Ra4 safelight

[DREW WILEY]

Fuji's own official recommendation per spec sheets is, preferably, total darkness; but if you must, briefly use a doubled-up (two of them) no.13 dark amber filter in conjunction with a 10 watt bulb - in other words, you're going to have damn little light anyway.

I don't think RA4 papers are any faster than they were in the 90's, or even 70's, except perhaps those specifically designed for automated rapid Photofinishing snapshot throughput. I've always worked in total darkness. The only exception is when aligning big heavy rolls onto my cutter shaft, when I might need to use my tiny Jobo Minilux amber light for a few seconds at a time.

 

[koraks]

I don't think RA4 papers are any faster than they were in the 90's, or even 70's, except perhaps those specifically designed for automated rapid Photofinishing snapshot throughput.

All present production color papers fit in the latter category and yes, they are faster than prior to 2003 when digital exposure took over the market by storm. That's well documented.

 

[DREW WILEY]

By "Photofinishing" I meant products like CA Supreme, designed for a second or so. The relatively slight decrease of exposure time in the broader CA lineup simply can't imply TOO much faster exposures, not if those big rolls have to be fed at a rather consistent pace clear through the cutter, large laser machines, and RA4 system itself. I am aware of an increased sensitivity to certain hues for sake of laser exposure, especially green, and other "improvements" like better black DMax which would effectively equate to a little more exposure speed. And the newer lasers themselves have probably been tweaked too.

But those of us who work with wide rolls in the darkroom, or paper sizes cut down from those, tend to have an ample surplus of colorhead lumens to begin with. So it is all relative. Chromogenic paper has always been comparatively fast to enlarge, certainly compared to chromolytic. I had to substantially decrease the brightness of my own big enlargers once the Ciba days ended.

Regarding safelights, they've always recommended total darkness. And now that would seem to be even more important.

 

[koraks]

By "Photofinishing" I meant products like CA Supreme, designed for a second or so.

All present-production Fuji papers ranging from CA to CA Supreme all the way up to Maxima use the same emulsions, all of which are optimized for digital exposure. Speed is virtually the same, give or take a small margin.
All present-production Lucky papers are also optimized for digital exposure.
I don't know how the speed of the Lucky papers relates to Fuji, but I expect it to be in the same ballpark. Kodak Endura used to be a bit slower (half a stop or so if memory serves) than Fuji.
I don't know whether FujiFlex is a slower emulsion. I don't expect so, since it's optimized for digital exposure just like the other materials.
None of these papers are designed for "a second or so", and all are optimized for the microsecond to sub-microsecond exposure times common in laser and LED exposure systems. All of these materials will still expose fine with much longer times, up to at least ca. 10 seconds for the Fuji papers. Beyond this, non-linearities may or may not occur.

I am aware of an increased sensitivity to certain hues for sake of laser exposure, especially green

With the advent of digital, two factors were changed first and foremost:
1: Speed increased by a stop or so, for all layers.
2: High-intensity / short exposure reciprocity failure performance was improved to allow for sub-microsecond exposures.
Here's an example taken from a Kodak white paper of how this impacts optical/'analog' exposure of an old-style paper (right-hand set of curves) vs. a new-style 'for-digital' paper (left-hand set of curves):

Note similar speed for the three color channels, as well as the speed increase (shift to the left) of the 'for digital' paper vs. the old product. FujiFilm followed suit when Kodak started down this route.

By nature of the concept of RA4 paper, whenever the speed of the emulsions change, they need to change by virtually identical amounts. So an increased sensitivity in just one color layer did not happen, as it would have rendered the product unusable. Since this is inherent to the concept, it doesn't matter if we discuss Fuji, Kodak or Lucky papers since they are all based on the same principles to prevent cross-contamination between the channels through relative emulsion speed differences between the layers.

The speed gain of the modern papers does have implications for how much stray light we can get away with compared to the papers from before ca. 2003.

 

[DREW WILEY]

I haven't noticed any significant increase in Fujiflex speed between the older version and the current type II. There is a difference in gamut and contrast, for the better. The speed and starting color balance is very similar to the various Super C products which I used prior to them being digitally optimized. And I still have no reason to think Fujiflex suffers at all in visual quality when optically enlarged. There is a minor difference between additive versus traditional subtractive colorheads, but not enough to worry about. True additive enlargement essentially mirrors the kind of hue response laser exposure units deliver, but is sharper and certainly more seamless in my case at least due to direct optical workflow.

Better green optimization was needed at the exposure/material R&D interface because that was the weakest exposing laser. In fact, there were no adequate green diodes. The green came from filtering it out of a more dominant red. I don't know if that is still the case or not; I haven't kept up with the "latest and greatest" laser tech since I retired. I doubt that Chromira platens have changed, but could be wrong in that case. It just doesn't affect me personally; and every lab owner in this immediate neighborhood who once did do laser printing has retired, so I can't ask them.

I have pretty much total control over any stray light, so can't comment on the effect of that.

From my reading of actual published changes in Fuji specs, they seem to have incorporated several gradual changes in color response which Kodak did not. But again, it makes no difference at this point, since Kodak paper is essentially either dormant or outright extinct now. Thanks, however, for pointing out the changes in reciprocity failure response, since that would factor into high speed printing behavior versus
longer exposures.