I haven't tried it, but it sounds like an interesting combination. The Massive Dev Chart (www.digitaltruth.com) suggests 9 minutes in straight Perceptol for an EI of 100 with the original APX 100. That's probably a good starting point.
Perceptol is similar to Microdol-x, I've found that APX 100's Exposure Index is ISO 32, and takes 18 minutes to develop in Microdol-x 75F 1:3. Your mileage may vary.
My results were densitometry tested.
So, after searching and searching for an answer as to how long to do it, I just did it.
Almost every google just turns up recipes for APX/Rodinal, I found some nice shots taken with the APX/Perceptol combo but no times.
There's nothing wrong with resurrecting a 10-year old thread, it seems to be the only thread on the net I've found about this combo, so I may as well add my experiences to somewhere it'll be found.
Firstly, the contradicting times (everything is 1+0, 20C):
MDC says APX100 ei100 for 9 minutes (with note 'older version of this film, starting point time may differ'. My version were two 9x12s expiry 2004, so I figured 'older' is what I wanted).
Perceptol packet (bought new this year) plus every Ilford literature says APX100 ei50 for 9 minutes, ei100 not recommended. This may or may not refer to any 'new' APX100 that's out there.
Given that I'd already shot the film at ei100, what do I choose, 9 minutes or 9 plus a push? (Yes, I have rodinal around, but I specifically wanted to try Perceptol, I mixed it today for this).
Doing some deductive work as to what constitutes a 'push up to box speed', I considered that for FP4+ the times were ei50 9 mins, ei125 12 mins. PanF ei25 is 9 mins, ei50 is 14mins. Kentmere 100 ei50 for 9.30, ei100 for 12.30.
(Side note: the packet also doesn't make sense for HP5, ei250 is 13 mins but ei400 is 11 mins?)
Anyway, I was thinking I'd need to push a bit past 9 mins, but didn't want to over-push just in case the MDC was correct for ei100@9mins. So I took a stab at 11 minutes.
Results: Well, they're hanging to dry right now. One of them is sort of OK, just a bit on the thin side, maybe half a stop to a stop out? The other is rather thin. Not as thin as some of my other stuff thin, I'll be able to scan some detail into it I'm sure, but nowhere near perfect.
More detail: the first was taken with an orange filter with a 2-stop compensation. The thinner one was taken with a CPL with 2-stop compensation. All the RVP50 I shot at the same time with the CPL has come out half a stop too dark, so that might explain the disparity between the two films. Even taking that into account, I still think I'm at least half a stop below where I should be.
So 9 mins at ei50 sounds right, but I'm thinking next time at ei100 I'll be going for at least 14 mins, maybe more (if there is a next time at ei100, now that the perceptol is mixed I might just shoot ei50 for a while).
Thanks for posting this - I shoot a lot of APX 100 (when I'm shooting) and usually use Rodinal, which gives me images I like a lot. I'd be interested in using Perceptol as an alternative. If you choose to post images, that would be welcome.
Yeah, why not.
Here's a scan of three shots at once (if I do them individually then it changes pareameters and the results aren't comparable).
Top is the 'almost decent' one with the orange filter in Perceptol.
Middle is the 'rather thin' one in Perceptol.
Bottom is for comparison, from the same packet, ei100, 1:100 rodinal stand for an hour, to show what 'fully' dense looks like compared to the top two (although even with this one the highlights aren't blown out).
Still, not to say that the top two are no good, but they'll just need a bit more work in the scanner/enlarger to get looking good. But I'm definitely going to add some extra time in next time I rate at ei100.
ok, maybe I'll try diluting as one-shot with the next box (I've already started reusing with this packet, so if I dilute I'll enter a whole world of mathematical pain).
As for the grain size, I'll have to do a side-by-side comparison of the APX in Perceptol and Rodinal to see how the grain compares. Definitely with the rodinal I could still see the grain (albeit at ridicuslous enlargements for a 4x5), so I'm interested as to how Perceptol compares.
I also did two sheets of Delta100 in Perceptol yesterday in the Jobo (ie continuous agitation). The negs look nice and dense, I'll see how they compare to the APX in perceptol and rodinal in a few days.