Agitation. constant vs Intermittent. Opinions

Started 4 months ago | Discussions thread
Bags27 Contributing Member • Posts: 960
Re: Chemical considerations

On their website, they say:

If you chose to develop with 270ml of chemicals, then yes: you will have to perform a continuous agitation, we suggest to use the additional crank which is more comfortable for continuous agitation. If you instead fully submerge the film with 500ml then you can turn the knob every 30 seconds, or experiment with different intervals of your choosing.

If you were using a Paterson tank, you'd fill it with a minimum of 290ml for 135 film and 500 ml for 120 film, because of the way reels are resized and stacked. But I suspect that the way film gets threaded into Lab-Box, the amount of developer doesn't depend on whether it's 135 or 120 film.

270ml will cover ~ 1/2 the roll of either film size. In the Paterson, the idea is that 290mi will completely cover a 135 reel and 500 will completely cover the 120 reel.

So, the default assumption always with a Paterson is that the film is completely submerged before we consider the question of the affects of agitation.

So, to begin to extract useful information from those who use a Paterson (or similar) tank for development, I suspect it's important to be using 500ml in the Lab-box.

But even then, the application to your needs will be somewhat different. With the Paterson (or similar), agitation both circulates developer, but also circulates air: inverting the Paterson, even with the film completely covered in standing position, means there are moments when the film has no contact with developer. I don't think that's the case with agitating the 500ml of the Lab-box.

If, on the other hand, you use the 270 fill method, your film will be exposed to air for 1/2 the time of each continuous rotation. And that's more exposure to air than will happen with Paterson agitation.

So, the varying methods of agitation will produce different effects between development tanks and the Lab-box.

Thanks for posting: I doubt I'd ever buy it, but have been curious.

Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow