Microphen life?

[varjag]

Well, a Microphen substitute strictly speaking; I mix it myself although the formula is supposedly the same.

It recently went through my 20th roll of film, with no visible sings of degradation. Initially it a 1 liter of stock, but a few rolls ago I spilled it (duh) and it became 0.5 liter - just enough to fill my tank.

When should I expect it to go bad? What is its typical life?

Also, when mixing I've used a shot of vodka to dissolve phenidone (the solution still smells of alcohol), can it affect the longevity?

 

[JimL]

Hi Eugene,

It's been a while since I used Microphen but I seem to recall that I increased the developing time by about 5% after each film when using 1 litre of stock. I arrived at this figure from trial and error (emphasis on error!) My tank only held about 600ml so after development I was advised to re-mix the tank contents with the remainder of the litre of stock solution before re-using. This gave me pretty consistent results.
I discarded the developer after developing 10 35mm or 120's as per Ilfords instructions, but there was never any sign of developer exhaustion so maybe it could have gone on for longer. I never wanted to risk losing a film so I didn't push my luck. Sorry I can't be of more help on this matter.
I would, however, suggest that developer is cheap and at 20 films developed, you've had your money's worth out it. The way I look at it a new batch of stock solution is cheap insurance against losing an important shot.
As for using a shot of vodka to dissolve the phenidone, I have never mixed developers from raw ingredients so I can't comment on it's effect. I'd probably have drank the vodka and stirred for longer!

Regards,

Jim.

 

[kaiyen]

I use 12 rolls per liter as my rule of thumb. No particular reason, I guess. Just that I've heard some recommend 10, and I one accidentally went to 15. The latter scenario needed more time, which I inevitably forget to do, so I have since gone with 12 and haven't noticed any major issues.

allan

 

[varjag]

OK, I developed two more rolls in it last night and poured it down the sink.

The negs again have turned out fine; no sign of degradation whatsoever. But perhaps it was time to ditch it, just as mentioned, to be on the safe side.

Now gonna try if Diafine is for me.