Simulating Orthochromatic film

Tim Gray · Jul 24, 2007

Ok, this is more of a question about filters, but is closely related to B&W film. I'd like to play around with the orthochromatic look (blue-green sensitive, no red). I understand there were films like Tri-X ortho available in days past, but no longer. I also understand that a 44a filter will get you close enough to this look with pan film. Lastly, I understand that 44a filters are only available in gelatin, which I'm not particularly interested in.

How close is the B+W 470 Blue-Green filter to a 44a?

If that's a no-go, is there any chance of getting a manufacturer to make a 44a or equivalent filter in a non-gelatin variety - something I could easily screw into my camera lens and leave mounted unobtrusively?

noseoil · Jul 24, 2007

You might take a look at Efke (Adox) 25. It has a similar sensativity to red / blue. Not a full ortho look, but close. tim

Nick Zentena · Jul 24, 2007

Could you do multiple exposures?

1st a Blue

2nd the green

Or reverse the process.

Both filters should be easy enough to find.

Michel Hardy-Vallée · Jul 24, 2007

Why not buying real ortho film instead? Depends on your location, but in North America, I would buy from Freestyle some of the following products:

http://www.freestylephoto.biz/sc_prod.php?cat_id=&pid=1000002485
http://www.freestylephoto.biz/sc_prod.php?cat_id=&pid=1000002128

Rollei Ortho is also available in 120. What a filter will never be able to simulate is the incredibly fine grain, biting sharpness (yes, you can have both!) and fantastic gradations of such films.

I have two 35mm shots on ortho film in my gallery:
(there was a url link here which no longer exists)
(there was a url link here which no longer exists)

The hydrant picture shows well the gradations these films are capable.

AgX · Jul 24, 2007

If you want to stick to filtration then give cc-filters a try.
(2x 50cyan)

Donald Miller · Jul 24, 2007

You can not filter a panchromatic film to achieve orthochromatic spectral sensitivity. In other words if the sensitivity does not exist in the emulsion then no amount of filtration will accomplish that.

Photo Engineer · Jul 24, 2007

Sorry Donald you are incorrect!

A panchromatic film can be filtered to give ortho sensitivity. Use of a Blue + Green by any method described above will properly achieve it.

After all, a panchromatic film is nothing but an ortho film with red sensitivity added added. All true pan films contain within them ortho sensitivity.

PE

AgX · Jul 24, 2007

Donald,

What would be the significant difference between the sensitive spectrum below 580nm of a panchromatic sensitized film and the sensitive spectrum of an orthochromatic film?

(There are a lot of films around and even much more sensitation curves to be found in literature.)

Donald Miller · Jul 24, 2007

I am relying on the information that has been reported many, many places among others by Ansel Adams in The Negative, as I recall.

Ole · Jul 24, 2007

Donald Miller said:
I am relying on the information that has been reported many, many places among others by Ansel Adams in The Negative, as I recall.

Ansel Adams' technical information wasn't always correct, unfortunately.

It's easy to take away sensitivity with filters, but impossible to add it. So you can remove red-sensitivity with cyan filtration, red and yellow with blue, and so on.

Donald Miller · Jul 24, 2007

Ole, That may be true...have you personally duplicated an ortho emulsion by filtering a pan film? I am not being smart with you on this...just that it has been spoken of many times over the years and the concensus has always been that an ortho film can not be duplicated by filtering a pan film. I would personally like to see a comparison of this...it would be great if it worked that way.

I am no fan of Adam's by the way...but he did work very closely with Kodak, Polaroid and other manufacturers...so maybe their scientists did not have it figured out very well back then either?

You are saying the same thing that I said...that you can not create something that is not there already by filtering.

For instance can one have light colored leaves like an ortho film by cyan filtering a pan film?

Tim Gray · Jul 24, 2007

As someone with a somewhat technical background, I fail to see how filtering out red light of a film sensitive to blue/green/red (panchromatic) wouldn't leave you with an exposure based on blue/green (orthochromatic) light. Sure, it's not exactly like a given orthochromatic film since I'm sure the sensitivities are slightly different, but that's just splitting hairs.

I'll check out the Adox, but I figured if I could get a filter for ~$50, I could use it when I wanted and take it off when I didn't.

I'll also look into the 50 cyan filters. No word on the B+W 470? Guess I might have to try it myself... Thanks!

Ole · Jul 24, 2007

Donald Miller said:
For instance can one have light colored leaves like an ortho film by cyan filtering a pan film?

That was most visible when using a light yellow filter on ortho film. Have you tried a green colour-separation filter, one stop overexposure and generous development?

I have - and it works. I'll do one this weekend, then we can see.

Michel Hardy-Vallée · Jul 24, 2007

Tim Gray said:
Sure, it's not exactly like a given orthochromatic film since I'm sure the sensitivities are slightly different, but that's just splitting hairs.

As I mentioned, if you want to have the Ortho look, you need the extremely fine, sharp grain, the contrast, and the gradations.

It's true that removing some red light will give you a closer-to-ortho look, but the spectral sensitivity "footprint" varies between films, so the blue-to-green sensitization of a pan film may not necessarily look like that of currently available ortho film.

Sure it's splitting hair a bit, but try at least a roll of real ortho film, and you will know whether your filter solution is close enough, no?

Donald Miller · Jul 24, 2007

AgX said:
Donald,

What would be the significant difference between the sensitive spectrum below 580nm of a panchromatic sensitized film and the sensitive spectrum of an orthochromatic film?

(There are a lot of films around and even much more sensitation curves to be found in literature.)

I think that a comparison of a negative shot of foliage with a pan film and an ortho film will answer your questions. The pan films are relatively blind to blue, green, cyan...the exception is the one that Tim (Noseoil) mentioned. While it is not a true ortho film, it comes closer than any current true pan film that I can think of.

Tim Gray · Jul 24, 2007

mhv said:
Sure it's splitting hair a bit, but try at least a roll of real ortho film, and you will know whether your filter solution is close enough, no?

Absolutely true. Worth a couple bucks to find out. On the other hand, I also want to experiment a bit with the ortho sensitivity, but not necessarily to replicate the look. Could be fun to try it out with other types of film...

Donald Miller · Jul 24, 2007

Ole said:
That was most visible when using a light yellow filter on ortho film. Have you tried a green colour-separation filter, one stop overexposure and generous development?

I have - and it works. I'll do one this weekend, then we can see.

Ole, That is interesting. While you are out this weekend you might try the same set up on a red barn with foliage in the same scene. That would be a real test. That is what I would like to see.

Jim Noel · Jul 24, 2007

If you are using 4x5 sheet film, I believe Ilford still produces Ortho+, an in camera film rated at 80. This is a true ortho film and produces cloudless skies, light leaves and grass, and the purpose for which I use it, opens up shadow areas in the image.

Jim

AgX · Jul 24, 2007

Donald,

Before posting I looked through most of the relevant datasheets. I saw no significant difference. Though there is at least one orthochromatic film which has not that decrease of sensitivity at around 500nm. As said before there are many films around and there are some differences in their spectral curves.

However looking through my bookshelves I saw the most different (historic) curves. In so far it could be that Ansel Adams had experienced spectral characteristics at orthochromatic materials, different from the characteristics of those around now.

jim appleyard · Jul 24, 2007

I've simulated, to some degree, an ortho look with pan film by using a Tiffen 80B filter. I like to do it this way; some ortho look without buying a whole roll (fun as that may be!)

removed account4 · Jul 24, 2007

hi tim

paper makes nice orthochromatic film -
paper is fun shootin' and cheep too

john

Photo Engineer · Jul 24, 2007

Donald;

Having done lots of spectral sensitizations and learning it at the knee of both Howard James and Paul Gilman, I can say that the filtration route will work, Ole is correct, and Adams appears to have started another myth somehow.

The filtration has to be good or you do lose a lot of overall speed. For example, a poor cyan filter will remove too much blue light if it has unwanted absorption. A daylight balanced film will also perform differently than a tungsten balanced film. (I am speaking B&W here and with some films the balance does differ.)

But, if done carefully and with forethought, along with a few tests, it will work just fine.

PE

Photo Engineer · Jul 24, 2007

jnanian said:
hi tim

paper makes nice orthochromatic film -
paper is fun shootin' and cheep too

john

I agree John, but if you use a VC paper, then the green and blue subjects have different contrasts. Ilford MGIV paper has an ISO speed of about 25.

PE

panastasia · Jul 27, 2007

QUOTE: "It should be noted that a panchromatic film can be used to simulate orthochromatic or blue-sensitive rendering using filters."
Ansel Adams, THE NEGATIVE, pg. 25, subject: Spectral Sensitivity.

Was Mr. Adams incorrect?

Harrigan · Jul 27, 2007

According to what I was told by the phd's in optical lens design at Kodak the colors in fact blend together and overlap in a small area. Its incredibly difficult to filter out all the red unless you very carefully study the spectral response of the film and filter out some of the other colors where they overlap. So to get a panchro film to be pure ortho is really very difficult.

Simulating Orthochromatic film

Tim Gray

noseoil

Nick Zentena

Michel Hardy-Vallée

Membership Council

AgX

Donald Miller

Photo Engineer

AgX

Donald Miller

Ole

Moderator

Donald Miller

Tim Gray

Ole

Moderator

Michel Hardy-Vallée

Membership Council

Donald Miller

Tim Gray

Donald Miller

Jim Noel

AgX

jim appleyard

removed account4

Photo Engineer

Photo Engineer

panastasia

Harrigan

Simulating Orthochromatic film

Membership Council

Moderator

Moderator

Membership Council

Privacy & Transparency

Privacy & Transparency