Small tank agitation w/reels - uniformity?

I've researched this everywhere I can, read everything I could find, and am still failing to achieve uniform development across 35mm roll film frames when developing in small tanks.

But only with modern films i.e., 400TX, 125PX, and HP5+. For some reason regardless of agitation technique uniformity is quite good with Arista EDU Ultra II 200.

I've tried slow inversion, 'torus' rolling, vigorous fast inversion (as if tossing a can from hand to hand including rotation), single reel tank, double reel tank with empty reel and enough chemistry for only one reel, etc. and I end up with either bromide streaks from the sprocket holes, clouds around the sprocket holes, or excessive development along the edges. The streaks and clouds are always on the side of the film nearest the top of the chemistry surface when soaking.

Out of all the options a relatively slow hand-to-hand can-tossing technique seems to work best with rapid inversion and rotation but no large vertical movement or shaking. Uniformity is still not perfect though. I use the same technique for stop, fix, and wash, fwiw.

I thought using half the chemistry of a two reel tank would work better than a single reel tank with the same amount of chemistry but there's no substantial difference that I can see. Maybe I'm not allowing enough dwell time at the end of each inversion. I'm stumped and it's getting aggravating after a lot of film. The few rolls that've come through OK are way overdeveloped (but that's a separate problem) and I've no real idea what was done differently with them - figures.

Any suggestions, pointers, youtube video references, etc. would be greatly appreciated. TIA

What developer are you using, what sort of developing time, and do you presoak?

I'm wondering the same.. What developer?
Are you getting bromide drag from a formula with too much bromide? Also, is your tank one of very small volume, and is the reel in it too tightly? I've found that I get best results when using tanks that allow the reels to move around a little during agitation. When you can hear them going "clunk" (steel reels & tank), then all is good.

Thanks guys, forgot those pesky details.

This seems to be true using PF TD-16 1:1, XTOL 1:1 (to a much lesser extent), HC110 (D) (a bit less of a problem), and especially PF DD-76. The tanks are Kindermann or generic SS with Kindermann lids, the reels are Hewes, and I can feel the reel moving in the single tank but not so much the reels in the two reel tank. I use 250ml of solution to keep things simple and it's more than enough to cover a reel with film although not by much.

Most of the tests have been with 12exp rolls although some 30 and 36 exp rolls aren't substantially different. I have to say though that the worst uniformity is on the frames near the outside of the reel which doens't make a lot of sense. Also, come to think of it, I've used 4-reel tanks with the loaded ones at the bottom and another spaced with an empty reel between and another above, using a lift rod. The bottom reel was more uniform but excessive dev along the edges while the upper reel showed clouds along the topmost edge. The 4-reel tank is always used with 850ml of solution.

Developing times are anywhere from 2-12minutes. All chemistry is brought to temp in 1000ml pyrex beakers in a tempering bath and temp compensation is achieved using an RH Designs ProcessMaster II. A digital thermometer is used to make sure all solutions are within a half degree C of each other and the bath prior to starting.

No presoak is used but the tank is dropped back into the tempering bath between agitation cycles. Cycles are continuous for the first 30s (<5min total) or 60s (>5min total) and two inversions every 30s or 60s, respectively. Stop is continuous agitation, fix is the same as develop except the number of inversion cycles is 10 instead of two. Drain and fill is attempted to be complete within 10s although that's not always successful.

Lessee, what else? All chemisty is made in lab glassware with boiled distilled water and stored in Qorpak amber Boston Rounds with teflon lined caps. Fix and stop are mixed with unboiled distilled water as needed, stop for DD-76 is plain DW. Wash is plain DW held in beakers as well. Other than the stainless probe of the digital thermometer the chemistry never contacts anything but glass. Bottled chemistry is stored in the dark but temps range up to 80F during the summer. No chemisty is more than a couple of months old. If I missed anything, please let me know.

justpete said:

...I use 250ml of solution to keep things simple and it's more than enough to cover a reel with film although not by much.

...Cycles are continuous for the first 30s (<5min total) or 60s (>5min total) and two inversions every 30s or 60s, respectively.

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Try using just a little more developer. Sounds like you might be losing a little on inversion and that top edge of the film may be fully submerged only part of the time. Your initial agitation time seems more than adequate, but the number of inversions per cycle is kind of low and slow. Try doing 5 quick and snappy inversions in 5 seconds each 30 seconds, or 10 in 10 seconds each minute. You really can't overdo this. Most of the problems I've seen have been the result of timid agitation techniques rather than too vigorous.

FWIW, I do 4 inversions at each agitation, never do developing times less than 5 minutes, and usually use Xtol at 1:1 or lately, 1:3. I process roll films in stainless and always fill the tank, with reels, and solution, always at 68/20 deg. No problems with uneveness or bromide drag.
PE convinced me to pre-soak, but I didn't for years, and haven't noticed a difference in terms of even or uneven development either way.

My advice would be similiar to Franks, more chem, two reels in a two reel tank, more or more vigorous agitation. If that doesn't resolve it, try pre-soaking, especially if you're processing for very short times.

I would strongly suggest staying away from combinations of film, developer and temperature that result in times less than five or six minutes !

Also, the agitation sometimes sounds extreme - after all, the aim is to get fresh dev at the film regularly, rather than to create localised high-speed swirls of developer. A couple of slowish inversions (four or five seconds each) per thirty seconds, with a 1/3 turn of the tank when you put it down (to avoid any accidental repeated effect when doing the same thing every time) works fine for me.

If you do a test with the wash-water and take the lid off a tank to look at how long the liquid takes to get out of the funnel and down into the tank (when there is film in the reel), you will see that it is several seconds. Inversions more rapidly than that time, may just make for foamy developer and possible marks at high-speed flow locations around the reel, especially if you do repeated high-speed inversions in exactly the same way every time.

As mentioned by Frank above, The volume of developer also needs to be enough to comfortably cover the reel(s), as well as having enough active developer to do the job, though that should only get tricky with high dilutions of course.

Unless you have really disgusting tap-water (ie. fine sediment, or not for human-consumption), then you might be able to save some money and gain convenience by just using filtered-water for everything except the final rinse.

All this works fine for me anyway.

I use the same brand of tank and reel, but in the 120 size and have always filled the tank with 500ml of developer; this pretty much completely fills it up. I've never had any problems with this set-up but did experience some similar problems with a palstic paterson tank which I didn't fill all the way because it could take a litre of liquid.

I've always been surprised how vigorously you can agitate the tanks without getting any problems (except maybe higher contrast negs). There are a number of videos on youtube that show people developing b&w film, maybe you could have a little look to get an idea of how much you can agitate while developing.

All good suggestions above. The only thing I can add is to increase your development times to close to 10 minutes (find the temp and dilution to facilitate this), use enough developer to FILL the tank, and don't agitate too vigorously. Try a higher dilution for HC110, or D76 1:1. I've never used Xtol.

Rick

Agree wholeheartedly with the 'fill the tank' recommendations.

I had your problems when I was doing the 250ml in the 500ml tank, way too much 'sloshing' going on and a huge amount of flow through the sprocket holes.

I went to filling the tank completely and I think you'll find your problem goes away if you do the same, coupled with gentle agitation to prevent highlight blocking.

-Fred

I agree with Frank Schifano: Use a little more developer to guard against leakage and increase the number of inversions at your half-minute intervals. (I use 4 inversions in 5 seconds.) That said, I've never filled the tank when the film only occupies half the tank. That's always seemed pointless to me, and I've never noticed differences between half-full tanks (for two-reel tanks when developing one reel) and full tanks (which I do use when I put two reels in a two-reel tank).

There are videos on YouTube of film development. I don't have any URLs offhand, but you could do a search.

One more suggestion, albeit a more radical one: You could ditch the SS tanks and get a Paterson, AP, or similar plastic tank that permits "twirl stick" agitation. My impression is that most people prefer inversion agitation, but a few prefer to use the twirl stick. It's conceivable that this method would give you fewer problems than inversion agitation does, just because of your own idiosyncratic approach to both methods.

You don't need to abandon the steel tanks/reels to try twirl agitation. I, when I feel the need, simply rotate my steel tanks in the same manner as I would with my Paterson tanks and get exactly the same effect. The laws of physics are the same whether you twirl the film in stationary solution or twirl the tank/reel/film in a stationary solution. I see no difference in the quality of the final negs. In fact, I happen to prefer the quality of negs that are twirled rather than those that are agitated like a washing machine. Highlights aren't nearly as dense and more separation in the middle tones.

Just my .02,

-Fred

Another vote for extra dev in the tanks - better a little extra than not enough.

Don't fill the tank to the brim though - you need a little room to mix the dev up as you agitate - the sloshing causes turbulance in the liquide and it is this that mixes the chemistry up.

If I use only part of the tank, I leave the other reals in place and make sure there is a good half inch (10mm) of spare depth in the developer

I agiate by rocking the tank from one hand to the other - one hand at the bottom of the tank and the other at the neck - one second to turn upside down and another to turn it right way up again. Repated 6 times and leave to stand for the remainder of the minute

I have nevr seen negs that have suffered from excess agitation - but I have seen evidence of too little (mine included sadly)

Martin

OK, after eight hours and sixteen rolls, some observations:

Nothing seems to faze Arista EDU Ultra II 200. Presoak or not, gentle agitation or vigorous, full tank or just barely enough, it comes out even as can be every time. But Tri-X, Plus-X, or HP5+? Not so much.

Dilution and developer don't seem to make a difference. Tri-X at an EI of 250 through TD16 1:1 or XTOL 1:3 looks the same, with or without a presoak. Development along the edges of the frame adjacent to the sprocket holes is heavier than at the center but it's a narrow area and densest closest to the middle than the ends. Might've been the illumination on the gray card but it doesn't show up on the Arista which was shot at the same time in the same setup.

With more vigorous agitation in TD16 1:1 thin dark lines appear radiating from the edge of the film toward the center, between the sprocket holes, as well as from the center of the sprocket holes themselves, surrounded by a slightly lighter area. I'm assuming this to be surge related but not enough of a surge to create large visible 'clouds' of lower density. And again it occurs only on the top of the film even when the tank is filled more than normal, although the tank is not filled completely. The areas along the edges where the development is denser occur top and bottom though.

HP5+ doesn't respond to a presoak at all as far as I can tell. It does however show a more pronounced sensitivity to agitation, at least in TD-16 1:1. The same agitation that produced the thin dark lines described above left large surge clouds along the top edge's sprocket holes and a much wider region of excess development along both edges. It was really obvious. I'm guessing I managed to not fill the tank that time. And as I recall, this was the roll agitated every 30sec during a 10-12min dev time so it would appear that too much agitation isn't a good thing.

Another roll of HP5+ developed immediately prior, also in TD16 1:1, came out nearly perfect but with the faintest of streaks in the lowest density frame and again only along the top edge. It was presoaked for more than five minutes and agitation during development was very light with little rotation. I couldn't duplicate it with another two rolls though, agitation was probably too intense. And I probably didn't have the tank as full either.

Plus-X was strongly streaked in TD16 1:1 even though it was presoaked. Another roll came out pretty much the same. But neither was developed with a full tank. Tried again with two more rolls and made sure the tank was nearly full. The heavy streaking wasn't there but some slight surge cloud-like streamers were. Agitation was probably too intense and with too much rotation. No obvious overdevelopment along the edges adjacent to the sprocket holes though.

I searched youtube and found a number of videos showing agitation methods. It doesn't look like I'm doing anything much different from most anyone's demonstrations with the exception of imparting a lot more rotation at each inversion.

Looks like the modern films are touchier, or the Arista stuff is peculiar to itself, dunno. Thanks to everyone for all the help, it's been invaluable. I'm getting closer but am bummed about not being able to get consistent even results with any film. Whatever it is I'm not doing right I'm missing it completely.

If anyone has any further suggestions or things to try please let me know.

TIA, Pete

How fast are you filling your tanks? With 120 and developing in stainless tanks with the slower filling plastic tops, I fill the tank in the dark and drop the loaded real into the solution.

With 35mm I do continuous agitation for 30-45 seconds, and then two inversions with a twist every minute, this agitation thorough but gentle, taking about 8 seconds.

jmcd said:

How fast are you filling your tanks? With 120 and developing in stainless tanks with the slower filling plastic tops, I fill the tank in the dark and drop the loaded real into the solution.

With 35mm I do continuous agitation for 30-45 seconds, and then two inversions with a twist every minute, this agitation thorough but gentle, taking about 8 seconds.

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As quickly as possible but within ten seconds is rare, usually longer. Longest times were occurring when I was trying to control the amount but it's quickest when I just fill the tank. When filling the tank I have it tilted over initially and bring it upright as it's filled to avoid trapping any air. Last time I deliberately checked for an air bubble by rapping the tank with the cap off I didn't see any but it does seem slower than it ought to be.

Another thing, and this is probably key, the most non-uniform development occurs on the film that's on the outside rather than nearest the center. And it's a short roll, only 12exp I've rolled myself with a bulk loader. So it takes up about half the radius of the spiral.

Duh. This would be where the developer is moving fastest during inversion. I think I need to roll up a 30 or 36exp roll and run that through the same process to see if it comes out ok.

I don't have a darkroom light-free enough to drop the film into an open tank so I'm limited to using daylight tanks and pouring the chemistry in. Agitation sounds about the same although I started with two inversions instead of five at each agitation point. Maybe I should try that again when using a full tank.

justpete said:

Another thing, and this is probably key, the most non-uniform development occurs on the film that's on the outside rather than nearest the center. And it's a short roll, only 12exp I've rolled myself with a bulk loader. So it takes up about half the radius of the spiral.

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This, in combination with your comment that you impart more rotation to your tank than you see others doing in their videos, makes me think the rotation may be the issue. One of the objections I've seen from others to "twirl stick" agitation is that you'll get different amounts of development on inner vs. outer parts of the spiral with this method. It could be you're seeing something similar, but manifesting itself mostly along the edges. If so, cutting back on the rotation as you invert your tank should help a lot. It's worth trying, at any rate....

srs5694 said:

This, in combination with your comment that you impart more rotation to your tank than you see others doing in their videos, makes me think the rotation may be the issue. One of the objections I've seen from others to "twirl stick" agitation is that you'll get different amounts of development on inner vs. outer parts of the spiral with this method. It could be you're seeing something similar, but manifesting itself mostly along the edges. If so, cutting back on the rotation as you invert your tank should help a lot. It's worth trying, at any rate....

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Oh! I hadn't ran across this issue while searching, disregarding those returns as I don't use a Paterson tank, hmmmm. Correlation - kewl. Thanks!

I just spooled up a couple of 36exp rolls each of Tri-X, Plus-X, and HP5+ for testing with XTOL 1:1 (ran out of TD16 today) to see if spiral-fill makes a significant difference. Now I can make a more reasonable comparison by not using much if any rotation while inverting the tank. Big help there, tnx again.

I use Hewes SS reels for both 120 rollfilm and 35mm - I presoak with tempered DIW, I always fill the tank with developer. I always agitate gently. My development times are always 10 minutes or more. No uniformity problems, no streaking, with any of the developers I use.

srs5694 said:

This, in combination with your comment that you impart more rotation to your tank than you see others doing in their videos, makes me think the rotation may be the issue. One of the objections I've seen from others to "twirl stick" agitation is that you'll get different amounts of development on inner vs. outer parts of the spiral with this method. It could be you're seeing something similar, but manifesting itself mostly along the edges. If so, cutting back on the rotation as you invert your tank should help a lot. It's worth trying, at any rate....

Click to expand...

Oh! I hadn't ran across this issue while searching, disregarding those returns as I don't use a Paterson tank, hmmmm. Correlation - kewl. Thanks!

I just spooled up a couple of 36exp rolls each of Tri-X, Plus-X, and HP5+ for testing with XTOL 1:1 (ran out of TD16 today) to see if spiral-fill makes a significant difference. Now I can make a more reasonable comparison by not using much if any rotation while inverting the tank. Big help there, tnx again.

Tom Hoskinson said:

I use Hewes SS reels for both 120 rollfilm and 35mm - I presoak with tempered DIW, I always fill the tank with developer. I always agitate gently. My development times are always 10 minutes or more. No uniformity problems, no streaking, with any of the developers I use.

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Good to hear there's hope for me yet then.

I take it you don't use much rotation (if any?) when inverting?

Divided D-76 results show no dev artifacts

I'd forgotten I'd shot 24 12exp rolls of which 8 were developed in Formulary DD-76 a few days ago.

While measuring the 16 other rolls this morning I checked the uniformity across the frame's short dimension and it can be as much as a full stop from center to edge. The density of a given exposure also increases as much a third to a half a stop from film end to start, or outer to inner surface on the spiral.

These numbers hold regardless of presoak or developer or film, with the exception of Arista (Foma) 200. However, the edge to center uniformity of the Arista film is no better than any of the others, it just doesn't 'look' as bad since there aren't any dev artifacts.

Measurements of the DD-76 rolls show a much better edge to center uniformity. Base+fog variance is typically 0.05-0.08DU from edge to center and symmetrical. 'Zone' V measures about a third of a stop, worse case, from center to the top edge and about the same variance as b+f on the bottom edge. The variance from start to finish on any of the 8 rolls is essentially zero, unlike the 16 other rolls.

There are absolutely no development artifacts visible on any of the 8 rolls run through DD-76.

I'm assuming this is due to the minimal developer activity as it soaks into the emulsion. I'm also assuming the slight asymmetrical edge to center density variance is due to the inversion rotation during the accelerator bath. The tank was filled each time with only enough fluid to cover the film in the spiral, or about 250ml in a single reel tank. Agitation was 30s+5X/30s for both bath A and B. Some rotation was imparted but not as much as during the dev tests with the other 16 rolls.

Too bad DD-76 is wayyyy too active for any of the films under test, shot at either box speed or +2/3 stop, at least for an opal bulb condenser enlarger. Times would have to be reduced to as little as 30s-1.5min which just isn't going to work, I think. I haven't plotted and fitted the full data yet, just the endpoints and center so this could change.

Would a much longer presoak with agitation (30s + 5X/30s) make a difference with the non-divided developers? Seems like it'd have to be on the order of 5min or more given the one single artifact-free result with HP5+ in the 16 roll group. Anyone have a recommended time?

I don't know that I have ever had - under agitation failures - I have certainly had over agitation failures. Sometimes less is more and you don't want the velocity of the liquid too fast or you will have streaks near the spools. - NEVER go under 5 minutes. Always use enough chemistry to keep the developer out of exhaustion.

Use the proper amount of soup for the film in the tank; or even a little more, if possible. And with ss reels, put enough empty reels in the tank to keep the loaded reel in place when agitating. You do not want it sliding up and down in the soup when you invert the tank. My .02.

Cause - Senrac w/heat

Tried hanging a roll instead of running it through the Senrac and there weren't any marks of any kind other than the obvious ones from water running down the length of the film.

Took a few of the previously processed flims that had obvious marks or streaks on them and rerinsed in distilled water for a total of 3min w/agitation and then ran them through the Senrac without heat - marks and streaks are gone.

This explains the one good roll of HP5; I remember one develop cycle where I discovered the Senrac heat wasn't on as the drying cycle ended but didn't have time to redo it.

Along the way Edwal LFN didn't help and if anything made it worse mainly with emulsion damage from bubbles that turn out to take quite a bit of force rapping the tank to dislodge. No bubbles using only distilled water so LFN kinda does the opposite of what's expected. And this was at one drop per liter of distilled water dilution, half that called for in the bottle's instructions. :confused: