Red safelight with Ilford M.IV RC 44M paper

[Joao Marques]

When i print B&W paper I use a red safelight(ilford SL1) in the darkroom,
but today I bought a box of paper (ilford multigrade IV - RC 44M pearl)
and the in the box was written that i have to use a light-brown
safelight.
Can i use the red (SL1) safelight with no problems or do i have to get a
different safelight?

[MarB1]

Just do a safelight test and see, in my expirience graded and VC papers
have no difference in the safelights they need. Mark bau

[SX in HUF]

In article <41tgn8$5...@vivaldi.telepac.pt>, Joao Marques
<jan...@telepac.pt> writes:

Joao,

Most B&W papers are orthochromatic, meaning that they are not sensitive to
red light. The exception I can think of is Kodak Panalure Select which is
panchromatic so that it can be used with color negs. I use Ilford MG IV
with a red safelight and find that it works just fine. Many makers of B&W
paper suggest using the Kodak OC safelight because its brownish/amber
color is safe and is easier to see by. Whenever I try a new paper I
always do a safelight test just to make sure. Hope this helps. :-)

Eric Dawson

[Michael Gudzinowicz]

Joao Marques <jan...@telepac.pt> writes:

>When i print B&W paper I use a red safelight(ilford SL1) in
>the darkroom, but today I bought a box of paper (ilford
>multigrade IV - RC 44M pearl) and the in the box was written
>that i have to use a light-brown safelight. Can i use the
>red (SL1) safelight with no problems or do i have to get a
>different safelight?

Prior to the introduction of variable contrast papers in 1940,
papers were sensitized only to blue light, which is still true
of graded papers. At that time Kodak and others recommended
using an OA safelight filter, which is greenish-yellow. Since
the papers weren't sensitive to green light, the safelight's
spectrum more closely corresponded to the eye's senstivity,
and was quite bright.

The OA greenish-yellow filter could not be used with
orthochromatic films, however, since they are sensitized to
green as well as their inherent blue sensitivity. Therefore,
deep red filters were still recommended for their use,
especially since some, like Tri-X Ortho are far more sensitive
to light than papers.

Variable contrast papers are sensitive to blue and green
light (not red or IR) like ortho films, but they are much
slower. Therefore, amber (yellow-brown, orange, OC) filters
were introduced in lamps which were too bright for use with
orthochromatic films, but which worked reasonably well for
VC/MG/MC papers. Therefore, people who had been using the OA
green-yellow filter were urged to switch to the "bright" OC
filter (the red filter was safe with graded or variable
contrast papers, but not everyone used them).

I suggest that you expose a strip of VC paper to lightly fog
it using no filter on the enlarger, and cover half while it
remains on the easel or near developer for 5 - 10 min,
whichever is closer to the safelight. Develop it, and see if
it is fogged. The 4 red safelights lights I use in my darkroom
are "safe" with ortho films (though I only use one while
developing by inspection) and with variable contrast papers,
up to 1/2 hour exposure. I've even left paper a few inches
from the lights for 10 min, without fog, while OC filters will
fog paper that close in less than a minute. I'm not familiar
with the SL1, so do the tests.

[Wendy]

Joao,
I am not familiar with your particular darkroom safelight but
perhaps all you might need to do is just get the additional
filter...I used Ilford papers with a Kodak safelight, and put on
the light-brown or "amber" filter. If my paper still fogged...I used a
lower wattage bulb and/or moved the light further away from enlarger and
paper safe! BTW: The filters on the Kodak safelight where
interchangeable!
Regards,
Wendy

[Graham A. Patterson]

On 28 Aug 1995, Joao Marques wrote:
> but today I bought a box of paper (ilford multigrade IV - RC 44M pearl)
> and the in the box was written that i have to use a light-brown
> safelight.
> Can i use the red (SL1) safelight with no problems or do i have to get a
> different safelight?

The colour _should_ be safe, but the strength of the bulb may be too
high. Try a fog test by placing strips (in darkness) on your enlarger
baseboard and wet area, with a coin on them. Switch on the safelight, then
add a coin alongside the previous ones every couple of minutes for a total
of 10 minutes or so. Process the strips, and see what you get. They should
be plain white if your conditions are safe. If you can see signs of the
coin shadows then you have a problem. I am assuming that you have no
white light leaks!

I use an orange (Paterson) 15 watt lamp at just over 1 metre with no
problems. I keep red for process films.

-- Graham Patterson http://www.rdg.ac.uk/PRIS/Sed/graham.html/graham.html
Sedimentology: The hard study of soft rocks
*** Opinions expressed are mine unless otherwise stated ***

[wen...@interramp.com]

Hi Folks....well I figured you would be waiting for the ILFORD
response..... (FYI, the ILFORD SL1 is actually the safelight, not the
safelight filter).....ILFORD recommends either the KODAK OC or ILFORD
902 safelight filters, which are amber/light brown colored. The red
safelight filter is NOT recommended with black and white photographic
papers, since it will expose them much faster than the recommended
ones....
Hope that helps.

Wendy Erickson
ILFORD PHOTO (USA)
TECHNICAL SERVICES

[Michael Gudzinowicz]

Wendy Erickson <wen...@interramp.com> writes:

>Hi Folks....well I figured you would be waiting for the ILFORD
>response..... (FYI, the ILFORD SL1 is actually the safelight, not the
>safelight filter).....ILFORD recommends either the KODAK OC or ILFORD
>902 safelight filters, which are amber/light brown colored. The red
>safelight filter is NOT recommended with black and white photographic
>papers, since it will expose them much faster than the recommended
>ones....

After reading your reply, I tested Ilford MGIII Deluxe,
Polycontrast Rapid III, Flexicon, and Agfa MG variable
contrast papers. To avoid differences in illumination, a Kodak
OC, Premier OC, Kodak Series 2 Deep Red and a non-descript
deep red filter from a Kodak safelite were placed directly on
the papers, and were exposed by three 1000 watt lamps bounced
off the ceiling of the darkroom (the filters were on an easel
on the floor at the center of the room - filter positions were
changed though illumination was even).

With all papers, the deep red filters were "safe" (base white)
while the OC filters permitted fogging. The addition of a
"light" red filter (approx equivalent to a 25A) prevented
fogging with the OC filters.

This seems to agree with the spectral characteristics of the
Kodak filters. (From the SPSE handbook - all densities < 3 from
200-500 nm.)
Diffuse Density
------------------------------------------
Filter: OA OC #2 #1 #1A
Green- Amber Deep Red Light
Wavelength Yellow Red Red
---------- ------ ------ ------ ------ ------
500.00 3+ 3+ 3+ 3+ 3+
520.00 3+ 3+ 3+ 3+ 3+
540.00 2.97 3+ 3+ 3+ 3+
560.00 1.20 2.90 3+ 3+ 3+
580.00 0.80 1.05 3+ 3+ 3+
600.00 1.00 1.00 3+ 3+ 3.00
620.00 1.40 1.40 2.90 2.00 1.40
640.00 2.00 2.00 1.60 1.20 0.40
660.00 2.40 2.40 1.20 1.10 0.20
680.00 2.85 2.60 1.10 1.00 0.15
700.00 2.95 2.80 1.10 1.00 0.10

Although Kodak recommends the #1A, #1 and #2 filters for use
with different ortho films, it appears that the #2 is "safe"
with variable contrast papers. According to the SPSE handbook,
the OA filter was used with slow enlarging papers and contact
papers, and OC with fast papers (presumably due to changes in
sensitization - Brovira fogs under an OC filter/not under a #2).

If the Ilford red filters permit fogging of variable contrast
papers "much faster" than OC filters, what is the mechanism?

If their transmission characteristics "leak" UV, blue or green
light, they would be unsafe with ortho films, which are faster
than papers.

[Olivo Miotto]

"Graham A. Patterson" <slsp...@reading.ac.uk> wrote:
>
>I use an orange (Paterson) 15 watt lamp at just over 1 metre with no
>problems. I keep red for process films.
>

Really? You mean you don't do films in the dark??? Can you expand on that?
Thanks
O

-----------------------------------------------------
Olivo Miotto
Institute of Systems Science,
National University of Singapore,
Heng Mui Keng Terrace, Tel: +65-772 6644
Singapore 0511. Fax: +65-778 2571

Email: ol...@iss.nus.sg
WWW: http://www.iss.nus.sg/index.html

[wen...@interramp.com]

Thank you Michael Gudzinowicz.....I was quoting from ILFORD
literature, not from scientific testing, but Michael is right. My
colleagues from the UK in Tech Services tell me that true red
safelights ARE much safer than the amber ones, because they transmit
less (or even no) green light. They are generally not recommended to
work with because they are dark and can be unpleasant to work
under.....Thanks for setting us straight! I learned something!

[Rene Bilodeau]

In message <425v9r$1...@holodeck.iss.nus.sg> - Olivo Miotto <ol...@iss.nus.sg> w
rites:
:>

:>"Graham A. Patterson" <slsp...@reading.ac.uk> wrote:
:>>
:>>I use an orange (Paterson) 15 watt lamp at just over 1 metre with no
:>>problems. I keep red for process films.
:>>
:>
:>Really? You mean you don't do films in the dark??? Can you expand on that?
:>Thanks
:>O

When he refers to "process" films, he's talking about ortho film. The kind
used by printshops for black & white line art. It can be developed under
a red safelight.

Cheers, Rene

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[Graham A. Patterson]

On 1 Sep 1995, Olivo Miotto wrote:
> "Graham A. Patterson" <slsp...@reading.ac.uk> wrote:
> >problems. I keep red for process films.
> Really? You mean you don't do films in the dark??? Can you expand on that?
> Thanks

Lith or Line graphics art films are orthochromatic as a rule, hence the red
safelight. These are known (to me) under the heading of 'process films'.
A red safelight with normal panchromatic film stock is _not_ recommended!

-- Graham Patterson http://www.rdg.ac.uk/PRIS/Sed/Graham