Tuesday, November 1, 2011

First results with Phenidone/Ascorbate developer and learning to use it.

My first experiments with this developer resulted in underdeveloped films.
To demontrate what it looks like I'll post these images here.

Take a look at the shadows. There is no details in the shadows. The highlights have some details, but not like it should be. The tonal scale is somewhat strange. Not directly short, but there is something missing. Grains are also visible. All kinds of microscopic dust shows up so to make a half-decent image it takes a lot of cloning away dust spots.

I tweaked the settings of the scanner in all ways to make some useable scans.


This image is captured on a Kentmere 400 film, shot at ISO 400.
Take a look at the shadows. No details!


This is a crop from the previous image.
Here it is easier to see that the shadows lacks details.

I have use an unsharp mask to increase sharpness. This makes the grains and scanner artifacts more visible.

The images are useable, but not perfect.
This is the results from thin and underdeveloped negatives.

You can get this from using any developer, including Caffenol and this one.

Michael mentiones that the activity in this blend is a bit off the sweetspot, so the development times is a bit longer than anticipated.

In addition to this, I used the temperature-time correction chart at Digitaltruth to correct development time for 23C instead of 20C. It seems that this chart isn't correct for this film and this developer. Reading Kodaks charts reveals that they are different for each film and developer. Both time differences and slope of the curve varies from film type to film type.

Increasing development baseline time from 6.5 minutes to 8.5 minutes and NOT correcting for 22C temperature gave me the close to perfect negatives for the images I posted earlier today.
Not correcting for temperature will give about 0.4 stops push according to the time-temp chart and push-processing tables. Looking at the negatives I will say that it may be about 0.2 stops push. Nothing to worry too much about with other words.

This image is from the last fil through the developer. Take a look at the shadow details in this image. There is a lot more detail in the shadows. The scanner software was not tweaked in any way to get this image. Just set white and black points. Turned down brightness just a tad.
The image has much better tonality and the grains are quite fine. The scanner hasn't generated any strange artifacts caused by a thin negative. All in all a much better result.

Some small adjustments now, and we have a real good developer.

2 comments:

  1. Looks like your dev times are lining up more with Xtol 1:1 than D-76. This dev is more similar to Xtol anyway as Xtol is essentially ascorbate + phenidone + sulfite while D-76 is metol + hydroquinone + sulfite.

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  2. I don't know what else you guys have in mind but I would like to suggest a few test candidates as well.

    The first is PCB (20g borax + 6g ascorbic acid + 0.15g phenidone in 1L water) for a re-usable developer. It just seems to go on and on with no change in activity.

    The second is an adjustable one-shot dev using a 1% metaborate solution (6.92g borax + 1.45g lye in 1L water) and varying amounts of PC-Glycol (10g ascorbic acid + 0.25g phenidone + propylene glycol to 100mL). Using the pc-glycol at 20mL/L in the metaborate solution activity is similar to D-76 and you can go as low as 8mL/L pc-glycol for a much slower stand developer (this is PCM). I tested 20mL/L, 16mL/L, 12mL/L, 8mL/L, 4mL/L as this is easy for me to measure in a 250mL tank (5mL, 4mL, 3mL, 2mL, 1mL).

    I find making PC-Glycol as above is a very convient way of keeping ascorbic acid + phenidone in ideal proportions ready to make whatever dev I want by varying the PC-Glycol quantity and the alkali.

    I received an e-mail some time ago from someone that tried the PCM developer and they found it worked well for them.

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