So Tell Me About Ilford Perceptol

Hi Everyone,

In a recent magazine article the author (the name of the magazine and

author escape me although I think it was a UK based magazine)

reviewed some black and white products. One of the developers he

raved about was Ilford Perceptol which he described as being the best

choice for an accutance developer, better then Rodinal. Today at Bel

Air Camera in Westwood CA (to stock up on Rodinal actually after

hearing the news about Agfa) I saw two packages of Perceptol. I

thought I read in the archives that this developer was discontinued.

So maybe these two are old stock or Perceptol is back on the market?

The box described the developer as fine grain. Accutance developers

as most of us know are not fine grain. So what can you say about this

developer like what are it's strenghts, weakness, keeping properties,

ect. It's a powder and I've always used liquid concentrates so is it

easy to mix? Is it a one shot use? I shoot a lot of 120 Ilford PanF+

and Fp4 along with an occasional Efke roll. Most shooting is street

photography in afternoon sun so I'm always intersted in keeping skies

and sidewalks from blowing out.

Thanks,

Marc

My experience with it is limited, but here goes. It was one of the Ilford products destined for the chopping block last year, but I think it survived. In any case, Microdol-X from Kodak is reputed to be very similar or identical in composition. Perceptol gives very fine grain and a loss in speed (around a stop or so). I used it with FP4 Plus and HP5 Plus at dilutions of 1+1 and 1+2. Development times are long. I scan my negs, and found that Perceptol works well for this purpose -- I think that it gave me my "most scannable" negs ever from HP5 Plus.

 

If you want to read a lot about Perceptol and its relatives, check out "Edge of Darkness" by Barry Thornton. He talks quite a bit about the advantages (in his view) of metol-only developers (Perceptol and Microdol) in terms of edge sharpness and other factors.

 

I'm not sure about the keeping time. I had used up my 1L of stock solution in about six weeks and it was fine. I used the working-strength developer one-shot.

 

Given the film combinations you mention (PanF and FP4 in 120) I'm not sure how much you'd benefit from Perceptol. If you're regularly blowing out highlights you may want to think about revising your dev time and/or diluting your current developer. But it can't hurt to try Perceptol.

By comparison of description, working times, and characteristics, Microdol-X and Percceptol are pretty much functionally identical. My observations are with Microdol-X and I'd expect Perceptol to behave similarly.

 

If you use the developer full strength, you can expect to lose about 1 stop of speed in exchange for finer grain. As you dilute the developer, you can expect to see progressively more film speed and grain. At 1+3, you're back to box speed, more or less, with almost no grain amelioration and some acutance. Pretty neat trick! Since the only developing agent is metol, contrast is kept in check making it a good choice for scenes with a high scene brightness ratio.

Thanks for the replies guys. On a side note what exactly is meant when a developer causes a loss of film speed? I asked this question before some time ago but I still don't understand how this is possible. While I've yet to do actual film tests I have pulled my film a stop in bright sunny conditions and then cut development 30% on a couple occasions with so-so results. If I use a developer like Perceptol full stregnth which you say causes a loss of speed then I would have to push my iso a stop and then increase developmet to get the best results correct?

Thanks again,

Marc

Marc, no, you would shoot it at eg iso50 rather than iso 100 and develop at the given times. this isn't pushing or pulling. the film simply needs more exposure to give shadow detail with perceptol full strength than say Xtol.

It's a superb developer which at its highest dilution does give excellent acutance. It's a metol-only formulation and gives beautiful rendering of highlights. Try it with a 25 ASA film at 1+3 dilution - it was excellent with the late lamented Agfa APX 25.

 

Once mixed it's best to use it fairly quickly. Alternatively store the stock in a number of smaller bottles.

 

It's still listed in Ilford's range.

In my experience (some testing and a few rolls), perceptol 1+3 doesn't fully regain box speed, at least in HP5+ and Tri-X. Grain is similar to D-76 1+1, and acutance is to my eyes better. Right now it's my main developer; I still have gallon boxes, instead of the pansy liter ones.

 

I was testing Crawley's FX-2 at the same time, while comparing acutance developers. FX-2 is speedier, but grainier, and has, in 35mm, too distracting edge effects for my taste.

 

I shoot Tri-X at 200, develop for 13' at 24C in perceptol 1+3, three gentle inversions each minute. That gives me a CI of 0.44.

 

HP5+ takes 14' to reach the same CI, speed 200. Speed was determined as the point where avg gradient from z1 to z2 is 1/3 of the avg gradient from z4 to z6.

Perceptol is a very fine grain developer. At stock strength, grain size is incredibly small. I shoot Pan F+ @ EI 25 and FP4+ @ EI 50, develop stock strength, and love the results!. I've also pushed HP5+ all the way up to EI 1600 (development time guessed) with pretty good results.

Accutance isn't bad at 1+1, and I've never used higher dilutions (it's not the look I go for).<p>

When Ilford was in trouble, they stopped manufacturing powdered chemicals. The Ilford rep on the Ilford user forum website reports that Perceptol is being made again (thank God!), and should be back on the shelves soon. I've found Microdol-X to be an okay substitute, but I really don't like the brown stain is leaves on my negatives. By my non-scientific measurements, Perceptol yields slightly finer grain than Microdol-X.<p>

Mixing powered developers (both Perceptol and Microdol-X) is easy if you intend to use the full carton quantity. Just remember to pour it slowly to avoid creating much dust.

Pan F+ seems like it would be a tough one on the street, especially in MF. It's

best rated 25-32 (this all has probably been said), then throw a filter on there,

and then if you want any DOF. Perceptol is the only developer I use with this

film, ISO32, 1+2 13.5 mins @ 70f. Tripod and mirror lock, too.

 

Diluted Perceptol has a compensating effect that helps keep the highlights

there. And in MF, I can't find the grain on an 8X10 proof.

WOW; If Perceptol is making a comeback what about Ilfobrom? I did use Perceptol for portraits with good success but find the speed loss too much for general work.HP5 is very good with Perceptol. If I remember correctly I cut it 1:2 & at times 1:3. At 1:3 the developing times were,I think, about 21 mins.

If you want to use diluted Perceptol, which is certainly a very good choice, you should beware that Ilford recommends the use of at least 200ml of stock solution per role of film. At a dilution of 1+3 you would get 800ml diluted developer and you need a tank that is big enough. Of course you could try less developer.

 

Stefan