Can someone explain the meaning of "orthopanchromatic" (Acros)?

[Gerald C Koch]

White - Red = Blue + Green = Cyan

Very brief description of a minus-red filter.

http://midopt.com/filters/lb120/

 

[GarageBoy]

I've only shot acros with landscapes, what's wrong with Caucasian portraits with it?

 

[mshchem]

The explanation is different. It is a translation error.

The original ACROS datasheet, in japanese, stated that the spectral response was "sakura-chan-kotesu-asahi", which means:

"the quality of panchromatic response good for representing cherry blossom flowers correctly in film, despite caucasian people ending up looking like spending way too much time on a tanning bed."

Which of course describes perfectly Acros 100 spectral response. Japanese people are honest. At the release of Acros 100 the original brochure consisted solely on pictures of Cherry blossom flowers, plus a fine portrait of Muhammad Ali. No other people was portrayed in the brochure.

The english translator thought this meant "correct panchromatic" and thus the english datasheet says ORTHOPANCHROMATIC.

I HAVE TO RESURRECT THIS! This is the best thing I read in years
Mike

 

[cliveh]

I am not surprised that the OP is confused. Orthopanchromatic is a very dumb term that unfortunately has caught on. The prefixes ortho and pan are contradictory. Putting them together is nonsensical. Something like the expression "military intelligence."

Dead on, it is either panchromatic or orthochromatic. There is no such thing as Orthopanchromatic.

 

[dE fENDER]

...There is no such thing as Orthopanchromatic.

There is, but I' sure it has no relations to any modern film. For example, it described at the book of famous hungarian photographer Ieno Dulovits "Meine Technik - Meine Bilder" (released at 1951) and there is an photo example of this film(Photo no. 116) there.

Last film of this sensitivity was, perhaps, some kind of agfa isopan:

 

[benjiboy]

* orthopanchromatic means it has a similar spectral sensitivity to the human eye.

 

[dE fENDER]

* orthopanchromatic means it has a similar spectral sensitivity to the human eye.

No. It calls superpan.

 

[bascom49]

I shot several rolls of Acros in my studio under tungsten lights. No matter how much exposure I threw at it I never got any useable negatives, all were too thin.

 

[DREW WILEY]

If you take a middle of the road pan film like FP4 and use a light yellow green filter like a Wratten 11 or Hoya XO, you get a similar effect to ACROS. On the other hand, if you use a deep red filter any stronger than a 25, like a 29, you just get hard cutoff. So the orthopan classification is completely appropriate. The only other modern film of this type was Efke 25.

 

[DREW WILEY]

The advantages of this is that you get a bit sharper imaging structure due to less long-wavelenth scatter, yet still have much of the versatility of ordinary pan film. You just give up technical applications requiring extended red or deep red sensitivity. The other advantage to orthopan is a more naturalistic rendering. This is especially apparent to someone like me who does a lot of mountain and forest photography.

 

[mshchem]

The advantages of this is that you get a bit sharper imaging structure due to less long-wavelenth scatter, yet still have much of the versatility of ordinary pan film. You just give up technical applications requiring extended red or deep red sensitivity. The other advantage to orthopan is a more naturalistic rendering. This is especially apparent to someone like me who does a lot of mountain and forest photography.

I know that some recommend green filters for portraits. Does this make Acros a good portrait film?
Best Mike

 

[lantau]

Dead on, it is either panchromatic or orthochromatic. There is no such thing as Orthopanchromatic.

So what do you think about the compass direction 'East-South-East'? You increase spectral sensitivity (prefix Pan) and then take it back a notch (preprefix Ortho).

 

[removed account4]

everything is a made up word until its used by many people
the meriam webster dictionary used to have to see a word in print
using a specific meaning a certain amount of times before it was
taken for consideration as a word for their dictionary .

orthopanchromatic has been a term used for decades, it is nothing new
it means what denise wrote a couple of years ago

Just of bit of additional geek:
From the Focal Encyclopedia of Photography", 1960 edition,
ORTHOPANCHROMATIC. (Correct pan).
Term used to describe materials sensitized to all colors of the visible spectrum but
with an evenly balanced red sensitivity. In this they differ from the excessive red
sensitivity of some high-speed panchromatic emulsions which are produced to give
speed as a first consideration.

 

[DREW WILEY]

Mshchem - yes, I have often used a light yellow-green Hoya XO filter for TMax100 outdoor portraiture to prevent Caucasian skintones from looking bleached-out or ghosty, just like Kodak recommends. With Acros, this kind of correction is essentially built in. In landscape work, foliage is more buoyant, skies more naturalistic.

 

[DWThomas]

I can get great clouds in a blue or light blue sky without any filters. If you do need to burn in a sky to bring out cloud detail, it does not create exaggerated grain in the sky. It's safe to give a little extra exposure because the highlights won't blow out.

I'm glad to read this as it correlates with what I have experienced. I've not done any truly serious tests but I found the need for putting on a mild yellow filter was not needed to get a bit of life in the outdoor sky. That made me a bit suspicious of the frequently claimed low red sensitivity -- so re-reading this forgotten thread it appears more like full pan with the blue sensitivity trimmed a bit.

Alas, a recent thread suggests by the time we hammer out an agreement on the right words -- it will be gone!

 

[DREW WILEY]

No. It's the red sensitivity that's trimmed back a bit - clearly evident in the published spectrograms. But the complementary effect is to make the film seem proportionately more sensitive to green. Blue sensitivity per se differs quite a bit among various pan films.

 

[NedL]

Hi Drew, You're right, but I think it's both.
Here's acros:

And here is Adox CHS 100 II:

I think there are four things that "characterize" these films:

1. sensitivity does not skyrocket and get extreme at wavelengths below 450 ( does not over-emphasize blue, violet and UV )
2. the "dip" near 500 helps suppress that end of blue ( including some sky ) and separate the green
3. the sensitivity is increasing again in green ( probably helps separate the different shades of green )
4. not much sensitivity above 650

Those graphs match my experience... I'd say acros has a more pronounced "good clouds, good green separation" than CHS II, but they are similar. Maybe acros has the blue toned down a bit more and the greens tuned up a little higher.

 

[DWThomas]

No. It's the red sensitivity that's trimmed back a bit - clearly evident in the published spectrograms. But the complementary effect is to make the film seem proportionately more sensitive to green. Blue sensitivity per se differs quite a bit among various pan films.

Yes, it's trimmed "back" in terms of wavelength cut-off at 630-ish, but I was speaking of the amplitude across the spectrum before cut-off where it seems to me the blue end is lower than the "near red" end compared with some other films. Anyway, I think NedL has a good explanation for what's happening, and as noted, I've observed that.

 

[DREW WILEY]

I'd pretty much agree with that assessment too.

 

[Arklatexian]

I haven't gotten a clear answer, but I have read alot of about how Acros is orthopanchromatic? Does this simulate some kind of filtration by increasing or decreasing sensitivity to a particular spectrum? My rudimentary understanding would have been that something is either ortho or panchromatic, but not both?

Lastly, what filter would simulate Acros on a regular film? ...Considering I don't think Fuji will make the stuff forever.

Films described as "orthopanchromatic" have been around for years. The much admired Verichrome Pan (not Verichrome) was one and, in the right hands, made beautiful pictures as does, I understand, Acros. The film was/is different from a "panchromatic" but one handled in the darkroom in complete darkness as with any other panchromatic film. You can blame marketing for the plague in Europe, the earthquake in San Francisco and most anything else that you don't advocate or agree with but not for calling Acros "orthopanchromatic"........Regards!

 

[mshchem]

Mshchem - yes, I have often used a light yellow-green Hoya XO filter for TMax100 outdoor portraiture to prevent Caucasian skintones from looking bleached-out or ghosty, just like Kodak recommends. With Acros, this kind of correction is essentially built in. In landscape work, foliage is more buoyant, skies more naturalistic.

Perfect I've got plenty of Acros 120 and just got a mint old Fujica G617 , and I am planning on doing more outdoor portraits with 6x6 etc.
Best Regards Mike

 

[flavio81]

I HAVE TO RESURRECT THIS! This is the best thing I read in years
Mike

Mike,

I have been absent from this forum since it changed name from APUG to the currently unpronounceable name.

I'm so glad to find your post as the first thing I see after logging again.

Cheers!

 

[cliveh]

I get that there may be a product called orthopanchromatic, but it reminds me of an ad I saw entitled semi-permanent eyelashes.

 

[DREW WILEY]

Panchromatic is a family, in broad distinction from blue-sensitive, true orthochromatic, infrared, X-ray, etc. Within each of these major categories there can be significant differences. For example, Orthopan Acros is the opposite of extended-red or near-infrared panchromatic films. Put a very deep red filter on the
latter types and you get a semi-pan/semi-infrared image. Try that with Acros, and you might as well leave the lens cap on!

 

[cliveh]

Instead of calling it orthopanchromatic, would a better term be extended orthochromatic?