz. I know about the reduced

highlight contrast, but don't know if we're talking 2% or 20%.

[davidrwilliams]

I finally took some time to shoot and process 120 Acros.

 

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I agree with John Hick's comments elsewhere regarding how difficult

120 Acros is to load onto a developing reel. I use Patterson plastic

reels, and struggled for a what seemed like forever to get the film

to even load - it almost as though the reel was wet (but I know that

it wasn't).

 

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Once the film was processed (Xtol 1:1 for 9 minutes) the negs looked

good and printed nicely, but 120 Acros shows more newton rings in a

glass carrier than I've seen before. Although I use an "anti-newton"

glass carrier where TMX sometimes shows a slight newton ring (but 100

Delta has never shown any), 120 Acros had newton rings everywhere.

 

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While 120 Acros produced good sharpness and gradation, the newton

rings and loading problems in 120 are a real problem for me. I find

this strange as I've had no problem loading 35mm Acros into the same

type of developing reel, or with newton rings when printing 35mm

Acros with the same glass carrier. Although the 120 Acros dried

reasonably flat, it seems as though the different film base in the

120 format is a problem.