Ra4 safelight

[pentaxuser]

Just out of curíosity, koraks what was your safelight and what were the settings you used? By settings I mean the same kind of info that BMbikerider has given?

Matt, again out curiosity have you ever used a safelight for RA4? If so what was it and like koraks can you give similar details

Thanks

pentaxuser

 

[MattKing]

Matt, again out curiosity have you ever used a safelight for RA4? If so what was it and like koraks can you give similar details

Thanks

pentaxuser

Only in a small commercial lab - and only immediately outside the area where the several hundred foot rolls of paper were actually opened and loaded into the printer.
I do have a fair bit of experience though with implementing the Kodak safelight test, with a variety of materials: https://www.kodak.com/content/products-brochures/Film/KODAK-A-Guide-to-Darkroom-Illumination-K-4.pdf

 

[mshchem]

I started when I was a kid with a Kodak beehive style darkroom lamp with a #10 Wratten filter. After you were in the dark for 5 or 10 minutes you could see a faint glow if you stared right at the lamp.

No such thing as safe visible light with the latest stuff from Fujifilm.

Still if you are agile and quick you can get away with it.

Don't be shocked if you end up chasing your tail.

 

[koraks]

Just out of curíosity, koraks what was your safelight and what were the settings you used?

The safelight is 590nm LED, this is comparable to the Heiland units.
The 'setting' is not something that has any meaning outside my particular setup. It's pwm-ed at a duty cycle of 1/255 and these strips are fed with 24V IIRC (although I may have connected two 12V strips in series; I did that on one of the channels but would have to look up which). Again, all this doesn't matter - what matters and what I tried to demonstrate (and I think successfully so) is that a test that shows when the whites fog to cyan is not indicative of the truly safe level of a safelight.

Also, you'll notice a link in my post to a rather lengthy blog I posted that gives detailed information about the safelight setup; that blog in turn links back to an earlier blog where I discuss the light fixtures I built of which this safelight arrangement is part. If you're interested, feel free to give those a read.

Still if you are agile and quick you can get away with it.

Yes, a dim light for a very short duration can be OK; it's essentially what @DREW WILEY also explained earlier in this thread. That's one of my conclusions at the end of my blog. I also explain there why I find that of limited practical value.

 

[pentaxuser]

Only in a small commercial lab - and only immediately outside the area where the several hundred foot rolls of paper were actually opened and loaded into the printer.
I do have a fair bit of experience though with implementing the Kodak safelight test, with a variety of materials: https://www.kodak.com/content/products-brochures/Film/KODAK-A-Guide-to-Darkroom-Illumination-K-4.pdf

Thanks. Do I take it that this included RA4 materials and what was the safelight you used when implementing the Kodak safelight test for such materials

pentaxuser

 

[pentaxuser]

Thanks Koraks Al I can say is that unless BMbikerider has deliberately lied about his set-up and I think we can dismiss that out of hand or he was mistaken in what he believes to be the results of his tests then all we can conclude is that in the set-up he has he gets satisfactory results from his settings with the Wotan DUKA light.

On that basis I can see no reason why anyone else with a DUKA light cannot replicate his settings of a variation thereof depending on the dimensions of their darkroom

Primarily or so it seems to me to be the case, this information is designed to be helpful for anyone such as the OP who is considering trying RA4 printing but wanting to be able to see where they are going in their darkroom when processing RA4 or in the OP's case has discovered that what they have is not quite what a DUKA can give them due to the light's wavelength problem

It was never designed to persuade those for whom total darkness is perfectly suitable that a DUKA is worthwhile. If it was designed for the purpose of changing minds then Photrio will prove to be "stony ground" on which to scatter any seeds in the hope of a harvest

pentaxuser

 

[koraks]

@pentaxuser I feel you need to re-read posts 48 and 49 again, until you understand the implications.

The margins for using a safelight with color are really, really narrow. Post #48 demonstrates primarily how easy it is to misjudge this and lure oneself into a false sense of security. Post #49 is an attempt (apparently in your case, so far a failed attempt, frustratingly, although I personally think the example images are crystal clear) to explain why this is the case.

 

[pentaxuser]

Before I comment on your comments in perhaps a later post can I first ask a few questions:

1. Your safelight is an LED operating at 590 nm The DUKA in question is a sodium light operating at 598 nm You have already said that an LED ( the OP's in this case) operating at 580 nm will not work and clearly it does not as the OP testified to So is there any possibility that a DUKA sodium at 589 nm might be sufficiently different to your LEDs at 590 nm to account for the differences in your tests compared to BMbikerider's tests?

Turning now to the respective illumination levels between your light and his, can you be sure that his cannot be set to an illumination level that gives him his 2 mins or very close to that and still allow him enough light to see his way around?

I ask these questions because clearly your tests and his both of which I have looked at are clearly different and I can see why anyone with your results may well conclude that ant safelight for RA4 is unsafe except for a few seconds which I agree are so marginal as to be virtually unusable

So far all we can conclude is that your tests result in different outcomes from BMbikerider's tests and anyone examining yours and his respective post can see

What I am trying to establish is what may be the causes of those different results

pentaxuser

 

[koraks]

So is there any possibility that a DUKA sodium at 589 nm might be sufficiently different to your LEDs at 590 nm to account for the differences in your tests compared to BMbikerider's tests?

BMbikerider's own test demonstrates the DUKA fogs RA4 paper. The fog on his test strips matches that on mine; it's both the same cyan. It seems that my 590nm LEDs do the same thing to RA4 paper as his 589nm LP sodium light. It would of course be sheer magic if this weren't the case, so practice at least time does live up to simple logic.

Turning now to the respective illumination levels between your light and his, can you be sure that his cannot be set to an illumination level that gives him his 2 mins or very close to that and still allow him enough light to see his way around?

Yes. At that level, there is an effect on color balance. The result is a cyan cast (which in fact is partly also a crossover - even worse). That is what my post #49 addresses.

clearly your tests and his both of which I have looked at are clearly different

They are not different. In fact, they confirm each other extremely well. We both show that our respective safelights fog paper white to cyan given enough exposure.

Then I did an additional test that @BMbikerider did not do, and that test is crucial in understanding why these safelights aren't so safe as you and him assume. I used an exposure that does not produce a cyan cast to the whites, but that exposure level does in fact affect the color balance of the print within the borders. This shows that any conclusion along the lines "x minutes does not give me cyan borders, so it's safe" is massively unreliable.

So far all we can conclude is that your tests result in different outcomes from BMbikerider's tests

No, we cannot.

Since we're asking questions of each other for clarification, perhaps you can answer me this one: can you please explain to me in your own words what the two experiments I posted in #49 are about and what information follows from them? And once you've done that, could you please explain how that information relates to the experiment reported on in #48?

 

[MattKing]

Thanks. Do I take it that this included RA4 materials and what was the safelight you used when implementing the Kodak safelight test for such materials

pentaxuser

No.
Those RA4 materials were the materials available decades ago, and actually the handling goal was to not expose those relatively very expensive rolls to any safelight exposure - the safelight was there as a fully emergency-only backup.
And I wasn't the one who did the sort of thing as safelight tests in that lab.
My experience with the Kodak safelight test is with a variety of other materials, even though the test is designed to be used with colour materials as well. The experience provides me with knowledge about how to test safelights and materials - which is much more complex than many understand - and how to interpret results.

 

[geirtbr]

I use cheap yellow led 3w or 5w e27, in kodak lamp. I wrap some blank orange color film around it, and put kodak OC filter on top, and point it to the roof. I have also tried ilford 902 filter and it seems to work okay, but I keep that lamp a bit away as it is not as good fit as the kodak one. I try to limit myself to 1 minute of exposure for the paper. Seems to work, there is no cyan staining on it.

 

[mshchem]

1/4 inch Masonite is an absolutely safe safelight filter.

 

[koraks]

Seems to work, there is no cyan staining on it.

Have you done a color shift test, where you expose one half of the paper to the safelight and the other not, and then print an image on the entire sheet?
As shown earlier - several people seem to erroneously believe that a test that shows cyan fogging of the whites is reliable. It very much isn't.

 

[pentaxuser]

No.
Those RA4 materials were the materials available decades ago, and actually the handling goal was to not expose those relatively very expensive rolls to any safelight exposure - the safelight was there as a fully emergency-only backup.
And I wasn't the one who did the sort of thing as safelight tests in that lab.
My experience with the Kodak safelight test is with a variety of other materials, even though the test is designed to be used with colour materials as well. The experience provides me with knowledge about how to test safelights and materials - which is much more complex than many understand - and how to interpret results.

Thanks Matt What you have said is all about your experience and that's fine but I am unsure how this helps with any kind of resolution/reconciliation with whether the Wotan DUKA is a safe light for current RA4 paper

pentaxuser

 

[pentaxuser]

BMbikerider's own test demonstrates the DUKA fogs RA4 paper. The fog on his test strips matches that on mine; it's both the same cyan. It seems that my 590nm LEDs do the same thing to RA4 paper as his 589nm LP sodium light. It would of course be sheer magic if this weren't the case, so practice at least time does live up to simple logic.



Yes. At that level, there is an effect on color balance. The result is a cyan cast (which in fact is partly also a crossover - even worse). That is what my post #49 addresses.




They are not different. In fact, they confirm each other extremely well. We both show that our respective safelights fog paper white to cyan given enough exposure.

Then I did an additional test that @BMbikerider did not do, and that test is crucial in understanding why these safelights aren't so safe as you and him assume. I used an exposure that does not produce a cyan cast to the whites, but that exposure level does in fact affect the color balance of the print within the borders. This shows that any conclusion along the lines "x minutes does not give me cyan borders, so it's safe" is massively unreliable.


No, we cannot.

Since we're asking questions of each other for clarification, perhaps you can answer me this one: can you please explain to me in your own words what the two experiments I posted in #49 are about and what information follows from them? And once you've done that, could you please explain how that information relates to the experiment reported on in #48?

We are getting close to or have maybe reached a "last man standing " contest in this thread. My experience in RA4 printing wit a DUKA light was much the same as BMbikerider. The difference is that I may have been using pre-digital paper as I declared although I cannot be sure that it definitely was. BMBikerider is fortunately a current user of RA4 and has posted his results and conclusions I see differences in those results and conclusions from yours

What conclusions others reach is for them However they deserve to see what the differences are, That was my motive in pursuing this. All of which was prompted by simply trying to place before the OP who seems to have stopped visiting us what is the range of experience on attempting RA4 with a DUKA safelight and offering him a solution that allows him or any other user who wants to see what he is doing when processing RA4

As he, the OP, appears to have ceased to visit us then there is little point in continuing this thread on my part

pentaxuser

 

[MattKing]

Thanks Matt What you have said is all about your experience and that's fine but I am unsure how this helps with any kind of resolution/reconciliation with whether the Wotan DUKA is a safe light for current RA4 paper

pentaxuser

It helps you understand how to test the safety of any safelight, and it helps you understand how to interpret the results of any test you perform.

 

[koraks]

his results and conclusions I see differences in those results and conclusions from yours

Can you please specify which differences you see between his tests and mine? I know how our conclusions are different, but perhaps the penny will drop with you once you start actively thinking about what differences you think you see. Perhaps you then recognize that the differences you perceive mean something different than you now believe they do.

I'm trying to make you understand because I doubt you're the only one struggling with this. Apparently the concept of cumulative exposures is more challenging to grasp than I had anticipated. Since I'll write about it again in the future, it would be valuable to understand how people might miss the point. It'll help me put it more clearly next time.

 

[pentaxuser]

Well, koraks, you did make your point clearly in that your tests gave different results than BM bikerider's and you could see a shift to cyan in his 2 mins where I could see none. Nor for that matter could I see anything wrong with his "bee on a thistle" picture. You have made no mention of this picture but as it was done under what you appear to know as unsafe safelight then I assume that there is a cyan cast in his "bee" picture that you can see

I regard the picture as an OK picture but you may not. Again in the past what I see as OK you do not and I gave the example of David Lyga's negative that he developed and printed as did you when he sent the same negative to you. You saw colour cross over where David Lyga and I, did not. In my case, I had to base my judgement on what were scans of the prints of course

Returning now to the orins of the thread, the OP seemed desperately disappointed that his LED safelight produced what he described as excess blue which he was able to correct with filtration but which in fact may have been a cyan shift. Pity that we did not see his before and after shots and further pity that no-one( me included) asked him to show us the pics. Instead he very quickly was told in what I felt was a no uncertain manner that it was total darkness or nothing which must have come as shock given he had hopes that he had an LED safelight. At that point as my contribution to the thread I felt it was worthwhile to tell him that the Wotan DUKA ,at least in my case and one other case, namely BMbikerider's case may offer a solution

From my dissension to what appears to be "the norm" on Photrio of total darkness or nothing and offering the DUKA sodium light as a possible solution has stemmed virtually the rest of the thread to this point

A problem existed and was presented to us by the new OP for which he was asking for a solution. He was given 2, one of which was mine and BMbikerider's in the form of being able to use a DUKA at a low level which was "safe" as far as both I and BMbikerider were concerned In the latter's case he presented his evidence including a picture

It is for the OP or anyone else to look at the evidence and then decide if they see a shift to cyan which make their RA4 prints acceptable or not to themselves and those to whom they present them for viewing

It boils down to this from my viewpoint : Is there a scientific, measurable absolute in terms of where a colour cast/ colour crossover begins? Yes there might be.
Is there a level at which a DUKA safelight can be used which is practical in the aspects of sufficient illumination to process RA4 without bumping into objects and resulting in an OK print which avoids the persistent feeling of Ra4 printing being an uncomfortable experience. Yes in my book there is and BMbikerider's evidence points to that in my opinion

It doesn't in your opinion and in the opinion of some others here. Might such standards be of a more exacting and, dare I say it. a more absolute kind than most viewers of colour prints would apply? I believe that to be also possible

pentaxuser

 

[BMbikerider]

Firstly I want to stress there there is no shift in the colour on the ORIGINAL 2 min exposure test strip - I have it in my darkroom. There is an apparent change, however but that is not even all over, but this I will suggest is entirely down to a colour shift as a result of having to use the flatbed scanner on a low res scan which I find does not always reproduce accurate colours. If you look at the unexposed strip that has a slight colour shift as well! It is better to true than to falsify the results. The original was pure white as per the unexposed test strip.

Also anyone who has had to perform comparative tests during their working life will be aware that you have to have a control samples to compare like for like, one against the other, in similar conditions. In this case there were none. So Koraks comparison with mine is about as useful as a chocolate teapot! It may be accurate for the condition and location the test was done.

In addition, unlike me he does not give detailed information about the darkroom size and set up, the type of lamp that was being used, was it a DUKA? If so what setting was it adjusted to and how close was he to the source of light and was the light diffused.
His examples and written answer only indicate to me that these facts were not considered before attempting to rubbish my impromptu example, and I can only think it was done to show how good he is and is always the one to be believed - no one else.

Mr Koraks is so convinced in his opinion that he is right and no one else has that insight. It is just possible that he may be wrong. I know after over 3 decades of colour printing what I can and cannot do, and what light I can use in the darkroom when colour printing, so please give me some credit in that I may also have a little skill and knowledge and I could just be right.

 

[koraks]

@BMbikerider just do the same test I did. Expose one half of a sheet for 2 minutes to your DUKA safelight, mask the other half so it doesn't see any light whatsoever. Then print an image onto the entire sheet - that very same sheet. The borders should be white all around, but that's irrelevant. Look for a difference in color between both halves of the image.

The test you've done so far says very little, and the thistle print says nothing at all about the safety of your safelight.

 

[MattKing]

@BMbikerider just do the same test I did. Expose one half of a sheet for 2 minutes to your DUKA safelight, mask the other half so it doesn't see any light whatsoever. Then print an image onto the entire sheet - that very same sheet. The borders should be white all around, but that's irrelevant. Look for a difference in color between both halves of the image.

The test you've done so far says very little, and the thistle print says nothing at all about the safety of your safelight.

To make the test even more comprehensive,
Expose one third of a sheet for 2 minutes to your DUKA safelight , mask the other two thirds so they don't see any light whatsoever. Then print an image onto the entire sheet - that very same sheet. Then cover the third that already received a 2 minute safelight exposure and the middle third, and expose the remaining one third to a different 2 minute DUKA safelight exposure.
What you will end up with is a print that shows the effect of pre-print safelight exposure, print with no safelight exposure, and post-post-print safelight exposure.
If you see any difference in colour or density amongst the three portions of the image, your safelight is not safe for a 2 minute exposure duration.

 

[mshchem]

FROM FUJIFILM SPEC SHEET.

QUIT ARGUING THE OBVIOUS. IF YOU CAN'T AVOID IT USE A REDICULOUSLY DIM SAFELIGHT. DUKA OR ANY SODIUM SPECTRA LIGHT WILL GIVE CYAN IN THE FINAL PRINT. MAY NOT BE VISIBLE IN THE BORDERS, BUT WILL BE IN THE PRINT.

Handle in total darkness. If safelight use is
unavoidable, observe the following precautions.
 Expose paper no longer than 1 minute to light
emitted through two Fuji Safelight Filter No. 103A
(or Wratten Safelight Filter No. 13) in a 10 watt
tungsten lamp safelight located at least 1 meter
from the work area.
 Safelight filters fade with extended use and need
regular checking. Replace when paper fogging is
detected.
 Exposed paper is susceptible to safelight induced
sensitivity increases in the exposed area. For this
reason, exposed paper should be subjected as
little as possible to safelight illumination.

 

[mshchem]

Sorry I snapped

 

[BMbikerider]

@BMbikerider just do the same test I did. Expose one half of a sheet for 2 minutes to your DUKA safelight, mask the other half so it doesn't see any light whatsoever. Then print an image onto the entire sheet - that very same sheet. The borders should be white all around, but that's irrelevant. Look for a difference in color between both halves of the image.

The test you've done so far says very little, and the thistle print says nothing at all about the safety of your safelight.

You have missed the bleedin' obvious, where, I did point out in that comparative tests cannot be carried out to achieve accurate and worthwhile results unless the conditions they are done in identical or very similar circumstance's. This is why I made it clear what my setup was. You challenge me to do the same test as your self but you do not give any parameters where I can even get close to the setting you used. You do not say what setting your Lamp is. How far away from the paper the lamp is. Is the light diffused? The colour of the walls will also have a bearing on the result

You seem to be so entrenched in your conviction that you are right and should not be challenged. You cannot, or will not, accept any one else's opinions or findings. Other than your own estimation it is a case of my way or no way!

The original question posted my Markpot has had few responses which were only negative results from the other contributors to the forum, is that the way to treat a new joiner to the forum?

Yes, I have no argument over the fact that if the light is too bright it will cause problems of cyan casts, which is why I have the light on my lamp turned down to a level where I have a reasonable window of time where I can work and see what I am doing, It ain't rocket science is it.

I still reiterate that over my experience with a DUKA I have NEVER had a problem and making good colour prints is absolutely possible without all the hand wringing and worry bead overuse about colour casts. I have close to 100 mounted prints previously entered in competitions and were reasonably successful. The ones that were not non were criticised for 'odd' colour casts.

If the DUKA was a failure and didn't work, it would have been dismissed from day it was introduced however it wasn't and soldiered on until the common demise of colour printing. I don't know how many were made during the time it was available new, but judging be the number that are still available 2nd hand there must have been many, many thousands.

As for dark room working in very dim lighting, it makes life so much easier than fumbling around in total darkness. So you believe what you wish and condemn equipment out of hand whilst I will continue to use it quite successfully.

 

[koraks]

The reason why I suggest you do the test I suggested is to get rid of the comparative aspect. I had anticipated you would have been able to follow the same deductions I made, but apparently, they're too abstract or I didn't manage to word them in a way that you were able to follow. This must at least in part be due to my inability to express myself as clearly as I see it, since @pentaxuser is struggling with the same issue.

As to the testing parameters, here's what I suggest:
* Leave your DUKA at the same setting you currently have it at.
* Perform the safelight fogging step in the same spot you did it for the test you posted earlier.
* Use a 2-minute safelight fogging exposure; the one you claim (and I accept; you're in a better position to judge your own strips than I am and scanning does present its own problems) does not quite give a cyan cast on the white borders.
Otherwise, perform the test as I indicated in my earlier post (safelight expose one half of the sheet, not the other, then expose an image on the entire sheet) and optionally with the additional post-flash step recommended by @MattKing, although in my experience, there's very little difference between pre- and post-flashing color paper.

This test demonstrates how cumulative exposure works, which is the same principle applied in B&W printing when you 'flash' the paper. With B&W printing, this affects contrast, only, but due to the nature of color paper, it also affects color balance and crossover (since highlights are affected comparatively strongly). The test you've done so far does not take into account the principle of cumulative exposure. As a result, it seems that you're not yet aware of how profound this effect is.

You seem to be so entrenched in your conviction that you are right and should not be challenged. You cannot, or will not, accept any one else's opinions or findings. Other than your own estimation it is a case of my way or no way!

I understand it's very difficult to remain polite and constructive if you're absolutely convinced you're right and that the other person is wrong. If there's one thing we share in this thread (apart from our interest and appreciation of color printing), it's this conviction. Still, I think it would be wise for the both of us to keep the discussion limited to the subject matter, and try not to draw conclusions about each other's mental abilities.