Ilford's recommendation for TMY2 and TX in Perceptol... Why?

[Juan Valdenebro]

In their powder developers datasheet Ilford recommend different times -for Ilford films in Perceptol- at different EIs for each film, depending on dilution: stock gives less speed than 1+1, and 1+3 more speed than 1+1 as it's known... Of course differences are small: a third, two thirds, a stop from stock to 1+3...
But for TMY2 and TX, Ilford's advice is only 400 for TMY2 and only 200 for TX for all dillutions and stock...
Is it that at Ilford they prefer not to test those films too much?
Why the whole stop difference between both Kodak ISO400 films?
Thanks.

 

[halfaman]

They also recomend ISO 320 maximum for HP5 and Delta 400. It is not something about Kodak, Perceptol is not a speed enhancer developer.

"It is designed for use when very fine grain negatives are required and a decrease in film speed is not important."

 

[Ian Grant]

Their datasheet doesn't give mainy alternative EI's and development times for quite a number of films in Perceptol, that's mostly because you can't use the developer for push processing. Don't read too much into it Kodak developer datasheets give less data for rival films. While living abroadand travelling I found it hard to find any Kodak B&W films, their distributors had focussed predominatnly on the Minilab (colour) market. Ilford films were easy to find as were Foma which surpised me.

Ilford manufacture and sell significantly more &W films than Kodak, and they also know the relative volumes they sell of their film developers. Perceptol will have quite low sales compared to ID-11 and Microphen sales won't be much higher (than Perceptol).

Ian

 

[relistan]

My understanding of Perceptol is that it achieves fine grain by being highly solvent and then by some of the dissolved silver redepositing as fine grained silver chloride, which then also develops in place. D23 is a metol only developer that maintains box speed, so in Perceptol it must be this effect with silver chloride formation and deposition that decreases speed while also giving finer grain. I can imagine this effect varies a lot with dilution and also that some emulsions will behave differently depending on their original grain type and chemistry.

 

[Ernst-Jan]

Tri-X exposed at 200 works fine with Perceptol 1+3

 

[Ian Grant]

If you add 25g Sodium Chloride to D23 that's close to Perceptol.

Ian

 

[ic-racer]

Even in the scientific publications on which modern ISO film speed is based, the speeds intended as 'recommendations' only. In fact film manufacturers can choose some of the parameters for the ISO test themselves.

 

[tokam]

I'm just about to embark on a series of tests with Perceptol in an attempt to reproduce some stunning results I had with Tri-X and Microdol-X over 40 years ago.

From Ilford's spec sheets, one litre of Perceptol will process 4 x 36 exposure 35mm films; i.e. 250 ml per film. Sounds expensive to use at this amount.

For those of you who use it at 1 + 2 or even 1 + 3 this would infer that your total developer volume would be 750 ml or 1 litre. I cannot fit that into a Paterson Universal tank. So what is really going on with the minimum amount of developer per film.

Please advise.

Cheers, Martin

 

[Ernst-Jan]

I'm just about to embark on a series of tests with Perceptol in an attempt to reproduce some stunning results I had with Tri-X and Microdol-X over 40 years ago.

From Ilford's spec sheets, one litre of Perceptol will process 4 x 36 exposure 35mm films; i.e. 250 ml per film. Sounds expensive to use at this amount.

For those of you who use it at 1 + 2 or even 1 + 3 this would infer that your total developer volume would be 750 ml or 1 litre. I cannot fit that into a Paterson Universal tank. So what is really going on with the minimum amount of developer per film.

Please advise.

Cheers, Martin

I think that minimum developers isn't an issue with powder developers since de dillution is rather low. But I might be completly wrong with this assumption.
I have experience with developing 120 rollfilm in 500mL 1+3 Perceptol. So 125mL is enough for one film (120 and 135 have the same surface) anyway.

 

[Lachlan Young]

So what is really going on with the minimum amount of developer per film.

It's a question of consistency - what Kodak is suggesting with the 237.5ml stock developer/ 80 sq in film is that that is the average quantity above which there is no change in development time for all the emulsions they tested - a quantity of stock developer below that will still develop film just fine, but you may need to develop for longer. Different emulsions may vary in terms of absolute amounts of stock developer demanded - and tank shape/ type may alter this as well. A lot depends on how rigorously you are needing to work to a densitometer, or whether you are willing to iterate a bit. I recall that Ilford made no injunction against using 75ml stock Perceptol & 225ml water in the 300ml Paterson tank.

 

[Andrew O'Neill]

If you add 25g Sodium Chloride to D23 that's close to Perceptol.

Ian

Interesting... Thanks!

 

[tokam]

Thanks for the guidelines. The results I am trying to replicate involved heavily overexposed Tri-X and Microdol-X, of which, Perceptol is reputed to be a close equivalent, ( I know that the original Microdol-X had staining properties which Perceptol won't have).

Perceptol in Australia is now generally around $AUD 20.00 per litre so I'm a bit reluctant to spend $5.00 in developer per film. If I like the results I may have to look into making one of the clone recipes from scratch. For the purposes of this exercise I will probably be overexposing Tri-X and thus will need to develop at stock or 1+1 to cater for the 'loss of speed' inferred by the overexposure.

The back story to this old Tri-X film is that it belonged to a friend of mine who had just bought his first SLR, a Nikkormat with the 50 mm f2, and the first two films I processed for him were Plus-X. I suspect that when he shot the Tri-X he didn't know about resetting the film speed on the camera meter. I cannot remember what the darkroom prints looked like in 1975 but recently I revisited these negs and scanned them and the results were quite stunning with regards to sharpness and grain. (The negs needed a lot of PP to cleanup dust etc.)

Here is one frame in particular. Firstly full frame and then a crop.

 

[Ian Grant]

Interesting... Thanks!

Ilford published a short Technical Information Sheet P10 in I think 1965, in it they discuss adding Sodium Chloride to ID-11 and mention a developer ID-48, this is most likely Perceptol.

Ian

 

[Juan Valdenebro]

I'm just about to embark on a series of tests with Perceptol in an attempt to reproduce some stunning results I had with Tri-X and Microdol-X over 40 years ago.

From Ilford's spec sheets, one litre of Perceptol will process 4 x 36 exposure 35mm films; i.e. 250 ml per film. Sounds expensive to use at this amount.

For those of you who use it at 1 + 2 or even 1 + 3 this would infer that your total developer volume would be 750 ml or 1 litre. I cannot fit that into a Paterson Universal tank. So what is really going on with the minimum amount of developer per film.

Please advise.

Cheers, Martin

Hi Martin,
I decided to use a little less Perceptol per roll than it's often mentioned as optimal: I did my tests with 200ml 1+2, so a 600-650ml tank is required for it...
As you might have seen, Ilford's datasheet recommends, in the same paragraph, 250ml for Perceptol but a lot less for ID-11 or Microphen, so I guess there are reasons for that, but anyway, they talk about it only when they explain how to use a liter of stock for reuse... Of course less than 200ml can for sure make a negative too, but I prefer to say close to 250ml, so 200ml seem enough to me, but I'm not a Chemist.
I found 1+2 great for FP4+ and Perceptol in soft light, and final tone -overcast- is not soft at all... It's just perfect and really open after incident metering @80, for a Kaiser MF condenser enlarger using filters 3.5 and 4. This is optimal for soft light. Mixed scenes, or direct sunlight only, would require going to 64 and 50, and coming down to 8-7 minutes instead of 10. Four inversions in the beginning, and two every minute, at 24C, as there's no HQ and Metol alone doesn't produce high b+f. Grain is very small and sharp.
Tone is great, and grain too, but it's a slow combo for handheld portraiture when I meter @50 because of the yellow filter.
It's useable outdoors, though: for f/2.8 you get 1/125, 1/250 and 1/500 from normal overcast to bright overcast.
I just started testing TX: it seems grain is more present with TX than with FP4+.

 

[Juan Valdenebro]

Why the whole stop difference between both Kodak ISO400 films?

What a shame no one at Photrio knows...

 

[Juan Valdenebro]

There very likely is no real answer. You’re reading way to much into Ilford’s Perceptol guidelines for Kodak films.

I'm sorry to disagree, Michael... I'wasn't reading: I was only asking because I really don't understand.
And Ilford say -clearly- 400 for TMY-2 and 200 for TX.
I imagine they have a reason for that... I doubt they say that for nothing: that's why I said one of two, they don't care, or they have a good reason.
The whole stop of difference might have a real speed differnce base...
Thank you.

 

[Juan Valdenebro]

Thank you, Michael... Could it be that -true or not- Ilford found TMY-2 faster in Metol than TX ?

 

[Lachlan Young]

Thank you, Michael... Could it be that -true or not- Ilford found TMY-2 faster in Metol than TX ?

Or there's a simpler answer: the times for TMX and TMY in Perceptol appear to have not been updated since the mid 90s (but are close enough to current production materials), however 400TX's times appear in a revised data sheet from around the time it hit the market in 2002-ish. It seems to have been around then that Ilford got more a bit more thorough in giving EI's for other manufacturers' films in Ilford chemistry. From some very quick digging in old Kodak data, Ilford's numbers tend to suggest they might give a middling 0.5's contrast for 400TX, and a quick look at Delta 400's data for Perceptol suggests that Ilford reckon a 0.5 range G-Bar equates to a -1 speed loss, but a 0.62 G-Bar development equates to -2/3 at stock strength and -1/3 at diluted strengths.

 

[Juan Valdenebro]

Thanks again!
I stopped testing Tri-X in Perceptol because Tri-X is my main film for street at 640 in D-76, so I get Tri-X tone and grain all the time... So I decided -for a different enough look- to go for TMY-2 in Perceptol instead, for handheld portraiture in MF (FP4+ is more comfortable for fast 35mm lenses) so I won't be able to compare both ISO400 films by Kodak by now: that's why I asked... To start my tests with the first TMY-2 roll today I exposed a couple of frames at EI160, thinking like this: the film doesn't reach 400 in D-76, so I consider it 320 in MQ developers... With Perceptol 1+2 at 24C I'd say speed is a third lower, possibly close to 250... And the yellow filter I use takes two thirds, so EI160... I don't know if my condenser enlarger will require a little more film exposure. We'll see.

 

[Lachlan Young]

That's the most I can say, really. Years ago I did a large amount of Perceptol testing with various films.

Did you find Perceptol had much effect on the toe shape or not? That, or the effects of the higher solvency compared to D-76/ ID-11 seem to me to be the only realistic reasons that I could see Ilford suggesting overall lower EI's for Perceptol. To be fair, they also used to claim EI650 for HP5 in Microphen, but that seems to have quietly disappeared - though I note that DD-X and Microphen are claimed to deliver EI500 at G-Bar 0.62 on Delta 400, with 'box' speed claimed to be obtained nearer to the middling 0.5's

 

[Juan Valdenebro]

[QUOTE="michael_r, post: 2398423, member: 38467"
My conclusion was that I should just stick with XTOL as it is clearly superior. Nevertheless I have an affection for these simple metol- sulfite formulas.[/QUOTE]
What I didn't like about Xtol, is it didn't give me sharp grain, not even at 1+3. It is superior or not, depending on what every photographer considers superior.
Of course apart from the problems it's had recently and in the past, it's a good developer, close to D-76.
I understand a lot of people imagine the absence of grain implies higher photographic success. And I understand a hair more speed is also considered better by some photographers.
Why use FP4+ in Perceptol if Xtol is faster and gives less grain with, say, TMY-2?
Maybe because of the tone of FP4+ i Perceptol?
To some degree Xtol can shape a film's tone, but Xtol can't just replace all films tonalities in all developers.

 

[Juan Valdenebro]

Traditionally (as you already know but anyway), the Perceptol/Microdol type of fine grain developer is said to result in a speed loss due to increased solvent effect. The effect was likely more pronounced with the emulsions of the day.

Interesting... Tomorrow I'll expose the same two scenes I did today at 160, but at 250 in the same 120 roll: just to see if TMY-2 has good speed in Perceptol, closer to Ilford's recommendation.
Thank you, Michael.

 

[halfaman]

For TMY Tmax Dev does an amazing job of super fine grain without any speed loss. I don't think Perceptol can beat it, at least in terms of grain/speed ratio. TMY+TMax Dev is my choice in 35 mm when I need sensibility but grain is not welcome.

 

[Juan Valdenebro]

Hi, halfaman, I've used TMaxDev, and I like it too.
But in my experience it gives more grain than MQ developers, and a lot more grain than Perceptol...
My current Perceptol tests are aimed at portraiture, so even if I like sharp grain, I want it very small in this case...
Speed has no relevance here as I'll be using f/2 in 35mm and f/2.8 in MF, outdoors always.
TMaxDev is a great developer for TMY-2 and TMZ when speed is priority and grain is welcome. And its shelf life is amazing: years, even for an open, half empty bottle.
Wonderful tone and grain for TMY-2 at 800 and 1600, and for TMZ at 3200.
Have a nice day!

 

[halfaman]

It is clear that we have different perceptions about what "fine grain" is in 35 mm at ISO 400. I think it is just "undetectable" for you, while for me is "not distracting". But if you can see grain with TMax 400 in TMax Dev with 120 film (6x6 and beyond) you must have the eyes of an eagle!!