I tend to develop in batches so the bleach gets used for 4-6 carts of super 8 and then dispose of it after 2 weeks max, it slowly degrades into water over time which I think increases the pH, making the bleach less concentrated but also less stable. I check the pH to ensure its around between 2.6 to 3.4, lower pH is less active. Lower temp also makes it less active, so its a balancing act between temperature and pH - its not possible to determine the concentration of pH so I've found its better to dispose of it and use fresh peroxide if in doubt

@@adycousins OK, that's a useful starting point. Thanks again.

Keep it dark, cold and airless :-)

@@adycousins - Can you reuse the peroxide bleach? - Are there any other ingredients in the bleach?

@@geireplekake820 you can re-use the bleach for a limited amount but it becomes less stable and a bit more aggressive possibly due to dissolved silver acting as a catalyst and / or pH changes. The bleach is usually 9% food grade peroxide with added acetic acid stabiliser (98% 20-28ml per litre), or hydrogen potassium phthalate, which works better with a tiny amount of silver nitrate to act as a catalyst (this is based on a Kodak patent from mid nineties)

Although it mostly works, and I still occasionally use it, I find it a little inconsistent, with eg Tri-X 7266 presenting real problems with either blistering or incomplete bleaching, whilst Tri-X 7278 and Plus-X work quite well. I wouldn’t call it reliable as it really depends on the nature of the peroxide- which I’ve found to be variable. Kodak patented a series of peroxide bleaches in the mid nineties (as they sought more ecologically acceptable options), but switched from dichromate (R9) to permanganate (R10), probably because of the inherent problems with peroxide.

I should add that the faults are more pronounced with 8mm and 16mm compared to 35mm due to the level of magnification of the image required being much greater

thats correct :-)

sorry I don't know what you mean by 'see saw'?

@@adycousins oops pardon me, I mean by visual inspection.

@@irsan949 oh, I see, well its a bit tricky by visual inspection, because it may look complete but then when you've done the remaining steps you'll find staining and incomplete bleaching, and its too late to do anything about it. So I'd suggest starting with a test strip (about 10cm), giving it a long bleach - say 20mins, completing the process on the test strip and inspecting it after the whole process is complete, then if it is acceptable you may be able to reduce the bleach to say 15 minutes. If you're using D94 first developer and D95 second developer the actual development is really short (2 mins FD, 1 min SD) so bleaching becoomes the only long part of the process

@@adycousins Great. Thank you. That should give me starting point. 🙏🏻😊

No

If I used the D94 as a second developer the silver solvent in it (sodium thiocyanate) would dissolve some of the developing silver which would then deposit itself on the surface of the emulsion - it’s called ‘dichroic fog’.

About 1minute 45 seconds of super 8 at 18 frames per second

D94 Water - 750ml Metol - 0.6g Sodium Sulphite -50g Hydroquinone - 20g Sodium or Potassium Bromide - 8g Sodium Thiocyanate - 6g Sodium Hydroxide - 20g Water to make 1 litre

Orwo A71 distilled water: 700ml (or 2g calgon in tap water)
 sodium sulphite: 55g
 phenidone: 0.7g
 hydroquinone: 10g
 sodium carbonate: 55g
 potassium bromide: 10g
 water to make 1 litre pH 10.1

Thanks. Much appreciated is the time 12min for first defelper and 6 for the second

Ashley Hunter - First Developer is 2:00min at 20C, bleach is about 12-15min and Second developer is about 6-10min

Hi Adrian how are you sorry it been a while but I have got all the chemicals to have a go at this so it's 2m first defelper. 15min bleaching. and 6 Min second defelper also is the cemetery reusable or is it down the drain and thanks