C-41 Processing with a Jobo CPA-2

[donbga]

Can someone tell me what motor speed setting to use for processing C-41 film?

Thanks,

 

[jeroldharter]

This is all I could find:

Rotation Motor Control

This switch turns the rotation motor on and sets the speed. '0' is 'off.' The 'F' through '7' settings adjust the rotation speed from about 25 R.P.M. to about 80 R.P.M. (The normally recommended rotation speed is 'P' at approximately 75 R.P.M. with 1500, 2500, and 2800 series, and '4' at approximately 50 R.P.M. with the 3000 series tanks or drums.)

 

[donbga]

This is all I could find:

Rotation Motor Control

This switch turns the rotation motor on and sets the speed. '0' is 'off.' The 'F' through '7' settings adjust the rotation speed from about 25 R.P.M. to about 80 R.P.M. (The normally recommended rotation speed is 'P' at approximately 75 R.P.M. with 1500, 2500, and 2800 series, and '4' at approximately 50 R.P.M. with the 3000 series tanks or drums.)

So if I understand properly what you are explaining, use setting P for processing C-41 film.

Thanks,

 

[jeroldharter]

I think so. However, if you were doing C-41 for sheet film in expert drums (3000 series) then you would use "4."

I don't know how they came up with their settings.

 

[donbga]

I think so. However, if you were doing C-41 for sheet film in expert drums (3000 series) then you would use "4."

I don't know how they came up with their settings.

I'm using a 2523 tank for 4x5 shet film and 120 roll film. Is there a Jobo document that you know of that can expalin this?

Thanks,

 

[jeroldharter]

This is where I looked:

Dead Link Removed

 

[donbga]

This is where I looked:

Dead Link Removed

Thanks once again!

 

[Richard Harris]

Jobo increased the recommended speed for C41 I think following streaking problems. I still use the slowest speed on my 2 machines and have no problems whatsoever. Slow means less strain on the motor and gearing and less foaming. I don't profess to know more than Jobo but for 120 and 35mm in 2500 tanks slow is just fine I use 150ml of solution per 120 or 35mm 36exp.

 

[snallan]

I use the 'P' setting for all film development (B&W, C41, & E6), except when I am using Pyrocat HD, when I use the '2' setting.

 

[eumenius]

I use the 'P' setting for all film development (B&W, C41, & E6), except when I am using Pyrocat HD, when I use the '2' setting.

Yes, "2" setting is more appropriate for slow developers like Pyrocat-HD, but I prefer to hand-process my films with Pyrocat-HD due to loss of edge effects in rotary dev. conditions. Do you experience the same with your Jobo?

 

[snallan]

Yes, "2" setting is more appropriate for slow developers like Pyrocat-HD, but I prefer to hand-process my films with Pyrocat-HD due to loss of edge effects in rotary dev. conditions. Do you experience the same with your Jobo?

I've never hand processed film using the Pyrocat, so I couldn't actually say (though I have no complaints about my negatives ). I really chose the Pyrocat, because I wanted to use a staining developer for sheet film in the Jobo, though I am really tempted to try semi-stand development with roll films.

 

[eumenius]

Steve, give it a try - with roll films as well as with sheet films. I use for sheets my NIKOR 4x5 stainless steel tank, giving it a gentle inversion and shake every two minutes. The same applies to roll and 35mm films. Due to bromide diffusion, the black details in print will be surrounded with a gentle yet perceptible halo, and the overall sharpness will be higher. After all, this mode of agitation is the only permissible with Nikor without a risk of streaking around the "spider" inner separator part

I've never hand processed film using the Pyrocat, so I couldn't actually say (though I have no complaints about my negatives ). I really chose the Pyrocat, because I wanted to use a staining developer for sheet film in the Jobo, though I am really tempted to try semi-stand development with roll films.

 

[snallan]

Steve, give it a try - with roll films as well as with sheet films. I use for sheets my NIKOR 4x5 stainless steel tank, giving it a gentle inversion and shake every two minutes. The same applies to roll and 35mm films. Due to bromide diffusion, the black details in print will be surrounded with a gentle yet perceptible halo, and the overall sharpness will be higher. After all, this mode of agitation is the only permissible with Nikor without a risk of streaking around the "spider" inner separator part

I have some HP5+ to process, so I shall give that a try. I'll let you know.

 

[donbga]

I use the 'P' setting for all film development (B&W, C41, & E6), except when I am using Pyrocat HD, when I use the '2' setting.

It's funny that you mention this as I have to set the rotation rate to it's slowest setting to prevent the developer (PyroCatHD) from oxidizing. Once I figured that out my negatives came out perfect. Setting the speed at '3' yielded negatives that were virtually blank.

 

[snallan]

It's funny that you mention this as I have to set the rotation rate to it's slowest setting to prevent the developer (PyroCatHD) from oxidizing. Once I figured that out my negatives came out perfect. Setting the speed at '3' yielded negatives that were virtually blank.

Really, wow! I must admit, I never tried any faster speeds, I just went straight to the slow speed after having tested the Pyrocat rolling manually in a 2840 drum.

I also cheat nowadays. I read a comment by Sandy King (here on APUG, I think), that adding 5 - 10 ml/l of a 1% ascorbic acid solution to the working solution helped combat oxidation, and therefore general fog. So I now add 5 ml/l to my working developer, and have noticed a significant reduction in the colour of the exhausted developer; now it is a deep straw colour, rather than the pinky to ruby-red I used to get.

 

[donbga]

that adding 5 - 10 ml/l of a 1% ascorbic acid solution to the working solution helped combat oxidation, and therefore general fog. So I now add 5 ml/l to my working developer, and have noticed a significant reduction in the colour of the exhausted developer; now it is a deep straw colour, rather than the pinky to ruby-red I used to get.

The ruby red color describes exactly what the developer looked like and still does to a lesser degree. I think I still have more staining than I need so I'll definitely add the ascorbic acid.

Thanks for the tip!