[GeneV]

Here is the time/temperature chart:




And the table on which it is based:

Ilford Time/Temp Table

Steve

Can it really be the same for all developers?

[stevebrot]

Can it really be the same for all developers?

That is a good question and I am inclined to doubt it. My old Kodak "B&W Darkroom Data Guide" has a circular slide rule for film development that includes a linear scale for temperature correction that is intended for all Kodak materials available at the time of publication (1979). That slide rule yields temperature correction that reflects a little steeper curve than the Ilford graph or table, but is in the same ball park. Too bad the forum's BB Code implementation does not support tables, but here are some raw comparison numbers:

Ilford Table:

• 18C -- 12.30 minutes
• 20C -- 10 minutes
• 22C -- 8 minutes

Kodak Calculator:

• 18C -- 11.8 minutes
• 20C -- 10 minutes
• 22C -- 8.4 minutes

Note that the Kodak calculator uses a guide number (linear scale) based on film developer combination to determine the time/temp range. The temperature correction is universal across products for any particular guide number. So the only difference between the Ilford and Kodak calculation is the temp correction factor itself. How that was derived is anybody's guess.

My old Kodak guide is designed for older style emulsions. Looking at the data sheet for Kodak TMax 100 film, it is obvious that different developers require different times at different temps for that material. The same is true for Fuji Acros 100, but to a lesser extent. So...my conclusions about the time/temperature table are that is useful, but your mileage may vary. New style emulsions may not comply. Check first with the product insert and resort to the Ilford table when manufacturer's data is unavailable.



Steve

[GeneV]

OK, pardon the dumb question, but what does the "11.8s" mean?

[stevebrot]

OK, pardon the dumb question, but what does the "11.8s" mean?

Oops! That should have been minutes!

I will post a correction!


Steve

[GeneV]

I deleted the quote so no one is confused.

[digitaltruth]

The Massive Dev Chart is reliable. If you want to know more about it, then check out the User's Guide and FAQ here:

I often see comments in forums that make valid points about how information found on the internet is unreliable, and I appreciate that it is easy to think that the data in the chart might fall into this category, but nothing could be further from the truth.

One of the key aspects of the chart is that all user submissions have to be manually added by myself. No one can upload data directly to the chart, and the reason for this is to avoid erroneous information being posted. I personally check every entry to make sure that it appears valid when compared to existing data. Lots of entries are rejected.

There are over 8,000 entries in the database, so of course it is possible that one or two pieces of information are inaccurate. If you come across a time that seems wrong or produces bad results, then let me know. I want the chart to be as accurate as possible, so all problems should be reported.

In almost every instance where there is verifiable and reliable data provided by the manufacturer, this is the same data you will find in the Massive Dev Chart. However, its important to realize that the manufacturer's often change their own data, so there can be instances of conflicts.

If you have any questions about the chart, please write to the email address posted on our web site and I'll do my best to answer.

--Jon Mided

Digitaltruth Photo

[lbenac]

The Massive Dev Chart is reliable. If you want to know more about it, then check out the User's Guide and FAQ here:

I often see comments in forums that make valid points about how information found on the internet is unreliable, and I appreciate that it is easy to think that the data in the chart might fall into this category, but nothing could be further from the truth.

One of the key aspects of the chart is that all user submissions have to be manually added by myself. No one can upload data directly to the chart, and the reason for this is to avoid erroneous information being posted. I personally check every entry to make sure that it appears valid when compared to existing data. Lots of entries are rejected.

There are over 8,000 entries in the database, so of course it is possible that one or two pieces of information are inaccurate. If you come across a time that seems wrong or produces bad results, then let me know. I want the chart to be as accurate as possible, so all problems should be reported.

In almost every instance where there is verifiable and reliable data provided by the manufacturer, this is the same data you will find in the Massive Dev Chart. However, its important to realize that the manufacturer's often change their own data, so there can be instances of conflicts.

If you have any questions about the chart, please write to the email address posted on our web site and I'll do my best to answer.

--Jon Mided

Digitaltruth Photo

Inasmuch as you are in our backyard, I will feel free to put one comment.
I use the database to look at new film/developer combo and I find it quite useful (not gospel of course but great sounding board/starting point). One thing that I always find missing, is information regarding agitation.
This is likely because I am always using various level of agitation from none to every minute, but I would love to have this along with time and temperature.


Cheers,

Luc

[HGMonaro]

I used it the other night to get a time for APX25 in XTOL... worked a treat!

[PGillin]

It's pretty reliable chart, at least in my experience, but I agree with what Ibenac is saying, information on agitation would be nice. Still, the quality of information is good. I wouldn't trust the chart absolutely and entirely, but usually, if something sounds reasonable, I follow it.
Also the entire photo department at Corcoran College of Art and Design uses the massive dev. chart. It's up on the wall, right next to the film processing sinks.

[digitaltruth]

As it says in the User's Guide:

"Agitation: Wherever possible times have been listed which rely on the standard technique of 30 seconds continuous agitation after immersion, followed by ten seconds (three inversions) per minute."

This is the same format followed by most manufacturer's data sheets.

Unless a different agitation method is specified, the only variance is that if you are using a large tank which takes more than 5 seconds to fill, you should agitate for 60 seconds initially. Similarly, if you are using a very short development time of under 5 minutes, then you should increase the subsequent agitation to every 30 seconds.

Additional specific information, where available, is listed in the notes (if applicable) for each unique film/dev combination.


--Jon Mided

Digitaltruth Photo

[artobest]

You should try using the chart with an Agfa Rondinax! Of course, now that I'm familiar with both the box and the chart, I can usually extrapolate a useful time - usually a minute or so longer than recommended.

[icywarm]

Ok I have a strange question... the film I am wanting to use is not listed for 120 or 35... would there be a difference?

[HGMonaro]

some films do have different times for 35mm and 120. Usually not a huge amount though.

However, not sure what you mean.. is it not listed at all?

[icywarm]

Linking into the chart is tough it seems... but fomapan, d76 gives:

The Massive Dev Chart: B&W film development database

notice the blanks

[HGMonaro]

the Foma site (pdf) doesn't specific different times for different formats so I think you'd start with the times shown. The data for the sheet film seems odd, same time and film speed as the roll film when used 'stock' but different when diluted 1:1