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  1. #11

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    Update on the Oriental graded RC paper.

    The dim 11w safelight seems to work ok. There was no apparent fogging from about a minute's exposure for cuting to 4X5 and after exposure it was developed for 2 minutes then stop 30 sec. then rapid fix for 3 minutes. The safelight bulb is 4 feet from the trays. The whites look base white to me. For all it propensity to fog under safelight it sure seems slow when exposed to sunlight in my 4X5 pinhole camera. No faster than the Ilford MGIV, about ISO 6, go figure.

    I was hopeing a graded paper would show less contrast but the negatives look just as hard as the Ilford multigrade material. Must be all that blue in sunlight.

    My next experiement will use a grade #1.5 filter with the multigrade paper to see if that cuts contrast. If that dosen't work I'll re-read Joe Van Cleave's instructions on pre-flashing (thanks Joe) and take a look at his u-tube video.

    Wow! Paper negatives can be complicated!

  2. #12
    Rick A's Avatar
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    Pre-flashing helps tame contrast with paper negatives. You want to give just enough pre-exposure light to barely see any difference in the base white.
    Rick A
    Argentum aevum

  3. #13

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    From Oriental website
    "15W bulbs should be used and Kodak OC or a Ilford S902 Safelight filter are recommended. The safelight should be at least 1.2 meter from the bed of the enlarger or developer. After exposure, be careful not to expose the emulsion side of the print to light.
    Light Source
    In the case of VC-RCII, a tungsten or halogen light source can be used. VC-RC is designed to be usable with a dichroic color head. A magenta light source produces a high contrast and a yellow light source produces low contrast."

    So the conclusions are :
    paper is sensitive purple and yellow that mean red and blue and yellow.
    red safelight is not a good choice because the paper is sensitive to magenta and magenta is not monochromatic like light, magenta is red and blue.
    i think some kind of orange can be a choice for LED safelight, between red and yellow posible to be a gap in paper sensitivity. No idea if green could be a choice for safelight, tests or sensitivity curve could reveal that.
    if you want low contrast use yellow filter, if you want high contrast use red filter, blue spectrum is there as any paper have.

    Variable contrast is a balance between red and yellow light.

    Later edit

    Look what i google

    http://www.orientalphoto.co.jp/engli...hsg/index.html

    Look at sensitivity curve
    Last edited by F4user; 06-19-2014 at 12:55 AM. Click to view previous post history.

  4. #14

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    I wonder if this paper could be similar to the old Kodak Panalure? Made to be able to print color negatives. I have printed color negs on regular B&W paper before. It just took a lot of exposure, 2X~3X the time for a B&W neg and I used a graded FB paper. It worked, just not real well, prints were a little flat on the contrast.

    That was more than 20 years ago and I cannot remember the specific paper I used but I think it was Ilford FB graded, probably grade 3.

  5. #15
    Ken Nadvornick's Avatar
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    Red LEDs almost always require additional filtration to screen out minute spikes of blues and greens. I have been advised by someone working in the industry that these non-red colors can be caused by dopants that are introduced during the manufacturing process. The filter material of choice is Rubylith red masking film.

    To check your own red LEDs for unwanted emissions, darken the room completely, turn on the LEDs, and observe their light as it reflects off the recording-side surface of a common CD or DVD disc. Look carefully for very faint non-red bands of color alongside the dominant red reflection.

    When I performed this check on my own 635nm red LED bulbs I observed both faint blue, and fainter green, color bands. When I interposed a small sheet of Rubylith between the LEDs and the DVD, the blue and green bands disappeared from the reflection.

    My red LEDs are now covered over with a single Rubylith sheet. I have performed the pre-flash fog test using Ilford MGIV paper in five minute increments out to 60 minutes total, with no sign whatsoever of fogging. Without the Rubylith the same paper showed minor fogging after less than ten minutes, as I recall.

    Rubylith, itself being red, passes almost all of the "good" LED light, so there is no noticeable dimming of the safelight.


    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  6. #16

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    Yeah Ken, I tried the CD thing months ago and neither my son or myself could detect any other colors but red. I think the spectral response of this paper goes into the red. I have some 5X7 Arista RC grade 3 paper I have not opened yet, (it was for a different project) and I am going to see how that reacts to my LED safelight. As I noted, the 11w dim red safelight seems to work fine at 4 feet from the paper. It is really dim, even after my eyes adapt.

    Joe Van Cleave uses preflashed Arista grade 2 RC paper and has some really nice work on dispaly. I'll probably wind up going that route for paper negatives. Once I have a system that works for paper negs I intend to build an 8X10 sliding box camera.

  7. #17
    Ken Nadvornick's Avatar
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    Hmm... OK, it was worth the post. One never knows.

    But if you continue to be stumped it might also be worth factoring out the human eye(s) from the testing. You could try two identical sheets of pre-flashed paper in a fog test, both exposed for the same length of time to the red LEDs, but one covered with a sheet of Rubylith. That would give you a result that is independent of any observational error or bias.

    Best of luck...

    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  8. #18

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    @ pen
    what kind of Oriental paper do you have ? Read the label and write here.
    grade 2 RC means so little.
    RC means resin coated and mo more.
    There 2 type of safelight on Oriental specification Kodak OC or Ilford 902 and generic yellow-green
    so the type of the paper is important
    do you read the datasheet ? Below.

    http://www.orientalphotousa.com/msds/newseagull.asp

    Oriental RP-M Premium need yellow-green safelight.
    RP mean resin protected aka resin coated

  9. #19

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    @ F4user;
    I bought the "Seagull RP-M Premium M2"
    For some reason my box of factory sealed 8X10-100 sheets had no data sheet packed in it.
    So.....I checked the 'specifications' part of the B&H sales listing. I noticed that the safelight listed for my type of Ilford paper was the same for as for this paticular Oriental paper, "A Kodak OC or Ilford S902 safelight filter is recommened"

    Now here is where it gets tricky and my human reasoning failed me.

    Says me to myself; "I've no idea what a Kodak OC or Ilford S902 is or looks like but I've been useing this LED thing for 3 years with my Ilford paper and cannot even make the Ilford paper fog no matter how long I leave it out."

    Therefore.

    "If my Ilford paper calls for safelight "X" and it will not fog with my LED set up, then this Oriental paper that also calls for safelight "X" will be OK with my LED lights."

    That reasoning has proved faulty.

    I have also learned that good safelights cost a rather a lot of money, at least what I call a lot of money. Also, as I said, the dim bulb (the 11w safelight, not me) apparently works OK even if not specifically recommened for this paper. I see no trace of fog in the samples I've run so far.

    Thanks everyone for all the input. All of this started because of looking for less expensive alternatives to film for 4X5 and 8X10 cameras. As mentioned I've seen the work done by Joe Van Cleave and read over his descriptions of how he works. This is all an attempt to tame the contrast of paper negatives and even be able to capture a few clouds in the sky portion of the pictures. When I have time, in the next few days, I intend to try 'pre-flashing' this paper, running a test to see how long the optimal time will be.

  10. #20

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    @pen
    You have not answer to the question >> Have you read datasheet from my link ?
    Anyway, for your convenience i made for you a screenshoot.
    Do not trust "copy-paste" skills of a B&H bored employee
    In the specs it clear say green-yellow safelight so your assumption was totally wrong.
    My initial guess for orange colour was more close to Oriental specs.
    The paper seems to be sensitive to red spectrum even is not clear stated.
    On any manufacturer specs they say : "reserve to change without notice" and that is based on our money.
    If you prefer LED light you must change the colour - orange or yellow ( yellow , must be tested ) or ( orange should work ).
    Check LED manufacturers specs for wavelength. I think 600 nm should be fine for all Oriental papers. Look at 600 nm colour

    Click image for larger version. 

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    Later idea
    If you have a prism, make a exposure with white light through prism
    This clearly will solve the riddle.
    Last edited by F4user; 06-20-2014 at 01:59 PM. Click to view previous post history.

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