Adox MCP 312 Question
I've recently set up a darkroom and have a question about ADOX MCP 312.
According to the info sheet, 312 without any filter is a grade 2. The problem is, my exposure time for this grade is about 3 seconds, max. It's ever so slightly longer when I use the filters in the colour head for higher grades - and even shorter for lower grades. Can anyone tell me what I'm doing wrong? I should be able to have a longer exposure time, no?
My enlarger is an LPL D6700 with dichroic filters. The aperture on the lens is F11.
I'm processing the paper in Formulary 130, 1:1.
Thanks for any info - much appreciated.
I haven't used this paper but if the results look ok it's probably just really fast, and/or your enlarger is quite bright. You can add some neutral density to increase the times for dodging and burning or to increase accuracy (it's far easier to time, say, a 20 second exposure within a few percent than a 3 second exposure.) Since this is a color enlarger, just dial in equal additional amounts of each color over and above what you use for contrast control, say +20c, +20m, +20y. You can of course use more or less as needed.
Never used this paper but 3 secs is way way too short, especially at F11. Sounds like something is seriously out of place somewhere. Too bright a bulb is the first thing that springs to mind. You might want to check the lens diaphram to make sure it is actually stopping down ? Also how close is the enlarger head to the baseboard... are you doing very small prints ?
When I use my durst 1200 at 8x10" it's 3.7 seconds on F11.
So 3 seconds is possible. As mentioned maybe a less brighter bulb would help you.
I use a 150watt.
Does your enlarger have "light attenuators", that fit into a slot between the light source and mixing box? Some models of Omega enlargers come with several that have different hole patterns(IIRC). These are akin to ND filters to reduce the lamp brightness and lengthen exposure. The alternative is to use a ND filter.
Henry, what's the paper size? When printing on Agfa MCP 18*24cm I get roughly 15s at f/11 with filtering (colour head).
When you make small prints just stop down to the max. aperture. If the time is still too short you may add filters - equal values of CMY are simply a gray filter and prolong the exposure.
Ath - my paper size is 8x10, printing a 6x6 negative. I've read in a few places that stopping the aperture on the lens right down wasn't a good idea - but I'll experiment with the one I've got.
Rick - I'll check to see if the D6700 does have attenuators - not sure that it does, but I'll have a look.
Willie and Bill - yes, a lower wattage bulb might do the trick - I'll check to see what I have in there.
Roger - thanks for the pointer about increasing ND by dialing in equal amounts of CM&Y.
Stopping down a lens beyond f/11 or so introduces diffraction. This gives a slight unsharpness which is completely invisible at the magnification you are using. Stop down and be happy.
Originally Posted by Henry Yorke
I haven't used any "new" Adox/Agfa MCP 312 but did use the original Agfa stuff with a 100W tungsten halogen bulb in a Durst 605 and never got exposures this low for 8x10 and 6x6 negs. I can come close with Kentmere VC Select but at 5x7 and f8 and Kentmere is about one speed faster than Ilford whereas Agfa as it was and I presume Adox MCP as it is now and Ilford are about the same speed.
It tends to suggests there is something different about the OP's set-up. Not much margin for dodging. Most 80mm lenses go to F22 so only about 12 secs max and don't most 50mm lenses only go to f16?
5x7 prints' exposure would be very short indeed with no room for dodging at all.
Stopping down might solve the issue but I'd be inclined to look further for a solution.
Try a neutral density filter for on-camera use. That could give you a few stops depending on what neutral density filter you get. Usually they range from two stops to ten stops.