I've got some OA to try from Nik & Trick here in the UK, along with some Pyrocat HD. I'm currently using 510 pyro for half frame, and find 510 to give good results, but I find the working consistency a bit annoying so wanted to try some alternatives. No results yet, but it's handy to see your effective speed for HP5 in OA was lower, I'll keep an eye out for that on my tests.
It's really strange because it's not occurring anymore... I'm wondering if it was from undissolved chemical particles, that eventually went into solution... 🤔
Just an idea on the spotting problem. Once the working solution is mixed strain it through a chemical filter, or lacking that, maybe a drip coffee filter. There is a possibility that you are getting undissolved micro residue from one of the ingredients when mixing the developer. That it seems to go away when processed in some choices of fixer may just be that it is belatedly dissolving there. (Or I could be dead wrong.)
@@analogueandy8x10 It's funny. I thought something similar. But I know that you've been doing this way more than me. And the second test showed no spots, so, you knew it too.
I have been "EXPOSED" !!!!! ....and you can bet I do keep my shutter very cocked. Now I might have to try that Obsidian Aqua Velva stuff for a few PtPd prints as I do like the contrast. Thanks for the video. Great information Andy.
Found Propylene Glycol in a Veterinarian store used for treatment of cows with Ketosis. $30 CDN gallon. That is a very large amount of Catechol so I might be avoiding that developer as 510 Pyro works well on any film I have once I get the proper timing solved.
Great video! My theory on the spots is incompletely dissolved catechol or sodium carbonate. A speck of either would leave a high density spot on your film. For future reference, any time you don’t have a tested development regime for a film in OA, develop 1:500, 20C, 30 seconds initial agitation, then 10 seconds every three minutes. This works for almost any film, but not with TMX. I don’t know why. I wish I did. Instead, use a 1:250 dilution, and prepare to be amazed! Just kidding, but it is pretty impressive. Maybe it’s because I was never able to get results I liked at 1:500 and just wrote off the combination for years. A fellow photographer encouraged me to dig into the issue, and it turned out I didn’t have to dig very far. My first test was 1:250 and success! Pretty embarrassing. Anyway, OA is highly compensating and capable of pretty grotesque edge effects when a dilute solution (1:500) is combined with low frequency agitation. HP5 Plus is especially prone to wiry results, but if you increase the concentration and agitation frequency with a suitably decreased development time, you can get very smooth gradation. If you want to increase emulsion speed instead of exposure, you can add a few grains of Metol to your working solution, but before you do, try the standard regime at the top of my comment. It might turn out to be a non-issue.
OA is pretty remarkable. I believe the issue was undissolved catechol or carbonate. After a couple of days, it was no longer an issue. I will definitely try it at 1:250. I'll also try a bit of Metol and see how much the speed is affected. I guess I can add a wee bit to the working solution? I'd also like to say that your 510-Pyro is a pretty solid developer. Thank you!
@@analogueandy8x10 I’m glad 510-Pyro is useful for you. It’s been very good to me over the years. Lately I’ve been using a bastardized version of Rudi Hartung’s semi-stand method. I double my established time for a film in 1:100 dilution with standard Ilford agitation. If I don’t have an established time I use the mfg time for that film in D-76/ID11 stock. I agitate 30 seconds initially, then 10 seconds at halfway point of total development time. This method gives me pretty robust negatives suitable for darkroom printing. It’s long enough to be forgiving of small errors in timing, but short enough to do multiple batches in a session. For example, my time for Ilford Pan F Plus is 13:00, 20C. HP5 Plus is 15:00, etc.
I really love the contrast of the Obsidian Aqua
The flower in the pot photo is really nice, luminous is a great word
Thanks, Stephen!
This developer reminds me of an Italian developer called Ornano Neucleol B200. You do get full box speed with this two part developer, though.
i love your videos because you are a comedic genius
I've got some OA to try from Nik & Trick here in the UK, along with some Pyrocat HD. I'm currently using 510 pyro for half frame, and find 510 to give good results, but I find the working consistency a bit annoying so wanted to try some alternatives. No results yet, but it's handy to see your effective speed for HP5 in OA was lower, I'll keep an eye out for that on my tests.
Spots. Final rinse? Dust in the camera? Drying environment? Ceiling fan stirring up dust? Maddening, even if it didn't recur.
It's really strange because it's not occurring anymore... I'm wondering if it was from undissolved chemical particles, that eventually went into solution... 🤔
you are amazing! love your work!🙏🙏🙏
Just an idea on the spotting problem. Once the working solution is mixed strain it through a chemical filter, or lacking that, maybe a drip coffee filter. There is a possibility that you are getting undissolved micro residue from one of the ingredients when mixing the developer. That it seems to go away when processed in some choices of fixer may just be that it is belatedly dissolving there. (Or I could be dead wrong.)
I'll try that! Thank you!
@@analogueandy8x10 It's funny. I thought something similar. But I know that you've been doing this way more than me. And the second test showed no spots, so, you knew it too.
I have been "EXPOSED" !!!!! ....and you can bet I do keep my shutter very cocked. Now I might have to try that Obsidian Aqua Velva stuff for a few PtPd prints as I do like the contrast. Thanks for the video. Great information Andy.
Thank you! I need to now see if HP5 will make for a good carbon transfer print. The contrast looks appropriate...
Thanks for a very interesting video.
Found Propylene Glycol in a Veterinarian store used for treatment of cows with Ketosis. $30 CDN gallon. That is a very large amount of Catechol so I might be avoiding that developer as 510 Pyro works well on any film I have once I get the proper timing solved.
Did you find a vet shop online?
Great video! My theory on the spots is incompletely dissolved catechol or sodium carbonate. A speck of either would leave a high density spot on your film. For future reference, any time you don’t have a tested development regime for a film in OA, develop 1:500, 20C, 30 seconds initial agitation, then 10 seconds every three minutes. This works for almost any film, but not with TMX. I don’t know why. I wish I did. Instead, use a 1:250 dilution, and prepare to be amazed! Just kidding, but it is pretty impressive. Maybe it’s because I was never able to get results I liked at 1:500 and just wrote off the combination for years. A fellow photographer encouraged me to dig into the issue, and it turned out I didn’t have to dig very far. My first test was 1:250 and success! Pretty embarrassing. Anyway, OA is highly compensating and capable of pretty grotesque edge effects when a dilute solution (1:500) is combined with low frequency agitation. HP5 Plus is especially prone to wiry results, but if you increase the concentration and agitation frequency with a suitably decreased development time, you can get very smooth gradation. If you want to increase emulsion speed instead of exposure, you can add a few grains of Metol to your working solution, but before you do, try the standard regime at the top of my comment. It might turn out to be a non-issue.
OA is pretty remarkable. I believe the issue was undissolved catechol or carbonate. After a couple of days, it was no longer an issue. I will definitely try it at 1:250. I'll also try a bit of Metol and see how much the speed is affected. I guess I can add a wee bit to the working solution? I'd also like to say that your 510-Pyro is a pretty solid developer. Thank you!
@@analogueandy8x10 I’m glad 510-Pyro is useful for you. It’s been very good to me over the years. Lately I’ve been using a bastardized version of Rudi Hartung’s semi-stand method. I double my established time for a film in 1:100 dilution with standard Ilford agitation. If I don’t have an established time I use the mfg time for that film in D-76/ID11 stock. I agitate 30 seconds initially, then 10 seconds at halfway point of total development time. This method gives me pretty robust negatives suitable for darkroom printing. It’s long enough to be forgiving of small errors in timing, but short enough to do multiple batches in a session. For example, my time for Ilford Pan F Plus is 13:00, 20C. HP5 Plus is 15:00, etc.