Hand Processing Flicker Query

[Christian Flemm]

Dears,

I've been using a small Meopta tank to hand process approx. 5ft of 16mm film at a time, but lately have been noticing a flicker making its way onto the film material, whether I'm processing as reversal or negative. Here are two short tests, the first of which is in Tri-X reversal, and the second of which is in Double X negative (digitally flipped from neg to pos). I'm wondering if this is a result of over-agitation in the first developer (in both cases) or whether someone has a better idea.

The scans were produced on a homemade scanner, but I use this machine regularly for clients and know that it is not a factor in the image quality here (which was also apparent during projection).

Best,

Christian

[Christian Flemm]

Friendly bump :)

[Joerg Polzfusz]

I assume that the chemicals didn’t properly came in contact with the film all the time: not enough agitation, not enough chemicals (especially in combination with too much agitation and hence effects of the centrifugal force), film stuck on other parts of the film, …. But I am not an expert in this. 

Edited September 20, 2023 by Joerg Polzfusz

[Byron Karl]

This looks consistent with my past hand-developing results. I think the density fluctuation is part of the "look." I assume if you let it "stand develop," then the frames might get a more consistent development.

[Frank Wylie]

How do you agitate the film?  If you rock the tank or spin the reel in a set pattern, you can form standing waves within the developer that will produce varying densities. 

Unfortunately, you're not going to get commercial quality with small tank development on a reel, but you can get better results when you vary/break-up the agitation scheme to make liquid movement more random.  Of course, there are physical limits to how much force and direction  you can apply to both the tank and the spool, so be careful not to break anything.

That's why commercial processors weigh several tons and take up hundreds of square feet;  to provide the huge chemical reservoir of developer that is blasted impingement style against the emulsion as it runs through the development bath.

[Richard Tuohy]

It is an agitation thing (as others have suggested).  Especially for bw negative, developing motion picture in a spiral needs special attention to agitation to get a good result.  But you can get a perfect result.  Process with the lid off in the dark.  Lift the spiral right out of the tank every say 30 seconds and let it drip for about 3 seconds.  As you get close to the final time, put the lid back on and you can turn the lights back on.  Makes a huge difference.