Accidentally made negatives that work as positives with Arista Ortho Litho?

So I've always heard about (and noticed) the effect where some films, especially when a bit over exposed, can be tilted on their side and viewed as positives from the silver being viewed as, well, silver, instead of black. However, I accidentally discovered this effect is extremely prevalent with Ortho Litho with at least one developer, and interestingly, is exploitable with a huge amount of exposure latitude. The developer I used is "D-23LC", some concoction roughly equivalent to D-23 1+9 but with less sulfite. Exact formula for 500ml:

* Water, 450ml (I used tap rather than distilled. Either seems safe)
* Very small pinch of sulfite
* 0.75g Metol
* 6g Sodium Sulfite
* Fill to 500ml of water

There was another step. Unknown as of yet as to if it had any effect though (need to do another test with D-23LC without this step). I used a concoction that turned out to be off (oxidized it seems) composed of TEA, Iron Out (for sodium dithionite, a fogging agent), Sulfite, Lye, and some water. It was a stock, but seemed to go off in just 24 hours (sodium dithionite is fragile) from mixing. Either way, along with that was a large amount of pot bromide. 2.5g per 150ml. This functioned as a prebath for 5 minutes with agitation per minute. When initially tested this caused a visible, but manageable layer of fog and slight grain increase. On this test run where I noticed this effect, 3 days later, there was no visible fog at all, and the "toe" of shadow detail seemed to be very wide, as is typical with non-fogged ortho litho.

Anyway. Basically used this "D-23LC" with stand development. Agitation being extremely conservative. Just 30s initially, and then stand for 40 minutes. Surprisingly, no problems with uneven development, bromide streaks, or exaggerated edge effects. Then water stop bath, and finally TF-4 fixer for around 3 minutes.

Normally Ortho Litho is an extremely difficult to work with film for pictorial in-camera purposes. It is slow, requiring speeds of 1.5 ISO typically for good results. I've tried many developers, and the fastest I've ever felt was safe was 6, and even then 3 was preferred. With this run, the best looking negative was 12 ISO, with up to 50 remaining printable, albeit with lacking shadow detail. Of course, as usual with pushing film, there is a lot less over exposure latitude than usual and more contrast.

Anyway, so while hanging the negatives, I noticed that against a dark background I could clearly see a positive image. Decided to see how prevalent it is by putting it on the nearest black object in the room, a 3 ring binder. To my surprise, not just the over exposed images were visible, but every single image on the roll was visible, even the test chart shot at 50 ISO that was really quite thin! And even more surprising was that the highlights that looked straight up black, actually had some visible detail with this positive viewing method, though latitude isn't infinite of course. There is some noticeable missing shadow detail on the 50 ISO test chart, and some "solarization" (ie, highlights appear black instead of a warm silver) visible in the highlights of the 3 ISO test chart.

I've heard of some direct positive film processes that exploit this effect, but typically that is with making your own emulsion, and using specialty (ie, not 2 ingredient) developers and other things like bleaching etc. Is there an actual name for this effect, and could there be some way of exploiting this for unique "prints" or something similar? What could be the ideal background for this? How can I learn more!? I have way more ortho litho (I'd say about 24"x50ft left, at least) than I know what to do with so I'm always looking for ways to use this weird film in a way that makes it a bit more versatile than some 1.5 ISO film normally would be.

Oh, and also of course, crap cell phone pictures cause I have no idea how I'd scan this effect:

The actual negative view (bottom is 3 ISO, each image above is 1 stop faster)



The positive view:



(the bottom one on this was deeply over exposed and seems to have solarized back into a negative with this view)



(forgive the bad selfie)

I see that with underexposed plates. Essentially you’re getting into how ambrotypes are made.

Enjoy!

Jason

Unfortunately, I can't figure out a good way to get rid of the sheen of the film base which can make it hard to view, and the result is much less warm and duller when dry. According to ambrotype guides, the best thing would be to coat with lacquer so that it always appears "wet".

Also, the pre-flashing step which I thought was ineffective did have some effect, however, it's hard to judge. I processed another test roll completely skipping that step, but the test roll was taken in cloudy weather. The result is clearly much high contrast, with significantly less shadow detail, and around 1-2 stops slower. It also doesn't have the same warm tone as the previous test here while wet. So, it appears that something in my pre-flash step went off, but it's still doing something but keeping the fog to a non-visible level. It could be that the lye decomposed, reducing it's overall activity, but the fogging agent still seems to be alive. Another concern is that the metering might be off. I'm using a cheap Lubitel 166+ for these tests, and it's lens appears to be uncoated. This could be allowing a lot of UV light in, and I suspect this film may be more sensitive to UV than visible light, similar to old emulsions... and the UV of course isn't picked up by my meter. The ideal speed on this recent test is 12 ISO, so still a significant jump from 1.5 ISO. Either way, the lack of a warmer grey seems to make this quite a bit more dull as positives, even while wet. Unsure if the fogging agent or the large amount of bromide as a pre-bath is responsible for the warm tone