Banding ? Copex Rapid / Caffenol

[Thatspec]

Is this an agitation issue? The three frames closest to the center of the reel don't show it and most others do. Very light edges, darker center with banding. I used Fernando's very light Caffenol recipe at 16:30 70 degrees. 30 second initial and gentle swishing, three very gentle swishes on the minute. The three frames closest to the center received the best exposure to well mixed developer.

Content and perspective aside, I was in a hurry to get to my coffee...

[url=https://flic.kr/p/RUBS45]L1004750-2

And one without the banding. For as contrasty as the scene was, I couldn't be happier with this recipe if I could get even development with it;
L1004746

Actually, now I see it in that last one a little bit too, no banding but light edges...

Your opinion is appreciated, thanks!

 

[Thatspec]

Recipe was here in this 2014 thread;http://www.rangefinderforum.com/forums/showthread.php?t=144324&highlight=agfa+copex+rapid&page=2

I notice that in a later 2016 thread he seemed to up the concentration a little bit.

 

[Larry H-L]

Too little agitation in my opinion. This streaked look often shows up similarly with stand development.

 

[Thatspec]

Thanks Larry, I've never experienced it before but this was my first try with Caffenol. Unfortunately I can't invert this tank, forgot to bring the cap along. Next try will be with continuous agitation (swishing in my case) for the first 60-90 seconds with maybe twice the swishing on the minute. 16:30 is a little tedious to me so might try to up the strength 10% and reduce the time as a third try...

 

[Larry H-L]

If you have an inverted "T" rod to slowlly lift the reels totally out of the tank and re-submerge, every couple of minutes, IMHO, that would be preferable to swishing.

 

[Thatspec]

Good idea, unfortunately with a patterson tank the reel is pretty well locked down there. Have another roll of the Copex Rapid ready to go and will try the extended initial agitation and maybe just try to tip and swish on the minute. Anything would be more aggressive than the first try...

 

[Skiff]

My results with Caffenol have always been much worse compared to normal developers. Not only with this film, but also with lots of other films.
I am always using a densitometer and evaluate the optimal speed and characteristic curve for best tonality. And so far Caffenol could never compete with standard developers.
For Copex Rapid I am using the dedicated Spur Dokuspeed SL developer. I get optimal results with it.

 

[Fixcinater]

I would try a shorter initial agitation and do more frequent but shorter agitations. One rocking motion back and forth every 5 mins would build less contrast than a long initial session and yet keep the dev moving to prevent streaking.

I just did a 2hr what ended up being nearly stand dev and had streaks, got distracted by other things and so it went for over 1/2 hr without any agitation. Previous semi-stand routines with more regular single rocking motions every 15 mins did not have the uneven sky or banding issues. I also got an excessive amount of edge effects between some dark trees and lighter sky so they look like they were poorly dodged/burned.

 

[Ronald M]

Pick a developer like D76 and follow instructions. You will have less problems.

Streaks are either bromide drag from not enough/improper agitation or pouring developer into tank through the top allowing it to run over the film unevenly because of sprocket holes. Since your problem is in sections, I suspect the latter.



Solution is to drop the film into a tank prefilled with developer, cap, begin initial agitation immediately.

Rotate the tank during inversion so it is random.

Basic rule is agitation must be random and vigorous. Those who claim other wise are lucky. Kodak data sheets say 5 to 7 inversions in 5 sec with a small tank. Those here are not superior to Kodak.

You may pour thru the top with plastic tanks as they fill bottom up and do not wash over film.

 

[Thatspec]

Thanks everyone for the suggestions and information! This current roll came out much better albeit still needs some tweaking. I did a 90 second initial ag. and was more vigorous
on the minute, everything else identical to the previous roll. As mentioned, I can't invert in the Patterson but it does fill from the bottom and I'd agree the damage is done in the first moments or at least minute. Yes the banding is gone. I will blame some of the unevenness on the 'Flinstonesque' scanning procedure I'm using while on the road. Can't complain but looking forward to seeing what this really looks like.
From a couple of days ago;

I may at some point spring for the Dokuspeed but right now mixing this stuff up is more fun. I have plenty of Acros and D76 if I just want it to come out perfectly.

As mentioned, there is no KBr in this recipe and it's incredibly weak by any Caffenol standard. I will try a 20% stronger mix on the next roll and reduce the time accordingly. Would never buy Copex Rapid at home (Oregon), too expensive, but while I'm here may as well, it's 20% cheaper than Acros.

 

[Thatspec]

Ronald, you mentioned D76 which I have and usually use 1:1 on Acros 100.
Any opinions about using it on Copex Rapid at 50? Maybe 1:2 and around 15 minutes?

 

[Thatspec]

Latest results Copex Rapid 120 at 50;
I upped the concentration about 20% to
Soda 12g/L
Ascorbic acid 2.8g/L
Coffee 16g/L
I use half of the above for a 500ml batch mixed in Wiesbaden tap water at about 40C (goes in the tank at 21C)
15 min, 1 min continuous, then every min.

First is the worst... Interestingly this is the only shot that came out this way and it was the last pic on the role so center of the spiral in the tank. On the plus side my homemade adapter for the 45 apo-Grandagon seems to now be at the right thickness.
L1004808-2

After
L1004808

100% crop should be available on Flickr
L1004808-3

So short of throwing in a little KBr or trying my tank with the lid on so I can fully invert it, I don't know what else to do about the uneven development but am certainly open to suggestions. Experiments are on hold for the next month or so anyway while we go on a road trip around Northern Italy. I'll have no means to process images and will shoot mostly color on the trip. Think I'll likely spring for the dedicated dokuspeed developer for the Copex on my return so I have a base line as to what I'm shooting for here.

Hope that those of you continuing to experiment with Caffenol will consider posting here😀

 

[rfaspen]

I have to admit, I didn't read all the posts in this thread carefully, so maybe this has been suggested:

But, I've been using iodized salt in my caffenol formulations for years now. This is a kind of replacement for KBr. I started using it because I didn't have any KBr available when I first started using caffenol.

Now, I don't have any comparisons to show here but I'm generally successful with semi-stand development (with iodized salt). I've been unsuccessful too, but there's always risk with stand and semi-stand development and I just can't say it its because I used I-salt instead of KBr.

So...maybe give iodized salt a try? The replacement ratio is kind of high; I believe its 5:1 iodized salt to KBr, but I could be wrong so best to check that with the popular caffenol website.