Not so Magical Powers of Stand Development

DF Cardwell suggested to agitate every 5 min with Rodinal 1:50 and steel reels to get uniformity:
(there was a url link here which no longer exists)
I use his method with plastic reels and find 5 min a bit long.
I do this because he states extra shadow density is obtained , although it is not very clear to me from the curves he attached.
But he has 40 years experience.

michael_r said:

Note that halides released from the emulsion are not necessarily what cause the streaking. It depends on the developer formulation but the streaking/mottle can also be caused by developer oxidation products.

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Looking at it with a modicum of science, bromide drag should cause a halo effect rather than streaking, which seems limited to 35 mm film. I would suggest that the latter has a more physical cause than chemical.

michael_r said:

I just wanted to add that in addition to this, insufficient agitation can lead to streaking, mottle and/or general non-uniformity. I found this to be the case when I tested Rodinal/FP4 stand development. Uniformity was so poor it was difficult to perform sensitometric density measurements.

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That is exactly what I would expect, which i why I always agitate as recommended or at least every few minutes.

- Leigh