4x5 color negative processing problems

[James Via]

I have have had no luck finding a pro lab that can produce uniform processing. My 4x5 Portra VC shows irregular densities or mottling is clear a blue sky. This was all using dip and dunk. The one JoBo lab produced streaking. Film and equipment have been eliminated as possible cause - I have used different emulsions and have run Portra NC, Portra VC and Fuji NPS. B&W negatives from of the same shot look fine. Trans parencies look great too. This is a color negative processing problem. Anyone else experiencing this kind of thing?

[ronald moravec]

Mine goes thru 10 sheet expert drum using Tetenal Press Pack powder chemicals. Never a problem.

Dip and dunk sounds chancy with hangars unless they use gas burst agitation. Agitation is required every 15 sec. You can`t dip and dunk that fast. Mottling will result.

The six sheet Jobo reel will streak unless it is the newer one with the " wings" to hold the sheets on the reel or if they do not use them. Ask to see the equipment. Don`t tell why and if there are no holders on the outside, black plastic, ask about them.

If my Jobo quits, I will process color neg in a 4x5 Nikor tank. Inversion 1 per 15 sec.

I use Portra VC. The Tetinal chemicals are a near clone to c-41 . Others are not such as unicolor.

[paulr]

How much more difficult is doing your own c-41 than doing black and white?
I never considered doing it before, but now that I see what the lab charges, that could change.
I'm used to using a jobo tank on a roller base, and can typically keep my chemistry within a degree or half a degree.

[Mark_3899]

Easy. I've been doing it myself since 1985 when I worked on a hand line when I got out of art school. I process my 4x5 sheets in 3 Kodak hard rubber tanks which are placed in a Phototherm recirculating water bath. No problems.

[ronald moravec]

How do you agitate with the hangars and tanks? Kodak calls for once each 15 sec. I would raise, tilt one way, imerse, and repeat four times per minute alturnating direction of tilt.

[Mark_3899]

When I first immerse the film I agitate for 15 seconds, Then every 30 seconds I do what you describe above, which lasts about 15 seconds so in effect it's like agitating every 15 seconds. Since development only lasts 3 mins, 15 seconds it isn't too bad.

[Ed Richards]

I have good luck with Primary Color Lab in New Orleans, and they only charge $1.77 a sheet. It is generally out the door the day after they get the film.

http://www.primarycolorlab.com/

[James Via]

Interesting, I wasn't aware of people acutally hand processing C41 the very short development times spook me a bit. Trying to be consistant and all. So I've been doing more reserach on C 41. Any feed back on the different chemisty brands. One article I read stated that Kodak's Flexcolor chemistry produces a little less contrast than the others - that may mostly be true in automated machine processing. Has anyone tried C41 processing at temperatures lower than 100 - say 85 to lenghten the development time? I wonder too about push/pull processing for contrast adjustments.

Thanks

[Mark_3899]

I use Kodak Flexicolor C-41. For me the fact that it comes in containers to make 1 gallon, instead of 5 litres is a plus, it's also cheaper. I don't know about the lower contrast issue with the Flexicolor chemistry, that would only benefit my work anyway. As far as lattitude goes you really don't have that with C-41. It's not like E-6 where you can push and pull to the benefit of the shot. 3:15 is perfect for me because I'm focused on agitating the whole time. if it were longer I might zone out or get into the music I have playing.

[M Brian Mills]

I have done a fair amount of hand-processing C-41 film and have found that the single-most important part of it is a pre-soak. Without it I get all sorts of strange results and they have not been the happy-accident sort of strange results.
I have found that underdeveloping (at about 3 minutes) works well for me by giving the density that I desire which works hand-in-hand with my over-exposing.
I worried a bit about consistency, but then decided that there is a good chance that the labs I used were not so consistent themselves.
Chemistry at + or - 3 degrees and I still get results that I can easily work with.

[Dan Jolicoeur]

I have never processed color also and would like to give it a try because of cost. My question is; isn't this what a Jobo processor was made for? I guess most people are using them for B&W maybe?
Is there anyone out there using a rotary jobo(cpe, cpa,cpp) for C-41 and is it a fairly easy process? Also what about waste chemicals, can they go into the septic, small quantities?
Thanks ,

[James Via]

M Brain Mills

On the pre soak issue - Kodak does not recommend a presoak, it affects the D-max of the film and they say it will have inconsistant results. With todays C41 films a pre soak is unnecessary. I fully understand the need for and use a pre soak in my B&W and when I did E6. But with C 41 it is supposedly a no -no. It's just what I've learned from weeks of investigation into this matter of doing my own C41.
But if you are having success and are happy with the results then stick with it. Rules are made to be broken and in photography we are always breaking the rules to discover more creative ways to work.

Mark,

Could you explain your processing technique for us.

Also, I did read an article about C41 processing at 85 and the time for development was something like 7 - 8 minutes.

Thanks for all the responces.

[Mark_3899]

Well, 3 hard rubber tanks submerged in a PhotoTherm water bath. Kodak Flexicolor chemistry. (Dev, Bleach III, Fix) I let my chemistry temp. stabilize at 100*F (really the developer is the only critical temp to maintain) I load my film in SS hangers, put them in an empty tank and put that in the water bath for 5 mins to aclimate the hangers so they don't cause a temp drop in the developer.
3:15 in the developer agitated as I mentioned above. Drain the last 10 seconds of this time.
6:30 in the bleach, same agitation
turn on the room lights
3:15 wash
6:30 fix
3:15 wash
1:30 stabilizer, constant agitation. (don't heat this stuff, there is no need and you don't want to breathe the formaldehyde fumes)
I hang the film by film clips right out of the stabilizer.
The only other thing I'll add is I use an aquarium pump and air stone in my bleach tank for 15 mins just prior to processing. Bleach needs aeration to work efficiently.

I try and save up my color neg film in larger batches to be as economical as possible. I have used the same chemistry for two months with only a floating lid protecting it. When I worked in the color lab I replenished after each process. I just use my small tanks unreplenished until exhaustion. The rule is about 19 sheets of 4x5 for a 4x5 tank. You get two tanks worth of chemistry in a gallon kit. 38 sheets . Hope this helps.

[Mark_3899]

That's true about the bleach, fix and stabilizer, actually bleach can really be used even longer than that, but it's easier for me to change my bleach and fix together after my developer is exhaused so I easily know where I'm at in terms of exhaustion. I also attribute my flawless negs with the meticulous way I handle my chemistry.

[James Via]

Here's a good link to C41 information.

http://www.shutterbug.com/columns/0199sb_inthedark/