Harman Direct Positive Images

[JoeV]

I corrected the orientation of the two images posted above, as per Jimi's suggestion. Not sure why I didn't notice it earlier, but there you go. As a result, the Flickr links are broken, so I'm reposting the newly oriented images in this reply. Couldn't edit my original post.

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A brief session today in bright sunlight, just before noon local sun time. 4x5 Anniversary Speed Graphic with Ektar 127mm lens at F/8. Preflashed Harman direct positive FB paper, exposures 2 and 4 seconds respectively.

~Joe

[JoeV]

Nambe ware bowl with decorative gourd. Harman Direct Positive fiber paper in handmade 8"x10" nested box camera using a 265mm single-element meniscus lens stopped down to 9mm aperture, 4.5 minute exposure under indirect north daylight.

Paper was preflashed and developed with Ilford PQ liquid concentrate diluted 1+15.

~Joe

[JoeV]

Bottles, Harman Direct Positive fiber paper in handmade 8"x10" nested box camera using a 265mm single-element meniscus lens stopped down to 9mm aperture, 7 minute exposure under indirect north daylight.

Paper preflashed, developed in Ilford PQ liquid concentrate diluted 1+15.

~Joe

[JoeV]

Earlier this week I took a stroll down along Central Avenue, the old Route 66, in Albuquerque, equipped with 4x5 Anniversary Speed Graphic, Ektar 127mm lens and film holders loaded with preflashed Harman Direct Positive fiber paper. Here are some results. Scans from direct positives, spotted in PS.

~Joe

Zia Motor Lodge:

(Exposure: 2 seconds at F/22)

Fence:

(Exposure: 2 seconds at F/22)

Alley Door:

(Exposure: 2 seconds at F/22)

Shopping Cart:

(Exposure: 3 seconds at F/11)

[JoeV]

And one more:

Flying Star Cafe:

(Exposure: 2 seconds at F/22)

[Kimberly Anderson]

I have been playing with 'In-camera Monotypes' for a few years now. I have just received two boxes of the direct positive paper and am very excited about it.

Thank you for the pre-testing that you were able to provide Joe. It is very valuable.

We will be using this material as well as regular photographic paper for my daughter's science fair project which will deal with pinhole cameras.

Regarding the pre-flash...is there some scientific way to explain and measure how it decreases contrast? We can do step-wedges to show that it actually *does* decrease contrast, but do we know how and why it works?

This might be that grey area that makes photography more 'art' than 'science', which I'm OK with BTW...

When we get her project done we'll be sure to post a link.

Thanks again!

[JoeV]

@Michael;

There's a bit of science with preflashing. As I understand it, the various exposure stops in the zone system are logarithmic, representing a doubling or halving of the previous or subsequent zone's exposure. The idea of preflashing is to give the paper an additional exposure which, when added to the scene's exposure, increases the exposure of the shadow detail.

Now, the reason why this preflash exposure doesn't also significantly increase the exposure of the highlights can be seen from a simple examination of the various zones. Let's say a preflash exposure raises the shadow detail from zone II to zone III. Between zone III and zone VIII (peak whites) there are five zones of exposure. The amount of preflash exposure added to the shadows will increase the highlight exposure by 1/(2^5), or 1/32 of a stop.

The net effect in this hypothetical example is that a preflash increased the shadow exposure by one whole stop (from zone II to zone III), but only increased the highlight exposure by 1/32 of a stop. This happens because the zonal exposure scale is logarithmic. The preflash exposure is biased toward affecting the shadows more than the highlights. You'd hardly notice the extra 1/32 of a stop exposure to the highlights; thus, the effect is to reduce contrast overall.

I hope this explanation helps with your daughter's science project. Keep us informed of her progress, I'd be interested in how it turns out.

~Joe

[Kimberly Anderson]

Sweet info Joe. Awesome.

Then that would explain how the pre-flash works in the opposite direction when using traditional printing paper to add exposure to the shadows on the negative and toning 'down' the highlights? Then the opposite is true for making the 'positive', we pre-flash to add density to the shadow areas there as well correct?

This is making my head hurt...thanks for doing all the hard work.

[Kimberly Anderson]

Reciprocity failure is the first part of my daughters project. Color sensitivity is the second.

I don't anticipate any problems with loading it into an 8x10 holder. It's never been an issue in the past with any other of Ilford's 8x10 paper that I've shot in-camera.

[bracan]

First attempts with unflashed Harman Direct Positive paper rated 3 Iso, in fact it is 1,5 Iso. Next time...For portraits also please use orange filter which I didnt
Excuse me because of dust all over, dont have a time to remove.



Sinar P 8x10, Rodenstock Sironar 300mm f5.6 wide open, homongous amount of flash light, developed in Ilford Multigrade 1+9, fixed in Ilford Rapid Fix 1+4.

More tests to do.