Safelight fog is evident in highlights first. It will grey whites in black and white also as those are the areas most susceptible to increased exposure .
Well done BMbikerider to have solved the problem. I too have a DUKA and think the mechanical shutter around the bulb is the weak point. It is a fairly flimsy bit of kit and can easily get damaged under constant movement.
The Colourstar 3000 analyser instructions say to cut out the light totally when analysing the neg for colour balance but in fact this seems to be impossible as even when the lever is turned to 0 some light escapes the baffle. OK at that very low level the analyser's probe seems unaffected but constantly turning it down to 0 or nearly 0 is likely wear out the baffle mechanism linkage
I find that safelight conditions for a meaningful period will only prevail if the lever is turned down to somewhere around 5. At that level the Colourstar 3000 probe readings seem largely unaffected and it avoids turning the baffle up and down.
As long as you can see to do the basics then the lower the level the better. The possible alternative with a DUKA is to have the level a bit higher but cover the front of the DUKA with a lid of a 8x10 paper box while using the probe
I am sure I have seen some claims that the DUKA is safe for RA4 at levels which practically allow a book to be read but alas I haven't found this to be the case.
Three colour prints and two B&W produced after I 'cured' the safelight problem. The one with the motorcycle was the one which caused the initial concerns, at least now I have grey limestone walls instead of pink/brown ones The filtration was 15m/17.5 Y on a LPL enlarger. Film was Fuji 200 Superia, the print on Fuji Crystal Archive paper was developed in Kodak Ektacolour RA4.
The one with the two boats was processed exactly as the 1st print.
The one with the Old stone bridge was on Agfa Vista 200 (Possibly cloned Fuji 200 anyway) Filtration was 20M/22.5Y. Paper and chemicals as above.
The two B&W prints were taken on Kodak CN400. Filtration was 10m/10y and the paper and chemicals as above.
The camera was a Nikon F4 using a Nikon 28/85 for pictures 1,2,4&5. No 3 was a Sigma 15/30EX @15mm
Last edited by BMbikerider; 08-30-2012 at 02:28 AM. Click to view previous post history.
Very very nice. Congratulations.
Very nice indeed. The tones seem well balanced, the saturation neither too little nor too much. Most pleasing.
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BMbikerider. Well done. The stones are key here and in both the bike with wall and bridge shots they look spot on and every print looks fine
One question and two observations if I may.
Q. What light setting have you used on the DUKA? I note that you had said about 50%. My DUKA 10 goes from 0 to 35 so if yours is the same and I assume that it is, does this mean that you get away with at least 15?
The observations:1. The Y&M settings are lower than I have had on my Durst 605 ever but I have never used the new Fuji CA and OK my enlarger's dials may cover a different range(0-130).
I am interested in these settings as I will need to transfer to the new Fuji paper soon if I continue to do RA4.
2. When you do B&W you might want to consider a standard B&W safelight unless you have at least one or better two spare sodium lamps for the DUKA. The DUKA becomes a good doorstop if the bulb goes and new ones cost the earth. I conserve mine by using an Ilford 902 for B&W
Just a thought
Reply to Pentaxuser.
Yes the 50% setting is when I move the sliding lever into the middle of the scale. My darkroom is unfortunately shared with my motorcycle. I.E. it's primary function is the garage. On the upside, it is quite large, has a water supply and the DUKA is on a shelf about 8 feet away from the enlarger and the light is reflected off the ceiling so the light levels are quite low.
The colour filter graduation on a LPL Enlarger are scaled in Kodak Units which are significantly different from those used in a Durst Enlarger which has it's own scale. The only other make of enlarger that is different was the Leica V35 which has another scale again different to both.
Oh dear, yes I know that DUKA bulbs are now unobtainable (or I have not been able to find a source of supply), but luckily the unit I have was relatively little used before I bought it so should have a good amount of life left before it expires. I know that used units can be obtained relatively easily for around £60 so I may buy another whilst the going is relatively good.
But to conserve the life of the sodium bulb, I do use a an Ilford ceiling hung safelight which takes a normal 15watt bulb, of which I have a good supply.
I also use a wall hung lamp with a 100 watt blue coated bulb that gives off a light which is approx that of daylight, but obviously this is only used for inspection to assess colour balance after the print or test has been washed and dried.
Thanks for the reply, BMbikerider. My DUKA is much closer to the enlarger than yours which I admit I hadn't taken account of but when I get new paper I must try it on a higher setting as I might get away with as much as 10-12 which is a third of the way along the light intensity setting. I do so hate being in the dark, literally and metaphorically
I think the Kodak units cover an even greater range than the Durst 0-130 so you'd think that the equivalent Durst settings would be even lower than your Kodak ones on the LPL?
A puzzle but I can only do a fresh trial if and when I get FUJI CA paper.
The difference between Durst and Kodak units is, I think not a greater range, but a much steeper curve. the settings at zero on both types are where there is no filtration at all.. The LPL goes up to 200 units where yours 'only' goes to 130. However when the Magenta filter is set on 200 when I use Ilford or Kentmere papers, the contrast is supposedly equal to Grade 4.5; whereas at 130 magenta units on the Durst enlarger, will, so I am lead to believe, give a true Grade 5.
The filtration needed to get the B&W prints was 10m/10y, but this seems to be dependent on the age of the chemicals and the replenishment I use. (80sq ins = 10cc of replenisher developer). I bet when I next try to get B&W with Kodak CN400, the filtration will be different. At least it stops me getting bored!
I have also tried to get the equal tone using Ilford XP2 and failed miserably. Incidentally, no way, whatever I do, can I get a proper black, it is always dark brown. Quite pleasing but a totally different filtration setting with loads more magenta.