16mm Developing Tank Centre Fogging

Forum covering all aspects of small gauge cinematography! This is the main discussion forum.

Moderator: Andreas Wideroe

Post Reply
User avatar
gaugefilm
Posts: 131
Joined: Mon Feb 06, 2012 9:53 pm
Real name: Kevin Timmins
Location: Dudley
Contact:

16mm Developing Tank Centre Fogging

Post by gaugefilm »

Hi all,

I've been developing 16mm film now for a while in my lomo tank pretty successfully. However I'm pestered by one annoyance which is it's extremely difficult to agitate the film. This is how I've been using it:
Image
Tanks with no Spacers by Gauge Film, on Flickr

The above set up provides little agitation. I recently developed films with the cup turned and with a spacer:

Image
16mm Tanks with Smaller Spacer by Gauge Film, on Flickr

However this set up fogged the top edge of the film for about 15 frames towards the centre. It makes sense that the cup be rotated this way though because it fits snugly into the lid:

Image
Underside of the Lid by Gauge Film, on Flickr

I thought perhaps the spacer needed to be a little wider to lift the cup so I made one:
Image
16mm Tank with Large Spacer by Gauge Film, on Flickr

However rather than fixing the problem it now fogged around 30 seconds on the top edge of the film. I had thought about putting a bit of leader before the film in the centre but the tank just holds 100ft so it's not an option. Here is the only place where light can possibly get in the centre:
Image
Top of Tank by Gauge Film, on Flickr

If anyone can think of a way to keep the cup up as to improve agitation whilst keeping the tank light tight that would be amazing. I had considered making a black plastic disk the diameter of the internal tank. The disk could sit directly over the film, completely covering it (between the cup and spacer). If anyone has any other ideas, or knows why this might be happening please give me a post.

Thanks.
Kev
www.gaugefilm.co.uk
aj
Senior member
Posts: 3556
Joined: Thu Oct 02, 2003 1:15 pm
Real name: Andre
Location: Netherlands
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by aj »

The white material appears to let light through in the pictures. I.e. it is translucent.
You can imagine how little is needed to wreck your customers film.
Kind regards,

André
User avatar
livio
Posts: 167
Joined: Mon Sep 22, 2003 11:59 am
Real name: livio colombo
Location: milano - italia
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by livio »

Yes, probably the white stuff makes things worst. But I know the problem: even if my cup is black, with my (50 ft) Lomo tank I always make the first steps in very subdued safety red light. I only switch on the light after 30 seconds in the bleach (for b/w) or after 30 seconds in color developer (for color).
bye livio
User avatar
gaugefilm
Posts: 131
Joined: Mon Feb 06, 2012 9:53 pm
Real name: Kevin Timmins
Location: Dudley
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by gaugefilm »

Thanks both,

Can anyone tell me which way the cup was intended to be used? I don't always have the ability to work under a safety light so it would come in handy to make it light tight if possible.

The only way the spacers could have an impact is if the light was managing to pass through the central thread somehow where the cup screws into place. The translucent spacer came with the tank so I assume it shouldn't make to much difference below the cup. The key is blocking the light off at the cup. Perhaps a simple plate sitting in the bottom of the cup would do the trick? I'll try that next and report back.

Best
Kev
www.gaugefilm.co.uk
aj
Senior member
Posts: 3556
Joined: Thu Oct 02, 2003 1:15 pm
Real name: Andre
Location: Netherlands
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by aj »

Check the instructions and drawing here:
https://sites.google.com/site/olexservi ... processing

The cup must be fully opaque. I.e. no light may be transmitted through it all.
Kind regards,

André
aj
Senior member
Posts: 3556
Joined: Thu Oct 02, 2003 1:15 pm
Real name: Andre
Location: Netherlands
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by aj »

livio wrote:Yes, probably the white stuff makes things worst. But I know the problem: even if my cup is black, with my (50 ft) Lomo tank I always make the first steps in very subdued safety red light. I only switch on the light after 30 seconds in the bleach (for b/w) or after 30 seconds in color developer (for color).
bye livio

There are versions of the 50ft LOMO who have a problem with the small hole in the cup which allows the last drops to flow into the tank. It is too big and/or in the wrong place.
Kind regards,

André
richard p. t.
Senior member
Posts: 1004
Joined: Sat Oct 15, 2005 3:44 pm
Location: victoria, Australia
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by richard p. t. »

Hi Kevin,
the cup should definitely be 'up' and you should use the spacer. The problem I thinkn is that the cup is translucent. I think you are thinking in the right direction when you consider a light proof cup liner. You could even do a lot with black tape.

Livo - what AJ says about the little drain hole in the 50' lomo tank handle is quite right. You need to cover that hole with light proof tape. The hole was unnecessary - at least it is if you pour liquid in and out using the hose, rather than through the lid (which is not a good idea anyway).

richard
I run Nano Lab - Australia's super8 ektachrome processing service
- visit nanolab.com.au
richard@nanolab.com.au
woods01
Posts: 822
Joined: Thu Jul 31, 2003 3:09 am
Location: Vancouver
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by woods01 »

Interesting to see a different variation on this tank. On mine that particular piece is made out of black plastic. I would suggest a combination of some black tape and working in more subdued light that you presently are.
aj
Senior member
Posts: 3556
Joined: Thu Oct 02, 2003 1:15 pm
Real name: Andre
Location: Netherlands
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by aj »

richard p. t. wrote: Livo - what AJ says about the little drain hole in the 50' lomo tank handle is quite right. You need to cover that hole with light proof tape. The hole was unnecessary - at least it is if you pour liquid in and out using the hose, rather than through the lid (which is not a good idea anyway).

richard
Swapping the fluids through the hose may seem a bit slow option at first. But when you measure the needed time it is pretty quick. Especially when you measure to get a height difference and make gravity pull the soup in or out :)
I.e. hold up the hose with the funnel when pouring in and hold up the tank (or the hose low) when draining...
Kind regards,

André
richard p. t.
Senior member
Posts: 1004
Joined: Sat Oct 15, 2005 3:44 pm
Location: victoria, Australia
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by richard p. t. »

aj wrote: Swapping the fluids through the hose may seem a bit slow option at first. But when you measure the needed time it is pretty quick. Especially when you measure to get a height difference and make gravity pull the soup in or out :)
I.e. hold up the hose with the funnel when pouring in and hold up the tank (or the hose low) when draining...
Yes, quite so. Using the hose is the way to go. Pouring through the lid is unnecessary and risky as I say.
I run Nano Lab - Australia's super8 ektachrome processing service
- visit nanolab.com.au
richard@nanolab.com.au
User avatar
gaugefilm
Posts: 131
Joined: Mon Feb 06, 2012 9:53 pm
Real name: Kevin Timmins
Location: Dudley
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by gaugefilm »

Hi all,

Just wanted to say thank you for all the helpful advise.

The hole in the 50ft tanks are completely useless. I covered these up when I started using the tanks years ago. I never really understood their purpose (I suppose drainage if you pour from the top).

I've covered the white cup and translucent spacer with black tape. I still haven't had a chance to develop any of my own 16mm film yet but as soon as I get a day off I'll go and shoot some film and test it all out. I'm confident it'll work. The last 15 frames were barely fogged on the edges (just coming into shot) so hopefully it'll completely fix the problem. Fingers crossed!

Best
Kevin
www.gaugefilm.co.uk
User avatar
gaugefilm
Posts: 131
Joined: Mon Feb 06, 2012 9:53 pm
Real name: Kevin Timmins
Location: Dudley
Contact:

Re: 16mm Developing Tank Centre Fogging

Post by gaugefilm »

Just reporting back on this. I developed some of my own 16mm film last night. I taped up the cup and developed with only a 60W lightbulb in the room and it worked perfectly! I was also testing out my filmo 70DR after a shaft repair. Works great! It's great to know I can confidently process 16mm again now. Shame there wont be too much 100D left though. I'm down to 7 100ft rolls now I think. Terrible business.

Kevin
www.gaugefilm.co.uk
Post Reply