Help in calculating dev time for Delta 400

reysphotofilm · Aug 15, 2024

Hi everyone

I want to develop ILFORD delta 400, which I shot @800 iso.
Which as i understand means +1 stop push development. My first time pushing film

So, I’m a bit stuck with calculations in development.
I have a ready batch of Rodinal Spezial R09 1+30.
I found that develop time by Agfa for delta 400 which the R09 1+15 is 4.5 mins.
How do I apply it to my develop?

Big thanks in advance to the kind helpers

Paul Howell · Aug 15, 2024

From the Massive Development chart, in general I add 30% for each push, these are a starting point, many factors may be play with your film. camera developer combo.

Massive Dev Chart Film Development, Film Developing Database

www.digitaltruth.com

runswithsizzers · Aug 15, 2024

I am not a Rodinal user, so no help, but @reysphotofilm says he has "Rodinal Spezial R09 1+30" which is apparently different from the more common Rodinal 09.

When I search Digital Truth for "Rodinal Spezial R09" it tells me:

And searching for "Ilford Delta 400" plus "Studional" shows only times for 1+15:

The 4.5 minute time matches the time provided by Agfa according to the opening post. (the Notes say the 8 minute time is suspicious)

Perhaps the best solution for @reysphotofilm would be to forget about the 1+30 dilution and apply the 30% increase suggested by @Paul Howell to the time given by Digital Truth (and Agfa) for Studional diluted 1+15?

4.5 minutes = [(4x60) + 30] = 270 seconds x 1.30 = 351 seconds = 5 minutes 51 seconds -- is that right?

jeffreyg · Aug 15, 2024

I also can’t speak for Rodinal developers but I have used Delta 400 120 for many years with Ilford chemicals and found that one stop in either direction has worked well with the normal development time unless the lighting and subject need more contrast. If the images can’t be duplicated I would stick with the normal dilution and time. Otherwise experiment.

reysphotofilm · Aug 15, 2024

first, thanks to all who answered.
ok so now i noticed on the bottle of the developer a chart of 1+15 (attaching photo). i shot and developed many times tmax400 and fuji neopan 100.
it looks like it is just double the time for my dilution -> 1+30
the time i develop usually those films is tmax for 10 minutes and neopan for 7 minutes.

so can i assume the same for Delta400? for 1+30 its 9 minute?
and more important how much time to add because i shot @800 iso. 50%? 25%?

many thanks again

jeffreyg · Aug 15, 2024

runswithsizzers said:
I am not a Rodinal user, so no help, but @reysphotofilm says he has "Rodinal Spezial R09 1+30" which is apparently different from the more common Rodinal 09.

When I search Digital Truth for "Rodinal Spezial R09" it tells me:
View attachment 376336

And searching for "Ilford Delta 400" plus "Studional" shows only times for 1+15:
View attachment 376337

The 4.5 minute time matches the time provided by Agfa according to the opening post. (the Notes say the 8 minute time is suspicious)

Perhaps the best solution for @reysphotofilm would be to forget about the 1+30 dilution and apply the 30% increase suggested by @Paul Howell to the time given by Digital Truth (and Agfa) for Studional diluted 1+15?

4.5 minutes = [(4x60) + 30] = 270 seconds x 1.30 = 351 seconds = 5 minutes 51 seconds -- is that right?

jeffreyg · Aug 15, 2024

If it’s any help I looked in an old Ilford product data guide and it lists Delta 400 at 800 with Agfa Rodinal 1+25 for 12 1/2 minutes and not recommended at 1+50

Paul Howell · Aug 15, 2024

I think you might have thin negatives, as I get 12 minutes at 1:25 while the massive development chart recommends 16 mints. Why not use 1:25, very close to 1:30?

runswithsizzers · Aug 15, 2024

jeffreyg said:
If it’s any help I looked in an old Ilford product data guide and it lists Delta 400 at 800 with Agfa Rodinal 1+25 for 12 1/2 minutes and not recommended at 1+50

Paul Howell said:
I think you might have thin negatives, as I get 12 minutes at 1:25 while the massive development chart recommends 16 mints. Why not use 1:25, very close to 1:30?

I believe you guys are using regular old Rodinal, right? The OP is asking about "Rodinal Spezial R09" (aka: R09 Studio) which is a different developer. How much different I cannot say, but Agfa gives times for dilutions of Rodinal Spezial R09 only at 1+15 and 1+30, and NOT 1+25 or 1+50 as per common Rodinal.
---

@reysphotofilm, is there some reason why you would prefer to process your film in Rodinal Spezial R09 at 1+30 as opposed to 1+15?

You say, "I have a ready batch of Rodinal Spezial R09 1+30" Does that mean you have already diluted your entire bottle of Rodinal Spezial R09 to 1+30?

Paul Howell · Aug 15, 2024

Right, I missed that. I think the R09 confused me. Is Rodinal Spezial the same as Rodinal with sulfate added or completely different? Based on 1:15 I would to 5.5 68 Degrees.

reysphotofilm · Aug 15, 2024

runswithsizzers said:
I believe you guys are using regular old Rodinal, right? The OP is asking about "Rodinal Spezial R09" (aka: R09 Studio) which is a different developer. How much different I cannot say, but Agfa gives times for dilutions of Rodinal Spezial R09 only at 1+15 and 1+30, and NOT 1+25 or 1+50 as per common Rodinal.
---

@reysphotofilm, is there some reason why you would prefer to process your film in Rodinal Spezial R09 at 1+30 as opposed to 1+15?

You say, "I have a ready batch of Rodinal Spezial R09 1+30" Does that mean you have already diluted your entire bottle of Rodinal Spezial R09 to 1+30?

me and my friend started developing a year ago, and just used make a batch of 1L of developer. i dont remember the exact reason why. but thats the way we develop for a while. never encountered any problems usually found on the internet the develop time nedded. but now i'm a bit puzzeled.

john_s · Aug 15, 2024

Rodinal Special (also named Studional) is somewhat like Ilford DDX. Quite different to original Rodinal.

reysphotofilm · Aug 16, 2024

runswithsizzers said:
I believe you guys are using regular old Rodinal, right? The OP is asking about "Rodinal Spezial R09" (aka: R09 Studio) which is a different developer. How much different I cannot say, but Agfa gives times for dilutions of Rodinal Spezial R09 only at 1+15 and 1+30, and NOT 1+25 or 1+50 as per common Rodinal.
---

@reysphotofilm, is there some reason why you would prefer to process your film in Rodinal Spezial R09 at 1+30 as opposed to 1+15?

You say, "I have a ready batch of Rodinal Spezial R09 1+30" Does that mean you have already diluted your entire bottle of Rodinal Spezial R09 to 1+30?

not the whole bottle diluted. we made 1L -> 32ml of concentrated developer mixed with 968mL of water.

runswithsizzers · Aug 16, 2024

reysphotofilm said:
not the whole bottle diluted. we made 1L -> 32ml of concentrated developer mixed with 968mL of water.

Since you still have some undiluted developer remaining, you have options:

1. Use the 1+30 dilution you already have made, calculating your time as twice the 1+15 time which you have inferred from previous experience with other films in this dilution. And then adding some additional time for push processing. Or...

2. Mix up some developer at 1+15, and use the published time for your film (4.5 minutes), plus some additional time for push processing.

As for how much additional time to add, in his book, "Beyond Basic Photography," Henry Hortenstein says,
"After the film has been underexposed, it must be overdeveloped to create enough negative contrast for an acceptable print. The amount of development varies widely with the type of film, the type of developer, and the dilution of the developer. Here are general guidelines for pushing film..."

If underexposed by one stop, Horenstein recommends overdeveloping by 50 percent.

A quick look online shows other recommendations to increase development times vary from 20% to 50% for a one-stop push. If the roll of film you want to develop was exposed under harsh, contrasty light, it might be better to start with the shorter recommendations. But if shot under flat, low contrast light, then try one of the longer recommendations. The only way you are going to know for sure is to pick a time, see what you get, and go from there.

Let us know what you end up trying and how it worked out for you.

reysphotofilm · Aug 16, 2024

runswithsizzers said:
Since you still have some undiluted developer remaining, you have options:

1. Use the 1+30 dilution you already have made, calculating your time as twice the 1+15 time which you have inferred from previous experience with other films in this dilution. And then adding some additional time for push processing. Or...

2. Mix up some developer at 1+15, and use the published time for your film (4.5 minutes), plus some additional time for push processing.

As for how much additional time to add, in his book, "Beyond Basic Photography," Henry Hortenstein says,
"After the film has been underexposed, it must be overdeveloped to create enough negative contrast for an acceptable print. The amount of development varies widely with the type of film, the type of developer, and the dilution of the developer. Here are general guidelines for pushing film..."

If underexposed by one stop, Horenstein recommends overdeveloping by 50 percent.

A quick look online shows other recommendations to increase development times vary from 20% to 50% for a one-stop push. If the roll of film you want to develop was exposed under harsh, contrasty light, it might be better to start with the shorter recommendations. But if shot under flat, low contrast light, then try one of the longer recommendations. The only way you are going to know for sure is to pick a time, see what you get, and go from there.

Let us know what you end up trying and how it worked out for you.

Thank you very much.

so i developed it now for 15:45 minutes (9 mins standard develop time +50% push +20% because i already used the batch for other rolls)
there are results, hope they are good
now the roll is drying and soon ill start the scan.

hope you all have a nice Saturday.

reysphotofilm · Aug 16, 2024

So i have scanned.
first time pushing film, i think next time i should overexpose more (like relatively to the iso setting on the camera). very grainy in the under exposed shaded frames, yet direct sunlight gave pretty decent results.

Help in calculating dev time for Delta 400

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