Trying to find some information for dialing in neutral density to my new (used) Omega D5XL color head.

Steve Anchell's book on variable contrast printing says to dial in cyan for neutral densisty. I looked up a thread in the archives and saw recommendations to equal amounts of magenta and yellow.

Which is correct, or, like many things in life, are both correct? Is on method better than the other? Is there any rule of thumb for how may units to dial in to slow things down a stop?

I am trying to calibrate filter settings and other things, so I may be posting a few more questions in the next week or so. Thanks is advance for everyone's help.

-- jennifer (photomatic99@yahoo.com), April 19, 2002

Answers

Cyan filtration removes red light, to which the paper has very little sensitivity. So cyan filtration will not make a significant difference in the exposure, but will make the image harder to see for dodging and burning purposes; so I would not recommend using the cyan filter.

In theory, magenta and yellow in equal amounts should give neutral density for black & white paper. 30 points of each will equal one stop of exposure. I say in theory becuase in reality, the speeds of the different emulsions are not identical, so dialing in equal amounts can result in slight shifts of contrast. It's not much, but for critical work, it may make a difference.

David Carper ILFORD Technical Service

-- David Carper (david.carper@ilford.com), April 19, 2002.

Is there a 6x6 neutral density filter that can fit in the slot on the bottom of the mixing box of the Omega 5 DXL?

-- jennifer (photomatic99@yahoo.com), April 19, 2002.

There's usually a chart of VC filter combinations packed in the paper packaging; in the Ilford chart both single-filter contrast settings and two-filter settings are shown. The two-filter contrast settings in effect add ND so that exposures (theoretically) remain constant. If you don't have the little paper from the box the info can most likely be found in the appropriate paper manufacturer's web site.

Of course in this most perfect world it doesn't quite work but it's close.

If you want true ND you'll need to add an ND filter to the light path somehow. This could be as simple as film exposed to around middle grey, developed, and sandwiched with the neg you're printing.

-- John Hicks (jhicks31@bellsouth.net), April 19, 2002.

30Y+30M+30C=1 stop ND

-- Louis Jensen (jenluc@ix.netcom.com), April 20, 2002.