Oriental graded RC paper super sensitive to safelight exposure

pen s · Jun 17, 2014

I normally use a string of red LED lights for a safelight. Very bright and easy to work in. With the Ilford MGIV RC paper I've been using as paper negatives there has been no problem at all with safelight fog, even with prexposed paper left out for 10 or 15 minutes. Looking around on the B&H site I found Oriential grade-2 RC paper, 8X10, 100 sheets for $45, that seemed a good price and I had wanted to try a graded paper for paper negatives.

This paper fogged in the safelight, and I mean it fogged fast. Both products technical sheets call for the same color and intensity safelight and I admit the LED's are very bright but the data on the Oriental site does call this paper an extremely "fast" paper. I believe it!

When handling the Oriental paper I have switched to a very dim, 11w red safelight bulb and limited time out of the box as much as possible. However it does take a little time to cut the paper to 4X5 size before I stick it back in the box. I hope this will take care of the fogging problem.

I've used mostly Ilford paper for a long time and had never run across this problem before. I've got a couple of holders loaded and will be able to tell soon if this paper can be used for negatives as I had hoped.

darkosaric · Jun 18, 2014

Do you have other safelight, like Ilford 902? Maybe it is less sensitive to non red safelight?

pen s · Jun 18, 2014

darkosaric said:
Do you have other safelight, like Ilford 902? Maybe it is less sensitive to non red safelight?

I thought about that. B&H has a Paterson unit with a orange/red filter that might work. For right now I've switched to much dimmer light. I hope there is a threshold exposure for the Oriental paper and that the time / intensity of this light won't reach that point.

Busy life but later today I intend to test that hope and see if the paper can be used with my current equipment. Of course I can always find ways to spend more money but the use of paper as a negative is to save money and to make developing easy and comfortable since, at least with the Ilford paper, it can be carried out under safelight.

As they say, stay tuned.

Ian C · Jun 18, 2014

Oriental specifies the amber Kodak OC or the equivalent Ilford 902 safelight filter for all its black-and-white enlarging papers.

http://www.orientalphotousa.com/ns_vc_rcII.htm

F4user · Jun 18, 2014

You can check if your high intensity red LED is phosphor based. Those LEDs produce UV light and is downconverted to visible by phosphor like in a cold fluorescent tube lamp.
Expose a sheet of paper with UV filter over it and process it. If the area under the filter is not fogged that means the led is phosphor based and emit sone UV and is not appropriate to darkroom

Rick A · Jun 18, 2014

If an OC filter is safe then a red #2 filter is also. Red #2 filters are safest of all safe lights, and using a 15w bulb(either color). The caveat with any safe light is distance from materials. I don't think any safe light is safe at distances closer than one meter from work area.

Prof_Pixel · Jun 18, 2014

I found this interesting from the Kodak K-4 Publication: "The “safest” color safelight filter for a particular material is not always the recommended one. For example, a red safelight filter often has less effect on photographic papers than the amber filter listed in the table. However, most workers find that they can judge print density or perform other functions better under an amber light. (So, although it is a slight compromise in protecting the paper from fogging, an amber filter improves working conditions.)"

darkosaric · Jun 18, 2014

Prof_Pixel said:
most workers find that they can judge print density or perform other functions better under an amber light.

I have, and alway had dark red, and my friend had Ilford 902. When I went to his darkroom recently --> I want Ilford 902, much better print judge, at least to me.

F4user · Jun 18, 2014

My darkroom light was green !
Human eye is more sensitive to green and less light is needed to see things.

Rick A · Jun 18, 2014

Modern multi grade papers are sensitive to blue and green light.

pen s · Jun 18, 2014

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!

Rick A · Jun 18, 2014

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.

F4user · Jun 19, 2014

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

Dead Link Removed

Look at sensitivity curve

pen s · Jun 19, 2014

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.

Ken Nadvornick · Jun 19, 2014

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

pen s · Jun 19, 2014

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.

Ken Nadvornick · Jun 19, 2014

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

F4user · Jun 19, 2014

@ 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

pen s · Jun 20, 2014

@ 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.

F4user · Jun 20, 2014

@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

Later idea
If you have a prism, make a exposure with white light through prism
This clearly will solve the riddle.

pen s · Jun 21, 2014

Thank you F4user, yes I'd looked at that page a day or so past and that makes me think the information on the B&H website is in error regarding safelight for this product. The B&H site says OC safelight and I don't thing that is yellow-green, more of a brownish-amber if I recall correctly. Did you notice the last part of the second paragraph? "Be carefull with prints after they have been exposed to see that no futher exposure takes place" This almost sounds like they are saying 'after exposure processing should be done in total darkness.' I have always been told that exposed but unprocessed paper is more sensitive to fogging than unexposed paper right out of the box.

At this time it looks like I can get by with the 11w bulb about 4 feet from the work surface. It looks good at least up to 5 minutes exposure. Last night I ran a preflash time test and will expose that paper today to see if I can cut the excessive contrast with paper negatives.

I think eventually I'll order some Arista grade #2 RC paper from Freestyle and test it. This is the paper used by Joe Van Cleave in his excellant tutorials both here and on U-tube. I'd like to get the paper negative down to a standard procedure that is repeatable.

Then there is always the possibility of just buying some real, 100 ISO B&W 4X5 film. There has to be a first time for everything.

cowanw · Jun 21, 2014

F4user said:
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.

I won't get into whether Magenta has a wavelength all of its own, but I would like to read more about paper being sensitive to it, as well as "Variable contrast is a balance between red and yellow light".
Dichroic filters remove wavelengths of light; Specifically Magenta removes green and yellow removes blue. If white light is not used as a start, and only red and yellow light are used then VC papers (being sensitive to green and blue in everything I have read) won't be much exposed at all.
Perhaps Oriental papers have a different chemistry than other VC papers

F4user · Jun 21, 2014

Agree with blue-green balance of other orthochromatic variable contrast papers.
Bellow is a picture with spectral response of another Oriental paper and wrongly I asume 550 nm is yellow. Yellow is 580 nm centered and graphic below have a slight shift of middle peak to reds.
Topic starter have not clear say what paper is involved.
This is the reason for my statement.

pen s · Jun 23, 2014

So I'm mulling over this whole thread eh? So I sit down and pour a cold one, and as I'm sipping at my beer I start looking at the bottle.

Brown bottle. Kinda amber when you hold it up to the light though. And I start to think, (beer sometimes does that to you) and so I go looking for the LED flashlight and my roll of duct tape. (Also known as "the handyman's secret weapon" for all you Red Green fans).

So I tape the flashlight, a 24 LED model, to the side of the beer bottle, a 22oz. size, using the tape to seal off leaks of white light. And I set it in the space between the towel bar and the wall, reflecting off the ceiling. It was bright enough to see by but didn't fog that Oriental paper, at least not at 5 minutes.

Might make a good emergency safelight. The 3 AA batteries that power the flashlight will last about 3~4 hours and I could always wire in a mini plug socket and power it off 3 'C' cells in a seperate holder.

Now don't start in on me about spectral response and all that other science guy stuff. I practice empirical photography if you know what I mean.

darkosaric · Jun 23, 2014

pen s said:
beer bottle

Wow! This is what I call "look outside of the box" Nice!

Oriental graded RC paper super sensitive to safelight exposure

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