Pyrocat HD vs Hypercat

Spent some time yesterday pulling on a string after doing some Googling on Hypercat and Pyrocat HD. Found a lot of surprisingly vitriolic discourse between a couple of individuals and their supporters.

What I didn't find was a good 3rd-party comparison of the results between the two developers. I'm rather interested in trying out one of the two, as I've never played with staining/tanning developers before, and the advantages in terms of grain, acutance, and tonality seem very compelling.

I'm the opposite of interested in reigniting pointless bickering or politics about it.

If you use one or the other, which do you prefer? If you use both, what advantages/disadvantages do you see? If you have ever done side-by-side testing of both, what were your conclusions?

B, I've used PMK and now Pyrocat HD for decades now. I never saw any reason to test any "fringe" developers that didn't get produced commercially. Also as you hinted....J Defahr's public comportment put me off trying the hypercat as well.

GregY said:

B, I've used PMK and now Pyrocat HD for decades now. I never saw any reason to test any "fringe" developers that didn't get produced commercially. Also as you hinted....J Defahr's public comportment put me off trying the hypercat as well.

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I'm very much avoiding taking sides in what I see as an unnecessary conflict. And DIYing the developer is my plan anyway, so whether it's commercially produced or not is of no consequence to me.

Thing is, I've heard a lot of people say "I use Pyrocat HD and love it" and I've also seen people say "I use Hypercat and love it." I've yet to find someone say "I've used both of these and prefer X over Y." Any thread I can locate where both developers are discussed seem to be riddled with mod-deleted posts and a lot of emotionally charged discourse, but very little actual... real world comparison.

BHuij said:

I'm very much avoiding taking sides in what I see as an unnecessary conflict. And DIYing the developer is my plan anyway, so whether it's commercially produced or not is of no consequence to me.

Thing is, I've heard a lot of people say "I use Pyrocat HD and love it" and I've also seen people say "I use Hypercat and love it." I've yet to find someone say "I've used both of these and prefer X over Y." Any thread I can locate where both developers are discussed seem to be riddled with mod-deleted posts and a lot of emotionally charged discourse, but very little actual... real world comparison.

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I suspect a much wider use of Pyrocat HD..... good luck in your tests.
As I said, count me among the happy PMK & subsequently Pyrocat users....

GregY said:

I suspect a much wider use of Pyrocat HD..... good luck in your tests.
As I said, count me among the happy PMK & subsequently Pyrocat users....

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What dilution(s) do you favor?

In regards to Pyrocat-HD, it depends on the film. For HP5, I favour 1+1+50. If I want stronger edge effects, then I'll dilute it further, up to 1+1+200...and beyond.

BHuij said:

What dilution(s) do you favor?

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typically 1:1:100 ......although I've tried divided Pyrocat a couple of times but the regular dilutions seem to hold under very high brightness ranges. IMO it's an impressive developer.

I'll be heading down the same road myself -- ASAP -- but instead of asking if anyone has compared X to Y, I'll be deciding for myself by running my own pretty simple tests using my own gear and my own eyeballs.

I have all the chemicals I need, but I have yet to decide on the film(s) and formulas (there could easily be more than one). Now I just need to find some time. I know I left some of it around here somewhere............

BHuij said:

.....Thing is, I've heard a lot of people say "I use Pyrocat HD and love it" and I've also seen people say "I use Hypercat and love it." I've yet to find someone say "I've used both of these and prefer X over Y." ........, but very little actual... real world comparison.

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There might not be much difference, once each developer is mastered. I would be inclined to pick one, and then work with it. If something then seems not good enough, then it's time for further investigation.

Leaning towards Pyrocat HD... seems a lot more popular, and even if that's not an indicator that it's better, it's at least an indicator that it will be easier to find help and troubleshoot if something goes wrong.

I haven't conducted a strict test, but I have used both with the same films. Differences: Hypercat will lose about a stop of speed and suppress grain significantly, though resolution doesn't seem to improve. Being a single component developer, it's very amenable to compensation effects. In comparison, Pyrocat doesn't suppress grain as much, doesn't lose speed, and is less sensitive to compensation effects, though it still does a good job if used that way.

As a general developer, I'd choose Pyrocat. Hypercat (and the similar Obsidian Aqua) are more niche.

BTW, the final version of Pyrocat is Pyrocat HDC. It omits bromide and replaces metabisulfite with ascorbic acid. It's simpler and needs no water if made with glycol. Formula here:

Good to know. I would rather use the HDC version anyway

BHuij said:

Spent some time yesterday pulling on a string after doing some Googling on Hypercat and Pyrocat HD. Found a lot of surprisingly vitriolic discourse between a couple of individuals and their supporters.

What I didn't find was a good 3rd-party comparison of the results between the two developers. I'm rather interested in trying out one of the two, as I've never played with staining/tanning developers before, and the advantages in terms of grain, acutance, and tonality seem very compelling.

I'm the opposite of interested in reigniting pointless bickering or politics about it.

If you use one or the other, which do you prefer? If you use both, what advantages/disadvantages do you see? If you have ever done side-by-side testing of both, what were your conclusions?

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The ferocity of a debate tends to be inversely proportional to both it's importance and the actual knowledge of the loudest voices.

Over the past 50 or so years, I have made extensive use of: D-76, D-23, DK-50, HC-110, PMK Pyro, and Pyrocat-HD, with just a hint of Beutler's thrown in for fun.

What I have found is that no single developer handles everything well. Double X film just hates high dilution development, especially Pyrocat and PMK. It much prefers D-76 1:1. Fomapan 100 loves ultra dilute D-23 with a little sodium hydroxide thrown in. Tri-X thrives on Pyrocat-HD and PMK, and so forth.

What is important, though, is that each of these has to be understood in context of the subjects you're shooting and the SBR of the scene. For example, the image below was shot on a cloudy day with a really short SBR. I did it on Tri-X at full box speed, semistand developed in Pyrocat-HD 1.5:1:250 for an hour. That gave me the edge effects and the local contrast I was looking for. Had this been a normal SBR, this would have blown the highlights into outer space and made the mid tones look like garbage.

I remember a few years ago when I decided to go down the stand/EMA rabbit hole. Many people were curious as I was, and others were quite supportive. But there were a few that were just SURE it was trash it was all trash, by golly, and I was an inept "fraud" (that term was actually used) for even daring to show the results. I spent a profitable several years deeply exploring this and found where the sweet spot was where extended highly dilute development made sense.

So my counsel to you is ... try both your candidates under idential circumstances. No one can tell you which one is better. Only you can tell which is better, when it is better, and why.

Really nice photo - displays everything I'm hoping to get from trying out staining/tanning developers with that local contrast and acutance.

I think a big part of the reason that I'm so interested in trying this out (and also why I started experimenting with BTTB recently) is because of the theory behind compensating high-acutance developers. I shoot primarily nature subjects in overcast light or open shade. It's just what mostly ends up in front of my lens. So the ability to simultaneously increase local contrast in scenes with low inherent contrast, and help tame brighter highlight areas when I (for example) include a sky, all at the same time as introducing edge effects... sounds pretty ideal for about 90% of the photography I do on roll film.

BHuij said:

Really nice photo - displays everything I'm hoping to get from trying out staining/tanning developers with that local contrast and acutance.

I think a big part of the reason that I'm so interested in trying this out (and also why I started experimenting with BTTB recently) is because of the theory behind compensating high-acutance developers. I shoot primarily nature subjects in overcast light or open shade. It's just what mostly ends up in front of my lens. So the ability to simultaneously increase local contrast in scenes with low inherent contrast, and help tame brighter highlight areas when I (for example) include a sky, all at the same time as introducing edge effects... sounds pretty ideal for about 90% of the photography I do on roll film.

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You may find my notes helpful:


Just be careful, it easy to overdo this. Even though Pyrocat-HD is a semi-compensating developer, and even if you highly dilute it, it's easy to blow out the highlights while you're busy expanding the mid tones using EMA or (semi) stand.
You also have to watch, because the higher dilutions can yield very acute negatives that give you pronounced grain in small formats like 35mm.

For MF and larger, it's all good. Note that Pyrocat-HD is only somewhat compensating. So if you want to develop for a long time to expand mid tones but want strong compensation, I find that D-23 1+9 with 0.5g/l of sodium hydroxide for 60 min with an initial 2min agitation and one midpoint 15 sec agitation does that trick nicely. It will give you razor sharp negs at the expense of grain, which is why I don't do it with 35mm.

Anyway, it's fun to play with, just use good lab technique, gloves, eye protection, and an apron. The various components of these developers and things like sodium hydroxide are nasty if you get them on your skin or in your eye.

Yeah, I think for starters, I'm going to try it at the normal 1:1:100 dilution for HP5+, FP4+, and Delta 100 and just see if I like it significantly better than my old standby of Mytol stock or 1+1. I almost never enlarge 35mm past 11x14, so I can handle some grain, but I want to keep both that and any potentially exaggerated edge effects to a happy medium where they improve the sharp appearance of a fiber print without looking like I turned a Lightroom slider up to 100.

BHuij said:

Yeah, I think for starters, I'm going to try it at the normal 1:1:100 dilution for HP5+, FP4+, and Delta 100 and just see if I like it significantly better than my old standby of Mytol stock or 1+1. I almost never enlarge 35mm past 11x14, so I can handle some grain, but I want to keep both that and any potentially exaggerated edge effects to a happy medium where they improve the sharp appearance of a fiber print without looking like I turned a Lightroom slider up to 100.

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For 35mm, I'd give this a go:

• Expose your film at 1/3 stop slower than box speed
• Use a double height tank and place small inverted funnel on the bottom
• Put the loaded reel over the funnel nozzle and cover the tank
• Pour in Pyrocat-HD mixed 5:3:500
• Continuous agitation for 90 seconds
• 5 sec agitation at 7, 14, and 21min
• Pull at 28 min, stop and wash as usual
• Assumes 68F/20C

This is a form of Extreme Minimal Agitation. You can even reduce the intra-period agitations to just two at 9 and 18 mins.

This should give you good negatives, edge effects and mid tone expansion without clobbering the highlights or producing excessive grain.

(Keep in mind that the picture above is from a 6x6 Hasselblad negative so YMMV.)

A lot depends on what specific film is in question, your particular enlarging light source, and the kind of look you seek in your prints. I've tried quite a few pyro tweaks, including a couple of my own concoction, but never Hypercat. My favorite in terms of versatility remains PMK, but a lot of people must like Pyrocat HD for a reason. And I'm well aware of the "pyro wars" era; it was almost like a religious war.

If you do choose Pyrocat, I'd personally recommend using it conventionally at first, before trying any exotic "stand development" technique growing a Rip Van Winkle beard covered with cobwebs while you wait. Not everyone is thrilled with stand development.

The main reason for resorting to a pyro developer is to obtain the highlight controls its stain provides. Secondary edge and grain effects can vary significantly between different formulas, again depending on the specific film or films involved too. There is simply no substitute for doing an amount of personal testing to decide what you like best.

DREW WILEY said:

A lot depends on what specific film is in question, your particular enlarging light source, and the kind of look you seek in your prints. I've tried quite a few pyro tweaks, including a couple of my own concoction, but never Hypercat. My favorite in terms of versatility remains PMK, but a lot of people must like Pyrocat HD for a reason. And I'm well aware of the "pyro wars" era; it was almost like a religious war.

If you do choose Pyrocat, I'd personally recommend using it conventionally at first, before trying any exotic "stand development" technique growing a Rip Van Winkle beard covered with cobwebs while you wait. Not everyone is thrilled with stand development.

The main reason for resorting to a pyro developer is to obtain the highlight controls its stain provides. Secondary edge and grain effects can vary significantly between different formulas, again depending on the specific film or films involved too. There is simply no substitute for doing an amount of personal testing to decide what you like best.

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My consistent experience with both Pyrocat and PMK is that Tri-X loves it most and FP4+ is a close second. But, my use case is abstracts silver printed under a diffuse VC cold light head.

Tri-X in PMK gives the most glorious cloud edge effects when shooting landscapes. And Tri-X in Pyrocat can be made to really have edge effects that pop.

I do agree you have master the conventional use of the developer before you try these more abstruse development techniques (and my monograph/epistle/screed on standing development starts out by saying this as well). In any case, I cannot imagine trying PMK as a standing developer. I would imagine the streaking would be dreadful - but if someone's made that work, do share.

@chuckroast I actually just wrapped up reading your page on semistand/EMA, as it is relevant to my goals. You gave me the words to more precisely describe what I'm after here - it's not just edge effects for better acutance, and it's not just compensation effects (which I wanted not because I am averse to contracted "normal" development, but because with roll films I frequently have 5 or 6 frames with a sky and the rest without one). It's really that expansion of midtone contrast without also creating highlight areas on the film thick enough to be measured with a ruler.

The linked writings from Mr. Kachel were highly relevant as well. His article about local contrast hit my own frequent silver printing frustrations on the head. I have so many negatives that look perfect and should print easily due to the extensive calibrations I've set up for zone system use, and yet they come out looking flat and uninteresting on Grade 1.5 or 2, and I frequently have to resort to very odd multigrade dodging/burning schemes to get the "snap" I want in the important areas of the scene.

Lots of food for thought here. I am still in the middle of a BTTB vs XTOL 1+1 (actually Instant Mytol, but you get the point) comparison, specifically for 35mm film. Thus far I have found that my BTTB negatives come out denser and grainier than I want, without really delivering on the promise of additional acutance, at least not enough to justify the grain. But this is no showtrial, so I'm making sure the prosecution is allowed to fully make its arguments.

Unless I come out of those tests having absolutely fallen in love with BTTB and ready to serve my beloved Instant Mytol divorce papers, I believe I will move on to experimentation with Pyrocat-HDC next. I am only missing about two ingredients, neither of which is expensive or difficult to source. Ironically I seem to be treading a similar path as Barry Thornton, who started with normal developers, then got into (basically) two-bath D23, and ultimately ended his career using pyro-type developers.

It doens't make much sense to me to dive into stand/semistand without first getting some consistent results with a more standard 1:1:100 and 5-seconds-per-minute agitiation approach. It may be that the stain-related highlight suppression and grain masking on VC paper is enough for me, and I don't even feel a need to try out EMA.

But since I prefer to avoid blowing through rolls of film for simple density measurements, and believe in at least attempting to create some art along the way (otherwise this becomes an entirely left-brained experience that doesn't leave me feeling very fulfilled), it appears I have more than enough "fun experiement ideas" to last me the majority of 2025.

At any rate, I appreciated your write-up and resonated with many of the ideas.

BHuij said:

@chuckroast I actually just wrapped up reading your page on semistand/EMA, as it is relevant to my

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Happy you found it useful. Perhaps a little history might be of interest ...

I gravitated to this a number of years ago out of a frustration of having been a shooter for over 40 years - and a pretty consistent one at that - but I was fundamentally unhappy with my work. Like you, I discovered that what was missing was expressive mid tones.

The first year was endless testing of developer dilution, agitation schemes, film suspension experiments, and film types. Much of it was unsuccessful but it was instructive. (I have a background in science and engineering and an experiment that doesn't produce expected results isn't a "failure", it's telling you what the answer isn't.)

Once I conquered bromide drag and got the variables approximately under control, the next few years were about stretching these high dilution, long development times to their limits. As David Kachel says, "always go too far" (though he himself isn't much a fan of stand development and makes that pretty clear). It was by producing excessively contrasty middle tones, dense highlights, and generally ugly curves that I slowly began to tune these processes in a useful and productive way. This also caused me to rethink my negative "design" (a Steve Sherman term) for better printing choices in the darkroom.

The most recent hill I've climbed has been with Double X. I hadn't shot much 35mm in years, but this year I got Leica fever (a terrible disease to contract, trust me). I wanted to find a film/dev combo worthy of those wonderful lenses. After a LOT of "well, that's not it", I've discovered that Double X just hates Pyro and/or highly dilute developers no matter how I processed the film. It does seem to like D-76 1:1 just fine, which then revealed that, actually, it's not that sharp a film, probably because of the lack of an antihalation layer.

But the very best thing that came out of this, by far, was that I was shooting a LOT in every format from 35mm to 4x5. It's no exaggeration to say that I exposed more frames in the past three or four years than I did in the prior ten. Sure, a lot of them were test images, sure a lot of them were crap, but art is fundamentally about finding what to remove - it's a process of distillation and shooting that much help me find what not to do as much as anything else.

You can see some of the results here - most things from the last 4 years were part of this grand set of experiments:

DREW WILEY said:

There is simply no substitute for doing an amount of personal testing to decide what you like best.

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Blasphemy!