Jobo CPP3, pre wash and dev times

[Fatih Ayoglu]

Hi all,

I have managed to get (not quite sure if it was a right decision or impulse purchase) a brand new CPP3 with extra 3 reels for roll film and 4x5 negatives with a 25% discount.

While I was reading manual, obviously Jobo highly recommends prewash to take the film tank and everything else to the required temperature but also to make sure smooth development.

What I’ve realised is the fact that, they advise because of prewash, dev times are about 15% longer but then because it is a rotary development, the dev times should be 15%, which makes actually no change at dev times. So whether I develop films in Paterson with flip or in Jobo with prewash, dev times are the same?

Now that doesn’t make too much sense to me but then this is a German company so I assume they have done plenty of tests to claim that.

What’s your feedback? (On dev time, not my impulse purchase )

 

[ic-racer]

It makes sense.
Try it and report back.

 

[Alan9940]

Don't know what the "correct" answer is but I reduce development times, as shown on the MDC, by 10 - 15%.

 

[Neal]

First, congratulations on your purchase.

I use the 25XX series tanks in a home made CPE work alike and never have issues. Normally I use Xtol one shot with the Kodak published times without pre-wash. At times I have had to use the 10%-15% rule with some film/developer combinations and that works pretty well. Once I tried the pre-wash method using a published small tank/intermittent agitation time and that worked pretty well. Essentially, you're going to have to zero in on what works for you. I kept a notepad with times and temperatures that worked well for me but not suprisingly lost it in a recent move (there are still a unopened bins so there is hope).

In any case, you will love the Jobo system. I have had to go back to the conventional method for the last few months and I really do not enjoy it.

 

[Fatih Ayoglu]

Don't know what the "correct" answer is but I reduce development times, as shown on the MDC, by 10 - 15%.

And do you prewash the film?

 

[Fatih Ayoglu]

It makes sense.
Try it and report back.

When I prewash with Paterson tanks and use inversetion method, I’ve never extended my dev times and my negatives seem alright. Now I’m thinking of I have done wrong

 

[Fatih Ayoglu]

First, congratulations on your purchase.

I use the 25XX series tanks in a home made CPE work alike and never have issues. Normally I use Xtol one shot with the Kodak published times without pre-wash. At times I have had to use the 10%-15% rule with some film/developer combinations and that works pretty well. Once I tried the pre-wash method using a published small tank/intermittent agitation time and that worked pretty well. Essentially, you're going to have to zero in on what works for you. I kept a notepad with times and temperatures that worked well for me but not suprisingly lost it in a recent move (there are still a unopened bins so there is hope).

In any case, you will love the Jobo system. I have had to go back to the conventional method for the last few months and I really do not enjoy it.

Thank you

I plan to use XTOL-R or Rodinal 1+50. I guess I’ll start prewash w/ (published times -10%) as when I use Paterson+inversion with prewash, I don’t deviate from published times and it works ok (I guess)

 

[grahamp]

Historically (Jobo CPE2+ era) it was recommended that times be reduced up to 15% for condenser enlargers, otherwise use the published development times as the starting point. While I have a couple of enlargers that can use condenser heads, I cannot recall when I last used them! Back then, the concept of scanned images did not apply.

Just run a couple of tests and keep good notes, and you will know what works for you with your equipment and workflow.

 

[mshchem]

I use the recommended times that Eastman Kodak published when XTOL was introduced.

 

[Fatih Ayoglu]

I use the recommended times that Eastman Kodak published when XTOL was introduced.

With prewash?

 

[mshchem]

With prewash?

Kodak didn’t use prewash. No reason to. I have used prewash with C-41 to help warm the tank. With black and white at room temperature not sure it will make any difference???

It is interesting to see the pretty colors in the prewash

 

[mshchem]

FYI, I've never used the pre-programmed process timer, but the CPP3 does have a process timer with "official" times for color film process times.

 

[Alan9940]

And do you prewash the film?

Yes

 

[Ultraanalogic]

Hi all,

I managed to get (not quite sure if it was the right decision or an impulse buy) a brand new CPP3 with extra 3 reels for roll film and 4x5 negatives with a 25% discount.

While I was reading the manual, Jobo obviously strongly recommends prewashing to get the film tank and everything else to the required temperature, but also to ensure smooth development.

What I've realized is the fact that they say that prewashing will add about 15% to the processing time, but then because it's a rotary processor, it should add 15% to the processing time, which really doesn't change the processing time. So whether I develop films in Paterson with flip or in Jobo with prewash, the dev times are the same?

That doesn't make much sense to me, but this is a German company, so I assume they've done a lot of testing to make that claim.

What's your feedback? (On development time, not my impulse purchase )

I have been using rotative process since 30 years ago and I have never adjusted dev. time due to prewash step. Honestly, I never observe shifting or something strange with films.
NO PREWASH FOR COLOR FILM!!!!!!!!!!!!
And, believe me, the actual Jobo factory isn't the same as the old one.

 

[Alan9940]

After seeing the post above, I should probably note that I process only B&W film on my Jobo.

 

[Ultraanalogic]

Why? It's a pity to use a Jobo for BW only! Go with confidence with color too: it's just a matter of temperature

 

[Ultraanalogic]

May be you can start with a smaller machine like a CPE with or without the lift. More economical in both usage and maintenance costs

 

[Ultraanalogic]

Please write me privately if you need the Jobo CPA/CPP Instruction manual, where at the C41 chapter, they don't mention ANY prewash but only a prewarm step (really necessary with color processes).
Hope to be helpful

 

[Fatih Ayoglu]

Please write me privately if you need the Jobo CPA/CPP Instruction manual, where at the C41 chapter, they don't mention ANY prewash but only a prewarm step (really necessary with color processes).
Hope to be helpful

I have only seen it at their brochure, from their website. https://www.jobo.com//bin/ecms_streamer.php?emb_label=flyer_jobo_analog_2020_final&inline=

Towards the end there is section called PreWash


"In this context it is helpful to remark that JOBO clearly recommends to always pre-wash your film (and paper) in rotary processing for 2 to 5 minutes. Pre-washing allows the emulsion to soften up and absorb first water molecules. Keep in mind that, different from inversion processing, in rotary processing chemistry does not hit the whole film surface at once. Pre-washing makes sure that chemical is evenly absorbed by the emulsion in rotary processing of your film (and paper), avoiding unevenness and undulations on the film surface. Our service department found that 99% of customer complaints with unevenness were strictly correlated to the lack of pre-wash. Color-processing times remain unchanged even with pre-wash, whilst B&W development times need to be increased by an average of 20% compared to B&W development without pre-wash.
With inversion processing the pre-wash can be skipped as the whole film is always simultaneously immersed in chemistry. Due to the reduced agitation in comparison to rotary processing the development times are about 25% longer for inversion processing than they are for rotary processing to achieve the same density. As a rule of thumb, you can say that developing film in rotary processing with pre-wash will take about the same time as inversion processing without pre-wash at any given temperature. Most large format photographers know about the challenge of achieving evenness of processing when working manually. The larger the film format the greater this challenge becomes. Apart from perfect control of push & pull process, the evenness is one of the main reasons why a large format photographer should opt for the JOBO processor with Expert Drum."

 

[Fatih Ayoglu]

Thank you all, So in summary for BW and C41 films

PreWarm the tank (with or without water in) - My darkroom is in my basement and it is around 15C-16C during winter so I need to warm for BW films as well
Use published time minus 15% (That is also what Kodak document suggest)

So as long as the drum is rotating before I pour the chemicals, I believe this should be alright.

 

[Sirius Glass]

Why? It's a pity to use a Jobo for BW only! Go with confidence with color too: it's just a matter of temperature

I tend to do more black & white development than color with the Jobo processor because I do not like having to print each color photograph. I would rather send it out and not save up rolls of color film to process.


Welcome to Photrio!

 

[Neal]

With prewash?

No pre-wash. I follow the Xtol data sheet.

 

[Fatih Ayoglu]

It looks like nobody is doing pre wash

 

[Alan9940]

It looks like nobody is doing pre wash

I do the pre-wash for B&W film because:

1. Jobo recommends it in their operating instructions.

2. I run the pre-wash for 5 mins, per Jobo, because I believe it helps stabilize the internal temp of the tank and the film.

3. No scientific data to back this up, but I believe a pre-wash leads to more even development.

I know Ilford doesn't recommend it because something about a wash aid built into the film blah-blah, but I still do it and have never noticed that my negs suffer for it.

 

[koraks]

4x5 in 2500 series tank and 120 in 1500 series tank: I use a prewash to prevent surge marks along the film edges, for both color and b&w. I get uneven development without a prewash with these combinations. For 135 it doesn't matter and either prewash or not works OK. Development times for b&w aren't all that critical in my book so either go with the official time or deduct 10 or 15% or whatever, really. For color (C41) I just go with the official time.

The important thing is to establish what works for you; as you can tell from the varied responses in this thread there's no consensus and there's never going to be one, either. So read the posts for your amusement, then ignore them and TEST what works for you.

Have fun with the machine!