"Constant agitation during the first 30 seconds"...

[fred_obturateur]

Hello,

I think this is recommended by either Ilford or Kodak (or both... or neither!),

but I THINK I read this somewhere.

My question is : do you do this or do you simply do the usual agitation process

(every minute for Ilford every 30 s. for Kodak)?

Thanks!

[nbg90455]

That's what I do with TMax100 film in TMax developer -- 30 sec. agitation initially, and then 10 sec. per minute...

[erik_hattrem]

I do the same with ilford and fomapan 30 sec. then 10 sec every minute or 5 sec every half.

[yann1]

I've also heard this and that's what I do with HC110 and Rodinal for my films HP5 Trix Agfa.... But constant agitation should be soft, shaking too violently could cause the negs to fog.

[randall ellis]

This is done with all developing, even stand. For the first 30 seconds of developing you keep agitating the can, then for the rest of the development you do your normal intermittent agitation. This initial agitation prevents uneven development and air bells by allowing the film surface to become evenly saturated with developer.

 

- Randy

[graham john miles]

Just do a gentle rolling motion with the hand. Too fast and the developer will surge through the sprocket holes causing dark streaks. I should think that's happened to everyone at least once.

[ivan_dzo]

The aim is to wet the film with developer evenly. constant 30s agitation makes sense. You might get away without it, but why bother risking it?

[chris_waller]

I give six steady inversions in the first 30 seconds then one inversion every 30 seconds thereafter.

[nealcurrie]

I agitate for about 10 seconds when the developer first goes in, but I always presoak.

 

I've never noticed uneven development problems.

[fred_obturateur]

Thanks for the varied replies!

I was wondering if I should this because I had under-developed negs in the past even though I was doing things by the book (Tri-X rated 250 pre-soak 3 minutes D-76 1:1 for 10'30).

I'll try it and see if my negs aren't too hard.

 

Thanks again!

[big toys are better]

The most important reason for the constant agitation along with some sort of mechanical whacking of the tank at the end is to dislodge any bubbles from the film and ensure that the entire film surface is rapidly and equally wetted. I learned this the hard way early on, and have not suffered the bubble effect since (but ruined some treasured images because of that lesson). As long as the development time is fairly long, this should not cause streaking along the sprocket holes because the film is still just getting wetted in the first minute-- the developer has not yet fully diffused into the emulsion.

[paul_hoyt]

I have used constant agitation for the first minute for over 20 years. With roll film and Nikkor tanks and reels, I invert the tank every second for the first 60 seconds and then 4 inverts every 30 seconds until development is complete. I have used a variety of Kodak film and once I started the above agitation scheme uneven development went away.

 

Paul

[mendel_leisk]

"The most important reason for the constant agitation along with some sort of mechanical whacking of the tank at the end is to dislodge any bubbles from the film and ensure that the entire film surface is rapidly and equally wetted."

 

Good point!