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welly
7-Mar-2013, 17:48
I went out yesterday lunchtime to shoot a batch of tests as I've been a little frustrated with some of my negatives. I metered at 8 seconds for the shadows, 1/30th (it might have been 1/15 though - need to check my notes which are at home) for the highlights in the window and exposed all sheets at ISO50.

I put the shadows in zone 3 and exposed for 1 second at f/16. The film I was using was Fomapan 100 and developed in a fresh batch of D76 at 1:1. I'm using continuous agitation with the BTZS tubes. The tempering bath was at 24c and I let the chemicals in their caps and the tubes with the film in them temper for about 10 minutes so they should have been well up to temperature.

These were all scanned essentially the same way in Epson Scan. I corrected the output settings to go from 0 to 255 and the input settings to stop shadow and highlight clipping, as explained by Ken Lee.

My screen is calibrated with a Spyder 3 Elite although it tends to run a little dark.

So here are the results:

Developed for 3 minutes 30 seconds

https://lh5.googleusercontent.com/-BgIfhD1aiJI/UTkXoPDASUI/AAAAAAAAAS0/gA4w1GxhSQU/s863/Eveleigh+-+3+minutes+30+seconds.jpg

Developed for 6 minutes 30 seconds

https://lh6.googleusercontent.com/-iFfcEsAGWoQ/UTkXpzQuTvI/AAAAAAAAATE/qze0TmVwEjM/s863/Eveleigh+-+6+minutes+30+seconds.jpg

Developed for 9 minutes 30 seconds (scanned emulsion side up)

https://lh5.googleusercontent.com/-nRooeanEhsQ/UTkXqoz4fQI/AAAAAAAAATM/20qkhWDrhxs/s863/Eveleigh+-+9+minutes+30+seconds+%28emulsion+up%29.jpg

Developed for 12 minutes 30 seconds

https://lh3.googleusercontent.com/-vrHaKnh1Whk/UTkXnYH_AgI/AAAAAAAAASs/bF9oOM8Fdx8/s863/Eveleigh+-+12+minutes+30+seconds.jpg

Incidentally, when I scanned the negative emulsion side down, it was quite a bit darker than the other way round, and so I know to make sure to scan emulsion up.

I think there's probably a bit to get out of this. I'm wondering if shooting Foma 100 at ISO 50 is possibly not right for me. I may start shooting it at ISO 80 or even box speed. To me, with all the above taken into consideration, 3'30" looks pretty much on the money but developing time seems incredibly short considering I'm using 1:1 dilution. But it is exactly how I saw it, so that is good. Of course, I'm scanning negatives in, and my scanner hasn't been calibrated, so it could easily be that the image looks crazy bright to the rest of you. When I look at the negative, it doesn't look particularly thin or thick, it looks pretty good. I'd probably say looking at the actual 6'30" negative, it is probably the best out of them.

What I find most strange is that the window seems brighter in the 3:30 scan than the rest where I'd have thought it would have been the other way round. I will double check I scanned in the right order when I get home. It certainly makes me wonder about scanning and its consistency. Of course, I was shooting these over a period of roughly a minute/minute and a half (I was fairly quick in changing the film holders) so the light outside could easily, and quite possibly, might have changed.

My agitation of the tubes was pretty consistent I believe so a little surprised by the results. Anyway, if anyone has any comments, I'd definitely appreciate it.

chassis
7-Mar-2013, 18:11
These results are consistent with my experience. D-76 can be contrasty with continuous agitation, especially so when fresh.

I started using BTZS tubes with D-76 1:1 and Tri-X. I found myself wanting less and less contrast, and shortened development times over a period of time. Uneven development (streaks along the rotation path - across the 4" film dimension) started appearing. I wanted a workflow with lower contrast, and longer development times (at 68 deg F) so I tried 1:3 dilution, then settled on 1:2 dilution. I also went from continuous agitation to stand (no agitation after 2 initial inversions).

For me this gives the desired contrast, no uneven development, and reasonably short (10-12 minutes) processing times at 68 deg F.

With the lower contrast, stand development and more dilute developer, I am now shooting at EI100. It's working, at least for now.

Kevin J. Kolosky
7-Mar-2013, 18:28
you have a lot of different shadows there. which shadows did you put on zone 3, and what did you plan on being pure black with no detail? Was there any consideration for reciprocity.
And was your bellows draw longer than the focal length of your lens.

welly
7-Mar-2013, 18:47
you have a lot of different shadows there. which shadows did you put on zone 3, and what did you plan on being pure black with no detail? Was there any consideration for reciprocity.
And was your bellows draw longer than the focal length of your lens.

Hi Kevin,

I was using the shadows under the machine on the left (in the middle) for my zone 3. I've got to admit, I didn't even think about what was going to go to pure black. I might have to go back and have a look. There wasn't much bellows draw, certainly not longer than the focal length (was using a 150mm lens) and the Reciprocity Calculator app for my iPhone told me that 1 second on Foma 100 doesn't need any additional exposure.

But I've just read a few other sources that reports Foma 100 needs 1.9 seconds for 1 second. :( Which may go some way to explain and I do seem to shoot at 1 second a lot.

cowanw
7-Mar-2013, 19:14
If you are comparing contrast and development times don't you have to force one tone (say middle grey) to be the same in each print?

welly
7-Mar-2013, 19:35
If you are comparing contrast and development times don't you have to force one tone (say middle grey) to be the same in each print?

Unless I'm mistaken, that's what I did. I think! These are scans of negatives that in Epson Scan, the middle grey was set to 1.0 for each scan. Now I'm not sure if that middle tone value is relative to a particular negative or if that's a persistent value. I was using Ken Lee's scanning tips and used this method:

http://www.kenleegallery.com/images/scanning/AdjustedHistogram.jpg

as in ensuring my histogram wasn't clipping and the middle tone was set to 1.

sergiob
7-Mar-2013, 19:47
1 sec for Fomapan 100 should bring reciprocity failure into the equation, if my memory is correct. From the examples you posted I think you inverted the order in relation to development times. Looks like it to me, at least.

welly
7-Mar-2013, 19:52
1 sec for Fomapan 100 should bring reciprocity failure into the equation, if my memory is correct. From the examples you posted I think you inverted the order in relation to development times. Looks like it to me, at least.

It looks like it to me too but I will have to check when I get home, but I'm pretty positive that that isn't the case. I remember being very specific in the order I handled my negatives. Anyway, will have a look later.

Brian Ellis
7-Mar-2013, 21:22
Increases in development time primarily affect the highlights, not the shadows. So it's not surprising that all the black/dark gray machinery doesn't change much from one time to another. But what is surprising is that the closest thing to a highlight in the photograph (some of the window panes and the little white square on the right side of the machinery) actually get darker as your development times increase when it should be the other way around. Which makes me have the same question as sergiob - did you perhaps get the development times and images reversed when you posted the images?

welly
7-Mar-2013, 21:45
Increases in development time primarily affect the highlights, not the shadows. So it's not surprising that all the black/dark gray machinery doesn't change much from one time to another. But what is surprising is that the closest thing to a highlight in the photograph (some of the window panes and the little white square on the right side of the machinery) actually get darker as your development times increase when it should be the other way around. Which makes me have the same question as sergiob - did you perhaps get the development times and images reversed when you posted the images?

That's what puzzled me and was what I expected to see. I half expected at 12 1/2 minutes development time for the window to be blown out. I'm going to check tonight and rescan to make sure I'm not going nuts. Perhaps I'll have to run another test.

Anyway, thanks for your input so far!

BarryS
7-Mar-2013, 22:23
The image order has got to be reversed and your scanning technique is messing up the comparison. Essentially, you're adjusting each scan to each image and that doesn't seem like the comparison you intended. Can you scan all the images at the same scanner settings? You need a densitometer more than a scanner. Looking at the negs--the windows should go from a medium or medium-light density to fairly dark as you increase the development time.

Ken Lee
8-Mar-2013, 07:33
The photos are no longer visible. Did you take them down ?

I can't see any of them, but if they are 4x5 you can scan 4 of them at a time, so they will be scanned at the same setting.

It's best to test under ordinary circumstances where reciprocity is not an issue. Also under balanced lighting (not sunrise or sunset) where some light meters can be fooled by issues of color balance.

http://www.kenleegallery.com/images/forum/DiafineTest.jpg

Here's a test I did recently with TMY and Diafine. (Diafine is very "compensating" and even under noon day sun the high values are guaranteed to be printable, so these negatives may look a bit soft. Here we are more interested in how faithfully the low values are rendered.)

Exposed under noon sunshine, there are objects whose tonality is easy to recognize and compare after the shoot: some black cloth, white plastic, metal, gray plastic, etc. The white plastic object should not be pure white, because there is a reflection of the Sun on it too. That reflection can be pure white of course.

There is a white card in each photo, which shows the ISO at which the exposure was made. In the "correct" negative, even the white card has a bit of texture.

Another helpful suggestion is to consider that a "standard" gray card of 18% should be placed on Zone 5.5, not Zone 5. Kodak themselves recommends this in so many words. If we consider that the average scene is 7 zones, then Zones 8,7,6 and 5 correspond to 100%, 50%, 25% and 12.5%. Note that Zone 5 is 12.5%, not 18%.

The photos were all made at the same shutter speed - a typical speed like 1/60 - changing only the f/stop. No view camera adjustments were made. The subject was far enough away to eliminate the need for bellows compensation.

For the record, going back to 1970 every test I have ever made has directed me to shoot film at 1/2 the manufacturer's recommended ISO.

http://www.kenleegallery.com/images/forum/dptest.jpg

Here's a test of TMY and Divided Pyrocat HDC, made on a gray day. Note the natural appearance of the low and middle values: the black cloth, the blue painter's tape and the gray plastic spray bottle. That bottle is an ideal testing prop, as good or better than a face. It's already gray so there's no guesswork involved. The same is true of the "Sharpie" marking pen.

Ken Lee
8-Mar-2013, 07:43
the middle grey was set to 1.0 for each scan...as in ensuring my histogram wasn't clipping and the middle tone was set to 1.

The middle setting is for Gamma, the contrast curve. When it's 1.0, no curve is applied, and the result is "linear". I put that in quotes because with this kind of scanner and software we have only partial control: much is out of our hands.

The Epson scanner has a dynamic range that is equivalent to printing on Grade 1 paper. Therefore we can expect that the histogram of a "normal" negative will not occupy the entire range of the scanner. There should be some wiggle-room at both extremes.

welly
8-Mar-2013, 12:19
Oops. Deleted the files accidentally and now I can't edit my original post. I'll put those images here:

3'30"
https://dl.dropbox.com/u/24681282/Eveleigh%20-%203%20minutes%2030%20seconds.jpg

6'30"
https://dl.dropbox.com/u/24681282/Eveleigh%20-%206%20minutes%2030%20seconds.jpg

9'30"
https://dl.dropbox.com/u/24681282/Eveleigh%20-%209%20minutes%2030%20seconds%20%28emulsion%20up%29.jpg

12'30"
https://dl.dropbox.com/u/24681282/Eveleigh%20-%2012%20minutes%2030%20seconds.jpg

I'm beginning to suspect this is more about my (lack of) scanning ability than anything. As you guys have suggested "they're the wrong way round!" but I'm looking at the negatives at the moment and the 3'30" negative is by far the "lightest" negative, as I would expect. Why that would scan in as it has with the 12'30" negative being so dark is what has puzzled me for some time. Unfortunately I don't have a light box to show but the negatives look as I'd expect them (as far as density goes). I think I'm going to need to spend a bit more time with my scanner.

Ken Lee
8-Mar-2013, 13:14
I'm beginning to suspect this is more about my (lack of) scanning ability than anything. As you guys have suggested "they're the wrong way round!" but I'm looking at the negatives at the moment and the 3'30" negative is by far the "lightest" negative, as I would expect. Why that would scan in as it has with the 12'30" negative being so dark is what has puzzled me for some time. Unfortunately I don't have a light box to show but the negatives look as I'd expect them (as far as density goes). I think I'm going to need to spend a bit more time with my scanner.

It's best to scan them all at the same time if possible. Then you are comparing apples to apples, as they say. Each relative to the other.

It's hard to know which image is the literal representation of the scene because the lighting is non-uniform and non-trivial. It's hard to know which of the many shadowy areas were placed on Zone III. It might be easiest to do another test under more routine conditions, and make notes of the actual values as they were metered and where they were placed.

Placing a human face in the scene will also make it easy to determine which version feels the most like light.