Unicolor Drum

[arthur_nyc]

Hello All,

I am very new to 4x5 film and I have just purchased the Unicolor 8x10 drum. I

am wondering the amount of chemistry I need for developing 4 sheets of 4x5? I

will be using HC110 and

D-76. Any dilution rec. would be great. Also will I have to decrease the

development times? I do not have a motorized base and will be rolling the drum

by hand. Any ideas as to how far I should roll the drum? I have read that the

Unicolor base rotates the drum about 1.5 revolutions before going the other

way. If this is true i should have no problem doing this in the slop sink at my

local lab.

Thanks for your help.

Arthur, NYC

[hilander]

Hi Arthur,

 

Check this out:

 

http://www.largeformatphotography.info/unicolor/

 

It should answer most of your questions. There's also tons of other useful info on that site.

[pvp]

Are you the guy that outbid me? :-(

[Monophoto]

The web site that a previous poster linked is an excellent reference and answers your question about quantities.

 

As to how far to roll - if you examine the Unicolor drum carefully, you will find that when the drum is placed on its 'feet', the liquids are in a trough that is separated from the negatives (or paper). That makes it possible to pour chemicals into the spout. Then, when you tip the drum off its 'feet', the liquid then comes in contact with the negative/paper. If you are not using a roller base, the actual rotation is limited by the feet on the drum, and is only about 10-12" from end to end (less than 360 deg rotation).

 

It's true that the roller base rotates the drum more than a full revolution, but you really can't do that if you are merely rolling it on a counter.

[profhlynnjones]

Hi Arthur,

 

I have lots of experience with these and other drum systems going back to the 60's. I like the unicolor system for film and paper.

 

The Uniroller for agitation of drums is the best. Some others have lop-sided drivers thinking that end to end agitation will do a better job, but actually they cause streaking.

 

For b/w developers and chrome 1st developers reduce the development time by 15%. For all other solutions, keep them the same.

 

For both film and print processing, fill the tank with water at 1F degree warmer than than the developer (this will temperature control all of the film, reelsl, and drum and will pre wet the films for more accurate timing). After 1 or 2 minutes fully drain the water and start the development. None of the other solution temperatures are important, don't worry about them (unless the temp goes up by 20 or so degrees, or down below 65 degrees).

 

You will see the best development you have ever experienced with film. In actual tests in either roll or sheet, a target density of 1.00 +/- .01 to .02 and equivalent eveness will be experienced if your temps are correct. Certain prominent manufacturers state that +/- .20 is an acceptable density variation (a total variation of up to 1 1/3 stops!!), however I think that is horrid. The maximum tolerences should be no more than +/- .04 or .05 and a good drum system will exceed that.

 

Regards,

 

Lynn