Ilford Microphen/ID-68, origins and replenishment?

[MattKing]

It isn't clear to me why it is not possible to replenish Microphen from stock as is the case with Xtol or is it but the quantities of stock replenisher is so large as to be uneconomical?

Can anyone help with the "why not"

Because you can't .
It is difficult to design a developer where the needs to replenish chemical activity and to remove development byproducts can both be met by deleting and replacing the same volume of used working solution.
Most replenishers are separately designed chemicals that do a good job of replenishing used chemical capacity, but only do part of the job of dealing with the build-up of development byproducts. That is why the instructions for using them usually limit the amount of replenishment before the working solution needs to be discarded and replaced with fresh.
X-Tol and the recently discontinued T-Max RS are/were exceptions.
The market for special purpose replenishers was mainly high volume commercial processors that used deep tanks. That market is essentially gone. Before X-Tol those processors - using something like Microphen - might get a few weeks - sometimes a few days - of a working solution batch before it needed to be replaced due to the fact that it had been replenished so much. X-Tol was a great step forward for them.

 

[pentaxuser]

Because you can't .
It is difficult to design a developer where the needs to replenish chemical activity and to remove development byproducts can both be met by deleting and replacing the same volume of used working solution.
Most replenishers are separately designed chemicals that do a good job of replenishing used chemical capacity, but only do part of the job of dealing with the build-up of development byproducts. That is why the instructions for using them usually limit the amount of replenishment before the working solution needs to be discarded and replaced with fresh.
X-Tol and the recently discontinued T-Max RS are/were exceptions.
The market for special purpose replenishers was mainly high volume commercial processors that used deep tanks. That market is essentially gone. Before X-Tol those processors - using something like Microphen - might get a few weeks - sometimes a few days - of a working solution batch before it needed to be replaced due to the fact that it had been replenished so much. X-Tol was a great step forward for them.

Thanks Matt but I was seeking the reasons why What was it about the make up of Microphen that made it impossible to replenish compared to what it was about Xtol and Tmax RS that made this possible Was something missing in Microphen that was included in its replenisher that made the difference as they say

This is open for anyone to answer who knows what the ingredient(s) might have been

pentaxuser

 

[MattKing]

It isn't an issue of a magical ingredient.
It is an issue of what the developer is made from. That makeup gives it its development properties, but at the same time that makeup means that developing a film results in:
a) the creation of certain types and amounts of development byproducts; and at the same time
b) partial exhaustion of a certain amount of the active chemical components in the developer.
With that type of developer, there is no practical and consistent step that one can take - no amount you can discard (to remove byproducts) and no component that you can add (to add chemical activity and/or neutralize the effect of the byproducts) - that will compensate for both of those two actions at the same time.
X-Tol (and T-Max RS) were designed to self replenish - the components were fine-tuned to permit that. The other developers were designed to do things differently, so they can't self replenish. If you changed them to permit self-replenishment - assuming that you could - it would mean that they would work in a significantly different way and give different results with your film.

 

[john_s]

We all know about bromide which ends up in the developer and which is one of the limiting factors in replenishment. I was wondering about iodide, which is apparently a more powerful restrainer. Is there enough iodide in the newer technology films to affect adversely the use of replenishers? In which case, the old replenishment regimes, like 9mL per roll for Microphen, would be in need of revision.

 

[Steven Lee]

@pentaxuser I haven't explored Microphen outside of the Delta 3200 use case, so I wouldn't know how well it does or does not work with other films. Xtol remains my go-to general purpose developer which I use most of the time. I tried searching photo.net and photrio.com archives but haven't found any meaningful discussions about Microphen.

 

[Ian Grant]

It makes you wonder why Ilford ceased to make a replenisher for Microphen given its great economy when used that way?

A real pity for you, Steven. Ilford's price direct to the U.K. customer is now £8.28 and unless you use it 1+1 or better still 1+3 it remains relatively expensive. This is especially true when using higher speed films such as D3200 where Ilford give no times for anything other than stock. If its a 120 film that only 2 films per litre

That only leaves the re-use method where 10 films can be developed but as Ilford says, some inconsistencies in its action may arise and from another forum called FADU some experimentation may be needed on where in the 10 films an increase in the percentage time may be called for. From film 6 onwards times appear to increase dramatically by the addition of 90%

It isn't clear to me why it is not possible to replenish Microphen from stock as is the case with Xtol or is it but the quantities of stock replenisher is so large as to be uneconomical?

Can anyone help with the "why not"


Thanks

pentaxuser

Mike, Microphen is now only available in 1 litre packaging, ID-11 is still available in 5 litre packaging as well, but again with no replenisher. Below is from the 1960 Ilford price list

When I used Microphen at school, a few years later, I was buying the 2.5 litre packs of the developer and replenisher. Because of the vagaries of replenishment I wouldn't want to use a working volume of less than 2,5 litres, in order to achieve consistent results.

For comparison see the much larger packaging for Autophen and ID-11.

Ian

 

[pentaxuser]

View attachment 328876

When I used Microphen at school, a few years later, I was buying the 2.5 litre packs of the developer and replenisher. Because of the vagaries of replenishment I wouldn't want to use a working volume of less than 2,5 litres, in order to achieve consistent results.

For comparison see the much larger packaging for Autophen and ID-11.

View attachment 328877

Ian

Ian I am not sure if I have followed all of your reply correctly but are you saying that Microphen in its current form can be replenished with Microphen but it requires the so-called working volume that is used for the development to be 2.5 litres rather than the one litre of Xtol?

Have I got this correct and if so what might the replenishment rate be for each new film, is it back to your 9ml or is it a much higher replenishment rate?

Thanks

pentaxuser

 

[pentaxuser]

@pentaxuser I haven't explored Microphen outside of the Delta 3200 use case, so I wouldn't know how well it does or does not work with other films. Xtol remains my go-to general purpose developer which I use most of the time. I tried searching photo.net and photrio.com archives but haven't found any meaningful discussions about Microphen.

Maybe the only meaningful discussion about Microphen is here All I was trying to say was that without any possibility of replenishment there appears to be a "double whammy" with it, namely that according to Ilford it requires full stock for D3200 and if your main film is 120 then that's only 2 films per £8.00 pack

I was commiserating with you in that what you regard as a much superior developer with D3200, namely Microphen, becomes expensive without replenishment

pentaxuser

 

[Ian Grant]

Ian I am not sure if I have followed all of your reply correctly but are you saying that Microphen in its current form can be replenished with Microphen but it requires the so-called working volume that is used for the development to be 2.5 litres rather than the one litre of Xtol?

Have I got this correct and if so what might the replenishment rate be for each new film, is it back to your 9ml or is it a much higher replenishment rate?

Thanks

pentaxuser

No Microphen can only be replenished by its Replenisher. If it was possible to replenish with itself it would be uneconomic anyway.

Ian

 

[pentaxuser]

No Microphen can only be replenished by its Replenisher. If it was possible to replenish with itself it would be uneconomic anyway.

Ian

Thanks Ian

pentaxuser

 

[aparat]

This is a great thread. I am learning a lot!

I have recently mixed up a batch of ID-68, wanting to test it with Ilford Delta 100 to see if it gives any measurable film speed benefits over, say, ID-11. It turns out, it does. Most people would probably say it's nitpicking, but I am consistently getting around ISO 110, which is technically the highest Delta 100 speed I've recorded. Is it going to make a difference in normal photography? No! But it's fun to know that a home-brew developer can actually do this. I will also add that we're talking about differences small enough to be within the tolerance limits of my testing equipment, including my densitometer. At the very least, I am confident that ID-68 gives full box speed, and that's really good to know. It's also clean-working and gives evenly developed negatives. The stock ID-68 requires very short development times with Delta 100 for normal contrast. I would not recommend it for pulling, only for normal development and pushing purposes. A four-minute development time, using rotary agitation, at 20C, results in the CI of around 0.58. That's more "aggressive" than HC-110 B, in my experience.

I wonder how Microphen would fare in this test? Does anyone have experience comparing Microphen and ID-68?

 

[Craig]

That seems like an odd way to list prices. Why 160 /-, why not £8? I guess it keeps it to 2 columns instead of 3.

Can anyone comment on the properties of Microphen? It's main use seems to be speed increasing, but what if it's used at box speed, how would grain, acutance and contrast compare to ID-11?

If I'm not interested in the speed increasing properties, are there any other reasons to use it over ID-11 or Xtol?

 

[Ian Grant]

Craig, I guess the s/d prices are partially to make comparisons easier, 50kg of Hydroquinone is listed as 1818s 9d. It's also noticeable that prices are rounded to 3d, 6d, 9d, as there are 12d to a shilling this would indicate that it may also be to simplify addition.

Microphen/ID068 odes give a slightly different look compared to ID-11/D76, while grain is fine it's crisper so slightly more apparent, this also increases apparent sharpness, this is mostly because there's less silver solvency with the reduces level of Sodium Sulphite. In normal use it gives around 2/3 of a stop speed increase.

Given the choice of Xtol, ID-11/D76, or Microphen, I would use Xtol, I've used all three developer extensively, always replenished. I only used Microphen/ID68 for push processing.

Ian

 

[relistan]

It isn't clear to me why it is not possible to replenish Microphen from stock as is the case with Xtol or is it but the quantities of stock replenisher is so large as to be uneconomical?

Can anyone help with the "why not"

Replenishment is a tricky thing because you need to counter the various ways in which the developer will change based on the development products left behind and the partial exhaustion of the developing agents and sulfite caused by development. XTOL degrades to a certain point (that many people prefer) and then remains more or less equivalently active for a long time.

Microphen has phenidone as the primary agent, so it will be fairly resistant to bromide build-up. However it uses hydroquinone instead of ascorbic acid. The HQ vs phenidone ratio is more critical than the ascorbic acid to phenidone ratio. Additionally, some sulfite is exhausted by the oxidized HQ forming a sulfonate. Ascorbic acid does not do this. I need to go back to read what Mason said here, but I recall that the developer itself will not have the correct ratio to replace the phenidone, sulfite, and HQ. The replenisher is made to match what is exhausted for normal use. You would gradually end up with a formula that is all out of whack if you used the developer to replenish itself.

 

[Ian Grant]

It's worth adding that when Ilford were formulating Autophe they did extensive research analysing how the various components of the developer were depleted. Because it was a PQ developer bromide build up wasn't an issue, MQ developers like UD-11/D76 need bleed replenishment, this is where you remove some developer before replenishing, this is inefficient, and you had to change the developer completely past a certain point or it collapsed.

With Autophen Ilford could tailor the replenisher to more closely maintain the balance of the developer, this allowed top-up replenishment where you are just replacing what's used, very efficient. In one article Ilford mention one lab replenishing the developer for a period of years. They also had a bleed replenisher.
So with all the research from Autophen Ilford could formulate an efficient replenisher for Microphen, that's why the bleed volume is so small.

Ian

 

[aparat]

Here are my curves for home-brew ID-68 and Ilford Delta 100. Overall, it seems to be a very capable developer. Graininess is very nicely controlled, too. Again, not a good choice for pulling, but a great choice for normal and push-development.
delta100_id68 by Nick Mazur, on Flickr

 

[Craig]

Thanks Ian, a very helpful discussion of how Microphen works. My local supplier lists it as "Special order", so I might ask them to get some just to try it out. I can get some on Amazon, for only 5 times the price!

Aparat, when you present your curves, would it also be possible to label the contrast index of each line to get an idea of what an optimal developing time would be for a normal pictorial contrast range?

 

[aparat]

Thanks Ian, a very helpful discussion of how Microphen works. My local supplier lists it as "Special order", so I might ask them to get some just to try it out. I can get some on Amazon, for only 5 times the price!

Aparat, when you present your curves, would it also be possible to label the contrast index of each line to get an idea of what an optimal developing time would be for a normal pictorial contrast range?

Sure thing. Would that work? I never know how much detail to include. I've gotten comments from forum members being confused/distracted by the excessive jargon. Thank you, by the way, for clarifying some of that in another thread. I really appreciate it!

delta100id68family by Nick Mazur, on Flickr

 

[pentaxuser]

Thanks Relistan for the explanation in #64.

pentaxuser

 

[Craig]

That's a great graph, thanks!

 

[Ian Grant]

Thanks Ian, a very helpful discussion of how Microphen works. My local supplier lists it as "Special order", so I might ask them to get some just to try it out. I can get some on Amazon, for only 5 times the price!

I was very impressed with your local supplier, great shop, very knowledgeable, helpful, staff. I bought a few items hard to find here in the UK. I'm assuming The Store, I said jokingly they should open a branch here in the UK

Ian

 

[pentaxuser]

Aparat I take it that CI is contrast index and if so, to get an index of 0.70 the development time is 5.75 mins The Ilford time is 6:30 but this is for a GBar of about 0.62 which make comparisons of time and contrast very difficult for non technical types such as I

So is there a conversion formula that turns times for a CI of X into a GBar and if so what would a CI of 0.70 become as GBar

If your CI is exactly the same as Kodak's CI and I imagine it is then can I presume that if Kodak gives times for a CI of about 0.58 it would recommend a much shorter time for D100 and Microphen than does Ilford recommend with its Gbar of 0.62?

Ilford gives 8 mins for TMax 100 which suggests a difference of 1 min 30 sec to achieve the same GBar of 0.62 but why this should be is something I cannot work out

As a comparison does Kodak give its own times for Tmax 100 or D100 in Microphen? This may help establish the relationship between GBar and CI

Thanks

pentaxuser

 

[Craig]

I'm assuming The Store, I said jokingly they should open a branch here in the UK

Yes, The Camera Store. Peter and Julian are great, I've been shopping there since they opened it 25+ years ago. They should open a branch there, would be easy as at least one of them is a UK citizen.

 

[aparat]

Aparat I take it that CI is contrast index and if so, to get an index of 0.70 the development time is 5.75 mins The Ilford time is 6:30 but this is for a GBar of about 0.62 which make comparisons of time and contrast very difficult for non technical types such as I

So is there a conversion formula that turns times for a CI of X into a GBar and if so what would a CI of 0.70 become as GBar

If your CI is exactly the same as Kodak's CI and I imagine it is then can I presume that if Kodak gives times for a CI of about 0.58 it would recommend a much shorter time for D100 and Microphen than does Ilford recommend with its Gbar of 0.62?

Ilford gives 8 mins for TMax 100 which suggests a difference of 1 min 30 sec to achieve the same GBar of 0.62 but why this should be is something I cannot work out

As a comparison does Kodak give its own times for Tmax 100 or D100 in Microphen? This may help establish the relationship between GBar and CI

Thanks

pentaxuser

Very good questions. Let me see if I can answer them.

First of all, I must point out that my curves are for a home-brew ID-68, not for Microphen, so I cannot guarantee that Microphen would yield identical results. I have ordered a one-liter box of Microphen and will test it at some point to compare.

Contrast Index and Ḡ are similar but different, and, unfortunately, there's no conversion formula. For most curves, they are going to track very close together, so much so, that I would not worry about them being different for the purposes of everyday photography. I would just pick one of them and stick with it. I typically use CI because it's very widespread, easy to calculate, and its definition is unambiguous.

To help figure out development times, contrast, etc., in my program, you can generate a curve of any Ḡ or subject luminance range, and that should be helpful. For example, here, I generated a curve with Ḡ = 0.62. It would need a development time of 5.17 minutes, according to my program.

delta100_id68Gbar_0.62Curve by Nick Mazur, on Flickr

Having said that, the calculations included in the table (left upper corner of the plot in post #68 above) do not account for lens flare. With average flare, to obtain the Ḡ of 0.62, you would probably need to develop for around 6.5-6.75 minutes. You can look it up on the plot below. This is because lens flare reduces contrast. It can be handled by adjusting metering and exposure prior to taking the picture, or, afterwards, by calculating its effect on negative contrast and modifying development time, accordingly:

delta100_id68Gbar_gtime by Nick Mazur, on Flickr

Unfortunately, I haven't tested TMAX 100 with ID-68, so I cannot help you there. However, I would not put too much stock into the differences between recommended development times by either manufacturer. We do not know exactly how they arrived at their recommendations. The data sheets are, in my experience, not always consistent. They do help very much, don't get me wrong, but I would only take their recommendations as starting point values, only.

And finally, the photographic film has a very non-linear response to exposure and development. This is why a certain interval, say 1.5 minutes, only makes sense, relative to a particular exposure/film/development combination. This is also partly why there is not fixed conversion formula for Ḡ and CI. So If I tested T-MAX 100 and Delta 100 in one developer, the established differences would not always hold in another developer.

 

[Craig]

As a comparison does Kodak give its own times for Tmax 100 or D100 in Microphen?

In the film tech sheets that I have seen, Kodak only gives times for Kodak developers. The Kodak developer tech sheets do gives times for films other than Kodak though.