Having problems with perceptol 1:3

I was curious as to the benefits of Perceptol at a dilution of 1:3 with Fuji Acros in medium format and HP5+ in large format (8x10).

I have an X-Rite 810 densitometer, so I ran my typical test for EI in both formats, 0.09-0.11 above b+f, 100 EI for the Acros and 320 EI for the HP5+ under tungsten lights.

My target is a large 18% grey card, 2 feet square metered with a Pentax spot meter for zone I and VIII.

I used 125ml of Perceptol with 375ml of H2O for the Acros, hand agitated. My agitation schema was four inversions at the top of each minute. My densitometer reading at 18 minutes for Zone VIII is 1.24 above b+f.

I used 250ml of perceptol with 750ml of H2O for the 8x10 sheet of HP5+ and developed two sheets using trays, one sheet at a time. My agitation schema was lifting the front, then the rear, then left side, then right side. That would be one agitation. I agitated continuously for the first 30 seconds and then one agitation each 30 seconds. Again, this is exposure under tungsten lights, big 4k mole richardson softlights.

At 15 minutes my zone VIII densitometer reading was 0.94 and at 18 mins for the second sheet my zone VIII reading was ..... wait for it, 0.94.

I have considered developer exhaustion for the second sheet, so I am going to mix 1:3 again using 250ml of Perceptol and see what happens. Theoretically a sheet of 8x10 should equal a roll of 120, so 250ml for two sheets should be fine.

I have read that one liter of perceptol should yield four rolls of film, however here on Apug I have read that 120ml per roll works.

In the mean time does anyone have any insight that they may care to share ?

I had always used perceptol at 1+2, hoping to gain benefit of acutance without too much increase in grain.

I develop 8x10 Ilford HP5. I have difficulty sometimes getting density. I signed up to have the densitometry service done by Fred Newman, and it was not very successful at 1+2, so Fred talked me into standardizing at 1+1.
So, that is what i have done.

At 1+2, and especially at 1+3, you have to give a whole bunch more exposure (your working EI is much lower) to get it to come out. At 1+1, my HP5 working EI is about 250 for normal contrast developing, so at 1+2 it would probably be even lower, and 1+3 lower still.

I can't say if too little solution is the problem. I was using one-shot in BTZS tubes on 8x10 at 1+2 i only have 80ml of stock to make 240 ml working. I had no problems in getting negatives with seemingly good density at normal contrast, as long as i had sufficient exposure. But maybe it was the problem getting any density at N-2 and N-1 when Fred first did those tests.

In my gallery is Freedom Tower Rising done 8x10 HP5 developed Perceptol 1+2 normal. I used the arithmetic mean time between 1+1 and 1+3. The negative is rather sweet, at least it came out ok. I can't find my notes at the moment on what EI i made exposure for.

I always use a much larger quantity of working solution when I use Perceptol/Microdol (my homemade) at any dilutions. If I do a roll of 35mm I'll always use my two roll 120 tank and reels for spacers. I don't thin you should be losing that much density with 1+2 or even 1+3. Yes, at 1+2 I almost always give 1/2 to 2/3 more exposer depending on the scene and hardly ever see box speed of the film I'm using. The speed lose is just a fact of life with Perceptol or Microdol. I personally stick to 1+2 most of the time, but lately I've been a Pyrocat-HDC and Xtol-R guy. With medium and large format I don't see a lot of gain with using Perceptol for my work.

bascom49 said:

...I used 250ml of perceptol with 750ml of H2O for the 8x10 sheet of HP5+ and developed two sheets using trays, one sheet at a time...At 15 minutes my zone VIII densitometer reading was 0.94 and at 18 mins for the second sheet my zone VIII reading was ..... wait for it, 0.94.

I have considered developer exhaustion for the second sheet, so I am going to mix 1:3 again using 250ml of Perceptol and see what happens. Theoretically a sheet of 8x10 should equal a roll of 120, so 250ml for two sheets should be fine...

Click to expand...

As your results confirm, 250ml of stock Perceptol for 160 square inches of film isn't close to "fine." It's far too little. In fact, it's half of what is needed.

bascom49 said:

...I have read that one liter of perceptol should yield four rolls of film, however here on Apug I have read that 120ml per roll works...

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It's your option to take the word of APUG "experts" when their posts directly contradict what HARMAN specifies. Then you can enjoy exhausted active developer ingredients and a hard negative density limit. Is that "working?"

Using less developer concentrate / stock solution than a manufacturer indicates is necessary might, depending on scene content, produce a sub-optimal but salvagable negative. Following directions eliminates uncertainty. The choice is yours: confidence or crap shoot.

michaelorr said:

At 1+2, and especially at 1+3, you have to give a whole bunch more exposure (your working EI is much lower) to get it to come out. At 1+1, my HP5 working EI is about 250 for normal contrast developing, so at 1+2 it would probably be even lower, and 1+3 lower still.

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Setting aside the effect of using too little stock Perceptol in any dilution of 1+1;1+2 OR 1+3, I had always understood that higher dilutions gave more speed. This appears to be borne out by the Ilford spec sheet where it lists stock at a lower speed than 1+3 where it says that HP5+ can be rated as high as 320

pentaxuser

pentaxuser said:

Setting aside the effect of using too little stock Perceptol in any dilution of 1+1;1+2 OR 1+3, I had always understood that higher dilutions gave more speed. This appears to be borne out by the Ilford spec sheet where it lists stock at a lower speed than 1+3 where it says that HP5+ can be rated as high as 320

pentaxuser

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It does, but it's still shy of box speed. At least for me anyway. With some films I was 1/3 to 1/2 stop below box speed. With others I was more like 2/3 stops slower than box speed. I settled on 1/2 stop with HP5+ with 1+3 and 2/3 stop with 1+2. Works for me, but it might not wok for you.

@pentaxuser that is a good point - over stock, the speed of film possible goes up when diluted from stock. Contrary to advice i have that at in BTZS tubes if i don't have enough stock solution in my working solution it shouldn't matter, your comment and @Sal Santamaura seem to be tracking.

On 8x10 i decided that getting tested results at 1:1 were more important than trying to find how to make 1+2 to work in BTZS tubes. Not sure the acutance is as acute a discrimator in this format. May be a big deal in roll film.

Given that i gave up the acutance or grain trade-off - i probably will move to DD-X or HC-110 in the future. So much easier to work with when i develop so few films per session ans so few sessions per month.

Editing this comment - Thornton did point out that there was a particular weight of sodium sulfite in the working solution that was needed to get below that would activate the acutance choice. I chose my 1+2 dilution initially to get to that point.

So, tonight I developed an HP5+ 8x10 sheet exposed for Zone VIII.
I used 250 ml of Perceptol with 750ml of H20.
My previous sheet developed at 15 mins measured a density value of 0.88 above b+f.
Tonight's sheet developed at 18 mins measured a density value of 1.00 above b+f.
At this rate I'm approaching stand development times.
So, I'm off to start working with Xtol replenished, Rodinal.

Why would somebody be using a Microdol/Perceptol 1:3 on large format, especially 8x 10? Or Microdol at all, for that matter? That's not what Microdol 1:3 is for at all. It doesn't have the "energy" (my word for it). Thats for the small film where it excels. Pardon me--2 fingered typing. The big film is where you use the DK50, D-76 and the like, to me anyway. The Microdol is the small film stuff. For that it a magic potion at 1:3. I tried it on big film and never again.

Eagle Blue said:

Why would somebody be using a Microdol/Perceptol 1:3 on large format, especially 8x 10? Or Microdol at all, for that matter? That's not what Microdol 1:3 is for at all. It doesn't have the "energy" (my word for it). Thats for the small film where it excels. Pardon me--2 fingered typing. The big film is where you use the DK50, D-76 and the like, to me anyway. The Microdol is the small film stuff. For that it a magic potion at 1:3. I tried it on big film and never again.

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Well, this winter I'm planning on printing 48" by 60" inch prints. I have a huge horizontal enlarger with an Omega F color head, 4' by 6' vacuum easel and auto focus to boot. So, I was interested in large format fine grain negatives.
But, like you, never again.

"Always read the directions"
Well after reading Ilford s data sheet times for HP5 in Perceptol 1:3 are 25 mins.
Might as well keep moving ahead with it...

bascom49 said:

Well, this winter I'm planning on printing 48" by 60" inch prints. I have a huge horizontal enlarger with an Omega F color head, 4' by 6' vacuum easel and auto focus to boot. So, I was interested in large format fine grain negatives.
But, like you, never again.

Click to expand...

Even at a 6x enlargement off 8x10 you're going to be hard pressed to tell a difference between grain size/ sharpness etc from different developers. Getting the right contrast matters far more. I'd try D-76/ ID-11 or XTOL, possibly, but I'd also look closely at my tray temperatures over such a long development time - a 2c drop will have a drastic effect on density if not compensated for. Trays lose heat much more dramatically than tanks.

Lachlan Young said:

Even at a 6x enlargement off 8x10 you're going to be hard pressed to tell a difference between grain size/ sharpness etc from different developers. Getting the right contrast matters far more. I'd try D-76/ ID-11 or XTOL, possibly, but I'd also look closely at my tray temperatures over such a long development time - a 2c drop will have a drastic effect on density if not compensated for. Trays lose heat much more dramatically than tanks.

Click to expand...

Thanks and well noted. So far my strategy in general is to keep my darkroom at 68 deg F. That does help keep temps in check generally, and I do look at the starting temp and the ending temp.
As a side note, I do have jobo cpp2 processors, but the time to set them up, bring everything to temp and then process was a drag. I find that I like simple technique with hand agitation better,
even with longer developing times. It is nice to just mix developer, check temp, load a reel and go. In the back of my mind I'm also concerned that if I rely too heavily on the Jobo and it fails I'll be stuck
until I find a replacement or buy a new cpp3 (expensive). So, tanks and reels for 120 and 35, trays for 8x10.