DK-50 Dilutions

[voceumana]

I'm looking for guidance on using DK-50 at 1:3 dilutions, and approximate starting developing times, especially with modern films (TMY-2, Acros).

There's supposed to be an old thread in the articles on DK-50, but as the front page of this forum says "*DATA FROM THE OLD SYSTEM IS BEING IMPORTED SOON, PLEASE DO NOT RE-ADD YOUR OLD CONTENT."

Seems it's been being imported soon for the last year or so. Anybody have the info from that old posting?

Thank you for any suggestions.

[Christopher Walrath]

Wirelessly posted (BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

My old dtat guide has a time/temp chart that indicates 6.5-7 minutes at 68F. Does not specify any particular film but it's a starting point.

[jnanian]

hi voceumana

not sure if you searched here for dk50 threads
but http://www.apug.org/forums/forum37/1...0-its-use.html
might be helpful ...

i have never heard of diluting it as you suggest. the best use of dk50 is straight, with sheet film.
i used it for a long time as i was a lab-person for a portrait photographer trained in the 20s/30s ...
i processed armloads of 5x7 sheets of tri x and tri x ortho, straight never dilute developer in deep tanks.
the trick with a lot of deep tank developers is they need to be mellowed to work best.
that means not to dilute them, but to process a bunch of film in them so they get oxidized
and then use it. i replenished ours for a certain number of films through it, and then when i mixed fresh
i left about 1/3 a tank of spent developer to mellow the new, so it would work right ...
besides 5x7 sheets, i processed my own 4x5 (hangers) and 35mm ( on a bent coathanger ) in the same tanks
and got very good results. grainless, nice contrast ...

i wish i could be of better help for dilute dk50 ...
digitaltruth doesn't even have times for this developer, dilute ...

if you have a green safelight, you could always develop by inspection
and get a better idea on what your times should be.
there is a very good article here .

good luck!

[jnanian]

Wirelessly posted (BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

My old dtat guide has a time/temp chart that indicates 6.5-7 minutes at 68F. Does not specify any particular film but it's a starting point.

that is for dilute ? or straight ?
i used to process sheets of tri x around that time/temp
and i wasn't using dilute developer ...

[Ian Grant]

Geoffrey Crawley discussed using dilute DK50 in a series of eight articles on Developers in Dec/Jan 1960/61 in the British Journal of Photography.

The data was included in subsequent BJP Almanacs /Annuals. You need to make up an additional solution of approx 8.3% Sodium Metaborate (Kodalk). This is said to give "a useful balance of natural acutance, gradation and speed qualities with controlled contrast rise" Effectively this is 1+4 with additional alkali.

Dilute DK-50

Part A
Stock DK-50 (full strength)

Part B
Sodium Metaborate (Kodalk) 83.3gms (1oz)
Boiled Water to 1 litre (12oz)

To use:

2 Parts A - DK50
1 Part B
7 parts water

Development times: FP4 8-9 mins @ 20°C, Pan-X 10-12 mins, Tri-X 13 mins.

Hope that helps

Ian

[Christopher Walrath]

Wirelessly posted (BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

The dataguide I have said straight solution. I personally don't use. Just relaying info.

[voceumana]

Anchell/Troop's Film Developing Cookbook mentions DK-50 1:3 as well as BJ Dilute DK-50, and indicates it gives close to a straight line curve without "blowing out the highlights" and suggests the higher dilution for modern films (possibly even 1:6 for TMax if I remember right). But alas, no suggestions on starting times. There outta be a law...when a book recommends a developer it should have to say how to use it, at least as a starting point! DK-50 is recommended for subjects of limited contrast range such as studio work.

This is the reason for my interest in the developer at this dilution.

Ian: Thank you for the BJ recommended times--it gives me some starting points.

Charlie Strack

[Ian Grant]

Charlie, the FDC dilution is essentially the same 1+4, Troop has used a weaker solution of Metaborate, also he's taken Crawley's figure of 1oz Metaborate in 12oz water (83.3gm/litre) and and substituted 50gms Metaborate/litre. Perhaps you took the 1+3 figure from the 1+1+3 Troop gives as the working solution.

Ian

[lamda]

A Kodak data sheet (F-4017) from 2007 for Tri-X 320 and 400 shows some times for DK-50 1:1.

[Ian Grant]

The BJP - Crawley - Dilute DK50 uses additional Metaborate to maintain it's activity at 1+4 and keep development times within reasonable parameters. Crawley published this version of the formula Jan 27th 1961 in the BJP, the Metaborate solution is given as 10z in 12oz water, (83.3g/litre), same as the 1976 BJP Annual version I gave above.

Ian