Okay, all you armchair photographers...

[rowland_mowrey]

James;

 

I would like to extend the life of this thread if possible, or at least follow your suggestion for carryover. I have the proofs and have done more work on the Portra family of films that I am goint to post as soon as they are dry. I have more to do.

 

Elliot;

 

You are in for a small surprise. The proofs don't exactly agree with your prediction.

 

To all;

 

The 800 and 160 proofs are drying as I type. I did an over and under exposure series on-easel from 4.5 to 32 of the 160 and then just printed the 800 at the center point. First, since the color balance and exposures were right on, I know that my C41 process was ok. I made the correct exposure first time around.

 

Second, the latitude of the Portra films surprised me all the way from the 800 Portra to the 160 portra. Just as a teaser, with appropriate exposure, the prints from the 160 looked good from 800 to 50. The 25 was pretty bad. Looks like the film is more of a 200 speed than 160 in my camera. The prints with the 160 exposed at 800 indicate that with no push, usable prints are obtainable.

 

I plan to do some work with the 400 and 800 to get more data, and enlarge some of the negatives up to maybe the equivalent of 16x20 for sharpness and grain. It is so hot here that darkroom work is kinda ungood though.

 

Summer finally arrive in Rochester. Maybe it will snow tomorrow, who knows.

 

Ron Mowrey

[James G. Dainis]

Ron,<BR>         This thread is not going to disappear. It will be in the archives for a long, long time. I didn't expect this thread to go so far. I started it because I accepted Steve's challenge to get out of the armchair and over/underexpose some film, and was rather surprised at the results.

[rowland_mowrey]

Thanks James.

 

The results I have as straight prints are going to surprise you as well.

 

They are dry now, but it is too late to scan tonight. I'll have a few posts here tomorrow.

 

Ron Mowrey

[l_a_k_h_i_n_d_e_r]

FWIW, I decided to make a Macbeth chart with the values as per the reference I quoted above (i.e Fraser/Murphy/Bunting, pg 221). This might

come in handy as a point of comparison (or confusion?). This chart was created in RGB mode, and then saved as Jpeg.<div></div>

[rowland_mowrey]

Here are the proof prints. I will be making 4 posts of the individual proof sheets. The center point on my enlarger is f16.

 

The first is f5.6, or 3 stops over exposure, therefore the ISO 50 and 25 exposures are more properly exposed. I would have done better if I could have given them one more stop.

 

Print order from left to right, top to bottom.

 

ISO 160 check. ISO 800, 200, 50.

 

Bottom row, ISO 400, 100, 25.

 

Portra 160 VS.<div></div>

[rowland_mowrey]

To continue, here is f8.

 

Any blemishes you see are due to the plastic negative file which held the negatives in place.<div></div>

[rowland_mowrey]

Here is f11<div></div>

[rowland_mowrey]

This is the center point, f16, on my enlarger. It gives properly exposed prints for normally exposed negatives at this light intensity.

 

Remember, these are contact proofs with the negatives in a plastic carrier to hold them in place, and a glass proofing easel.<div></div>

[rowland_mowrey]

And finally f22.

 

I did f32, but the d-max was down and the prints were not very good.

 

I also did the 800 speed.<div></div>

[rowland_mowrey]

As a final note, the scanning and uploading process introduced artifacts such as the red mottle in the d-max (black) areas of the prints. It is quite obvious in the f22 print.

 

We can only make generalizations about the grain and sharpness, but it is quite obvious that the 160 film is usable from 800 to 25 with quite good results between 400 and 50. I can say the same about the 400 and 800 films within the limitations of my camera. The films looked good there up to 1600.

 

I left the images at 1:1 (8x10) even though this makes it somewhat inconvenient to see the entire print. I suggest you download them and view the smaller versions in Photo Shop. I did not apply any correction to the images during scanning. No dust removal (obvious heh) and wanted you to see them as is, as much as that is possible with any conversion like this. They were treated like any other proof print in my enlarger. The extra care goes into the final prints, so please excuse my dust.

 

This is not my idea of a 'good' test, but was one I could run in limited time and with limited resources. A good test would include at least one, preferrabley 3 models to test various skin and hair colors, and would also include exposures indoors with flash and tungsten light.

 

I would like to see the same series on Fuji 160, 400 and 800 run to see how it does. Anyone out there up to it.

 

I commented before that my C41 process was in control, as these prints were all right on my centerpoint for balance and speed. The process included a total of 2 220 rolls and 4 120 rolls 3 of which were these tests and the other 3 were my own work.

 

In the near future, I hope to enlarge just a portion of these frames to the equivalent of 16x20. That is why the chart is small on the frame, so it gives me that leeway. That should give us an idea of grain and sharpness. I did not have the resolution charts printed yet to include in these tests.

 

Regards.

 

Ron Mowrey

[bill_tuthill]

Lakhinder Walia's color chart looks muddy to me, so here's another

that more closely matches Nikon D70 or Olympus E-1 output. It's in

GIF so you can adjust individual color patches more easily.

[elliot_n]

'Elliot - You are in for a small surprise. The proofs don't exactly agree with your

prediction.'

 

Huh? I think they agree exactly.

 

This is what I said:

 

'Prints from the frames over-exposed by one, two or three stops will all look the same

as the print from the properly exposed frame. Prints from the underexposed frames

will look flat and lifeless.'

 

And that is what I see in your test results.

 

All the overexposed shots look fine. Ok, the shot that's a 1/3 of a stop underexposed

looks alright too. But as soon as there is any significant underexposure (the frame

rated at 400ASA (i.e. 1 1/3 stops under)), I see a critical lack of contrast that leads to

a flat and lifeless image (I'm looking at the last contact-sheet you posted).

 

There are no blacks in the image rated at 400ASA, and if you printed it down there

would no whites. The image at 800ASA is flatter still.

 

Of course there is a degree of subjectivity in claiming that these underexposed

images are either 'good' or 'acceptable' - I mean they're better than nothing - but I do

know that my clients would find them totally unacceptable. That is why I always rate

neg film at 1 stop over - then I have a safety net if the cloud thickens slightly or the

model backs off from the softbox.

 

This thread evolved from another thread in which Steve Levine claimed that good

results could be had by uprating your film by as much as three stops (e.g. rating

400ASA film at 3200ASA) and then processing normally (I believe James was

referencing this thread in his title). And James's results seem to bear Steve out (I

wonder if they both use the same type of minilab). James's 3 stop underexposed print

has remarkable shadow detail and contrast.

 

I am sure that this is all down to the software that the Frontier minilab employs.

 

Those who use Frontiers or other digital minilabs should pay attention, because

getting an extra 3 stops out of any colour negative film is A VERY BIG DEAL.

 

But for the rest of use who still prefer analog prints over digital prints, the old advice

remains the same - whatever you do, DON'T UNDEREXPOSE COLOUR NEGATIVE FILM.

 

(Thanks for taking the time to run the test. It took me a while to decode it. It would

be nice to see colour-corrected 8x10s from each of the brackets).

[elliot_n]

Just a small nit to pick. Earlier you said:

 

'The 25 was pretty bad.'

 

The 25ASA exposure only looks bad because it is fogged. This is a side-effect of the

contact-printing process. If you placed the neg in a masked neg carrier and made a

print, I'm sure it would look very nice.

[rowland_mowrey]

Elliot;

 

Please compare the 160 exposure at f16 with the 400 exposure at f22. They are a close match in overall contrast and color saturation, and the color quality isn't bad. The 800 actually looks better than the 400 in the f22 proof. Of course the background is not great. The contrast in the holly bush is low, as to be expected, but it isn't as you said that "Prints from the underexposed frames will look flat and lifeless".

 

Of course it isn't perfect, I never said it would be. But consider that this was with straight processing, and not a push. With a push, the results would probably be even better.

 

So, I think, given the words you used, the prints of the 400 and 800 are not flat and lifeless. And with a push, they would improve.

 

Under some conditions, people can expose the Portra 160 to 800 and get (my words) usable results. This is better than losing the shot entirely. Under some conditions, using 400 at 800 or 1600, and 800 at 1600 or 3200 will give usable results as well. Pushing of any of these films will improve the quality somewhat. I think we agree on this.

 

Also, some manipulation on-easel and individual correction would make these prints even better, I think. There is not much color balance shift in the exposures. How do you think individual color correction would help?

 

Again, I wonder how a similar test with Fuji film would look, with the use of the color chart.

 

I think we were surprised at James' tests, but mine tend to agree with his. In addition, I believe Steve Levine said negative films have 10 stops overexposure latitude.

 

I do agree with you that this type of mistreatment of film does not yield the highest quality. If you rate film 1 stop over, then you would rate 160 at 320? Do I take you right? Or did you mean 1 stop under and you would rate 160 at 80? I usually rate my films under by about 1/3 stop. This gives me latitude when I need it, not the other way around. Your statement is not clear to me. It seems to indicate the opposite of what you want the way I understand things.

 

By underrating films ISO, you overexpose it, and by overrating an ISO, you underexpose it. Therefore, 160 at 80 is underrated by 1 stop, and the negative is darker or overexposed, but at 320 it is overrated by 1 stop and the negative is lighter or underexposed.

 

It seems to me that the films I tested are slightly underrated from the actual EI that I observed. That is a good conservative measure.

 

Ron Mowrey

[elliot_n]

'Please compare the 160 exposure at f16 with the 400 exposure at f22.'

 

Ok, So that's top left on the penultimate contact sheet compared to bottom left on

the final contact sheet?

 

'They are a close match in overall contrast and color saturation, and the color quality

isn't bad.'

 

Whilst you see prints of a similar quality, I see a good print and a bad print. I don't

see a 'close match' in contrast at all.

 

How come?

 

I guess you're focusing on the colour chart (a low contrast target with maybe a 3 stop

range), whereas I am looking at the whole image (the chair, the chair's shadow, the

bush, and even the neg rebate).

 

If you look at the whole image I'm sure you'll agree that the 400ASA image suffers

from a significant reduction in contrast.

 

I'm more interested in the whole image than the test chart, and to me the 400ASA

image shouts 'underexposure!'.

 

--------------

 

'With a push, the results would probably be even better.'

 

Agreed

 

'So, I think, given the words you used, the prints of the 400 and 800 are not flat and

lifeless.'

 

We'll have to agree to differ on this.

 

'Under some conditions, people can expose the Portra 160 to 800 and get (my words)

usable results. This is better than losing the shot entirely.'

 

In what scenario would someone 'lose the shot entirely'? In most cases, I would prefer

a punchy print with a little blur to a flat print with critical sharpness.

 

'Also, some manipulation on-easel and individual correction would make these prints

even better, I think.'

 

Yes, you could print on Endura Ultra and then burn around the chair to try to pump

up the contrast.

 

'There is not much color balance shift in the exposures. How do you think individual

color correction would help?'

 

You're right - the colours are fairly similar. The densities are quite variable though,

which makes the test a bit confusing. I just meant it would be nice to see the brackets

fine printed to a closest match.

 

'I think we were surprised at James' tests, but mine tend to agree with his.'

 

I don't think so.

 

'If you rate film 1 stop over, then you would rate 160 at 320? Do I take you right? Or

did you mean 1 stop under and you would rate 160 at 80? I usually rate my films

under by about 1/3 stop. This gives me latitude when I need it, not the other way

around. Your statement is not clear to me. It seems to indicate the opposite of what

you want the way I understand things.'

 

Yes, sorry, I got confused - I meant that I always over-expose negative films by one

stop. So I rate Portra 400VC at 200 (metering with an incident lightmeter).

[rowland_mowrey]

Elliot;

 

Thanks for the clarification.

 

I think there are two differences here to be resolved. First, I'm looking at the actual prints and you are looking at scans. I believe that under good illumination the prints appear closer together than they do in the scans.

 

Also, I was not clear in my last post on what images to compare.

 

f11 print - upper right (ISO 50)

 

f16 print - leftmost single (ISO 160)

 

f22 print - left lower (prints should have better match) (ISO 400 bottom)

 

Or:

 

Leftmost print in f11 example (ISO 160) vs lower row left (ISO 400) of f16. These two in particular are quite similar even in the shadow detail and are quite good in saturation and contrast.

 

In full daylight, in the original. these look very good and with precision printing more could be done to match them.

 

As I said above, this test is rather simplistic having no real flesh tones for comparison, nor have we compared different illuminants. And, as you have said, no true professional would do this intentionally except for special effects or to capture a scene that otherwise would be lost. There have been scenes that I have taken that needed the capture with no motion, in direct opposition to your suggestion of capturing with blur. This is particularly true in high speed motion detection for engineering purposes where such exposures may be necessary.

 

In the final analysis, photographs of charts is nice, but can be misleading. You can't sell these photographs. You need real subjects, but the charts help calibrate possible ranges available for use when necessary.

 

Oh, the ISO 25 scan is worse than the print cf the bottom right of the f8 example. I don't think I had the prints in hand when I made that comment, but if I did, I had misevaluated the ISO 25 results.

 

Again, thanks for your additional information.

 

Regards.

 

Ron Mowrey

[elliot_n]

Yes, when compared on the darker contact-sheets, the 160 ISO and 400 ISO images

do look more similar.

 

I can still see the faded look of underexposure in the 400 ISO image (especially in the

bush), but I can accept that for some people this wouldn't be a big problem.

 

Regarding overexposure, many people seem to believe that by overexposing they can

increase a film's saturation and contrast (I think there's a thread running on this topic

at the moment). My tests indicate that this is not the case with Kodak's Portra films.

[rowland_mowrey]

Elliot;

 

See Joe Manthey's explanation and elaboration on this in the other thread.

 

In as much as you increase contrast, you increase saturation. However, it depends on exposure, film and a lot of other factors. Sometimes, contrast can give the subjective illusion of increased saturation. Just as increased contrast can appear to increase sharpness.

 

This is all bound up in the way the eye integrates an image, but the film is analong with no integration (in a sense) and digital is of course, digital.

 

I plan on trying some additional prints to try to match the various exposures. I'm curious as well about how these 3 films perform.

 

Well, thanks for the clarification. I think we are pretty much in agreement. Overexposure is good, and underexposure is bad. Correct exposure is best and professionally desirable.

 

Sometimes over or underexposure is expedient, and within limits can give limited acceptable results. Over and underexposure are usually limited to a max of about 3 stops on either side if you want usable results, but 1 stop if you want more acceptable or professional quality results with overexposure preferred.

 

Underexposure with a push process is sometimes useful.

 

Does that seem to summarize things?

 

Thanks again.

 

Ron Mowrey

[elliot_n]

'Does that seem to summarize things?'

 

Yes.

 

But for my way of working, Portra's window of good exposure is from box speed to

about 3 stops overexposure.

 

I see no negative effects from overexposure within this range.

 

With even slight underexposure, I feel that Portra films suffer a reduction in contrast,

which produces a flat print.

 

As well as always exposing Portra films properly, I often push process these films to

gain additional control of colour and saturation. A half stop push is fairly standard for

me. On occassions I'll push up to two stops.

[elliot_n]

Sorry, that should read:

 

'to gain additional control of CONTRAST and saturation'

[rowland_mowrey]

Elliot;

 

I certainly can't disagree with you. However, others have stated in other threads here that pushing does not increase saturation and have cited the Ctein review to support their position.

 

I agree with you and disagreed with their assertions. I believe that a push will increase contrast and saturation. There is support for both views on the other thread.

 

The contrast and saturation levels increase in varying amounts from film to film. Therefore, one may see a small increase with one film and a larger increase with another film. In that, I agree with some of the observations posted.

 

In addition, I would like to add that the pictures I posted were under optimum lighting conditions whereas normal underexposures would usually be done with poor lighting. This predisposes the photographer and those who view the underexposed results to refer to them as being flat and desaturated due to the poor lighting.

 

I would like to suggest then that the flatness and drabness we associate with underexposures, often comes in part from the lighting conditions that led to the need for underexposing the film in the first place.

 

Anyone care to comment on that?

 

Ron Mowrey

[bernhard]

"I would like to suggest then that the flatness and drabness we associate with underexposures, often comes in part from the lighting conditions that led to the need for underexposing the film in the first place.

 

Anyone care to comment on that? "

 

Sure.

 

Mostly under dim lit conditions the color balance is off, especially under tungsten light. Inevitably (at least) one of the color layers gets less exposure than the others (=underexposure) and you either end up with a flat tonality or if you try to correct for this (especially in the digital [minilab] domain) you'll amplify the grain.

[rowland_mowrey]

Bernhard;

 

I agree.

 

What about the pictures above then? They were made with 'good' lighting. No rebalancing was needed. Does this mean that over and under exposures are made better when used with good light sources, or that over and under are made worse by the bad light sources.

 

If so, then I would infer that it is more acceptable and useful to use underexposures in particular when the light source is balanced and bright, and avoid some of the consequences of having to rebalance a tungsten or other 'bad' source.

 

This is the way I am leaning right now. The underexposures were surprisingly good in good light. I have done enough available light to recognize the grain and balance problems you point out. I have also done enough underexposure in good light to indicate that problems with washed out color and grain are minimized in this good light to make it more acceptable.

 

Ron Mowrey

[bernhard]

"If so, then I would infer that it is more acceptable and useful to use underexposures in particular when the light source is balanced and bright, and avoid some of the consequences of having to rebalance a tungsten or other 'bad' source."

 

 

I agree (also with the rest of your post).

 

When shooting under tungsten balanced light I give more exposure, depending on how much color balance correction I intend to up to 1 1/2 stops with Press 800.

[elliot_n]

'When shooting under tungsten balanced light I give more exposure.'

 

Me too. Portra 800 needs an extra stop and a half under tungsten, if it's going to be

fully colour corrected during printing (any less exposure and you get weak blacks

with a blue cast). Alternatively, I'll use a Lee 80A filter which soaks up a stop and a

half of light.