Tri-X 400 @ 200... Why?

[Marco S.]

I am trying to understand why some photographers rate Tri-x at 200. What are the benefits of doing this rather than rating it at box speed?

I've been developing it rated at 400 in Rodinal 1:100 for 20 minutes @ 20C with very good results 120 size. I find that my negatives look much sharper that the Acros 100 with a bit more grain.

I might try it at 200 if anyone can recommend some starting times for development in Rodinal or HC-110 (which I haven't tried using yet).

Regards,

Marco

 

[DWThomas]

I run Tri-X at 250 and develop in HC-110 1:63 ("Dilution H") for about 9 minutes; inversions for 30 seconds, then 3 inversions (about 5 seconds worth) each minute thereafter. I like what I'm seeing. But in all honesty, 200 to 400 is one only one stop and there are a number of areas where minor procedural differences in exposure, camera and processing (or personal taste!) could vary that much.

My 0.02,
DaveT

 

[glbeas]

Some developers cause a loss of film speed, so it needs more exposure. Other times the photographer may want to tailor the films contrast to a particular paper which may call for less development and more exposure to compensate. One result of derating the film is to get richer shadow detail.

If your combination gives you the results you want, whats to worry about?

 

[waynecrider]

It really depends on the developer your going to soup the film in. Some are speed increasing and some decrease the speed while some are speed maintaining. Generally most pyro developers or glycin developers are speed decreasing; There are others. In the speed increasing category are developers such as Acufine, Acutol, alot of the FX line and even Xtol besides others. The thing is, is that with any particular film in a specific developer you will find it affects either the shadows, mid-tones or highlights differently besides the grain, or it may add a stain. That's why alot of people out there use a particular film in a specific developer to get a different, let's say, look.

 

[Pinholemaster]

Shadow detail, but I usually rate it at 320 ISO.

 

[Rolleiflexible]

Better shadow detail and smaller grain. I expose TX400 at EI 200 and soup it in an HC-110 solution of 900ml water +5/8 oz. HC110 syrup, for 6 minutes at 68F. Works like a dream for me. Look at the squares in my portfolio here -- all were shot on TX400, and exposed and souped to this recipe.

Sanders

 

[pgomena]

There are a lot of factors involved, including metering, developer, and scene contrast range.

I found that Tri-X at 400 gave me empty shadows in D-76 1:1 at Kodak's recommended development time. Rating it at 200 and pulling back on the development about 20 percent gave me much better results. I finally settled on EI 200 with D-76 1:1, 8 minutes, 68 degrees F/20C. With HC110 dilution B, I found EI 200, 5 minutes, 68 degrees F/20C, continuous agitation for the first 30 seconds, then two VERY GENTLE inversions at 30 second intervals worked pretty well. (These times were for the 1990s version of Tri-X, not the new stuff . . .)

You just have to test it.

Peter Gomena

 

[mmcclellan]

If you simply do a "film speed" test using the Zone I threshold exposure, almost any developer for any reasonable amount of development will reveal the true exposure index of the film. My own test of Tri-X showed that to be 200 (for the 400 speed Tri-X) and many photographers find this to be true as well. In fact, almost every film I've ever tested ends up rating at about half the manufacturer's suggested ASA. Part of that is due to marketing hype by the manufacturers to get maximum speed out of the film for marketing purposes.

My Pan-F (ASA 50) usually goes at 32 and only Agfapan 25 actually came out at 25. Even Efke 25 ended up at 16 for me, although others find it higher.

It's all about getting good shadow detail then adjusting the chosen developer's development time to give a proper Zone VIII density -- but that's another test.

As others have said, you need to test it for YOUR conditions, but don't be surprised if the exposure index (EI) comes out lower than the ASA. Good luck!

 

[Roger Hicks]

I am trying to understand why some photographers rate Tri-x at 200. What are the benefits of doing this rather than rating it at box speed?

Dear Marco,

(1) Tonality. Many people prefer the tonality they get with a little more exposure. I personally prefer 1/3 to 2/3 stop more for this reason.

(2) Sloppy metering. ISO speeds are based on the amount of exposure required to give shadow detail. Meter the shadows (using the shadow index on a spot meter) and you will get printable shadow detail at the ISO speed, Use any other technique -- broad-area metering, incident-light metering, grey cards -- and you risk under-exposure if the overall subject brightness range is more than about 5 stops. The easy way around this is to give 1 stop extra at all times.

(3) Under-development, either through the use of speed-reducing (usually fine grain, or simply unsuitable) developers or reduced development time.

Ignore anyone who talks about 'true film speed'. ISO speeds ARE true film speeds, in the sense that they are scientifically reproducible and will with competent metering (and development to ISO contrast) give shadow detail (#2 above) though thery will not necessarily give the tonality you like most. Also, there are individual variations in meter accuracy, meter technique, shutter speed, lens flare and more which make it eminently sensible to vary your film speed to get the effect you want. This is however a personal EI, and NOT a 'true film speed' in the sense that ISO speeds are.

The penalties for over-exposure are increased grain and reduced sharpness, so it is not a good idea to overdo things, especially with 35mm. With MF it's less important and by the time you get to LF grain doesn't matter at all and sharpness with any modern film is not an issue.

The manufacturers and standards bodies can't win. Until about 1960, B+W film speeds incorporated an additional 1-stop safety margin, i.e. what we would call an ISO 400 film today was rated at ISO 200 (all right, ASA 200) in those days. Just as today we have a vocal minority complaining that films aren't 'really' as fast as their ISO speeds, in those days there was a vocal minority complaining that ASA speeds gave dense, grainy negatives with reduced sharpness.

There's a free module on ISO speeds in the Photo School at www.rogerandfrances.com that might be of interest.

Cheers,

R.

 

[reub2000]

There's a free module on ISO speeds in the Photo School at www.rogerandfrances.com that might be of interest.

Wouldn't it be better to link directly to the article?

 

[Roger Hicks]

Wouldn't it be better to link directly to the article?

Yes it would, but I don't know how. Sorry.

Cheers,

R.

 

[Ole]

http://www.rogerandfrances.com/photoschool/ps iso speeds.html

Cheers

 

[Roger Hicks]

http://www.rogerandfrances.com/photoschool/ps iso speeds.html

Cheers

Thanks Ole,

How do you do that?

Cheers,

R.

 

[Soeren]

Thanks Ole,

How do you do that?

Cheers,

R.

Its only a matter of copy/paste from the address bar or whats it called.
Cheers
Søren

 

[mikebarger]

I to recommend a film test, I use Fred Picker's method. Tri-x tested at 400 for me.

Mike

 

[Rolleiflexible]

Roger makes a good point. There are a ton of variables involved in exposure calculations. My experience with most B+W films is that they are amazingly forgiving of overexposure, but not at all tolerant of underexposure. So, not only do I lower my rating for TX by a stop, but I also err always on the side of overexposure when metering and setting my shutter and aperture. I could probably get away with less light, but I don't want to risk an underexposure so I don't.

Sanders

 

[Marco S.]

I still haven't done a film speed test, better get started. I don't have a spot meter, I use a incident light meter and take an average reading of light falling on the subject. I'll do a search for the Fred Picker method.

Thank you to all you took the time to respond.

Regards,
Marco

 

[Earl Dunbar]

The penalties for over-exposure are increased grain and reduced sharpness

Roger: I'm not sure what you mean by "over-exposure". Do you mean more exposure than "box speed", i.e., one's personal EI rating, or over-exposure from one's tested EI? The reason I ask is that, like many others, I shoot Tri-X @ 200/250, which I arrived at through the standard "Zone I threshold" test. My development times are then based on the time/temp/agitation sequence to get a Zone VIII exposure to print to Zone VIII at the same print exposure time/conditions that give a Zone I print from the Zone I test exposure. Of course, I also check to make sure Zone III exposures are correct.

When I do this, I find grain, especially, is somewhat better than at box speed ... due to reduced time I suspect.

 

[film_guy]

What about rating the film at box speed aka 400, but giving it slightly longer exposures during shooting by giving it a +1/3 to +1 exposure compensation? Isn't it the same as rating the film at 320 or 200 and shooting it at 0 exposure compensation?

 

[Earl Dunbar]

film_guy: Yes, it is. So why not just set the ASA/ISO to one's personal EI? Why fiddle with compensation?

 

[film_guy]

I find it's actually easier to set my in-camera ISO speed to 320, and set it to +1/3 compensation, when shooting 400 film, and ISO speed to 640 plus the +1/3 compensation when shooting with 800 film. This is just in case I unintentionally underexpose a scene by 1/3 to 1/2, and still have enough information on the negative for the shadows.

 

[Rolleiflexible]

At least with a film like Tri-X, it's pointless to fret about 1/3 stop increments. It's not gonna matter 99 percent of the time. It's a false precision -- there are too many other variables at play, for a 1/3 stop difference to be material.

Some day when you're bored and lonely, go somewhere with controlled light, put your camera on a tripod and shoot something -- anything. Vary your exposures by 1/3 stop. Then vary them by a stop. Be completely irresponsible, live large -- overexpose by 2 or 3 or EVEN 4 stops! And, if you're shooting at EI400, underexpose your last frame for a stop. Then go home and process according to your normal recipe. With the possible exception of the last frame, you should find all the images printable, and no noticeable difference in the 1/3 stop variances.

Shoot enough of it, and you'll learn from your mistakes that Tri-X is a very forgiving film, in exposure and in processing.

Sanders

 

[reub2000]

Agreed. 1/3 stop won't make much a difference. I've learned that it's pointless to even bracket Velvia 100 in half stop differences. Black and white negative film is much more forgiving. Generally if you give the negative enough exposure you can print it.

 

[RalphLambrecht]

Wouldn't it be better to link directly to the article?

If I get something for free, I don't complain about some ads. Anyway, Roger has a lot of other good stuff on his site. Good to get a chance and reminder to look at the rest.

 

[MattKing]

If I get something for free, I don't complain about some ads. Anyway, Roger has a lot of other good stuff on his site. Good to get a chance and reminder to look at the rest.

Wise words, from someone else who also "has a lot of other good stuff on his site" .

Matt