Uneven development for 120 film

[merelyok]

Hi all,

I've moved from 35mm B&W self-processing to 120mm self-processing. I haven't had much problems with 35mm but i seem to be getting uneven development issues with my 120mm developing.

I use a Paterson tank which states 500ml of developer for one 120mm reel.I use exactly that amount. i use HC-110b (usually with T-max 100, one off. I tried FP4+ once and got the same problems again). I'm getting nice tones (or rather i think i do, but the uneven edge is really bugging me.) There seems to be some purplish left-over on the film edge, which i believe could be anti-halation resiude.

My agitation technique is to inverse the first 30 seconds for the 1st min and 10 seconds for every min thereafter. I use ilfotec rapidfixer thereafter for 6 mins, washing for 10 mins under cool water.

Some sample pics:

(note uneven contrast on left)

(on right)

I'm starting to think i need abit more than the 500ml of developer recommended by Patterson. Also, i reckon its not a camera problem since i've used a Mamiya, a Minolta and a Bronica and get the same results.

Anyone have any idea?

Thanks!

 

[cabbySHE]

Paterson is a reliable brand in darkroom product.
I'd not encounter problem like yours, but experienced buckle negative due to sloopy loading of film onto the spool.
Have got only this to suggest : ( sound stupid though )

* Put the empty spool into the tank and fill with 500 ml of water and see whether it is enough to cover the whole spool.

* Test process one empty roll with 500 ml
* One roll with more than 500 ml

The last picture has got a telltale sign that the left edge is normally developed.

 

[catchlights]

if you did fill up 500ml of developer, but did you push the reel all the way down to the bottom tank till it move no more?

 

[welspain]

* Put the empty spool into the tank and fill with 500 ml of water and see whether it is enough to cover the whole spool.
.

:bsmilie: have the same problem with 1st roll before, i did this and 500ml as stated in the tank is not sufficient, should use 700ml to be safe.

 

[catchlights]

couldn't be. it takes only 500 ml for 120 film, perhaps you'd put the reel stop at the bottom instead at the top

 

[merelyok]

Nope, i def. got the reel rights..

anyway, i tried 600ml this morning and its gone! It's evenly developed now (as compared to the last 4 rolls that had the same problem).

Same agitation, same developer, same film, same agitation technique..

So i guess the extra 100ml helped. (as suggested by alucard on another forum).

Cheers!

 

[cabbySHE]

Nope, i def. got the reel rights..

anyway, i tried 600ml this morning and its gone! It's evenly developed now (as compared to the last 4 rolls that had the same problem).

Same agitation, same developer, same film, same agitation technique..

So i guess the extra 100ml helped. (as suggested by alucard on another forum).

Cheers!

Should have written to inform the manufacturer, perhaps in return as courtesy of thanks, a 3 spool developing tank in the mail.

 

[Dream Merchant]

Paterson tanks sometimes have different depths (for the same product - System 4: 2 x 135 or 1 x 120 capacities).

IF you have the deeper tank, and would like to save some chemicals, I have the slightly shallower tank ... in case you're interested in swapping.

My shallower tank can't take my 4x5 sheets of film. :sweat: