I have recently been getting back into film work, now that i have a proper large format scanner.
After being rather unimpressed by my old go to developer, Rodinol. I got myself a pack of basically every standard developer from kodak to test with.
After a quick test series on my usual film, Fomapan 100, i found HC110 to have the most potential, so i started my investigations there.
using the Density values of 0.1 for zone I, and 1.3 for zone VIII i set out to determine the actual film speed of Fomapan 100 and HC110, as well as the optimal development for it.
This was spurred on, by a few photographs taken in 9x12 cm, having essentially no shadow details left, and tonality being rather unimpressive. Below is an example image of Fomapan 100 in HC110 20° for 6 min, using the massive dev chart specs.
The scanner struggled to scan this, and a lot of adjustments in photoshop where needed to get even close to a usable image. Needless to say, i did not even try printing it with standard contrast paper.
Now to my actual measurements. After improvising a Densitometer from one of my microscopes, a light dependent resistor and a precision calibrated multimeter, i set out to measure the actual values needed to get Fomapan 100 to behave with HC110.
Materials:
Camera: unknown make 9x12 cm with Rodenstock Symetrical Anastigmat 135mm F4.5
Film Stock: Fomapan 100, freshly ordered from Fotoimpex. Tests where done initially on 9x12 sheets, and then verified on 18x24 using my oldest camera
Light source: Visatec Solo 400 and Wilimax octobox
Light meter: Sekonic l758D
Densitometer: Leitz Ortholux microscope, 4x Achromatic objective, Periplan 10x eyepiece with LDR taped on it, viewing through a Trinocular prizm. Illumination was Köhler, checked against my Zeiss Spectrophotometer and AFGA film scanner (both at a different location, thus the need to improvise one)
Developer: HC110 (new formula) ordered with film, mixed 1:31 (dilution B) with softened tap water
Stop bath: Citric Acid in Tap water, 1:25 from stock solution containing 25% acid
Fixer: Adox Adofix Plus mixed 0.1g/ml in Distilled water, measured using 1mg watt balance
Hypo: Potassium Sulfate 10g/l
Methodology:
Determination of film speed:
6 masks where created of thick card stock (amazon envelopes), to fit over the 9x12 cm film adapter, and able to secure into the 9x12 film holders, while permitting the darkslide free movement. The masks contain 6 holes of 16mm diameter in sets of 3 per line, spread so that 12 fit on a 9x12 sheet.
The so shielded film was set into a no name camera containing a Rodenstock Doppel Anastigmat lens, previously cleaned both inside and out.
The camera was set at infinity focus, and placed at a distance of 30cm from a dark matt grey board at 90° to the lens axis. This was then illuminated by a strobe from 50 cm away (from surface of octobox diffusor), placed at a 45° angle to the camera. A lightmeter in spot mode was placed next to the camera with a 5° offset from its main axis and pointed to the same spot as the center of the lens. (both camera and lightmeter on tripod). This setup was done in my improvised darkroom, aka my basement bathroom.
12 exposures where then made, with the lens in Bulb mode, opening only manually moments before firing the strobe by hand, and closing soon thereafter. The light meter was set to -4EV, and exposures from ISO 25 up to ISO 200 where made in 1/3 stop increments.
The film so exposed was then developed normally according to the massive dev chart, and each value read by my densitometer. During development i had made a small error, in that i let my chemistry cool down to room temperature, which ended up being 19°C exactly.
Development sequence as fallows:
2 min; presoak in water; 1 minute stand, and 1 minute continues agitation by lifting the front of the tray by 1/2"
6 min; development ; 20 + 30 seconds continues agitation, fallowed by 15 seconds every minute, last 5 seconds out of tray while preparing to transfer to stopbath
1 min; Stop bath; Constant Agitation
3 min; Fix; Constant Agitation
1 min; Hypo; Constant Agitation
20 min; Wash Tap water at 19°C running at 0.5 l/min into an inclined tray
1 min; Adoflow Allowed to dry for 4 hours, i later skipped this step as stated below
Exposure was controlled via a combination of changes in strobe power, and aperture, as indicated on the meter.
The film speed thus found, was ISO32, much to my surprise.
I then repeated the above using only 6 fields, to verify my measurement.
Development time determination:
Now that the film speed was determined, i made another mask, which exposed 1/3 of the negative in a vertical stripe. Using this, and the above arrangement, i created a test film containing a Zone VIII stripe, as well as a Zone I stripe. The center, left unexposed was used to measure the base density.
This test film was cut into strips of 15mm width, and developed in 30 seconds increments within the HC110 bath.
I have found, that a development time of 5 minutes at 19°C will yield zone 1 density of 0.1 and zone VIII density of 1.3
Further tests where conducted to determine expansion and contraction development times according to the works of Ansel Adams.
It was thus found that a development time of 4 minutes yielded a N-2 contraction and a 6 minute development a N+2 expansion. N-1 and N+1 appear to be 30 seconds from my experiments.
Measurements of densities was conducted on wet film, by placing it onto a clean slide, and covering with a cover glass. This yielded a lower error then semi dry measurements, and was choses for convenience as i did not want to wait hours per measurement.
Experimental exposure:
In order to check my measurements, i decided to compose a quick test scene within my darkroom, metered with the above value for ISO and developed according to my measurements.
Visually it turned out considerably better then my previous attempts at using HC110 on Fomapan 100, and testing with my AGFA scanner confirmed the density range that was expected to be present, based on meter readings.
The test image also featured a color checker passport, to obverse the color rendering of fomapan 100
I was quite pleased with the tonal range present, and using the insight gained from the above image, i decided to compose and shoot a still life i had been wanting to shoot for the better part of 2 weeks. This image was composed using a different camera, namely my custom build 18x24 from around 1850, and a ICA 240mm F5.5 Lens.
Illumination was created by 2 Visatec (Broncolor) Solo 1600 strobes. Exposure was done in a room with only minimal darkroom lighting, due to the camera not having a shutter.
The thus resulting image looks as fallows:
I must say, i am fairly pleased with its tonal range.
Needless to say, further experimentation is required to determine if 20°C temperature works also, in addition to other Dilutions of HC110, as well as the 2 Bath method suggested by Ansel Adams, originally intended for thick film emulsions, but appears to work with Fomapan 100 as tested on a unused test strip from the above. Also, i need to test the effect of the Softened tap water.
I hope this short summary of my measurements is of help to anyone and that my photographs are at least half decent.
Notes:
I intend to run further tests on Fomapan 100 with different Dilutions of HC110, as well as other developers. These will be added to this thread and linked (assuming possible) below in this first post.
Additionally, i want to measure other films, including ones of the XRay Variety.
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