Accounting for different temp according to Microphen's manufacturer suggested development times

[Eggvillan]

Hi -

Very new to all of this. I'm going to try to develop 400 Tri-X that I rated at 1600 with Microphen.

Massive dev chart says i should go 12 minutes at 68ºF. Ilford's manufacturer data agrees: https://www.ilfordphoto.com/amfile/file/download/file_id/733/product_id/551/

I'm confused about how to adjust for different temperature because Ilford's manufacturer information seems to give conflicting advice. Do i keep it at 12 minutes because the temp is between 68–75º, or do i decrease the time?

On page 4, the manufacturer sheet states, "MICROPHEN can be used in the temperature range of 20–24ºC (68–75ºF). For processing at other temperatures (i assume this to mean temperatures outside of 8–75ºF, right?) increase the given development times by 10% for each 1ºC (2ºF) drop in temperature and decrease the given development times by 10% for each 1ºC (2ºF) rise in temperature. Alternatively use the time temperature graphs below" (emphasis and parenthetical added)

According to the time graph included on the data sheet, working at 72ºF means i should only develop for just under 10 minutes (a 20% decrease in time based on the 4ºF rise in temp). So which language do i pay attention to???

"For processing at other temperatures" - i'm not processing at another temperature, I'm processing at "the temperature range of 20–24ºC (68–75ºF)." So do i stick with 12 minutes at 72ºF, or do i adjust my time to ~10 minutes?

 

[Ian Grant]

Go by Ilford's recommendations, you must stick to one temperature so if 72ºF then adjust as per the Ilford chart.

Disregard that 10% per 2ºF it's not logical.

Ian

 

[Eggvillan]

Go by Ilford's recommendations,

But... which one?

• The recommendation regarding "temperature range of 20–24ºC (68–75ºF)"
• Or the one regarding "processing at other temperatures" (but which also seems to include temperatures in the 68-75 degree range)?

..... is this just my lawyer brain finding ambiguity when there might not actually be any?

 

[R.Gould]

There is a chart on the ilford site which gives you the changes to make for different temps, it is downloadable and printable, I use myself all the time, it is on the wall of my darkroom, covers from 18 to 27, just check the suggested time for 20 then read across to your temperature and process at that, My water out of the tap is anything from 22 to 25 this time of year so it is invaluable, I suggest you look it up, as Ian says,make sure that you stick to the same temperature
Richard

 

[Ian Grant]

The default is always process if you can at 20ºC / 68ºf, they seem to be saying either or and the other temperatures relates to the times they give for 20ºC.

Ian

 

[tedr1]

There is a rule for 68-72F given on the chart, use it.
If for some reason the chart range is exceeded then apply the other rule which uses per degree adjustment.
It is normal to arrange that the temp is 68F, this is done by careful mixing of the fluids using water at the correct temperature, which may be arranged using a microwave or mixing hot and cold water. ALL the fluids must be at 68F including the stop bath, the fix and the wash water. Allowing fluids at different temps (more than a few degrees) to contact the film risks permanent and disfiguring damage to the image (reticulation).

 

[JWMster]

Maybe I'm a goofball, but I've tended to use the MassiveDeveloping chart website for time/temp conversions: http://www.digitaltruth.com/devchart.php?doc=timetemp
I'm new at this, but up to about 40 rolls so far, and this has never let me down (yet). Not to say it won't, but so far, so good.

 

[Eggvillan]

Maybe I'm a goofball, but I've tended to use the MassiveDeveloping chart website for time/temp conversions: http://www.digitaltruth.com/devchart.php?doc=timetemp
I'm new at this, but up to about 40 rolls so far, and this has never let me down (yet). Not to say it won't, but so far, so good.

I didnt know this existed - thank you!

 

[tedr1]

I trust the developer manufacturer's data sheet rather than the massive website because there are (at least) three variables with developers; time, temperature and agitation. All three have be controlled using great care in order to produce satisfactory and consistent results. Failure to keep time, temperature and agitation consistent always causes inconsistent results. For example what agitation process is used has a major effect on contrast, the number of inversions, and the time interval between inversions, has to be controlled and be repeatable, there is no single standard "intermittent agitation process". Especially when starting out, when there are already too many distracting uncontrolled variables, the use of strictly consistent processing steps is a very good way to avoid confusion and wasted effort. One way to do that is to begin by using the exact process steps given in the developer data sheet. If there isn't one, pick another developer that does have one, Ilford among others are excellent at this.

 

[MattKing]

Very new to all of this. I'm going to try to develop 400 Tri-X that I rated at 1600 with Microphen.

Massive dev chart says i should go 12 minutes at 68ºF. Ilford's manufacturer data agrees: https://www.ilfordphoto.com/amfile/file/download/file_id/733/product_id/551/

You may have missed this, but the 12 minute recommendation in the data sheet appears to be for ID-11, not for Microphen.

 

[Ian Grant]

You may have missed this, but the 12 minute recommendation in the data sheet appears to be for ID-11, not for Microphen.

Eggvillan, Matt is right - however these development times are starting points and with no figure given for Tri-X in FS Microphen @ 1600EI I would suggest 12mins at 20ºC would be fine, you don't want to under-develop a push processed film.

Ian

 

[Craig75]

But... which one?

• The recommendation regarding "temperature range of 20–24ºC (68–75ºF)"
• Or the one regarding "processing at other temperatures" (but which also seems to include temperatures in the 68-75 degree range)?

..... is this just my lawyer brain finding ambiguity when there might not actually be any?

No. It is contradictory and you will end up with different times following the different instructions they gave (from my quick scan through pdf on my phone).

Just try and stick to one temperature and dilution and change time as needed as you go through yr films. Keep as many constants as you can and just change one variable.