tim_curry

Evan,

 

I think you may have done a proper test, but more information would be helpful. I did a film test recently with a white/black subject. Used a north facing white stucco wall and a black poster board (close to black, but not pure black). Used a spot meter to determine zone 1-8 on the white wall (texture) and the black poster board to see where it fell as zones became brighter (sort of a double check and contrast range as well).

 

After development, I first determined a pure black exposure time for film base plus fog density of unexposed film on my paper with my enlarger and my chemistry (unexposed edges of the film must be black on a proof sheet, or there is no valid test). Next started comparing a test strip of known values (Stouffer step wedge) to my film results and notes. Once I had a film speed, the highlight values were determined with a step wedge and development times for a good contrasty shot with whites and chromes (motorcycle in full sun).

 

Results were Efke25 @ asa12 in PMK Pyro 7:00 @ 70f (thanks to Ed for his input). Please note, PMK will typically reduce film speed by a stop so it would be better if we knew your complete process a bit better.

Just a side note to the Southwest trips in July. In Tucson and much of the Southwest our rainy season (read "Monsoon") starts July 4th most years. You can expect some intense rains, wind, thunderstorms and heavy weather. These build into the afternoon due to ground heating and extra moisture in the air.

 

PLEASE watch out for flash floods in canyons which can occur in lower elevations where there is no rain falling. These storms are beautiful, but have a shower cap or plastic tarp ready for your camera if it is set up and the clouds look dark. You may get a chance to see some truly spectacular storm clouds over the mountains and canyons complete with lightning and hail.

 

Flagstaff areas: Oak Creek Canyon, Walnut Canyon, Grand Canyon, San Francisco Peaks.

Tucson areas: Saguaro Monument west or east.

What I use as a rule of thumb, 200 times the focal length.

50 mm lens (about 2") would be 33'

150 mm lens (about 6") would be 100' etc.

I would also suspect bad seating of the film holder. A small portion of the dark cloth, a twig or leaf and you have a problem.

 

Were you outside in bright sunlight? Did the film stay in the camera in the ready position for a long time before taking the shot? Was the exposed film left out in the sun for a while as you were preparing the next shot? Any bright reflective surfaces near the film when it was out of the pack? Any variation in normal procedures can cause a problem, before the shot, during or after.

Make sure you have a cloth with a white side and a black side. Wear a head band to keep sweat out of your eyes. Use deodorant. Use insect repellant. Drink lots of water. Don't eat a big meal, just a salad if you must eat first. Wait until October (when it gets below 100f).

Shoot only at night |-)

Tim, Tucson, Arizona

I used my spot meter and a gray card to test for film speed / zone placement. The "subject" was a north-facing white stucco wall splitting the field by a black poster board. I reasoned that my meter/card was the constant and the film speed the variable.

 

Run a series of exposures with varying film speeds and make notes about the dark and light when processing is done and proofs are made. Will get you pretty close in one roll of film.

Try looking at Ed's site (unblinkingeye.com) in the PMK Pyro times. I think you will find a reasonable starting point if you use the PMK data for your first test (no idea about the ABC/PMK times, but you should be very close with this as a reference). Run a test strip with 35mm or 4x5 first to get in the ball park. You will most likely be using an ASA of 1/2 the manufacturer's rated speed.

 

Use distilled water for development to keep times consistent. Make sure to agitate properly.

One thing I have noticed when using tank development and Efke 25 is the amount of color in the presoak water. When it is dumped prior to actual development there is a lot of residual color rinsed from the film (anti- halation backing I suppose) at this time. I know it must be just a water soluble dye of some sort, but I don't know if it could affect any chemical action in the developer, so I am cautious and always do the presoak.

I tried Ed's suggestion on time & temperature and it worked out very well (E.I. 12 and 7:00 @ 70f), much better than I could have hoped. This combination seems to yield a very useful rendering of the zone system with this film. Shadow detail is visible into the lower zones (zone 1 at times when viewed under strong lighting) and highlights are full and subtle.

 

Metals such as chrome really shine with a radiance which is real. Tonal gradation is excellent and 35mm portraits cropped and blown up to 8x10 show no visible grain! This is amazing film if you are able to deal with long shutter times and relatively static compositions. Use this as a starting point for 35mm & 4x5 and please email me if you find these numbers to be off.

I'm trying to establish a baseline for Efke 25 in PMK pryo developer.

Planning on using it in 4x5, but I need a starting point, so I've

processed a roll of Efke 25 (35mm) using E.I.25, 32 & 50 with a white

wall & a black sheet of paper on a northern exposure wall in afternoon

light in clear sky (zones 10-1 each asa). I ran 11:00 min @ 70f in

10+20+1000 PMK, 0:15 sec agitation, 1:00 min water stop, 3:00 min in

TF4, 2:00 min in the used PMK and 30:00 min wash.

 

Negatives look O.K. (?) but I don't have a darkroom setup for printing

and I have no experience in developing, printing or evaluating B&W

negatives (have to start somewhere, so...). I can't seem to find

anything on Efke 25 in PMK, except a time of 4:45 & 5:15 from an old

post in 1999, which seemed way too short based on other times & my

trials with FP4+. Does anyone have any times which could be shared?

Did I over-develop and increase contrast too much? Thanks

I've recently built a 4x5 "box" camera with this lens. The comment about a good lens and not as good shutter seems to be correct. While I have not had any problems with the shutter, it is definately older technology which was made inexpensively. It does work and is able to function properly. The lens is sharp and takes excellent pictures. It is able to cover 4x5 and maintain very acceptable sharpness to the edge of the film. I use color transparency film and have absolutely no complaints.

 

The coverage would limit movements severly, but without movements, as in my design, there is ample coverage at reasonable cost. While a very crude camera by today's standards, the box camera works very well, especially with a tripod and smaller f stop. Depth of field with this lens it very good above f22 so movements are not a necessity the way I use it (landscapes).

tim curry, tucson, arizona