• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

510 Pyro and Pyrocat HD, is there really a difference?

lorenzoalinari

Member
Allowing Ads
Joined
Jan 11, 2022
Messages
13
Location
Italy, Florence
Format
35mm
Hi everyone, I've searched around the internet regarding this question but I couldn't really find anything useful, strangely, so I'm sorry if it has been asked many times before.
I've been curious to try 510 Pyro for a while now, I read countless threads with people either swearing by it as the best developer there is and others saying it's really not that different from any standard developer. I decided to just try and see for myself. I'm especially intrigued by the alleged shadow detail retention while maintaining very fine grain, which should be good for pushing film (right?) That would be ideal now that it's dark outside. I'm not a frequent shooter so I've always ever used HC-110 and Rodinal.

Anyways, getting 510 Pyro would cost me 45€ including shipping, whereas I found that I can get Pyrocat HD for just 25€, which also has a great shelf life. I read that the former is pyrogallol based, whereas the latter is pyrocatechin based, however I don't understand what that means for the final negative. Does 510 Pyro perform better than Pyrocat HD or are they mostly the same in your actual experience? Thank you!
 
Lorenzo, I've used PMK and Pyrocat HD for decades now. Buy the Pyrocat for 25€ and try it. I have never had the desire to look for something better.... (50cm x 50cm print)

 
Last edited:
Firstly, IMO there is no "best developer." That said, the main difference between 510-Pyro and Pyrocat-HD is the stain color. The former leans more toward green/yellow, while the latter leans toward a brownish color. But, I've used both formulas over the years (as well as several other pyro-based developers) and have found that the stain color obtained is somehow related to the specific film developed. No idea why, but that's what I've observed in my own use.

Another difference is how they'll print, if you print in a wet darkroom. The 510-Pyro negative will tend to hold back the high values (not as much as PMK, in my experience) while the Pyrocat negative will print with a fairly straight line to its curve. For me, Pyrocat negatives seem to provide an increase in contrast with modern VC papers, but it's easily remedied.

Oh, and 510-Pyro will last just about forever. Opinions vary widely on Pyrocat, but I've had it die within one year of mixing. It does keep better if mixed in Glycol, but I've had that, also, within a shorter timeframe than what I typically see reported. And, what has always bothered me about its "death" is that it's a "sudden death" (like Xtol) and you don't know until your negatives don't develop properly! I still use Pyrocat because I think it's a great formula, but I tend to mix it in small quantities every six months and toss what I didn't use.
 
I use Pyrocat - I found the necessary ingredients more easily, and it’s not as toxic. After two years, the concentrate is like new, it hasn’t changed at all, but my version is glycol-based.
The main difference I can think of is that Pyrocat is a two-part developer, which gives you the freedom to adjust the ratios between Part A and Part B depending on the results you want. In other words, it’s more flexible.
 
YES, there's a difference and IMO the differences are significant. I never really liked 510 pyro because there's nothing in my view that it does particularly well. Pyrocat HD is in my experience the superior option of the two.
 
Aside from pyrogallol/pyrocatechin, there’s also the metol/phenidone difference. Pyrocat HDC might be more directly comparable to 510 pyro, because both use phenidone and ascorbic acid. I haven’t used 510 pyro so I’ll leave that part of the discussion to others, but pyrocat HD and MC are wonderful developers and do last for quite a while in glycol.

You don’t state how you’ll be printing, but the stain color will primarily affect VC papers. Given the price difference why not try the pyrocat? You won’t be unhappy with it and it will give you a baseline for what to expect from a pyro developer.
 
Last edited:
Of the various tinkerers Sandy King at least went to the effort of carefully testing Pyrocat-HD and attempting to show / characterize the results (speed, image structure, characteristic curves) as objectively as reasonably possible. It does this, it does not do that. Etc. Most other concoctions around are pretty haphazard. They will develop film, but that’s fairly trivial.
 
I've used both in both conventional and extended development schemes.

As noted upthread, 510 is pyrogallol based and tends to stain deeper and more greenish/brown. When printing with VC papers, this tends to reign in highlights well with big SBR subjects.

However, I found nothing that 510 did in everyday practice, that Pyrocat-HDC doesn't do pretty much just as well and for a lot less money. I mix my own HDC for a fraction of the cost.

If you're scanning, I'd stick to HD or HDC because the extra staining in the 510 will just be a scanning nuisance.

So, for day in day out stuff, I'd stick with Pyrocat.

For scenes with a huge SBR, I'd consider 510 for smaller formats where PMK tends to show more grain.

The other often forgotten do-everything developer that is dirt cheap to make is D-23. It is the "Swiss Army Knife" developer that has a ton of interesting ways to be applied.
 
Thanks everyone for the thorough replies!
After what you said, I'm definitely leaning towards Pyrocat, it seems hard to justify the extra money for 510.
There are not many times listed on the massive dev chart (especially for Kentmere films, which is what I mainly shoot at the moment), but I guess finally learning to do my own testing is gonna be part of the fun.
I still don't have a darkroom set up yet, so I'm just scanning, but I do plan on having one soon (I already got two enlargers for 35mm and 120) and printing what I've been shooting throughout these years on VC paper
 
I had never really used 510-pyro until a few weeks ago. My main film developers are Adox XT-3 R and Pyrocat-HDC. I have tried almost all versions of Pyrocat and most were excellent, but settled on HDC. What I found was what has been mentioned above and that is that when I print a negative developed in 510-pyro I have to boost my VC head by at least a half to one full grade higher than Pyrocat-HDC negatives. Of course I haven't really fine tuned my developing with 510-pyro yet. I think 510-pyro is a very good developer on its own, but the only reason I tried it was that I already had all the chemicals to make it. If I hadn't had the stuff needed to make it I wouldn't have messed with it.
 
I agree Andy and think I could really get to like 510-pyro. In fact I would use 510-pyro for my staining developer if Pyrocat-HDC didn't exist. My 510-pyro negatives seem plenty sharp enough with very low overall fog. I haven't tested it for film speed with any of the films I use so maybe that might be a negative. Other than that I like it.
 
If you are making prints there is a difference because of the stain color but if you are scanning there won't be much. I used PMK for about a decade, then Pyrocat P for about a decade, and when I compared prints I found I preferred the highlights of PMK (which would be similar to 510 Pyro) so I switched back to PMK for the last decade or so.
 
I scan and wet print both. I do prefer staining developers for wet printing, but that's my preference. I think that PMK, 510-pyro or any of the Pyrocat formulas pretty much boils down to personal preference. I've seen excellent results from all of them. It's like a new pair of shoes, not so good to walk in at first, but as time goes on they seem to fit a whole lot better. Of course some shoes never fit good at all.
 

Very much consistent with my own findings, but PMK has two drawbacks in my exprience: It's too grainy for 35mm, and you cannot use it for semistand/EMA extended development because it oxidizes too fast and develops unevenly if it's not agitated a lot.
 
I have not found a pyro type developer that performs better than PMK. Sometimes Pyrocat HD simply renders too much razor-sharp detail for my tastes, kinda like oversharpened Photoshop work.
 
I haven't tried 510-pyro with 35mm at all yet, but Pyrocat-HDC works fine with 35mm. Actually, most all my 35mm is done in XT-3 R as I prefer the look, but some really high SBR scenes get Pyrocat-HDC.
retina_restoration said:
I have not found a pyro type developer that performs better than PMK. Sometimes Pyrocat HD simply renders too much razor-sharp detail for my tastes, kinda like oversharpened Photoshop work.
Click to expand...


I know Pyrocat-HDC is a very sharp rendering developer, but I have never had it look digitally over sharpened. Well, maybe my old eyes are just a little duller than yours Paul.
 
I found PMK tends to give more of a gradual "highlight roll-off" (shouldering) whereas the curves I've seen for Pyrocat HD (I've never tried it myself) are "straighter". It would make sense as I think one of Sandy King's goals was to make a developer that would also work well for negatives destined for alt processes where higher density ranges are generally preferred.

No idea about sharpness.

PMK was originally basically a derivative of Wimberley's and then later Wimberley made his original formula more dilute.

retina_restoration said:
I have not found a pyro type developer that performs better than PMK. Sometimes Pyrocat HD simply renders too much razor-sharp detail for my tastes, kinda like oversharpened Photoshop work.
Click to expand...
 
after some problems with bad chemicals, i finally have a working pyrocat-hdc.
When wet printing i'm finding that the contrast is really low (landscapes, pretty normal contrast scenes), too much to obtain a decent print, with no local contrast in the midtones.
Is it me or it's more suitable for very high contrast scenes?
 

I've been using this developer for many different subject luminance ranges. What are you rating your film at? Sandy King states that it gives a third stop more speed, but that has not been my experience... For example, I expose HP5 at EI 250 for normal SLR's.
 

fp4 at 80/100, i've only tried it with large format so i spot meter and i tend to be quite generous with the exposure.
never tested dev times, i'm using 1+1+100 at 11minutes, more or less what https://www.pyrocathd.5x4.co.uk/ suggests.
 
tykos said:
fp4 at 80/100, i've only tried it with large format so i spot meter and i tend to be quite generous with the exposure.
never tested dev times, i'm using 1+1+100 at 11minutes, more or less what https://www.pyrocathd.5x4.co.uk/ suggests.
Click to expand...

I use mainly large format. I rate FP4 at EI 64.
 

Many of us here use it for SBRs of all kinds, in normal development, in extended development, and pretty much every way a developer can be used.

If you are getting consistently low contrast, there are a number of possible
causes:

  • Inadequate exposure. Try rating your film at an EI that 1/2 box speed to see if this helps.

  • Underdevelopment and/or lack of agitation

  • A faulty batch of developer. The ascorbic acid in HDC needs to be fairly fresh. If the powder is discolored, it need to be replaced. Ditto the phenidone. Similarly, you have to pay good attention to the weights and proportions and the order of mixing the chems.
Any time I make up a new batch of HDC, I run a test roll through it to confirm the developer is working as expected.
 
Isn't the OP asking about differences between 510 Pyro and Pyrocat HD so what's the relevance of PMK, other than it is another staining developer that is different from the two the OP want to know about ?

pentaxuser
 
You must log in or register to reply here.
Menu
Log in
Register