Rollei RPX 25 in Rodinal ? (real Rodinal, not the R09 stuff)

[Leigh]

Has anybody used this combination?
I'd be interested in your experiences.

TIA

- Leigh

[cuypers1807]

I am curious as well. I primarily use D76 with RPX25 and it my favorite film for the DR5 direct positive process.

[Greg]

From my darkroom log:

120 RPX 25 shot at ASA 25
Rodinal 1:50
68 degrees
12 minutes
little underexposed but negatives superbly sharp

next time rate as ISO 12.5
try with a 9 percent Sodium Sulfite solution and adjust time

The low ISO of 12.5 didn't thrill me and I was only enlarging my 120 negs to max 11x14, so RPX 25 seemed like an overkill to me. Switched to RPX 100 and RPX 400... still have some rolls in the freezer which I will now use.... forgot I had them there. Hope this info helps you in some way.

[Leigh]

Very interesting, Greg. Thank you.

I'm surprised that you found underexposure with 12 minutes in Rodinal 1:50, given
the datasheet recommendation of 11 minutes.

Could you expound on the 9% Sodium Sulfite, please?

I too seldom go larger than 11x14, although the darkroom is set up for 16x20 max.

- Leigh

[Greg]

Very interesting, Greg. Thank you.

I'm surprised that you found underexposure with 12 minutes in Rodinal 1:50, given
the datasheet recommendation of 11 minutes.

Could you expound on the 9% Sodium Sulfite, please?

I too seldom go larger than 11x14, although the darkroom is set up for 16x20 max.

- Leigh

My enlarger back then had an Aristo diffusion head so I preferred a denser negative with a full range of tones. I normally start off by exposing at half the mfg.'s published ASA... I just like a lot of shadow detail and with roll film am using the camera's meter. Using a 9% Sodium Sulfite solution instead of water gives you finer grain and less sharpness (practically never saw the difference cause never made extreme enlargements) but more importantly the highlights never blocked up.

[Leigh]

Using a 9% Sodium Sulfite solution instead of water gives you finer grain and less sharpness (practically never saw the difference cause never made extreme enlargements) but more importantly the highlights never blocked up.

Hi Greg,

Is that for diluting the Rodinal or as a pre-soak before development?

Thanks.

- Leigh

[Taija71A]

Hi Greg, Is that for diluting the Rodinal or as a pre-soak before development?

Leigh, it is for 'Diluting' the Rodinal Film Developer.
--
If you Google: "Adding Sodium Sulfite to Rodinal Film Developer"...
You will find a 'wealth' of valuable information.

Thank-you! -Tim.

[Leigh]

OK. Thanks.

- Leigh

[Taija71A]

No problem... You are more than welcome.

[Jac@stafford.net]

The 9% solution was a common alteration suggested by Edwal for his FG-7 in the Seventies (perhaps earlier). Looking at my negatives of that era suggests that it was a bad idea. Not fatal, but the loss in acutance is regrettable. i reverted to D-76 1:1.
.