Help please: Shouldn't unexposed RA paper develop white?

dslater · Jul 31, 2012

The thing that is so troubling about this is that none of my paper is showing a yellow shift. Both the CA and the Endura I tested last night are essentially grey. I'm sure light leaks aren't the problem as my darkroom is in my basement and last night I was working down there with the basement lights off. So I had a darkroom inside of a dark basement.
I do believe the paper I got from Ultrafineonline was fogged by a safelight when they were cutting it - that paper had a strong cyan cast to it.

The only reason I brought up radon is there is another thread here where someone ( I thought it was you PE, but I might be wrong ) stated that the aging of paper is caused by cosmic radiation. But maybe that's way off base.

In any case, I've resigned myself to the fact that I need to get new paper and chemistry from a reputable dealer - namely Adorama. Yet another delay which wouldn't be a problem except for the fact that we just bought a new house. We're moving on Friday, and I'll no longer have a darkroom until I build on in the new house.

I have a place where I can probably set up an enlarger temporarily and I can process in the bathroom using my Jobo, but I'll lose my tempered water and be back to messing around with a conventional faucet and a lab thermometer - a time-consuming and frustrating process.

Photo Engineer · Jul 31, 2012

Aging of film or paper is caused by both heat and radiation. The faster the material the faster it ages. Heat aging can cause fog, contrast changes, and speed changes. Radiation damage generally shows up as fog.

Frozen materials or refrigerated materials age primarily by radiation damage due to the lower temperature. However, radiation damage is so slight with papers that it should not be a problem. But, I have never had to deal with radon.

PE

EdSawyer · Jul 31, 2012

with some of the recently outdated endura, the only difference I can notice (yellowing) is on the paper borders, not in the actual print itself. If that is the only place it is noticed, then effectively it's a non-issue IMNSHO.

frotog, sounds like something was wrong with that paper other than age. I have older endura than that that still prints fine. As to questioning testimonials re: longevity of color and ability of us over-40 men to differentiate, take this test and tell us how you do. Then at least we will know what your discrimination ability is. ;-)

http://www.colormunki.com/game/huetest_kiosk/

dslater: good luck with the move and new products from adorama. hopefully that will cure things. I live in NH too, LMK if you need anything in getting a new darkroom set up (presuming you are still in NH area possibly...) Not sure how you process color, but my output improved a lot after switching from single-shot drum usage (cibachrome drums) to a replenished tabletop processor (Fujimoto Cp-31).

FWIW,

-Ed

dslater · Jul 31, 2012

EdSawyer said:
dslater: good luck with the move and new products from adorama. hopefully that will cure things. I live in NH too, LMK if you need anything in getting a new darkroom set up (presuming you are still in NH area possibly...) Not sure how you process color, but my output improved a lot after switching from single-shot drum usage (cibachrome drums) to a replenished tabletop processor (Fujimoto Cp-31).

FWIW,

-Ed

Hi Ed,
I like the idea of a better print processor. Does this http://www.ebay.com/itm/Fujimoto-Photo-CP-51-Image-Processor-/110904489382?pt=LH_DefaultDomain_0&hash=item19d26c35a6#ht_3879wt_1396 Fujimoto Cp-31 look like it's complete?

pentaxuser · Jul 31, 2012

EdSawyer said:
with some of the recently outdated endura, the only difference I can notice (yellowing) is on the paper borders, not in the actual print itself. If that is the only place it is noticed, then effectively it's a non-issue IMNSHO.

-Ed

That has been my limited experience as well. I have a pack of oldish 5x7 endura and it is the paper borders that show a slight yellow. The prints seem fine.

pentaxuser

frotog · Aug 1, 2012

"Seems fine" is the operative phrase. If you see a yellow cast in the border, you'd better assume that it's in the image as well. You might think that you've dialed in enough blue to make it neutral but in the process gamut is being suppressed and the print suffers. For some the difference might appear too subtle to notice (until the print is compared with a print made from fresh stock) . But when color is critical (printing editions, matching prints or simply making a fine print), the shift is unacceptable.

Of course if you're tray processing or doing rotary then you're probably not making half and quarter point cc corrections in order to dial in a perfectly balanced print and none of this will matter because what you're holding in your hand will look just fine.

Roger Cole · Aug 1, 2012

Gerald C Koch said:
Some years ago I bought some BW paper from them that was not just fogged but actually black for a 1/4 inch along one edge. Vowed never to buy from them again.

Similar story. I bought some expired but supposedly cold stored and "tested and it's fine" Elitechrome from them. It's dead of old age junk. Never again.

Photo Engineer · Aug 1, 2012

In some cases of aging paper or fogged paper, it discolors from the edges inward. This is due to the fact that air or light can affect a stack of sheets more easily at the edge where the sheets are exposed.

This type of change would not be as bad at the center of a print.

PE

frotog · Aug 1, 2012

Photo Engineer said:
In some cases of aging paper or fogged paper, it discolors from the edges inward. This is due to the fact that air or light can affect a stack of sheets more easily at the edge where the sheets are exposed.

This type of change would not be as bad at the center of a print.

PE

While I've seen this happen with b/w paper, I've yet to see the first signs of aging color paper as anything but universal change of the reference white to an increasingly buff-white. While I have not measured the change across the entire sheet of out-of-date paper with a densitometer, cutting the blix processed sheet in two so as to visually compare the edge with the center shows little difference in the base white if any at all.

PE, if I'm understanding you correctly the aging of frozen paper is mostly due to radiation fogging. Isn't this a different kind of degradation than that of materials improperly stored in hot or humid conditions? And if so, does radiation affect a stack of sheets more so on the edges?

Photo Engineer · Aug 1, 2012

Ambient radiation does indeed "age" all analog products. This cannot be avoided by low temperatures, but this process is very slow and very minor compared to humidity and oxygen. Humidity and other atmospheric agents seep in from the edges and affect photo products.

I have seen sheets that were brown in a halo around the center which was normal, tut this is an extreme. Usually, you see a slight yellowing at the edges. Radiation causes a gradual overall fog like appearance.

PE

EdSawyer · Aug 1, 2012

dslater: that ebay link is a CP-51, the bigger brother of CP-31. i have one of those too, though not set up currently. That one is not what I would consider complete. You really would want the W/D unit too which is 2 more baths plus a dryer. You could make do with the one picture but would need separate wash and dry stations (manually). CP-51 will do 20" wide paper, cp-31 will do 12" wide paper. CP-51 requires 240v power also. (CP-31 is 110v). Baths on CP-31 are 2L, baths on CP-51 are 6L. I use the Cp-31 a lot and find it a good managable unit with reasonable size limits. I have the full Cp-51 setup too, but I haven't the space or power configured for it yet, though someday I will get around to that.

Pricewise I think you might be able to do better also. I got my Cp-51 with W/D unit for $250, it needs major cleaning but it is complete and working. (Shipping was $400). I picked up my first CP-31 in mint shape, with W/D unit, and replenisher from a university for $300 total. I bought a second CP-31, also complete as mentioned (though not nearly as clean) for $100. New these setups ranged from $12-20k. There's several other CP-31/51 users here on Apug, some good info in the past messages... worth a search.

thanks
-Ed

Arkasha · Aug 2, 2012

Photo Engineer said:
Ambient radiation does indeed "age" all analog products. This cannot be avoided by low temperatures, but this process is very slow and very minor compared to humidity and oxygen. Humidity and other atmospheric agents seep in from the edges and affect photo products.

I have seen sheets that were brown in a halo around the center which was normal, tut this is an extreme. Usually, you see a slight yellowing at the edges. Radiation causes a gradual overall fog like appearance.

PE

Do you know offhand the radiation's wavelength(s)?

Thanks.

Photo Engineer · Aug 2, 2012

The ambient radiation I refer to is cosmic radiation. In some rare cases it is due to the presence of Radon gas.

As such, the energy is measured in electron volts IIRC.

PE

ath · Aug 2, 2012

Photo Engineer said:
As such, the energy is measured in electron volts IIRC.

And are best described as particles and not waves (hence no wavelength)

Arkasha · Aug 2, 2012

Photo Engineer said:
The ambient radiation I refer to is cosmic radiation. In some rare cases it is due to the presence of Radon gas.

As such, the energy is measured in electron volts IIRC.

PE

Interesting. However, this is a bit puzzling, too. I just checked, and apparently almost 90% of cosmic radiation is alpha particles. Helium nuclei can't penetrate a sheet of paper, let alone a cardboard box and black bag. The remaining 10% are either "heavier nuclei" or electrons.

If this is so, then putting the paper (still in its box) into a larger box, and then into a larger still metal box (grounded) should shield the paper from electrons. And even an aluminum box should prevent most of the heavier nuclei from getting through, unless the particles are quite energetic.

Photo Engineer · Aug 2, 2012

Heavy particles do reach the surface of the earth. The energy is quite high.

Try here: http://www.sciencenews.org/search/s...&sort=SORT_BY_RELEVANCE_MODE&find_submit=Find

They ran a recent article on Cosmic Rays and discuss the various particles, energies and the penetration of the earths atmosphere and magnetosphere.

Over time, enough reach the earth to begin fogging film. There is a lengthy thread on this and the amount and type of metal needed to afford protection. I suggest that rather than duplicate this thread here, you look up that old thread.

Lots of good stuff there.

PE

dslater · Aug 2, 2012

EdSawyer said:
dslater: that ebay link is a CP-51, the bigger brother of CP-31. i have one of those too, though not set up currently. That one is not what I would consider complete. You really would want the W/D unit too which is 2 more baths plus a dryer. You could make do with the one picture but would need separate wash and dry stations (manually). CP-51 will do 20" wide paper, cp-31 will do 12" wide paper. CP-51 requires 240v power also. (CP-31 is 110v). Baths on CP-31 are 2L, baths on CP-51 are 6L. I use the Cp-31 a lot and find it a good managable unit with reasonable size limits. I have the full Cp-51 setup too, but I haven't the space or power configured for it yet, though someday I will get around to that.

Pricewise I think you might be able to do better also. I got my Cp-51 with W/D unit for $250, it needs major cleaning but it is complete and working. (Shipping was $400). I picked up my first CP-31 in mint shape, with W/D unit, and replenisher from a university for $300 total. I bought a second CP-31, also complete as mentioned (though not nearly as clean) for $100. New these setups ranged from $12-20k. There's several other CP-31/51 users here on Apug, some good info in the past messages... worth a search.

thanks
-Ed

Thanks for the info Ed. I'll keep my eye out for a Cp-31.

newcan1 · Aug 5, 2012

would a slight yellowish cast be improved by a final rinse incorporating optical brighteners? I've done this with older b&w paper where the base had become off-white, and the results were impressive. However, that was a case of a yellowed base, not yellow base fog.

Photo Engineer · Aug 5, 2012

The developer and the paper base itself contain brighteners, but this is offset by a UV absorber.

PE

Help please: Shouldn't unexposed RA paper develop white?

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