Re: [Leica] Agitation - Surge

["Joe Codispoti" <joecodi@thegrid.net>]

In my experience, streaking or surge is caused by the solution passing over
the sproket holes. This however can happen in sheet film as well where there
are no sprocket holes. In sheet film it is caused by the solution "surging"
throught the holes of the film hanger.
As Dan pointed out, it is more noticeble in under developed film (the
solution develops more where it rushes past the holes).
To avoid surge, one or more of the following techniques can be employed:

1. Fill the tank completely. No air space to allow the solution to move
quickly.
2. Immobilize the reel (s) by inserting a film can whith the bottom removed
so that it can be compressed forming a spring that pushes the reel down
(insure that the tank lid is tight and will not come open from the
pressure). A  reel allowed to move freely within the developer can cause
surge.
3. Use even agitation, not too short and violent nor too long and slow. Two
to three inversions (3 to 5 seconds) is average.
4. Use a dilution combination that allows adequate time for even
development. Too short a development time is asking for uneven results.
5. Be consistent in the way you develp/agitate so as to avoid surprise
problems. If a problem arises, most likely it is due to some difference in
your routine.

Keep in mind that if adapting these techiniques represents a deviation from
your routine, adjusting developing times may be necessary.

Joseph