Harman Direct Positive Images

[MAubrey]

Do you have any rule of thumb for in camera preflash?

My guess would be to start with some rule like 'preflash with diffuser for 1/3rd of the metered exposure' obviously one would have to bench that against the actual light transmittance of the filter etc.

Tim Layton has a discussion on youtube on preflashing with tracing paper like what I do (at about 2:20):

https://www.youtube.com/watch?v=N1nhN_057FE

[John Olsen]

Do you have any idea how long the pre flash lasts?

I'm doing my preflash under my enlarger before cutting down to 4x5 sheets. I did tests to find what it took to make a minimal change on a black test strip. I prefer doing it beforehand for predictability and also to avoid yet more sources of errors when out shooting.

[John Olsen]

Selenium toning of Harman paper:
I posted earlier a pinhole image that was a little washed out, both because of subject matter and some overexposure. I hoped that selenium toning might firm up the shadow tones a little. Using the Biggerstaff recipe of 1:20 dilution at 70 F I toned the 4x5 sheet. After 4 1/2 minutes the image started browning and at 5 minutes there seemed to be some deepening of shadows. However, the browning moved faster than the deepening so I pulled it at 5 1/2 minutes. It's hard to say whether the darkening paid off and the color change was certainly more than I wanted. (It's OK in this case, because it ends up being an accurate color for the actual scene.)

[locutus]

Tim Layton has a discussion on youtube on preflashing with tracing paper like what I do (at about 2:20):

https://www.youtube.com/watch?v=N1nhN_057FE

Thank you! watching now :-)

[John Olsen]

More 4x5 pinhole camera Harman images, each at 12 1/2 minutes under heavy overcast.


Sheepherder's Cabin on Engel Farm, built 1900-10.


Ebey's Ferry House, South View

[John Olsen]

Pratt Farm barn in a 21 minute pinhole exposure, heavy overcast of course.



Pratt Farm shed in 57 minute, even gloomier exposure in a light rain. Now I know that I don't need to consider reciprocity failure with Harman paper.

[John Olsen]

Yesterday's light rain was perfect for a 4x5" pinhole back at the Engel Farm sheepherder's cabin. Another 57 minute exposure.

I think the contrast is starting to weaken and needs fresher Dektol for the next excursion. This was 12 4x5's in one quart of Dektol 1:2.

[SMBooth]

Nice set John

[locutus]

Lovely pinhole shots, motivation to try some DP outdoors again for me!

[John Olsen]

Lovely pinhole shots, motivation to try some DP outdoors again for me!

Thanks. You might note that my own DP languished in the fridge for 1 1/2 years because it seemed too contrasty and unpredictable to use. Now that I have standardized on low contrast lighting of neutral-colored objects it is working more reliably. Admittedly, that limits my subject matter.
Give it a try yourself.