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View Full Version : Will a Refrema do better than some other C41 processor?



Frank Petronio
20-Nov-2007, 06:02
What's the deal with these? Edgar Praus is putting one in -- will it show in my film? Or is it just that it is a top of the line machine that will make the lab more productive?

David A. Goldfarb
20-Nov-2007, 06:16
Well, for rollfilm, there will be no reels to load or rollers to get dirty. For sheet film, it should be able to handle ULF sizes. I suspect it isn't too hard to order custom frames for less common formats, if there is sufficient demand. You can also program pushes and pulls for easy repeatability. They're neat machines.

Sal Santamaura
20-Nov-2007, 09:35
Edgar's been doing C-41 sheets in Jobo Expert drums on Autolabs, hasn't he? If so, I'd ask him about how even the Refrema results are before using it for color negative sheets, especially those larger than 4x5. I've never seen dipped-and-dunked C-41 sheets come out even. Doesn't mean they can't, I just haven't found anyplace yet that can make it happen.

David A. Goldfarb
20-Nov-2007, 10:27
I've had 4x5", 8x10" and 11x14" E-6 done at Duggal, which uses large dip and dunk machines, and they've come out fine.

Sal Santamaura
20-Nov-2007, 12:15
I've had 4x5", 8x10" and 11x14" E-6 done at Duggal, which uses large dip and dunk machines, and they've come out fine.Yes, E-6 works fine. Frank's question and my reply were about C-41.

bob carnie
20-Nov-2007, 14:53
Refema is top of the line dip and dunk processor.
For C41 with proper replenishment it should be first rate.

For Black and White and Colour Neg we use one shot Jobo process for all chems. But I would not turn my nose up on Refema for C41, I do not like replenished B&W though.

Mick Fagan
21-Nov-2007, 01:12
For dip and dunk processing, the shorter the developing time, the greater the possibility of unmatched developing of some sheets.

I am not familiar with the Refrema dip and dunk machines, however I have worked with three different types and they all have one thing in common, a rack system that lifts, moves along, then dips into the next bath.

With all of the C41 baths I have worked with, their dip and dunk cycle is 3 minutes and 30 seconds and it works like this:-

Film is loaded onto a vertically hanging rack, depending of format size you could have 2 sheets, 8x10 hanging in a landscape format, 4 sheets 5x7 hanging in a portrait format or 8 sheets of 4x5 hanging in a landscape format. These are just three of the racks I have used and are/were the most popular sheet film sizes for C41 when I was doing this.

Once the film is loaded in total darkness, the operator would slide the rack onto the catching hook area.

Once a cycle is completed the rack is lifted vertically, then moved along until it was over the bath, then the rack is lowered into the bath, nitrogen bursts were happening whenever a rack was being lowered, once lowered nitrogen bursts were at set intervals during the entire time the rack is in the bath.

At 3 minutes and 15 seconds the rack is lifted out, it stops for a few seconds then moves and is then lowered into the next bath. This transition from one bath to the next, takes 15 seconds.

With C41 the first bath is extremely short, therefore any deviations can make a difference, especially to density, although these are extremely minor and can and would normally be corrected in printing. These days I assume most places scan, but there are quite a few that still do normal colour printing.

What we found with practical experience in the C41 dip and dunk process, was a major density difference between the bottom two sheets, and the top two sheets on the 4x5 rack. Effectively the top two sheets were pull processed by a of a stop, compared to the bottom two sheets, which had a push of a of a stop.

Often this isnt a problem, but it wasnt great either. Our in-house solution was to simply only use the middle 4 holders for 4x5 and appropriate changes to the other formats.

C41 roll film in dip and dunk is problematic, as no matter what you do, one end of a 120 roll has to get more development than the other end.

With 35mm film this is worse, the film is so long (36 exp) that the film is hung over a roller and weighted with a single double clip. Pretty much like a tie would be draped over a coat hanger. The emulsion is always facing outwards, or should be, sometimes you get confused and the emulsion is inwards facing. Dont ask!

One must remember that with C41 and 3 minutes and 15 seconds development, it can be interesting and difficult to ensure you have consistency with various formats and the amount and way you attach and lower film.

With E6, things are a lot better, the first bath is wider and the film is dipped for 315, gets raised then lowered back into the first (elongated) bath. With the longer first bath times the error becomes what it can/could be in the shorter C41 process.

Now Im not saying dip and dunk is bad, it can be extremely efficient, as well as terrific consistency, but unless it is running with film reasonably constantly, it can be a little difficult to ensure it is bang on the money.

Now a lot has changed regarding film processing machines, as well as the formulae and film makeup. Also I am unfamiliar with the Refrema machine, but the basic concept of dip and dunk developing may be an issue in some ways.

I just thought I would add some of my observations because I know a lot of people only know film-developing machines that they see in the one-hour retail labs. They are invariably roller transport (RT) machines and they have their issues as well, but that is another story.

My personal take on film developing is that the less a film is handled the less it may be damaged.

Mick.

David A. Goldfarb
21-Nov-2007, 07:01
Thanks for the explanation, Mick. I wasn't aware that C-41 would have different problems from E-6.

Mick Fagan
23-Nov-2007, 05:25
David, not a problem.

Mick.

David Vickery
26-Nov-2007, 00:32
To Mick's excellent description I would ad that the dip and dunk machine is much easier to keep clean and has fewer parts to break and maintain than the roller transport machines. It will save the lab lots of maintenance time.

If you have a good relationship with this lab, you can probably discuss this potential consistency problem with them and maybe they could always put your film in the same place on the racks every time. (they would probably have to actually like you to do this for you, though)

IanMazursky
2-Dec-2007, 01:38
From my experience, they must have figured out a way to mitigate the variations in the process.
My lab (LTI in nyc) uses refermas in c-41, e-6 and one other in B&W but I cant remember the manufacturer.

All of my roll (120-220) and sheets are even and consistent. They process hundreds of sheets and rolls a day.
Also most of my clients use them also. I drum scan allot of c-41 and e-6 film processed in D&D processors in sheets and rolls. They are very consistent.

I have had some variations in the past with other labs in nyc. They would not let me in back so i dont know what processors they where using.