Change from Tmax to Acros

I've been using TMAX 100 so far with HC-110 achieving quite good results. However, since my TMAX stock is almost gone I was thinking of giving Acros 100 a try cause I was planning on shooting some long exposures as well (supposed to be good for this).

Could you please advise exposure times for HC-110 Dil.B (1+31)? An app I have suggests 5 min at 20c but the official Fujifilm data sheets has 4.5 min which i trust is a little on the low side. Everything normal, shot at 100 ISO.

Furthermore in regards to the reciprocity failure of Acros, if I plan on shooting a 3 min exposure I should increase by half a stop so it should be 4.5 min right?

Fuji's data sheets good, yea Id use 4.5 too.

Regarding reciprocity failure - a whole stop is a factor of two, so one-half stop is a factor of square root of two (1.414...) so your starting point of 3 minutes would become about 4.2 minutes.

ACROS has very little recip failure. That's one of its appealling features. Another is that it has better edge acutance than TMX100. But for me,
it is realistically a little slower. I rate it at 50. Sorry, but I don't have my dev times here at the office. Also note that ACROS is orthopan rather
than pan like TMX. I love the stuff.

May I ask what the difference between orthopan and pan is?


Sent from my iPad using Tapatalk

Go to the Silverprint website http://www.silverprint.co.uk/ProductByGroup.asp?PrGrp=2221 and lookup Fuji Acros where you will find a Fujifilm PDF document, 6 pages with all the info you will need to get started with Acros.

Since you already use the massive dev chart app, may I suggest the reciprocity timer app?

It's awesome, and was designed by a member on the large format forum.

I own the more expensive pro version, but the regular version is excellent and I always use it for long exposures now. Very accurate.

https://itunes.apple.com/us/app/reciprocity-timer/id459691262?mt=8

Michael R 1974 said:

Is there really a difference or is it just a different name for the same thing? In one of Fuji's tech sheets for Acros they call it orthopanchromatic, in another tech sheet for Acros, Fuji calles it panchromatic. The spectral sensitivity graphs don't look like anything special.

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It's just a TINY bit Ortho... But it does give a unique little bump to the image IMO

I develop Acros 100 in HC-110 using 1:47 @ 7 mins. Works great.

StoneNYC said:

It's just a TINY bit Ortho... But it does give a unique little bump to the image IMO

Click to expand...

If you compare the spectral response of the Fuji 100 and 400 the 100 has a valley at 500nm. Hardly perceptible IMO even if clear on the graph, the red is ok though.

Pan and orthopan are quite different in terms of how they handle tones in nature. I especially like the orthopan sensitivity of ACROS in the mtns
and desert because certain things, esp foliage, looks more luminous and natural. The sensitivity to red still exists, but not as much as in a typical pan film. Therefore you never want to use a red filter stronger than a 25 or you'll simply be creating neutral density. The only other modern orthopan film was Efke 24, recently discontinued. When reading the graph you gotta remember that what SEEMS like a very small difference to the untrained can make a very real difference in practical consequences. Just make the mistake of putting a hard red 29 filter on ACROS and, even with the "correct" exposure you'll discover you lost a zone or two in the shadows. Conversely, a light yellow-green filter will behave like a hard deep green filter on an ordinary pan film, and your green might go too bright. Therefore it's not the "valley" at the green sensitivity point which distinguishes these difference, but clear at the far end of the spectral sensitivity, where red finally truncates.

Fuji does not call it panchromatic. Never did, except in a casual marketing sense. Read the actual tech data sheet. A true ortho film wouldn't respond to red at all, and most graphics ortho films are mainly blue sensitive anyway. ACROS responds to a bit of red, in contrast to extended
red pan films, which respond to a lot of red, but not necessarily IR. So it really is somewhere in between a taking ortho film and a conventional pan film.

My time is pretty close to 7 mins too

RattyMouse said:

I develop Acros 100 in HC-110 using 1:47 @ 7 mins. Works great.

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Mine is 7 1/2 minutes. I print with a diffusion enlarger. I print at about a grade 3.

Mainecoonmaniac said:

Mine is 7 1/2 minutes. I print with a diffusion enlarger. I print at about a grade 3.

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Sadly, I have not been able to get into printing yet, so I dont know exactly what a diffusion enlarger is or what grade 3 (paper I suppose) means.

Do you recommend that I move up to 7.5 mins in my Acros developing? I hope to print sometime in the future.

Thanks.

A diffusion enlarger has a diffuse light source - a lot of people print with a color enlarger and use the color filtration to control contrast on variable contrast paper, and color (dichro) heads are diffusion. Most black and white enlargers use condensers, lenses that focus the light somewhat. Grade 3 refers to paper contrast. A condenser enlarger produces slightly more contrast than a diffusion one. His negatives that print on grade 3 with is diffusion enlarger would probably need a grade 2 or 2.5 filter on my condenser enlarger. "Normal" for years was considered to be grade 2. Grade 3 is more contrasty. Most people try to fine tune their development times so that negatives of normal contrast scenes print well on a grade 2 or grade 3 paper or, these days, with grade 2 or 3 filtration on a variable contrast paper. I find most of mine print on 2, 2.5 or 3 and I tend to aim for about a 2.5 in fine tuning my development times. Graded papers, of which there are few left these days, come in full grades so you have either grade 2 or 3, though contrast can be fine tuned with different developers, dilutions, and a few other tricks like pre-flashing. Variable contrast papers allow in between settings. Filters come in half grade increments but those using dichro heads, either designed for VC black and white or color heads, can get even finer changes (you can also do it with filters by, for example, making half the exposure with a 2.5 filter and half with a 2 to get an effective grade 2.25 etc. but that's really splitting hairs.)

These days the few remaining graded papers usually only come in 2 or 3, sometimes 4. Variable contrast papers can produce from a very soft grade 00 to a grade 5, though they aren't at their best at the extremes.

Thanks Roger. I sure do have a lot to learn once I start printing. I wish I could do so now!

DREW WILEY said:

Pan and orthopan are quite different in terms of how they handle tones in nature. I especially like the orthopan sensitivity of ACROS in the mtns
and desert because certain things, esp foliage, looks more luminous and natural. The sensitivity to red still exists, but not as much as in a typical pan film. Therefore you never want to use a red filter stronger than a 25 or you'll simply be creating neutral density. The only other modern orthopan film was Efke 24, recently discontinued. When reading the graph you gotta remember that what SEEMS like a very small difference to the untrained can make a very real difference in practical consequences. Just make the mistake of putting a hard red 29 filter on ACROS and, even with the "correct" exposure you'll discover you lost a zone or two in the shadows. Conversely, a light yellow-green filter will behave like a hard deep green filter on an ordinary pan film, and your green might go too bright. Therefore it's not the "valley" at the green sensitivity point which distinguishes these difference, but clear at the far end of the spectral sensitivity, where red finally truncates.

Click to expand...

I'd accept that you are going to have troubles with contrast filters but you use filters at your own risk, a very light yellow is all you can use with ortho and it will have a larger factor than with a pan film.

The more annoying trap is e.g. if you are taking portraits some skin blemishes will be suppressed some accentuated relative to a pan.
Most films are super panchromatic and accentuate different blemishes.
You are in trouble with a sitter in either event.

Acros is a very good film, with a bit higher than usual highlight contrast. So it has a different tone curve than TMax 100 which is noticeable in the highlights. I think for general use, I'd prefer TMax 100, especially since they now cost essentially the same. Acros can be tamed with a compensating developer, such as Rodinal 1:50 with 3 minute agitation intervals. HC-110 dilution "H" (1+63) with less agitation will also achieve that compensation. I haven't seen any developer produce enough grain with Acros to be noticeable. It is quite incredible from that perspective. In fact, it can be very hard to focus with a grain focus finder.

As for reciprocity failure: I have not compensated for exposures in the many seconds, and the results are fine. But I haven't done minutes long exposures with it yet.

dorff said:

Acros is a very good film, with a bit higher than usual highlight contrast. So it has a different tone curve than TMax 100 which is noticeable in the highlights. I think for general use, I'd prefer TMax 100, especially since they now cost essentially the same. Acros can be tamed with a compensating developer, such as Rodinal 1:50 with 3 minute agitation intervals. HC-110 dilution "H" (1+63) with less agitation will also achieve that compensation. I haven't seen any developer produce enough grain with Acros to be noticeable. It is quite incredible from that perspective. In fact, it can be very hard to focus with a grain focus finder.

As for reciprocity failure: I have not compensated for exposures in the many seconds, and the results are fine. But I haven't done minutes long exposures with it yet.

Click to expand...

You can also tame it with Ilford DDX