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View Full Version : Developing N-1 or N-2, how much less time?



Daniel_Buck
11-Aug-2007, 12:47
Hello, I have a question in regards to placing highlights in the developing stages. Over and Under developing is something new for me, I haven't tried this yet, but I'm looking forward to giving it a try.

I'm currently developing Tri-X for 10 minutes (HC-110 at 1:31) first 30 seconds of constant agitation and 3 consecutive inversions after every minute of the remaining develop time. This has given me good results, and from now on I'll be considering this my 'normal' developing time.

For discussion sake, lets say I would like to bring my highlights in my negative down by 1 stop, or 2 stops. On the zone system, lets just say the highlights are are currently in Zone 9, and I'd like to bring them down to Zone 8 or even Zone 7.



Here is where my speculation beings:

Since each zone is a full stop of light (double or 1/2 the light), would this equate to 2x or 1/2 the development time to move the highlights up or down a single stop/zone? So, instead of 10 minutes develop time, 5 minutes develop time to bring the highlights down by one stop? (And 4x or 1/4 the development time to move the highlights up or down 2 stops/zones?) Is it as linear of an equation as this? Or am I sorely off base with my speculation?

I don't shoot alot of film (usually only 2 or 4 sheets per weekend) so I don't really have alot of time/resources to do extensive testing. What I'm looking for are some suggestions as to where to start my testing, to hopefully get myself off on the right foot.

Any suggestions as to where my starting point for testing should begin? Thanks for any thoughts!

sanking
11-Aug-2007, 13:16
Hello, I have a question in regards to placing highlights in the developing stages. Over and Under developing is something new for me, I haven't tried this yet, but I'm looking forward to giving it a try.

I'm currently developing Tri-X for 10 minutes (HC-110 at 1:31) first 30 seconds of constant agitation and 3 consecutive inversions after every minute of the remaining develop time. This has given me good results, and from now on I'll be considering this my 'normal' developing time.

For discussion sake, lets say I would like to bring my highlights in my negative down by 1 stop, or 2 stops. On the zone system, lets just say the highlights are are currently in Zone 9, and I'd like to bring them down to Zone 8 or even Zone 7.



Here is where my speculation beings:

Since each zone is a full stop of light (double or 1/2 the light), would this equate to 2x or 1/2 the development time to move the highlights up or down a single stop/zone? So, instead of 10 minutes develop time, 5 minutes develop time to bring the highlights down by one stop? (And 4x or 1/4 the development time to move the highlights up or down 2 stops/zones?) Is it as linear of an equation as this? Or am I sorely off base with my speculation?

I don't shoot alot of film (usually only 2 or 4 sheets per weekend) so I don't really have alot of time/resources to do extensive testing. What I'm looking for are some suggestions as to where to start my testing, to hopefully get myself off on the right foot.

Any suggestions as to where my starting point for testing should begin? Thanks for any thoughts!

Film developer combinations respond differently to increases and decreases in time of development. Process and paper also change the relationship.

However, in the specific case of Trix-X and HC110 1:31 I would offer the opinion that if N development is 10 minutes, N-1 would be about 5.5 minutes and N+1 about 18.5 minutes.

Sandy King

billparrott
11-Aug-2007, 13:44
Hey.. new guy here... just wanted to throw my .02 in... film development doesn't necessarily follow the same 'rules' as those for exposure. Mosts the information I have read suggests that n+1 should start at around a 40% increase and that n-1 should begin around - 30%.. so.. given your example.. you might try around 7 minutes first and work back from there.. anyway.. nice to meet you guys.. :)

billparrott

steve simmons
11-Aug-2007, 13:57
I would do 15-20% decrease for N-1 and 25% increase for N+1 with this combination.

steve simmons

kev curry
11-Aug-2007, 14:22
Heres a shortcut method of computing your N+ and N- Development times

Normal Minus
For your N-1 time multiply your Normal Development time by 0.7
For your N-2 time multiply your Normal Development time by 0.6

For eg if your N time is ten minutes your N-1 time would be 7 minutes
and your N-2 time would be 6 minutes.

Normal Plus
For your N+1 time multiply your Normal Development time by 1.4
For your N+2 time multiply your new N+1 time by 1.4

For eg if your N time is ten minutes your N+1 time would be 14 minutes
and your N+2 time would be 19.5 minutes

Chris Johnson in his book 'The Practical Zone System' gives the following times for


Tri-X / HC-110B

Normal / 6min. N+1 / 8.5min. N+2 / 12min. N-1 / 4.5min. N-2 / not recomended.

Paul O
11-Aug-2007, 14:23
I'd go with 7 minutes as a starting guide.

Daniel_Buck
11-Aug-2007, 15:45
thanks for the replies! I think I have somewhere to start now. Thank you!