Topic: Harman Direct Positive Speed Tests

[JoeV]

Some of you might know that I've been a fan of Harman's Direct Positive Paper, but due to some recent exposure issues I decided to retest the paper to determine its proper speed for daylight scenic photography. Today I did the testing while shooting an informational video on the process, which is linked below.

In practice, I've found it important to use consistent metering and exposure techniques, while development should also use a consistent dilution, temperature and time. Unlike with paper negatives, this paper doesn't like nearly exhausted or used developer, and it also will exhaust your fixer faster than conventional paper.

I hope you find the video useful.

~Joe

https://youtu.be/5yUuLi6PkTQ

[jojonas~]

well presented, joe

[jharr]

Good video Joe. I don't keep paper developer around since I don't make traditional silver gelatin prints. I have developed this paper in Rodinal 1:50 and in caffenol with contrasty results. Pre-flashing helps some. Have you used film developers with DPP?

[JoeV]

I haven't tried film developer, it does sound interesting. I didn't mention in the video that these tests were with pre-flashing.

And today I took my lessons learned in the video and applied them to the 8x10 sliding box camera, using ISO7.5, and now have several nice 8x10s of the Sandia Mountains.

You might have noticed toward the end of the video, when I showed the over-exposed 8x10, that the upper corners of the print were heavily vignetted. I fixed this problem with the sliding box camera by repositioning the lens a bit further forward, closer to where the waterhouse stops slide in place, and that eliminated the problem.

Thanks again for the feedback.

~Joe

[LT]

Hi Joe - great video and very helpful.

Be aware that DPP has a reverse reciprocity profile - fast exposures of less than 1 second will be under exposed - it is better to test this stuff at exposures of longer than 1 second.

I find it a complete nightmare to tame! even pre/post flashing can be unpredictable depending upon the final exposure time.

I guess the best approach is just to find what works for you!!!

good luck with it.

[John Robison]

Thanks for the presentation. I have some DP paper from Foma, bought from Freestyle several years ago and found it almost impossible to work with. I just shoot paper as a negative now, much easier to control. I've backed the Galaxy high speed DP paper Kickstarter project and intend to develop that as a negative also. I'm only interested in the fast ISO aspect of that paper. Another thing I found out when trying to use DP paper is that I don't like mirror reversed images, don't know why but they bother me.

[JoeV]

Leon: thanks for the tip regarding the negative reciprocity of Harman DPP. That does explain some effects I've seen. I think if I can keep daylight shots at the same shutter speed and vary the aperture, I'll be okay. I just need to do a separate calibration in cloudy and shaded light.

~Joe