Ektar vs New Porta 160

[sraichur]

Hello all,

Looking for opinions on

1. Dynamic range - Literature says 160 has +3/-2, I think, and Ektar is less.
I've scanned Ektar on a imacon x5. The highlights were shot at 4 to 5 stops over but the scan had no highlight detail.
I have read that Neg film can easily record 8 to 10 stops in the highlights. Do you need a drum scan to bring that out?.
Will Porta 160 give more latitude in the Highlights, if scanned on Imacon, or on drum sacnner?

2. The trade off might be grain size and or resolution?
Does 160 have obtrusive grain or lower resolution than Ektar?
My goal is to end up with 40x50 from 4x5 - 10x enlargement.

Thanks

[Ben Syverson]

The tradeoff is primarily sensitivity for granularity. For a 10X enlargement, a really great scan of Ektar will probably edge out the Portra, though they'll be close.

I haven't used an Imacon, but if it's clipping your highlights, try scanning as a positive and inverting. Color negatives compress a mindblowing amount of latitude within Dmin and Dmax.

[sraichur]

Thanks Ben,

sensitivity is not as important to me as latitude and grain.

I don't mind using Ektar ( for the lower grain) as long as it provides the latitude.
It's just the highlights blown at 4 stops up dosen't seem to good. I thought neg film could handle a lot more.

I'll try the inversion method and see.

I'm just wondering if Porta 160 will provide me with more latitude.

Thanks
Sandeep

[Ben Syverson]

Then I think Ektar is a great choice. Ektar has a slightly different characteristic curve (giving it more a punchy look by default), but they should both have similar latitude. If you're seeing clipped highlights at +4 stops, something in the scanning workflow is definitely to blame.

[J. Gilbert Plantinga]

Did you try boosting the exposure in FlexColor ( found in File->Setup: General Tab "Adaptive Light")?

[mdm]

You are confusing dynamic range with latitude. add at least 7 stops to the exposure latitude mentioned above for dynamic range.

[Ben Syverson]

I personally think dynamic range is misapplied in photography, but I'm solidly in the minority. Dynamic range SHOULD refer to the level of signal above noise, but in the case of negative film, that "signal" (density as an index of light) is in a nonlinear semi-logarithmic scale. So film's dynamic range varies from stop to stop.

Another way of thinking about it: you could have a special purpose high-contrast camera with 96db dynamic range, but only one stop of latitude.

"Latitude" more directly describes the range of physical light levels which a photographic system is able to reproduce. Unfortunately, because the noise level (and thus dynamic range) varies from stop to stop, the judgment of what constitutes "representation" is highly subjective. In other words, you may say "12 stops," but the darkest stop may be 50% noise. Some would find that objectionable, and call it 11 stops, etc.

Ultimately it's best not to get into the semantics. Either your scanner is able to read everything between Dmin or Dmax, or it's not. If you can scan chromes, then it should be no problem to scan negatives so that the orange base isn't clipping and the most dense highlights aren't sinking into pure black.

[Bruce Watson]

My goal is to end up with 40x50 from 4x5 - 10x enlargement.

First things first -- the image size on 5x4 film is less than 5x4. In fact, 5x4 film is less than 5x4. Make some measurements and see for yourself. I'm just saying that a 50x40 inch print is closer to an 11x enlargement, assuming cropping the film rebates out.

That said, I've got a couple of beautiful huge prints from 160Porta, a generation older than the current Portra films. One is 143cm wide, the other is 148.5 cm wide. Both are tack sharp and nearly grainless except in the brightest highlights where grain is visible if you are looking for it (nose on the print) but even then it's unobtrusive.

The current generation of the Portra films is the best photographic film ever made. It's really sharp, nearly grainless, has a huge dynamic range, excellent gamut, and excellent color accuracy. It's the only color film in my arsenal. I wouldn't hesitate to use it for any shot at all, and enlarge the hell out of it if that's what you want. It'll perform beautifully.

[Brian K]

I just did some tests of 120 ektar and 120 portra 160. The portra has more latitude, than ektar. Ektar is a bit contrastier, portra a bit flatter. In my tests the protra actually resolved finer details a bit better, but these were in the field tests and not as critical as a studio test, however the films were tested side by side on the same scenes.

Grain wise both of these films are pretty darn grainless viewed under a 40x microscope, and the enlargement of a 4x5 to a 50" print, an 11x enlargement given the real usable film area of a 4x5" is insignificant. If you use proper technique a 50" print with these films is nothing.

Also if it is your intent to scan the negs, and if you are working outdoors, i.e. uncontrolled lighting, you might want to err slightly on the side of underexposure. Scanners do not like density in negatives and denser negs have more apparent grain. Under exposing Portra by a 1/3 to a half of a stop while technically being a less perfect exposure, might give you a better scan result and final output. And Portra's latitude can easily handle that.

[Ben Syverson]

Underexpose negative film at your peril... Any scanner should be able to handle the Dmax of color negative. If it can't, use a different scanner.

[Noah A]

I did a side-by-side test with these two films (as well as Portra 400) a while back. I didn't save the scans but my conclusion was that the Portra 400, while still an amazing film, was grainier than the slower films.

When comparing the Ektar and Portra 160 the main difference was the contrast and color. The grain and sharpness were quite similar. I suppose I didn't check for latitude since I don't normally mess up my exposures. But both seemed to have plenty of range and neither one had blown-out areas in my test photos.

The Portra was softer and warmer. The Ektar had more contrast and the colors were more saturated. Especially the reds, which in my opinion were a bit over saturated. Also the shadows seemed to go rather blue, more like a transparency film. Of course if you're scanning these things can be adjusted to some extent.

If your scans aren't holding the highlights it seems like it might be a scanning problem. It's tough to blow the highlights on color neg film. I'd try scanning your Ektar again with the tips others have suggested. I'm no expert on the Hasselblad scanners, but I've used them in a rental studio and I've had my best luck doing raw FFF scans and playing with them later.

Once you get the scans under control, I'd suggest choosing the film which renders color the way you want. As Brian said, 40x50 is absolutely no problem for either film.

[photobymike]

Hello all,

Looking for opinions on

1. Dynamic range - Literature says 160 has +3/-2, I think, and Ektar is less.
I've scanned Ektar on a imacon x5. The highlights were shot at 4 to 5 stops over but the scan had no highlight detail.
I have read that Neg film can easily record 8 to 10 stops in the highlights. Do you need a drum scan to bring that out?.
Will Porta 160 give more latitude in the Highlights, if scanned on Imacon, or on drum sacnner?

2. The trade off might be grain size and or resolution?
Does 160 have obtrusive grain or lower resolution than Ektar?
My goal is to end up with 40x50 from 4x5 - 10x enlargement.

Thanks


Ektar in my opinion is a quantum leap in film technology. I have exposed in various sizes of Kodak Ektar film, about 500 dollars worth over the last year. The first thing i noticed is a higher dynamic range. This however is dependent on how its developed. I have seen this film developed in 4 ways. 1 Tetenal chemistry (the best way) 2 Fuji frontier processor (fuji chem). 3 Noritsu (kodak chem and second best). 4 Mystery dip and dunk processing (sent out). With all negs scanned on an Epson v750 with 3 different programs (Silverfast) was the best. Kodak Ektar seems to be made to work on my scanner. It is so easy to work with. Not much to do in color correction and color cast issues.

Tetenal gave the highest dynamic range that i have ever seen on a color neg... in a word WOW it was so "punchy" it was hard to scan. Also This film according to Kodak uses T-GRAIN technology. Any film that uses T-GRAIN seems to scan better with less apparent grain. Compared to other films that are not T-GRAIN like Kodak Portra 160 the grain structure is more pronounced in a scan, which may be more pleasing than than a scan that looks more like a digital photograph. I found that i got better results from 120 film versus 4x5 film. Smaller grain structure on my enlargements up to 16x20 max for me on my Epson 4800 printer. The 4x5 film had more dynamic range, probably because i used JOBO tank with Tetenal. My "ideal combination" is 120 film processed on a Noritsu machine that is within processor tolerances and clean rollers. I Know this is against common wisdom on negative size ect... This difference may be in the way the different way these negs are scanned.

[Brian K]

Underexpose negative film at your peril... Any scanner should be able to handle the Dmax of color negative. If it can't, use a different scanner.

Ben, I've owned film scanners for more than 20 years, I've owned an Imacon, the scanner which the OP references, I currently own an IQSmart3, and I have had my work scanned on nearly every high end drum scanner for a couple of decades. Basically put I have used the best scanners there are. And if they can't handle dense areas of negatives well, there is little other choice except intentionally using slightly thinner negatives.

What is ordinarily considered a perfect negative and exposure is based on the traditional requirements of wet darkroom papers. If you have a dense film neg in a conventional darkroom, you can just use a longer exposure or open up the aperture. Scanners do not have the ability to increase the time required until the light burns through the density. They have a set range. So dense negatives do not scan well. And as I specified, uncontrolled lighting situations, ones in which the contrast range of the scene is out of one's hands, often have highlights that have densities that scanners do not like.

Modern films like Portra have incredible latitude, and a 1/3 to 1/2 underexposure on a negative that is intended to be scanned is insignificant in terms of lost quality or information. You are far more likely to lose information in dense areas over thin areas.

And BTW this is not some thing I came up with although the 20 odd years that i've been scanning does confirm this, I have heard exactly the same thing from many highly experienced photographers with high end scanners who say the same things.

[Ben Syverson]

Hey, whatever works for you. In my own experience, negative films have virtually unlimited latitude in the highlights but very little latitude in the shadows. I would never, ever, ever intentionally underexpose a negative. I have plenty of incredibly dense negatives that scan perfectly well.

[Brian K]

Hey, whatever works for you. In my own experience, negative films have virtually unlimited latitude in the highlights but very little latitude in the shadows. I would never, ever, ever intentionally underexpose a negative. I have plenty of incredibly dense negatives that scan perfectly well.

Ben, you're right, neg films do have better latitude in the highlights, the problem is that the scanner doesn't.

Tim Parkin did a test of Portra 400, granted it should have more latitude that the 160 version, but if you look at his test you'll see that portra 400 at even 4 stops under produced a decent print (not perfect) So going 1/3 to 1/2 down, with the intent being to reproduce the image with a technology more favorable to slight under exposure is more an advantage than a issue.

http://www.onlandscape.co.uk/2011/05/kodaks-new-portra-400-film/

[Brian K]

Sandeep I posted a set of scans. The films used are Ektar and Portra 160. These scans have NO corrections, no sharpening no grain reduction and are dry scans. Wet scanning would increase the sharpness and lessen the grain so keep that is mind. The scans are at 4200 ppi and you are seeing a 100% pixel size.

I also show the original 120 film size so you can get just how small a section of the film is being displayed here. The equivalent size print at 100% would be more than 30". a 15x enlargement. The camera used a Rolleiflex 6008i with an 80mm Schneider at f 11. Scanned on an Iqsmart 3.

I don't know how well it will read here, but the portra 160 has more fine detail than the Ektar, and the grain difference is almost imperceptible. Also you'll notice that the Portra has better shadow detail.

[timparkin]

http://www.onlandscape.co.uk/2010/12/a-colour-film-comparison/

http://www.onlandscape.co.uk/2011/02/colour-film-comparison-pt-two/

http://www.onlandscape.co.uk/2011/06/colour-film-comparison-pt-3/

Not sure if these will be useful..

In my experience comparising Portra and Ektar, I would say Ektar has about 2 stops in the shadows before it starts going blue very quickly. Portra 160 has 3 stops in the shadows and is very neutral. Portra 400 has 4 stops in the shadows but tends to magenta.

As for highlights, Portra 400 has the most - quite ridiculous amounts. To give you an idea a little story may help. I was shooting a large group shot with a new GX617 and opened the shutter with a locking cable release and used the ground glass to focus. After focussing I loaded the film and only a minute later (roughly) did I remember I had left the shutter open. So at f/5.6 and over a minute instead of f/16 and 1/15 of a sec I reckoned 14 stops over exposed. And yet there was still an image which I scanned successfully.

Here are another couple of examples..

http://www.flickr.com/photos/timparkin/6596000435/in/photostream

http://www.flickr.com/photos/timparkin/6593816885/in/photostream/

http://www.onlandscape.co.uk/2011/05/kodaks-new-portra-400-film/

Tim

p.s. Ektar definitely has finer grain but 160 is pretty damned fine ... Portra 400 is quite a bit grainer.

[Matus Kalisky]

Tim, this is by far the very best real life film comparison I have ever seen. Thank you very much for your effort and time. While I have used most of the films you compared (though none of them in larger volume) I am surprised by the results. The Velvia 50 seems to have more shadow detail than Velvia 100. Color-wise (to my eye) the 400NC produces most pleasing color among the C41 films.

I would just pick Velvia 50 and Portra 400 and forget the rest :)

[Robert Jonathan]

I'm a negative newbie myself... I love the chromes, especially Provia 100F, but I would like to snatch up some boxes of Portra 160 and try it out.

How would Provia 100F compare to the new Portra 160 in terms of sharpness/fine detail, grain?

What I noticed in Tim Parkin's big camera test, is that in 8x10, the Portra 400 was actually out-resolving the Velvia 50.

[Drew Wiley]

Grain behaves differently between chromes and color negs. Ektar is much finer grained
than Provia or even Velvia, but perceived sharpness in a chrome is greater due to
higher contrast (though neg contrast can be increased several ways before printing).
With current large format films, graininess is rarely an issue in printing. But Ektar and
Provia 160 differ quite a bit in color characteristics. Provia renders neturals ala skintone
friendly, and is lowever overall contrast, whereas Ektar comes closer to the more saturated look of chromes. Handling shadows can be tricker with Ektar - they can go blue in open shade, like Monet painted shadows.

[sraichur]

Thanks everyone for the replies. However I'm more confused than ever now!

I'm reading that Ben is able to scan the highlights and pull all the detail out, but Brian is saying it's better to underexpose a little, and that some scanners cannot pull the highlight detail out. (if I understand all of you correctly!)

Tim it seems your test indicate that you can pull out great highlight and shadow detail from the porta 160. How about Ektar? How many Highlight stops can you pull out?

So Brian, when you were using the Imacon, were you able to pull out highlight detail 4 to 5 stop up or not?

That's what mostly use. I scan in the RAW FFF format and it is supposed to get all the range the machine is capable of.
For improving shadow detail on chromes I have also tried the imacon 'adaptive light adjustment' however it is not avaliable in RAW FFF mode, because the machine is supposed to pulling eveything out. I did try it to improve shadow detail on chromes and it didn't make any difference at all vs the Raw mode with no adaptive light.

I've been exposing my negs with the rule that i read on the forum, which is to place the shadows I want good detail in at -2 and let the highlights fall where they may.

I recently scanned a couple of negs (imacon X5 Raw format) where the shadows were 2 stops down and the highlights were 5 stops up. I'll try to post the scans. The brightest highlights were tree leaves with bright sunlight, and it seems there is no detail in them.

As for color and contrast, It definetly seems the ektar is more saturated and contrasty. However i have not compared it the the same exact scene with port 160.
Is it possible to adjust porta 160 to look like ektar, in Photoshop, but while maybee maintaining better color accuracy and more latitude during capture?

Or is it better to use Ektar and drum scan to get more local contrast and possible a little less grain?

[Ben Syverson]

Is it possible to adjust porta 160 to look like ektar, in Photoshop, but while maybee maintaining better color accuracy and more latitude during capture?
Yes, you can make Portra look like Ektar and vice versa. Some folks who shall remain nameless insist that you can never get a good match due to spectral sensitivity, but I've never been troubled by specters.

If fine grain is what's required and speed is not an issue, Ektar is a better choice than Portra. Portra may even resolve better, but Ektar is undeniably smoother. Latitude is a red herring, as they both have essentially unlimited highlight latitude.

[Zaitz]

Tim, thanks for posting those comparisons. I love your articles and work. Portra 400 looks pretty amazing. I need to go use mine up.

[Drew Wiley]

I"ll stay away from the specific issue of scanning, but underexposing a color neg film is almost always a bad idea. You can find plenty of past threads and a lot of
literature in general telling you why. Ektar is fussier than most, and either under or overexposing is not wise. Expose it with the same care as a chrome, and balance for the correct color temp with appropriate warming filters for excessive blue in the shadows, and you'll be fine.

[polyglot]

Ben, I've owned film scanners for more than 20 years, I've owned an Imacon, the scanner which the OP references, I currently own an IQSmart3, and I have had my work scanned on nearly every high end drum scanner for a couple of decades. Basically put I have used the best scanners there are. And if they can't handle dense areas of negatives well, there is little other choice except intentionally using slightly thinner negatives.

What is ordinarily considered a perfect negative and exposure is based on the traditional requirements of wet darkroom papers. If you have a dense film neg in a conventional darkroom, you can just use a longer exposure or open up the aperture. Scanners do not have the ability to increase the time required until the light burns through the density. They have a set range. So dense negatives do not scan well.

(snip)



Emphasis mine. That is not true, at least for the Nikon 8000 sitting on my desk. If you set the "RGB Gain" field higher, it takes commensurately longer to scan because of the dwell-time at each row; typical values for me are 1.5 for B&W, 2.5 for C41 and 10.0 (!) for bleach-bypass C-41. Cranking the gain to 10 means that a 6x7 scan takes over an hour instead of about 10 minutes and there is a very long and distinct pause between each scanline. Using this parameter, I can scan negs as dense as I like, for example (http://brodie-tyrrell.org/pad/index.php?id=2011/08/06).

You can't see through any part of that neg. And you can easily overexpose Portra by a good 3 or 4 stops without ANY degradation of highlight detail, assuming your scanning equipment (and skills) are up for it, so I could never ever recommend underexposure of C41 unless you deliberately wanted holes in your picture.

Keep in mind that some colour layers seem to fail earlier than others, so at certain shadow zones you're on the toe of one layer but not another layer, which means weird colour casts in your shadows.

[Brian K]

Guys, I think you're losing sight of the fact that the degree of underexposure I am talking about is just 1/3 to 1/2 stop which is nothing for the films we are discussing. I'm not talking about dropping your shadows into the realm of being without detail. Also erring on the side of slightly thinner means less obvious grain. which was a consideration on the part of the OP and who will not be wet mounting the negs which is one way to lessen grain when scanning.

PolyGlot, the scanner that the OP talked about is an Imacon, not a Nikon. You mention that by using RGB gain you are able to pull more detail out of a dense negative, but at the cost of a 10 minute scan taking an hour. Is there any practical advantage in having a scan take 6 times longer? There are downsides to that. Wouldn't you be better off if you didn't have to?

Anyway all I did was offer from my, and those of other professional's experience, that we find a slightly under neg easier to scan and yielding a better result. The proof is in the pudding. I don't think that anyone looking at the tonal ranges I achieve in my work is going to think that my process is flawed in that area. But to each their own.

[rdenney]

One factor that I discovered the hard way is that the output color space of the raw conversion needs enough gamut to cover the range in the scan. Even when we ask our scanner software to produce a TIFF, it's still performing a raw conversion--the raw conversion is always happening in the computer, not in the scanner. Thus, it is probably subject to our control. I was frustrated by the inability to scan through dense negatives using VueScan, until I started outputting files using the ProPhoto color space instead of the narrower sRGB color space. Maybe this is a mistake in the raw conversion software, but if I was having trouble with clipping, and I thought I'd already set the software not to clip, then the next thing I would check is the output color space. If I need to do a color space conversion, I do it in Photoshop where I have the most control and can see the before-and-after.

Rick "for whom VueScan's internal raw conversion works as well as the alternatives, if given room" Denney

[Drew Wiley]

There's a pretty big misunderstanding here about the film itself. The concept of latitude might make sense with an amateur point n' shoot film, but it's a mistake to
confuse it with the dynamic range of how a film is engineered. And with view cameras
the assumption is that we take the time to meter correctly. With a chrome one can
simply plop the thing on a lightbox and evaluate whether the shot is usable or not.
With negs it often requires either a scan or some kind of print to see if we're on target.
Depressing the exposure of Ektar, or failing to properly color balance it in the first place, might affect color reproduction in ways it is impossible to correct afterwards. Depends on the lighting ratio of the scene of course, and just how far off we expose it. But this is not a film with the degree of forgiveness of Portra. And even Portra works way better properly exposed. At something like sixteen dollars a shot for film and processing an 8X10, just how many exposures can someone "wing"? A half stop
won't make much difference with Portra, but it might with Ektar, and obviously can
be sheer voodoo with a chrome in contrasty lighting. Ektar ain't just souped-up Portra.
It is a somewhat different animal.

[Ben Syverson]

Yes, and it's also worth pointing out that clipping blacks with negative film is analogous to clipping whites with digital.

If you know you want to let your shadows go very deep in the print, then it's not a problem to underexpose by 1/3-1/2 stop. But you're giving up flexibility by doing so. If you're off at all in your metering, 1/2 stop can easily turn into a full stop or more, and then you're left with blocked up shadows and increased contrast.

One of the biggest reasons to use negative film is endless highlight latitude, and the next biggest reason is flexibility in tonal control. Why would you tie both hands behind your back?

[Brian K]

There's a pretty big misunderstanding here about the film itself. The concept of latitude might make sense with an amateur point n' shoot film, but it's a mistake to
confuse it with the dynamic range of how a film is engineered. And with view cameras
the assumption is that we take the time to meter correctly. With a chrome one can
simply plop the thing on a lightbox and evaluate whether the shot is usable or not.
With negs it often requires either a scan or some kind of print to see if we're on target.
Depressing the exposure of Ektar, or failing to properly color balance it in the first place, might affect color reproduction in ways it is impossible to correct afterwards. Depends on the lighting ratio of the scene of course, and just how far off we expose it. But this is not a film with the degree of forgiveness of Portra. And even Portra works way better properly exposed. At something like sixteen dollars a shot for film and processing an 8X10, just how many exposures can someone "wing"? A half stop
won't make much difference with Portra, but it might with Ektar, and obviously can
be sheer voodoo with a chrome in contrasty lighting. Ektar ain't just souped-up Portra.
It is a somewhat different animal.


First we're talking a 1/3 of a stop. I am willing to bet that few here take the time to actually do a film speed test using densitometry and have calibrated their meters to their film. Most here rely on box speed and assume that their lab is processing the film accurately. As someone who tested EVERY film emulsion he's used for the last 34 years, and who routinely, when shooting color and having an outside lab process that film, would test labs by sending identical test film to 3 or 4 top professional labs in Manhattan and then comparing the results, I can tell you that film speed, color and processing results vary from lab to lab, even the among the best labs.

So not wanting to beat a dead horse any further, experiment for yourselves. What I suggest may work well with your film, meter, lab, and scanner combination or it may not.

And BTW I am well aware that Ektar and portra are different and that is why i carry them both. One of the things that seems to always get lost in these film discussions is that there is no law that says you can't carry both films and use the one that is best suited to that particular situation. If the scene is flat I'll use a contrastier film, if the scene is contrasty I'll use a flatter film.

[Drew Wiley]

Good advice, Brian. I spent a lot of time and money last year actually printing Ektar
vs Portra. Mostly 8x10 film to 20X24 optically enlarged CAII prints, but also some smaller film sizes. Learned quite a few things the hard way about the differences. But
one thing which is probably applicable to all our respective individual workflows is to
test, test more, and then optimize the exposure to our specific needs. 8X10 color is just too expensive to be winging it. Ektar is a little more forgiving than typical chrome
film, but nowhere near as forgiving as Portra.

[Brian K]

Good advice, Brian. I spent a lot of time and money last year actually printing Ektar
vs Portra. Mostly 8x10 film to 20X24 optically enlarged CAII prints, but also some smaller film sizes. Learned quite a few things the hard way about the differences. But
one thing which is probably applicable to all our respective individual workflows is to
test, test more, and then optimize the exposure to our specific needs. 8X10 color is just too expensive to be winging it. Ektar is a little more forgiving than typical chrome
film, but nowhere near as forgiving as Portra.


Drew, testing is the only way to nail one's process. There are far too many variables in all of our set ups to have a "one size fits all" POV. Even down to our shutters, their apertures and speeds all vary, our meters vary, our thermometers vary, etc.

Portra is the film I recommend because it's nearly as good as Ektar when it comes to grain, I find it's actually higher resolving, and it has such incredible exposure latitude. It's very forgiving. And let's be honest here, if accurate color was the requirement then chrome film is the no brainer choice. As you pointed out, there's a lot of post exposure color reinterpretation that goes with color neg film. Which is why professionals always shot chrome.

I always find "which film is better" threads funny. The question should be, "what are the characteristics of this film and what is the best situation for it's use?" And then you carry as many films as raesonable to do what you need to do. Compromising on using a film in a situation that it is not best suited for already puts you in a hole.

[Drew Wiley]

Well I do tend to way more draconian in testing than most folks because I have very
specific hue rendition needs, and in this case, I don't want the traditional neg look.
Every medium has its idiosyncrasies, but Ektar can be coaxed into more of that chrome
look than other color neg materials. No silver bullet, but it looks like the best thing
so far. Takes a lot of post-processing work - in my case, advanced masking skills;
but PS could obviously be used too. I got a running start on this whole project as
insurance for the inevitable demise of Cibachrome (itself highly idiosyncratic).

[polyglot]

PolyGlot, the scanner that the OP talked about is an Imacon, not a Nikon. You mention that by using RGB gain you are able to pull more detail out of a dense negative, but at the cost of a 10 minute scan taking an hour. Is there any practical advantage in having a scan take 6 times longer? There are downsides to that. Wouldn't you be better off if you didn't have to?

Anyway all I did was offer from my, and those of other professional's experience, that we find a slightly under neg easier to scan and yielding a better result. The proof is in the pudding. I don't think that anyone looking at the tonal ranges I achieve in my work is going to think that my process is flawed in that area. But to each their own.

The point is that overly broad statements like "scanners cannot vary exposure time" are incorrect and misleading; they lead to suboptimal decisions in other parts of the work flow like deliberate underexposure. where such might not be called for by the artist's vision.

Obviously a 1-hour scan is somewhat undesirable... except that it produces a result possible only by extending exposure time (or cranking up the light intensity), i.e. analogous to printing-through the thick neg.

While I have never operated a drum scanner, I'd be a little surprised if you couldn't integrate the results over multiple revolutions to get more gain. An inability to scan even slightly-thick negs sounds like a severe drawback for what should be professional-grade equipment. If 1/3 of a stop is the difference between clipping highlights or not, the system is seriously fragile!

[Ben Syverson]

I certainly agree. If your scanner can't handle Ektar or Portra's Dmax, which is below 3.0, what on Earth would you do with a color slide, where all the shadow detail is above 3.0?

I fully trust that Brian K knows his stuff and is working based on years of experience and testing, but I respectfully urge caution when it comes to the dangerous practice of underexposing negatives.

I often rate negative film a full stop or more below box speed, because I know the highlights are trivial to capture and recover, and I've come to enjoy shadow detail. The argument against this is that you're pushing highlight details into the shoulder, making them noisier/grainier when they're recovered. But one or two stops is not enough to see much noise, and besides, we're talking about LF here. We have tonality to spare.

[Brian K]

The point is that overly broad statements like "scanners cannot vary exposure time" are incorrect and misleading; they lead to suboptimal decisions in other parts of the work flow like deliberate underexposure. where such might not be called for by the artist's vision.

Obviously a 1-hour scan is somewhat undesirable... except that it produces a result possible only by extending exposure time (or cranking up the light intensity), i.e. analogous to printing-through the thick neg.

While I have never operated a drum scanner, I'd be a little surprised if you couldn't integrate the results over multiple revolutions to get more gain. An inability to scan even slightly-thick negs sounds like a severe drawback for what should be professional-grade equipment. If 1/3 of a stop is the difference between clipping highlights or not, the system is seriously fragile!

Polyglot, I guess you're right about scanners, I was far too broad. But then again I never produce a neg so poorly exposed that it requires 6 times longer to scan to burn through the density. As my film is always properly exposed and I have very little experience dealing with poorly exposed negatives. If your film requires such a major correction then maybe you're not as dialed in as you think you are.

As for the 1/3 of a stop being a slight change, it's not because the system is "fragile" it's that a 1/3 of a stop underexposure will not deteriorate image quality in any noticeable manner, while giving you a hair less grain and a slightly better negative for the purpose of scanning.

Ben, I'm willing to bet if all of the film produced by LFF members were analyzed you'd find that most are not "perfectly" exposed, or that the speed they rate their films at and what their labs actually deliver is not accurate either. Most people don't do densitometry, most people do not test all their emulsions or continuously send comparative film tests to different labs (when shooting color). And that's one reason why there are people with poorly exposed negatives.

And Ben, when you're talking about "pushing highlight details into the shoulder" surely you're not talking about Ektar or Portra because they don't have a shoulder according to Kodak's characteristics curves. They have a toe, but they are pretty much a straight line all the way after that, no shoulder. But you also talk about often intentionally overexposing a full stop, are you suggesting that people overexpose by a full stop???? But my underexposing by a 1/3 is "dangerous"?

Why don't we just leave at the fact that we have calibrated our methods and materials and we have found processes that optimize our particular situations. But to others your mileage may vary so test for yourself.

[Ben Syverson]

Brian, 1/3 stop is almost too minor to detect, but the dangerous part is when human error or stop rounding creeps in, and all of a sudden it becomes 1/2 - 1 full stop.

The "danger" of underexposing is that you can lose shadow detail you meant to preserve. There is no danger in overexposing by a full stop, because you won't lose information. You'll just get a little extra density.

All negative films have a shoulder. It's not on the charts, because it's slightly beyond the normal range of exposure. You can see this by taking a photo that includes the sun. If the density curve was purely "straight", then the sun would go darker than Velvia black on the negative. Obviously that's not the case.

In any event, I agree that YMMV, and people should test more!

[polyglot]

Polyglot, I guess you're right about scanners, I was far too broad. But then again I never produce a neg so poorly exposed that it requires 6 times longer to scan to burn through the density. As my film is always properly exposed and I have very little experience dealing with poorly exposed negatives. If your film requires such a major correction then maybe you're not as dialed in as you think you are.


For a normal negative, absolutely your exposure times shouldn't vary much at all. The one requiring crazy long print/scan times was bleach-bypass, i.e. it contains most of the silver and is therefore far denser even than the D-max achievable with normally-bleached C41.

I don't do densitometry and sometimes I get my exposures (badly!) wrong but 99% of my exposures are good enough for chromes. I find myself varying scanner exposure by about half a stop roll-to-roll and that's all down to difference in base density from different brands of film. I tend to shoot often in pretty contrasty light though, so I might be more paranoid about shadow detail than is the norm ;)

[federico9001]

Portra is certainly easier to scan, more natural, more balanced.

But Ektar can be a cheaper option sometimes.

http://www.flickr.com/photos/castorscan/6766677823/in/photostream/

[paulMD]

Personally I think Ektar starts to get strange color casts easily, particularly with overexposure. The colors increase in saturation quite a lot and tend to take on a few characteristic shades. Reds all become fire-engine red. Yellows all become lemon yellow. Blues all turn cyan. Earth tones just seem to increase in saturation across the board. Thus, I view it as having a relatively narrow exposure latitude, I'm not really surprised to hear you shouldn't underexpose it either.

At least, that's been my experience scanning it with Epson's software. Lately I've been messing around with a trial of Vuescan. It seems to be able to keep color balance a lot more consistent than Epson because of the option to lock the film base color. Epson tries to re-interpret the colors every time and I doubt that helps matters.

[Ben Syverson]

Paul, the problem must be with the scanning software, not the film. Ektar is exceptionally neutral, and has an utterly gigantic exposure latitude.

[federico9001]

It depends....

anyway Portra is more neutral and has wider latitude, and a natural saturation

[timparkin]

As someone who tested EVERY film emulsion he's used for the last 34 years, and who routinely, when shooting color and having an outside lab process that film, would test labs by sending identical test film to 3 or 4 top professional labs in Manhattan and then comparing the results, I can tell you that film speed, color and processing results vary from lab to lab, even the among the best labs.

Hi Brian,

I'd be really interested in your testing results for neg films - Ektar and the two Portra's particularly. Also I'm interested in why you would recommend underexposure with neg film if you've tested and presumably use a spot meter? Wouldn't it be best to use the right exposure? I've only ever spot metered so I may not be clear on what 'correct' exposure means such that underexposing from that point would be better?

Also - what difference in density or latitude did you see from lab to lab?

Personally I've tested Porta and Ektar by simply bracketing an overall exposure from -8 to +20 stops and found Portra 160 to work from -2 to +18(ish) and Portra 400 from -3 to +19(ish) - basically it was almost impossible to overexpose unless you had 'bare lights' in a picture (i.e. bare street lights, the sun, etc).

Ektar was the surprising one as it really only seemed to be stable from -1 to +10. at -2 stops the colours would start shifting to blue. In the highlights I didn't look at colour shifts but normally I now grad skies with Ektar because the colour does change (see the film tests from onlandscape I mentioned earlier).

Tim

[nonuniform]

Underexpose negative film at your peril... Any scanner should be able to handle the Dmax of color negative. If it can't, use a different scanner.

Surprisingly, the new Portra films can handle 2 stops under and provide a usable image. Not perfect, but usable. I wouldn't recommend underexposing unless it were necessary, (or a giant mistake!), but it's not as bad as it use to be.

[Drew Wiley]

All you really have to do is study the tech sheets to get a lot better idea of what is going on than just
winging it. The point is not how much over or under exp can you get away with, but at what point will
it start affecting color balance. And in this respect, you don't have any where near the wiggle room that
you might think. Portra is engineered to be tolerant of quite a bit of abuse yet still deliver pleasing
skintones, but potentially at the cost of other categories of hue reproduction. Ektar actually has more
accurate shadow color reproduction but needs correct color temp filtration due to the dye curve characteristics. A lot of what people assume is "neutral" or "natural' really isn't - it's a conditioned
look that you want the film to be like, not what's really in front of the camera! We fool ourselves pretty
easily, and then blame the film when it does what its supposed to. None of these films is perfect, just
pretty darn good if you understand them.