I think the result of this comparison are quite as expected. Sodium hydroxide may be the most caustic chemical sometimes used in developers. It's common name is "lye", and it will burn exposed skin. It's also very hygroscopic, meaning that it absorbs water out of the air. This means that if you have a bottle of the stuff, the water it absorbs will make measurement of an accurate amount nearly impossible and will cake up in the bottle. D-23 is just metol (developing agent) and sodium sulfite (preservative). The sulfite also makes the solution slightly alkaline, which is required to activate the metol. Adding sodium hydroxide substantially increases the alkaline pH, causing the metol to be more active (faster developing; more grain). It's greatest effect here is going to be increasing the base fog.and reducing development time compared to straight D-23, with some contrast and grain increase. In summary, it just makes D-23 more like a number of other developers, however it lacks the restrainer added in those other formulas to keep down excessive base fog. I can't think of a single, beneficial reason to do this.
Thank, Andy. D-23 is all I use currently, usually 1:1, at stock solution for some pushing, and DD-23 with a 10% Borax solution for N-minus. I'm wondering what you've seen regarding speed loss with 1:3 compared with 1:1. I had tried it with N-minus after seeing the sparkling highlight detail, but the speed loss (confirmed by a number of others on the LF forum) was self-defeating, which is why a turned to DD. But for N development, it still seemed to lose speed compared with 1:1. Perhaps I needed a higher developer-to-film-area ratio?
At box speed with Pan F, I see a speed lost going from straight, to 1+1 to 1+3. How much? Not sure exactly. I'm planning to speed test at box speed with densitometre, though! Cheers!
No! There's is not enough silver halide solvent in dilute D-23 to produce dichroic fog. And modern films have special ingredients in them to prevent dichroic fog.
@@analogueandy8x10 Oxidation products of Metol in a low sulphite environment. The colour of the stain on the film is close to the colour of your spent developer.
I think the result of this comparison are quite as expected. Sodium hydroxide may be the most caustic chemical sometimes used in developers. It's common name is "lye", and it will burn exposed skin. It's also very hygroscopic, meaning that it absorbs water out of the air. This means that if you have a bottle of the stuff, the water it absorbs will make measurement of an accurate amount nearly impossible and will cake up in the bottle. D-23 is just metol (developing agent) and sodium sulfite (preservative). The sulfite also makes the solution slightly alkaline, which is required to activate the metol. Adding sodium hydroxide substantially increases the alkaline pH, causing the metol to be more active (faster developing; more grain). It's greatest effect here is going to be increasing the base fog.and reducing development time compared to straight D-23, with some contrast and grain increase. In summary, it just makes D-23 more like a number of other developers, however it lacks the restrainer added in those other formulas to keep down excessive base fog. I can't think of a single, beneficial reason to do this.
Thanks for sharing you work Andy much appreciated.
Cheers Andy, l learned a lot here, haven't used the D-23 yet.
It's quite versatile, for such a simple developer. I need to try out the replenished version. Cheers!
Thank, Andy. D-23 is all I use currently, usually 1:1, at stock solution for some pushing, and DD-23 with a 10% Borax solution for N-minus. I'm wondering what you've seen regarding speed loss with 1:3 compared with 1:1. I had tried it with N-minus after seeing the sparkling highlight detail, but the speed loss (confirmed by a number of others on the LF forum) was self-defeating, which is why a turned to DD. But for N development, it still seemed to lose speed compared with 1:1. Perhaps I needed a higher developer-to-film-area ratio?
At box speed with Pan F, I see a speed lost going from straight, to 1+1 to 1+3. How much? Not sure exactly. I'm planning to speed test at box speed with densitometre, though! Cheers!
Thanks for your video I ask you about what kind of film do you use?? haw many times you develop it with D 23?? Congratulations from ARGENTINA
The film in the video is Ilford Pan F 50, but I also use xray film and develop it in D-23 1+2.
@@analogueandy8x10 O thanks I use D23 for x ray rilms exposed 50 asa 1 +1
The stain might be dichroic fog maybe? If it has different colours in transmission and reflection, that's dichroic.
No! There's is not enough silver halide solvent in dilute D-23 to produce dichroic fog. And modern films have special ingredients in them to prevent dichroic fog.
@@RaghavendraUdupa lol small world 😅
I defer to your judgement on this.
It's a yellow stain, that wiped off with my fingers. I think it was caused by an excessive amount of sodium hydroxide...
@@analogueandy8x10 Oxidation products of Metol in a low sulphite environment. The colour of the stain on the film is close to the colour of your spent developer.
@@RaghavendraUdupa I think you may be right. Interesting. Thank you!