"True" E.I. 400 B& W Film?

[greg_whitten1]

I have been shooting Tmax 400 at 200 - 250 (Minolta, manual focus

35mm). When using a polarizing filter or various others (yellow or

orange), shutter speeds are getting very long, but the negatives have

been easy to print. I have processed with D-76 and developed paper

with Kodak Dektol and with ILford Universal. I print with a condensor

enlarger.

 

I would like to shoot a 400 speed film at 400, i.e., gain another

stop, without increasing grain. I am certainly willing to change

film, film developers and paper developers.

 

 

For those who have been down this road what have you found in terms

of a "true" e.i. 400 film?

 

(originally posted in the non-black and white film and processing

forum by mistake)

 

Thanks.

 

Greg

[jorge_oliveira2]

If you are looking for the 'old' speeed definition, that was 50% of 'modern' definition, just the so called 3200 films (Kodak, Ilford - about 800~1000 modern spec) or the Fuji 1600 (?) are 'old' 400 speed films. But they are much granier than the 400 modern speed films. (By modern I mean from the 50's to today).

 

Why don't you try 400TX in Xtol 1+2? It has an modern speed of 500 this way, so you may get decent results at 400. And fine grain.

[art_haykin]

The "true" rating of virtually any film is the one that works best for you. The proof of the pudding is in the eating.

[pascal_miele]

With your Tmax 400 use Tmax Dev or Xtol and the speed will be 400 and more.

 

In my opinion Tmax 400 with D76 is 400, but not if you have a special dev or your own way for the speed.

[gareth_harper]

The manufactuerers speed is usually spot on. Whatever film I am shooting I set the exposure in a similar fashion. For b&w films I find I have to adjust the dev time to suit the both my exposure method and the way I like my negs.

Bear in mind a polarizing filter will knock two stops off. A yellow maybe half a stop, an orange two stops and red about 3 stops (all off the top of my head). If you are using your cameras inbuilt meter it should compensate quite well for this.

Have a look at Kodak's web site for dev recommendations. If I remember they don't recommend an increase in dev time for a one stop push. I guess this is because of Tmax400's wide lattitude. I use Ilfosol S with Tmax400 and rate it at 400 or 800asa as required with a slight increase in dev time for 800asa. Kodak state the film will push all the way to 3200asa, so you shouldn't have any problem finding that extra speed. Basically you have to expose and develope to get the type of neg that suits the way you work.

 

As Jorge states I also find tri-x to be a wee bit more sensitive, but then again I'm very wary of tri-x negs getting thick.

[robert_davis2]

Like Art said. Your true EI is a result of your whole process.

[hkbmac]

Microphen Microphen Microphen!

[mike_scarpitti]

It has been my experience that the ISO ratings of 400 films are usually inflated above what EI will give the best quality. This is not a problem with the films but the system used to measure them. If you process them for best quality, you'll find an EI of 200-320 will give sufficient shadow detail.

 

The one film I can recommend for you is Neopan 1600 by Fuji. Its true speed is about 500-650 when processed for a realistic contrast. Bear in mind this film develops VERY rapidly, and the times may be too short for some developers unless diluted. D-76 1:1 is a good place to start. Try about 5-6 minutes, no more, to start. As I said, the film develops very fast.

 

http://www.digitaltruth.com/devchart.html

[mike_scarpitti]

I neglected to add that ISO ratings are made for diffusion enlargers, that's why they're inflated for users of condenser enlargers like you and me.

[andy_piper2]

I have found Ilford Delta 400 to consistently deliver more shadow detail than other ISO 400 films (TX, TMax, HP5, Agfapan, Fuji Neopan) given the same exposure. In the range of 1/3 to 1 stop more. All developed in Ilford DDX developer at 'normal' processing times.

 

It just delivers a bit more silver on film for the same amount of light and development. Should do the same in D76. Try a roll.

[severi_salminen]

I don't know the exact method how ISO speed is determined, but I don't think that the difference between condenser and diffusion enlarger has anything to do with it. The only difference between these two types is that they result slightly different contrast (about 0-1 grades) and that can be altered via development or filters. Same ISO/EI speed should apply to both cases.

[rustys pics]

Well, if you've got a polarizer on the lens, that cuts back 2 stops, and an

"orange" filter could cut nearly as much light too. If you're stacking them, then

it's amazing you're getting anywhere near ISO 200.

 

The math works like this:

TMAX 400 rated at 400 ISO per box, no filters.

Polarizer: - 2 stops = ISO 100

 

Try a more active developer, like TMAX liquid or Ilford DD-X. This ought to

give you a small speed increase when developed normally, and more if

pushed. The last thing you should do is switch film, becase you go back to

square one in determining your system ISO.

[mike_scarpitti]

Andy:

 

So far I have found Delta 400 delivers a bit less shadow detail in the developers I've used, but I have not used the one you mentioned. I've been using Acutol primarily, but I'm going to try FX-39 next. Delta 400 may be somewhat more developer-sensitive than others. Of course, if you're using a diffusion enlarger that may make a difference, and the Delta make simply reach more speed than others when given more development. Hve you played with Neopan 1600?

[mike_scarpitti]

Severi Salminen , nov 03, 2003; 04:00 p.m.

"I don't know the exact method how ISO speed is determined, but I don't think that the difference between condenser and diffusion enlarger has anything to do with it."

 

The ISO development is to a specified contrast that is close to that used for diffusion enlargers: actually higher! That means that those who use condensers have to cut back development considerably from ISO speed development, and a slight speed adjustment is made to compensate. Also, placing the shadows up a little higher on the curve, as Greg is doing (and as I do) gives a bit more uniform contrast throughout the tonal scale, especially when you use condensers. Greg's procedures correspond to what I do. His problem is he wants a faster film. The ISO 400 films need to be rated lower if you use a condenser enlarger.

 

See ISO 6:1993

[mike_scarpitti]

Severei:

 

I found something of interest:

 

http://www.usask.ca/lists/alt-photo-process/2003/apr03/0119.htm

 

"Contrast is important. The ISO standard is based on an

effective contrast index about right for diffusion enlarging

or contact printing. Developing to a lower contrast, as for

a condenser enlarger for instance, will result in a lower

speed."

[severi_salminen]

Mike, you are correct in principle, but in practice there should be no need to change film speed. Let's assume that the difference between cond. and diff. enalarger is 0.5 grades. 0.5 grade change can be countered with a density range change (on the film) of 0.1 units (this figure is taken from Ilford MGIV paper specs). And if the Zone X (I think you are familiar with these Roman Numerals) is altered 0.1 units, the change in Zone I is totally insignificant (well, probably around 0.01 units)-> no need to change the speed.

 

There is also great variation on condenser and diffuse enlarger lights: both can be more or less diffuse. But with careful testing one can determine the correct exposure and development.

[bruce watson]

I'm using TXT 4164 4x5 sheets. Kodak lists it as ISO 320. I find that developing in XTOL 1:3 for 10 minutes at 20C in a Jobo 3010 drum at ~30rpm (continuous agitation) gives me an EI of 400. YMMV of course.

<p>

The idea that there is a "'true' e.i 400 film" is, I think, misguided. Film alone is of questionable value. You have to consider the film/developer (temp, time, agitation...) combination to get anything useful. There are, for example, film/developer combinations that will get you to EI 400 and higher.

<p>

If you are really interested, Anschell and Troop explore the interactions of films and developers in quite a bit of detail in <i>The Film Development Cookbook,</i> which should give you a great place to start.

[scott_eaton]

I responded in the other thread, but it seems to have vanished. I've used all the current 400 speed B/W films and at one time had to establish processing times for my old lab based on general customer submissions.

 

In my humble opinion, HP5 and Delta 400 are the fastest of the bunch and easiest to get full 400 speed from without blocking highlights. Tri-X classic is very close behind, and will respond in kind if processed in speed or compensating developers.

 

TMY has never been a true 400 speed film in my experience, and is in fact around EI 320 under white light.

 

Tri-X pro is far from 400 speed and seems closer to around 250.

[mike_scarpitti]

Severi:

 

If you'll note I mentioned that the increase in exposure was primarily to move the shadows higher on the curve. ISO speed calls for underexposure and overdevelopment.

[lex_jenkins]

Ilford rep David Carper has quoted an Ilford engineer as stating that HP5+ in Microphen has a true speed of 500. (This reference is somewhere in the photo.net archives and possibly Ilford's own forum as well.)

 

My subjective evaluation indicates that the true speed of TMY in Microphen is also somewhere between 400-800. In Rodinal TMY is somewhere between 250-400.

 

I have no idea what developer is used for ISO testing so it's entirely plausible that different developers will yield different speed results. You could attempt to duplicate ISO methodology to achieve EI 400 from any ISO 400 film. Whether you'd like the results is another matter.

 

I would prefer to find the combination of film and developer that suits my preferences and make the minor speed adjustments necessary to get the best results. For example, even tho' HP5+ may deliver a true speed of 500 in Microphen, I find that combination very grainy. That film is much better at around EI 250 in ID-11 at 1:1.

[scott_eaton]

Due to the curve of TMY and TMX, and their greater emulsion efficiency, they *should* gain a greater increase in true speed when used in conjunction with speed developers vs traditional B/W films. This is why TMY responds so well to Lex's soup. What they do lose though is lattitude. Delta 400 or HP5 in HC110 or D76 should easily hit EI 400 with generous exposure lattitude and strong density range.

[mike_scarpitti]

The 'official' ISO developer is similar to D-76.

[mike_scarpitti]

My recommendation remains Neopan 1600 at 500-650 for a condenser enlarger.

[severi_salminen]

Mike, you said:

 

"I neglected to add that ISO ratings are made for diffusion enlargers, that's why they're inflated for users of condenser enlargers like you and me."

 

And I just wanted to point out that there should be no practical effect on speed (ISO or other EI) whether one uses condenser or diffuse enlarger. And does ISO really take the enlarger type into account? I though that ISO is all about getting a certain density range and measuring the density at certain speed point.

 

But, testing can help overcome all the assumptions.

[stephen_benskin]

I just want to correct a few statements made in this thread. Mike said, "ISO speed calls for underexposure and overdevelopment." No it doesn't. There is no place in the ISO standard or the background theory that collaborates this statement. Mike also says, "The 'official' ISO developer is similar to D-76." While at one time, this might have been accurate, the ISO standard since 1992 doesn't require a specific developer.

 

Severi has misunderstood Mike's point on the point of contrast stated in the standard. Mike said the degree of development required for the film before speed can be determined in the standard is the approximate contrast for a diffusion enlarger. While there is "no practical effect on spedd whether one uses a condenser or a diffusion enlarger," processing a negative to fit on one or the other will affect the film speed. And that was Mike's argument.

 

Finally, Greg there is no such thing as a "true" film speed.