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  1. #1

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    RA-4 filter settings, driving me nuts!

    Hello everyone i have started RA-4 printing today, forgot i have had a box of fuji crystal archive in my freezer for a while! i am also getting some paper off john from here soon the problems are as follows: i am using kodak colour plus iso 200 negatives, developed at the lab on a minilab machine. every enlargment i make has some colour cast, with nothing in between. 50Y 30M has an orange cast. Remove the 30M and its even worse! (50m, 130Y gave me the best results i have had, with a slight green cast, but the whites sucked!). i am using the fuji paper.
    i have tried so many combinations, even adding some cyan into the mix (making the cast redder). I am not sure where to go from here, i cant keep experimenting blindly, otherwise it will be a real waste of paper! I am using a safetorch, which i do not think is the problem, i placed some paper in the developer, then exposed it to the safetorch directly, which took around 2:30 minutes before i saw the faintest trace of fog, and i do not shine it at the paper directly while processing, the room is also light-tight. i did let the paper defrost overnight before printing.

    do you guys reccomend any settings to start with? I am using the kodak chemicals, first at room temperature, then at 38C (heated by floating bottle in water, thermometer handy). the 38C did nothing but decrease the time it took for the print to develop, room temperature being left about 1:30 minites before stop, then blix. any ideas as to what to do next? i did not add starter, i used the replenisher straight (for room temperature use)

    any filter settings you guys would reccomend would be brilliant

    many thanks

  2. #2
    Greg Davis's Avatar
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    Do you have a set of Kodak or Lee print viewing filters? They will help you determine what filtration to use to correct for a color cast.
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  3. #3

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    Ditto on viewing filters. What are you using for viewing lights?

  4. #4
    Mike Wilde's Avatar
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    Learning to print RA-4 is never easy to start with. Success will take everyone much longer than with b&w. I would suggest starting with 4x5" small prints as an economy measure to get you started.

    Always dry your test prints; wet they have a bluish cast. There is a small hair dryer on its own hook on the wall of the darkroom just for that task.

    Do you have any printing guide resources?

    A ring around poster that shows what the 'correct filtration' looks like, and what the print looks like with 20 too much of this, 20 too little of that, and exposure under and over by a stop or two is a great one to start with.

    The next helper is a set of print viewing filters, which helps you to see what direction to takes for the next filtration setting. You usually can tell the cast by eye, but the how much to correct is more challenging at first i.e 'it is off, but by how much'. I also have a hard time seeing the difference between a green and cyan cast.

    I am presuming you are using a dichroic enlarger. I began with colour printing (ep/2, quite a while ago) with discrete acetate filters, and needed to recompute exposure with each filter pack change. Dichroics do change the light density, hence time needed for equal exposure with filtiration changes. A simple exposure monitor, short of a full analyser can help with this. Use a diffuser under the lens to bring the scambled image closeer to grey if you are not sure of the colour response of your exposure meter.

    Dialling in Cyan , when added to existing M and Y filtration neutralized the Y and M, and gives you the first clue. In RA-4, exposure largely sets the red levels in the print. Magenta balances the green, and yellow balances the blue. I have a drawing of a circle in my darkroom, segmented up six ways with the sequence of a the primaries and thier subtractive opposites to remind me.

    The first thing I do whan printing RA4 with a new pack of paper or batch of chemistry, is to pull out my 'betty' negative and print it.

    It is a head and shoulders picture of my wife standing in our front yard holding a colour swatch page from an old Kodak darkroom Datatguide, beside one ear, and a 8x10 grey card beside her other ear. It was taken on a mostly overcast day, so there are no shodows on the cards or her face.

    The first thing I do when printing this is work on making the grey card grey, exposure wise, and then use the colour of the colur swatches, in the picture, compared to the colour in the book on the shelf to guide me for filtration.

    You may have old paper that has 'crossed curves'. The colur balance in the highlights is no longer the colour balance needed for the shadows. You do not tell us how long 'a while' is for the paper you are printing on. Colour paper only slows down it's shifts in the freezer; they do not stop. As most Kodak paper ages it looses red sensitivity, and needs more and more M and Y to counter this. I have printed 'normal to me' Kodak negatives with as much as 80M, 120 Y to get a good balance with this 6-8 year old paper.

    Usually for my filter packs for most Kodak and Agfa film the Y is about twice the M settings. Startring with 50M, 80Y is my defualt beginning filtration if I have no better starting filtration data.

    Running the chemicals at 38 versus room temperature should see the image develop faster. It will also affect the needed filter pack. No starter is fine; if you re-use the developer, as happens in a tray development situation it's pack settings will change gradually with time, but not enough to worry on what you can put though it in one night's work.

    Get used to working in the dark most of the time to see if the 'safe torch' is really all that safe. I use glow tape on the corners of benaches, sinks, etc to orient me, and havea place for everythin, and nothing else in the way when I start RA-4 printing.
    The paper, once it has been exposed is more sensitive to shifts from the safelight than unflashed paper.

    RA4 development is a develop to completion process. There is no need to judge how 'developed' the image is and pulling it early. If that is what you are doing to control density, expose less, and then develop all of them in the dark, face down, for whatever your completion time is

    I hope these comments help with your bring all of the variables that need to be controlled in RA-4 closer to being in control.
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  5. #5

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    I am defintely going to look into getting some viewing filters i decided to put the fuji away (is about 1.5 years old, was stored in "temperature controlled conditions" by the previous owner, then passed into my hands 2 months ago (box was still sealed)m and been in my freezer ever since, defrosted once to move house. I took out the aincent tetenal paper (is over 10 years old, ill hazard a guess, "cold stored" all its life (not frozen by the sounds of it), but i got 300 sheets for peanuts at 3.5x5 in, and they are better for practice. the results were as follows: M65 Y70, match what the print should be. the slight orange background due to the paper's age is no bother, this is only noticable on the borders and slightly affect the print! the blacks are not blue or dark red, but the proper black. the yellows and reds are how they should be and the cyanish background of the train floor (is a photo of a person) has come out well too not EXACT but hey, its a start!. developed at room temperature. M60, Y65 was required when doing at 36C (heated by floating the bottle in a sink of hot water, and measuring it, then quickly put into the tray. the blix stayed at room temperature, that being non critical with a stop inbetween. the higher temperature 1. developed the image quicker, 2. reduced the visability of that "old paper" yellow-orange cast and 3. produced richer colours, a tray time of 2 minutes.
    I should try 4 minutes, ra4 standing for "rapid access 4 minutes". prints viewed inside the kitchen with natural light, and then under a flurecent light.
    done in the dark.
    doing it with the safetorch (direct exposure to it 5cm away) (4 tries) resulted in the following.
    1. 10 seconds exposure to the torch, no change.
    2. 20 seconds exposure to the torch, no change.
    3. 30 seconds exposure to the torch, a magnita cast appearing.
    4. 40 seconds exposure magnita very strong over the image centering where the beam was strongest.
    as for the fuji, it only took 20 seconds exposure to the torch to produce the magnita cast, and from doing research the LEDs are only "centred" onto 590nm with a bit either side. that is probably half the problem i was having with the fuji paper.
    it warns in the instructions to only use it for a few seconds, and not directly which i was doing flicking it on every now and then for a second or two to find my tongs etc!
    the print viewing filters are next on my purchase list! got to wait until i get paid however
    the crystal archive settings seemed completely different, and i will not use it until i have completely got the hang of it, and got some more paper comming soon
    thanks for mentioning that ra4 is developed to completion, i was concerned about overdeveloping by leaving it in the tray too long!
    EDIT: i will keep processing at 36 degrees, the colour balance is much better overall! thanks to Ian C for reccomending it!
    Last edited by jm94; 05-27-2011 at 12:27 PM. Click to view previous post history.



 

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