Hey Alex, I think you wanted to say at 13:47 that LD50 of hydroquinone is significantly lower than that of pyrogallol, hence the latter is much less toxic 🤓
This series has brought me from thinking 510 Pyro might be a really bad idea for my home development to thinking it's probably the absolute best option for me 😄 everything you find online is that it's ultra mega instant death toxic when it really is safer than D76
Another very useful video, really must wear gloves next time I use this stuff. I mixed my own from chemicals supplied by James, great guy, who is always happy to help with any queries. I solve the glopey problem by weighing the concentrate though I can't remember the relative density of it at the moment.
I’m a bit tipsy and watching this on the train home. Absolutely fantastic to hear each part of the developer explained. 🙌 So compelling!! PhD guy to PhD guy, keep up making work on things that interest you! Sending good vibes! 🤗
great safety talk, a great topic, esp. for beginners as not doing any photography classes, its good to know, esp. if you intend on storing these in your domestic shed, or property.
The video just popped up in my recommended videos and I've got to say that it's awesome! Finally a channel with someone who understands chemicals and developers, because I never understand what wich developer really does. Thanks for the content!
This was a great video Alex. You explain this topic very well and I got to understand why we can obtain such a fine grain while keeping a good dynamic range and higher density negatives using this developer 😎👌🏽
The syringe/cap combo work really well in dealing with the viscosity and I have gotten better at handling this over time. I also regularly use 'normal' fixer without issue, at worst it may remove/reduce the stain in a uniform manner. Overall a great and fair review 🙂
Great video!! Super informative. I started with pyro developers because that is what my friends handed me down. I’ve used many since but always come back to my pmk lol
Absolutely loved the video: you tell an easy to follow story (well I listened to everything you said but it doesn't mean I understood the technical stuff) and put all into the vid what I can't be bothered to read! And you are a cutie to boot! I use Pyro510 and think James Lane is ace ...
The viscosity is the reason I've moved off of 510 for my half frame (I've tried a bunch but OA and Pyrocat HD are looking good so far). If the viscosity doesn't annoy you, then it is pretty magical for half frame.
This video was phenomenally good thank you! The point about the stain working proportionally to the silver isn't something I thought about in depth. I knew more density meant more stain but didn't think about reduced development of the silver. Brings up to questions: Are the archival properties of 510 as good given less silver? (I recall reading the archival properties with 510 are good, but curious if the stain is as stable as silver) I wonder if the stain may explain why I've been struggling a bit with getting the density I expect when using 510 with certain films (TMX notably). This seems film specific. For instance with Fomapan 200, I get great density with 510 at reasonable times and it's my preferred developer to use with Foma 200. But in TMX, feels like I'm chasing the density I expect. I use TF-5 for fixing currently (until I finish the bottles at which point I'll switch to Zone Imaging's Eco Zonefix which I now use for prints) which is alkaline. I use distilled water end to end and no stop. I do use hypoclear and maybe that's a thing?
One of the worst reagents I ever had to work with in a lab was gallic acid, which is 1 acid group more then pyrogallol if I remember correctly. Not for toxicity but for stickiness. Great little video though Alex :)
Hi Alex, What do you think about warming up a bottle with Pyro 510 a bit to get more viscous liquid ( I think I read it somewhere ) ? Would it damage the Pyro or not, or maybe there is some threshold ? Really looking forward to test it with Foma Ortho 400 ( because of your advices ! )
Zone Imaging recommend not storing it warmer than 20 °C long term but I imagine say 30 °C being fine for a bit to thin it out? I don't think it'll think out quite as much as you're hoping but it's worth a shot.
There isn't much reason to warm up the bottle of 510 Pyro as the supplied syringe and bottle adapter allows for quick and easy extraction despite the liquid being viscous However, there is one scenario where warming up the bottle is required - if you want to extract the last few ml then the warmed concentrate will become runny enough to pour out into a small measuring cup
Beem using this for a couple if years now. Been very pleased with it. Quock question and one you might want to think about in terms of disposal is can it go in a septic tank. Oddly specific I know but having moved to a house with a septic tank chemical disposal is a real concern. Fixer for example is a no-no. Interesting video btw. Now I know how it does what it does. Most educational.
James can answer better but septic tanks are such a specific case that my blanket answer is "don't" as I don't feel comfortable telling anybody it even *might* be okay.
@Shaka1277 this is a quick rough calculation: Typical 4 person septic tank is 2700l 0.004g/l is the pyrogallol LD50 for bacteria Aka 10.8g/2700l for LD50 10g of pyro in 1 bottle The rate of biodegradability of pyrogallol is 60% per 28 days - phenidone level is negligible as it's already a tiny fraction of the amount Xtol per litre has for example and TEA doesn't count either because it would be negligible also compared to the amount of TEA in the soap and other cosmetics like make up being flushed down the drain Let's say Richard is using 24ml a month and is sticking to the typical recommendation to refresh the septic tank every 6 months: First month = 2.4g 2nd month = 3.36g 3rd month = 3.74g 4th month = 3.897g 5th month = 3.96g 6th month = 3.983 Far below the LD50
@@Shaka1277 seems fair . Enlightened self interest on my part and increasing awareness of the need not to just "chuck it down the sink" . Especially as I want to do wet plate collodion and ALT processes. I know some people with septic tanks I've spoken to use evaporation tanks to produce a residue - not too sure what they do with that residue though.
i started off with d-76 because that's what everyone says you should start with. Then i heard about and started using rodinal because it has a long shelf life and good sharpness. the grain made me do some more research and switch to xtol. But now that i'm getting more into serious developing and not just playing around, i think i want to check out 510 pyro.... i don't shoot enough film for how much i want to develop lol
I recommand D76/ID11 or Rodinal as well. Note that sharpness also depends on dilution. More dilution, more sharpness. Less dilution more tones in short. But with Fomapan 100, I use HC-110
@@chriscard6544 yeah i've used 1 bottle of rodinal so far and a gallon of d-76 but i want to stay away from using hydroquinone developers. I've done lots of tests with xtol stock and 1+1 to get my personal development times and my only complaint is that the grain might be TOO soft. i'm still working on getting the results i want, which is why i'm interested in trying 510 pyro.
I found out your channel a few days ago... I LOVE your methodicity and such rich technical explanations. You are very clear, methodic, pleasant to listen to and give a ton of information. While I was watching this video a was preparing some questions to ask you but you already explained I wanted to have. I'm trying to study some chemistry of b&w photography I've always desired to understand since I was a child when my father used to prepare ID 11 at home with pure components. I have a university general chemistry knowledge but I have not a university level knowledge about organic chemistry - which I love. I'm reading a book from 1979 written by Walls and Attridge but I found something at college level that is Organic Chemistry of Photography written by Fujita that I'm going to buy too. BY THE WAY: one question I still have. Is there any way to guess by theory, their formula and configuration, that Idrochinon is more dangerous than Pyrogallol for life beings? I was incline to think that a molecule with 3 hydroxyls that can react were more dangerous than one with just 2. One thing I don't like of 510 characteristics you listed is its sensitivity to acid. I'm scated it could be damaged even by some weak domestic acid exhalation and I've heard it can spot deeply the sink or the toilette. Thank you!! and please go on like this.
Thank you so much! This is really nice to hear - especially that I answered your questions as you were writing them. :) No, formula and configuration alone cannot reliably predict toxicity, at least not in a general sense. There are distinct "functional groups" that are more typically present in biologically toxic compounds but these tend to be relatively larger and more complex, like enediynes or other so-called "toxicophores". It doesn't apply to anything as simple as an OH group though! Glucose has 5 OH groups in its ring form and that's much less toxic than ethanol, which has 1 :)
I think it's worth noting that if you buy (for example) TF-4 or TF-5 as a neutral fixer for your pyro negs, you can use it to fix all of your other film (and paper) as well. It's not like it ONLY works with pyro.
The name comes from pyrogallol being first discovered/made by pyrolysis of gallic acid. It's pyrolysed gallic acid, so pyro-gall- and the final "-ol" comes from the three phenOLic hydroxy groups. No explosion risk or I would have said so!
I would add that pyrolysis is the fancy word for thermal decomposition so pyrogallol is basically created from heating gallic acid to be thermally decomposed into pyrogallol
Very useful, thanks a lot! Just one - somewhat unrelated - question that I have in mind for a while and maybe you can answer that about disposal on dangerous materials... I have heard the potassium dichromate can be neutralised in vitamin C, but I don't know what dilution and how much vitamin C should be used, how long does it take, etc. Any knowledge on that? Thx!
Do you know how stable this oxidized galol is? When I have metallic silver, I know it's an element. It will be silver to the end of universe. But some oxidized organic crap? What is expected archive longevity of stained negatives?
Stability exceeds 5+ years for the pure chemical for biological research, which is a very high bar. I imagine decades isn't at all unreasonable for the stain with modern developers. It may be "crap" but the fact it forms means it's a stable end product.
The stain formed by pyrogallol is very stable and there are proven negatives, such as Brett Weston ones ranging from 40 to 90 years old, from old style pyro developers showing no change in stain levels from many decades ago - today's pyro developers will be even more stable Store your 510 Pyro developed negatives in acid free sleeves and somewhere cool away from light and they will be just as archival Remember that film is made from PET and gelatine which are organic
@jameslane3846 yes I know that substrate and gelatin are organic. In case of silver I had no concern that it will outlive the substrate. If pyro stain can do the same, I rest my case.
Hey Alex, I think you wanted to say at 13:47 that LD50 of hydroquinone is significantly lower than that of pyrogallol, hence the latter is much less toxic 🤓
Something always slips through in these longer videos. Thanks!
This series has brought me from thinking 510 Pyro might be a really bad idea for my home development to thinking it's probably the absolute best option for me 😄 everything you find online is that it's ultra mega instant death toxic when it really is safer than D76
Another very useful video, really must wear gloves next time I use this stuff. I mixed my own from chemicals supplied by James, great guy, who is always happy to help with any queries. I solve the glopey problem by weighing the concentrate though I can't remember the relative density of it at the moment.
Great presentation! I'm a big fan of 510!
I’m a bit tipsy and watching this on the train home. Absolutely fantastic to hear each part of the developer explained. 🙌 So compelling!!
PhD guy to PhD guy, keep up making work on things that interest you! Sending good vibes! 🤗
great safety talk, a great topic, esp. for beginners as not doing any photography classes, its good to know, esp. if you intend on storing these in your domestic shed, or property.
Thanks so much for this video! I'm a big fan of zone imaging 510 pyro and it's my developer of choice but I feel so much better informed now 😊
The video just popped up in my recommended videos and I've got to say that it's awesome! Finally a channel with someone who understands chemicals and developers, because I never understand what wich developer really does. Thanks for the content!
Really appreciate that Tim!
This was a great video Alex. You explain this topic very well and I got to understand why we can obtain such a fine grain while keeping a good dynamic range and higher density negatives using this developer 😎👌🏽
The syringe/cap combo work really well in dealing with the viscosity and I have gotten better at handling this over time. I also regularly use 'normal' fixer without issue, at worst it may remove/reduce the stain in a uniform manner. Overall a great and fair review 🙂
Great video!! Super informative.
I started with pyro developers because that is what my friends handed me down. I’ve used many since but always come back to my pmk lol
Absolutely loved the video: you tell an easy to follow story (well I listened to everything you said but it doesn't mean I understood the technical stuff) and put all into the vid what I can't be bothered to read! And you are a cutie to boot! I use Pyro510 and think James Lane is ace ...
Exceptional as always Alex, Edutainment at it's finest.
Finally a realistic presentation of this developer.
Thank you!
so informative. Thanks a million!
Very informative, I'm def buying some !
The viscosity is the reason I've moved off of 510 for my half frame (I've tried a bunch but OA and Pyrocat HD are looking good so far). If the viscosity doesn't annoy you, then it is pretty magical for half frame.
This video was phenomenally good thank you!
The point about the stain working proportionally to the silver isn't something I thought about in depth. I knew more density meant more stain but didn't think about reduced development of the silver.
Brings up to questions:
Are the archival properties of 510 as good given less silver? (I recall reading the archival properties with 510 are good, but curious if the stain is as stable as silver)
I wonder if the stain may explain why I've been struggling a bit with getting the density I expect when using 510 with certain films (TMX notably). This seems film specific. For instance with Fomapan 200, I get great density with 510 at reasonable times and it's my preferred developer to use with Foma 200. But in TMX, feels like I'm chasing the density I expect.
I use TF-5 for fixing currently (until I finish the bottles at which point I'll switch to Zone Imaging's Eco Zonefix which I now use for prints) which is alkaline. I use distilled water end to end and no stop. I do use hypoclear and maybe that's a thing?
ITS HERE!!!!
One of the worst reagents I ever had to work with in a lab was gallic acid, which is 1 acid group more then pyrogallol if I remember correctly. Not for toxicity but for stickiness. Great little video though Alex :)
😎
Hi Alex, What do you think about warming up a bottle with Pyro 510 a bit to get more viscous liquid ( I think I read it somewhere ) ? Would it damage the Pyro or not, or maybe there is some threshold ? Really looking forward to test it with Foma Ortho 400 ( because of your advices ! )
Zone Imaging recommend not storing it warmer than 20 °C long term but I imagine say 30 °C being fine for a bit to thin it out? I don't think it'll think out quite as much as you're hoping but it's worth a shot.
There isn't much reason to warm up the bottle of 510 Pyro as the supplied syringe and bottle adapter allows for quick and easy extraction despite the liquid being viscous
However, there is one scenario where warming up the bottle is required - if you want to extract the last few ml then the warmed concentrate will become runny enough to pour out into a small measuring cup
Beem using this for a couple if years now. Been very pleased with it. Quock question and one you might want to think about in terms of disposal is can it go in a septic tank. Oddly specific I know but having moved to a house with a septic tank chemical disposal is a real concern. Fixer for example is a no-no. Interesting video btw. Now I know how it does what it does. Most educational.
Hi Richard, yes it can but the size will determine how much and how often you can put into the tank
What's the litre capacity of your septic tank?
James can answer better but septic tanks are such a specific case that my blanket answer is "don't" as I don't feel comfortable telling anybody it even *might* be okay.
@Shaka1277 this is a quick rough calculation:
Typical 4 person septic tank is 2700l
0.004g/l is the pyrogallol LD50 for bacteria
Aka 10.8g/2700l for LD50
10g of pyro in 1 bottle
The rate of biodegradability of pyrogallol is 60% per 28 days - phenidone level is negligible as it's already a tiny fraction of the amount Xtol per litre has for example and TEA doesn't count either because it would be negligible also compared to the amount of TEA in the soap and other cosmetics like make up being flushed down the drain
Let's say Richard is using 24ml a month and is sticking to the typical recommendation to refresh the septic tank every 6 months:
First month = 2.4g
2nd month = 3.36g
3rd month = 3.74g
4th month = 3.897g
5th month = 3.96g
6th month = 3.983
Far below the LD50
@@jameslane3846 I believe it's 9000L (9m3)
@@Shaka1277 seems fair . Enlightened self interest on my part and increasing awareness of the need not to just "chuck it down the sink" . Especially as I want to do wet plate collodion and ALT processes. I know some people with septic tanks I've spoken to use evaporation tanks to produce a residue - not too sure what they do with that residue though.
i started off with d-76 because that's what everyone says you should start with. Then i heard about and started using rodinal because it has a long shelf life and good sharpness. the grain made me do some more research and switch to xtol. But now that i'm getting more into serious developing and not just playing around, i think i want to check out 510 pyro.... i don't shoot enough film for how much i want to develop lol
I recommand D76/ID11 or Rodinal as well. Note that sharpness also depends on dilution. More dilution, more sharpness. Less dilution more tones in short. But with Fomapan 100, I use HC-110
@@chriscard6544 yeah i've used 1 bottle of rodinal so far and a gallon of d-76 but i want to stay away from using hydroquinone developers. I've done lots of tests with xtol stock and 1+1 to get my personal development times and my only complaint is that the grain might be TOO soft. i'm still working on getting the results i want, which is why i'm interested in trying 510 pyro.
I found out your channel a few days ago... I LOVE your methodicity and such rich technical explanations. You are very clear, methodic, pleasant to listen to and give a ton of information. While I was watching this video a was preparing some questions to ask you but you already explained I wanted to have.
I'm trying to study some chemistry of b&w photography I've always desired to understand since I was a child when my father used to prepare ID 11 at home with pure components. I have a university general chemistry knowledge but I have not a university level knowledge about organic chemistry - which I love. I'm reading a book from 1979 written by Walls and Attridge but I found something at college level that is Organic Chemistry of Photography written by Fujita that I'm going to buy too. BY THE WAY: one question I still have. Is there any way to guess by theory, their formula and configuration, that Idrochinon is more dangerous than Pyrogallol for life beings? I was incline to think that a molecule with 3 hydroxyls that can react were more dangerous than one with just 2.
One thing I don't like of 510 characteristics you listed is its sensitivity to acid. I'm scated it could be damaged even by some weak domestic acid exhalation and I've heard it can spot deeply the sink or the toilette.
Thank you!! and please go on like this.
Thank you so much! This is really nice to hear - especially that I answered your questions as you were writing them. :)
No, formula and configuration alone cannot reliably predict toxicity, at least not in a general sense. There are distinct "functional groups" that are more typically present in biologically toxic compounds but these tend to be relatively larger and more complex, like enediynes or other so-called "toxicophores". It doesn't apply to anything as simple as an OH group though! Glucose has 5 OH groups in its ring form and that's much less toxic than ethanol, which has 1 :)
I think it's worth noting that if you buy (for example) TF-4 or TF-5 as a neutral fixer for your pyro negs, you can use it to fix all of your other film (and paper) as well. It's not like it ONLY works with pyro.
Yep, a less common fixer is something to be aware of but hardly an actual issue.
a question, is this really safe?, as the name pyro means fire, as in pyrotechnics (fireworks!) so any explosion risks here?
The name comes from pyrogallol being first discovered/made by pyrolysis of gallic acid. It's pyrolysed gallic acid, so pyro-gall- and the final "-ol" comes from the three phenOLic hydroxy groups. No explosion risk or I would have said so!
I would add that pyrolysis is the fancy word for thermal decomposition so pyrogallol is basically created from heating gallic acid to be thermally decomposed into pyrogallol
Is there a difference with Pyrocat-HD ?
Very useful, thanks a lot! Just one - somewhat unrelated - question that I have in mind for a while and maybe you can answer that about disposal on dangerous materials... I have heard the potassium dichromate can be neutralised in vitamin C, but I don't know what dilution and how much vitamin C should be used, how long does it take, etc. Any knowledge on that? Thx!
Chromates in their various forms are nasty stuff and I personally don't touch them, so haven't put any thought into their disposal.
Regarding fixer, I use Kodak C41 fixer for my B&w films. It is supposedly a more neutral fixer pH wise. Do you think that it would be OK for 510 pyro?
I don´t know this fixer, but i´ve used normal Adox Rapid Fixer and the stain is still there.
Do you know how stable this oxidized galol is? When I have metallic silver, I know it's an element. It will be silver to the end of universe.
But some oxidized organic crap? What is expected archive longevity of stained negatives?
Stability exceeds 5+ years for the pure chemical for biological research, which is a very high bar. I imagine decades isn't at all unreasonable for the stain with modern developers. It may be "crap" but the fact it forms means it's a stable end product.
The stain formed by pyrogallol is very stable and there are proven negatives, such as Brett Weston ones ranging from 40 to 90 years old, from old style pyro developers showing no change in stain levels from many decades ago - today's pyro developers will be even more stable
Store your 510 Pyro developed negatives in acid free sleeves and somewhere cool away from light and they will be just as archival
Remember that film is made from PET and gelatine which are organic
@jameslane3846 yes I know that substrate and gelatin are organic. In case of silver I had no concern that it will outlive the substrate. If pyro stain can do the same, I rest my case.
ima be honest... I didnt understand much :D
how much did james lane pay you to make this for the holiday season?
I wish. It anything he was complaining about how long it took to get done.
Hahahaha @@Shaka1277
Yeah, but how do I use it? Sigh... ok, I'm gonna read the documentation...
If you had a choice of only 1. Xtol or 510 Pyro? 😂
Hard question, probably 510.
Good man, @@Shaka1277🫡 😂